Cable control and operation in a motorized fitness machine

Abstract

A cable-operated exercise machine providing slack-compensating control of resistance force applied to a tension cable, the exercise machine comprising: the tension cable, configured to receive user force applied by pulling on a user end of the tension cable; a resistance motor applying the resistance force to a motor-coupled end of the tension cable, in opposition to the user force; and a controller comprising processing circuitry configured to: access data indicative of a momentum of components of the exercise machine, wherein the momentum of the components is coupled to movement of the motor-coupled end of the tension cable; determine an adjustment to the resistance force, wherein a size of the adjustment is determined, in accordance with the indicated momentum, to compensate against slack distance developing along the tension cable consequent to a potential rapid reduction in the user force; and signal the adjustment in resistance force to the resistance motor.

Description

PRIORITY CLAIM

[0001] This application claims the benefit of priority of U.S. Provisional Patent Application No. 63 / 780,328, filed on Mar. 30, 2025, which is incorporated herein by reference in its entirety.TECHNICAL FIELD AND BACKGROUND

[0002] The present disclosure, in some embodiments thereof, relates to the field of exercise equipment and more particularly, but not exclusively, to resistance cable operated exercise equipment.

[0003] Resistance training promotes the building and strengthening of muscles and bone tissue, and burns fat. Some motor-operated resistance training devices transmit resistance forces to users through a cable.SUMMARY

[0004] According to an aspect of some examples of the presently described subject matter, there is provided a cable-operated exercise machine providing slack-compensating control of resistance force applied to a tension cable, the exercise machine comprising: the tension cable, configured to receive user force applied by pulling on a user end of the tension cable; a resistance motor applying the resistance force to a motor-coupled end of the tension cable, in opposition to the user force; and a controller comprising processing circuitry configured to: access data indicative of a momentum of components of the exercise machine, wherein the momentum of the components is coupled to movement of the motor-coupled end of the tension cable; determine an adjustment to the resistance force, wherein a size of the adjustment is determined, in accordance with the indicated momentum, to compensate against slack distance developing along the tension cable consequent to a potential rapid reduction in the user force; and signal the adjustment in resistance force to the resistance motor.

[0005] According to some examples of the presently described subject matter, the components having momentum coupled to movement of the motor-coupled end of the tension cable include at least rotating elements of the motor.

[0006] According to some examples of the presently described subject matter, the components having momentum coupled to movement of the motor-coupled end of the tension cable include a spool on which the tension cable is wound.

[0007] According to some examples of the presently described subject matter, the size of the determined adjustment to the resistance force varies in magnitude as a function of a setting force, the setting force comprising a user-selected and predetermined level of exercise force which the controller signals to the resistance motor along with the adjustment.

[0008] According to some examples of the presently described subject matter, the size of the determined adjustment to the resistance force increases in magnitude as the setting force decreases.

[0009] According to some examples of the presently described subject matter, the determined adjustment to the resistance force is signaled for exercises performed with the setting force below a threshold, and not applied for exercises performed with the setting force above the threshold.

[0010] According to some examples of the presently described subject matter, the determined adjustment to the resistance force increases with increasing momentum of the components of the exercise machine coupled to movement of the motor-coupled end of the tension cable.

[0011] According to some examples of the presently described subject matter, the determined adjustment is signaled during extension phases of tension cable movement, and not applied during return phases of tension cable movement.

[0012] According to some examples of the presently described subject matter, the determined adjustment changes as a linear function of increasing velocity.

[0013] According to some examples of the presently described subject matter, the determined adjustment changes as a non-linear function of increasing velocity.

[0014] According to some examples of the presently described subject matter, the controller: determines an ongoing accelerating or decelerating phase of tension cable extension; and determines the adjustment according to the ongoing accelerating or decelerating phase of tension cable extension.

[0015] According to some examples of the presently described subject matter, the adjustment increases the resistance force during a decelerating phase of tension cable extension.

[0016] According to some examples of the presently described subject matter, the resistance motor comprises a rotary electric motor.

[0017] According to some examples of the presently described subject matter, the resistance motor comprises one or more electric motors.

[0018] According to some examples of the presently described subject matter, the exercise machine comprises one or more sensors coupled to provide the controller with the data indicative of the momentum of the components of the exercise machine coupled to movement of the motor-coupled end of the tension cable.

[0019] According to some examples of the presently described subject matter, the one or more sensors comprise at least one of: a rotary encoder measuring rotation coupled to movement of the tension cable, and a load cell measuring tension in the cable.

[0020] According to some examples of the presently described subject matter, the user end of the tension cable comprises an accessory connector configured to connect to one or more accessories through which the user force is applied.

[0021] According to some examples of the presently described subject matter, the exercise machine includes one or more of the accessories, each configured to be gripped by the user to apply the user force.

[0022] According to some examples of the presently described subject matter, the adjustment to the resistance force is determined to prevent, upon sudden removal of user force from the tension cable, a potential distance of more than 2 cm of further runout of the tension cable from the components having momentum coupled to movement of the motor-coupled end of the tension cable.

[0023] According to some examples of the presently described subject matter, development of slack distance is compensated against with respect to a potential rapid reduction in the user force which is substantially immediate, and to a reduced level of substantially no user force.

[0024] According to an aspect of some examples of the presently described subject matter, there is provided a method of operating controller processing circuitry providing slack-compensating control of resistance force applied to a tension cable of a cable-operated exercise machine, the method comprising: accessing data indicative of a momentum of components of the exercise machine, wherein the momentum is momentum of components with movements coupled to movement of a motor-coupled end of the tension cable; determining an adjustment to the resistance force, wherein a size of the adjustment is determined, in accordance with the indicated coupled momentum, to compensate against slack distance developing along the tension cable consequent to a potential rapid reduction in user force; and signaling the adjustment in resistance force to the resistance motor as slack compensation.

[0025] According to some examples of the presently described subject matter, the components having movements coupled to movement of the motor-coupled end of the tension cable include at least rotating elements of the motor.

[0026] According to some examples of the presently described subject matter, the components having movements coupled to movement of the motor-coupled end of the tension cable include a spool on which the tension cable is wound.

[0027] According to some examples of the presently described subject matter, the determining sizes the adjustment to the resistance force as a function of a setting force, the setting force comprising a user-selected and predetermined level of exercise force which the controller signals to the resistance motor along with the adjustment.

[0028] According to some examples of the presently described subject matter, the determining sizes the adjustment to the resistance force with increasing magnitude as the setting force decreases.

[0029] According to some examples of the presently described subject matter, the method comprises signaling the determined adjustment to the resistance force for exercises performed with the setting force below a threshold; and for exercises performed with the setting force above the threshold, determining not to signal the adjustment.

[0030] According to some examples of the presently described subject matter, the determining provides an adjustment to the resistance force which is increasing with increasing momentum of the components of the exercise machine coupled to movement of the motor-coupled end of the tension cable.

[0031] According to some examples of the presently described subject matter, the signaling of the determined adjustment is during extension phases of tension cable movement; and comprising determining not to signal the adjustment during return phases of tension cable movement.

[0032] According to some examples of the presently described subject matter, the method comprises determining the adjustment as a linear function of increasing velocity.

[0033] According to some examples of the presently described subject matter, the method comprises determining the adjustment as a non-linear function of increasing velocity.

[0034] According to some examples of the presently described subject matter, the method comprises: determining, automatically, an ongoing accelerating or decelerating phase of tension cable extension; and determining the adjustment according to the ongoing accelerating or decelerating phase of tension cable extension.

[0035] According to some examples of the presently described subject matter, the method comprises increasing the adjustment to the resistance force during a decelerating phase of tension cable extension.

[0036] According to an aspect of some examples of the presently described subject matter, there is provided a method of operating a controller to vary a resistance force applied to a tension cable of an exercise machine during changes in extension distance of the tension cable, the method comprising: estimating, by the controller, an ongoing acceleration of the tension cable; and determining an adjustment to the resistance force, dependent on the ongoing acceleration of the tension cable; and applying the adjustment to modify the ongoing acceleration.

[0037] According to some examples of the presently described subject matter, the adjustment is selected to be proportional to a baseline training resistance force.

[0038] According to some examples of the presently described subject matter, the adjustment is selected to simulate an inertial mass resistant to changes in acceleration.

[0039] According to an aspect of some examples of the presently described subject matter, there is provided an exercise machine comprising: at least one motor; a tension cable extending from a user end to an attachment to the at least one motor, wherein the motor provides adjustable resistance force resisting force applied from the user end; and a controller controlling the resistance force provided by the motor; wherein the controller comprises processing circuitry configured to: access data indicative of acceleration of the tension cable; determine an adjustment to the resistance force, dependent on the indicated acceleration of the tension cable; and signal the adjustment in resistance force to the resistance motor.

[0040] According to an aspect of some examples of the presently described subject matter, there is provided a tension cable exercise machine comprising a resistance motor, tension cable, and controller, wherein the controller comprises processing circuitry configured to: access data characterizing a decrease in extension distance of the tension cable; determine that the decrease in extension distance satisfies a fast tension cable return criterion; and in accordance with the determination, signal the resistance motor to reduce a velocity at which the extension distance of the tension cable is decreasing.

[0041] According to some examples of the presently described subject matter, the fast tension cable return criterion comprises movements of the tension cable indicative of release of the tension cable by a user while the tension cable is in an extended state.

[0042] According to some examples of the presently described subject matter, the resistance motor comprises a rotary electric motor.

[0043] According to some examples of the presently described subject matter, the exercise machine comprises one or more sensors coupled to provide the controller with the data characterizing the decrease in extension distance, used to determine that the decrease in extension distance satisfies the fast tension cable return criterion.

[0044] According to some examples of the presently described subject matter, the exercise machine comprises a tension cable brake, and wherein the reducing a velocity comprises activating the tension cable brake.

[0045] According to some examples of the presently described subject matter, the fast tension cable return criterion indicates that without activation of the brake, there is insufficient distance at an ongoing velocity to stop a collision between the tension cable and the exercise machine.

[0046] According to some examples of the presently described subject matter, the fast tension cable return criterion satisfied is indicative of a safety risk due to increased and / or increasing velocity of the tension cable.

[0047] According to some examples of the presently described subject matter, the fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied.

[0048] According to some examples of the presently described subject matter, the threshold velocity used is adjusted by reducing the threshold velocity as the extension distance reduces.

[0049] According to some examples of the presently described subject matter, the fast tension cable return criterion comprises a determination that return acceleration of the tension cable is indicative of a loss of user force.

[0050] According to some examples of the presently described subject matter, the fast tension cable return criterion comprises a determination that return acceleration of the tension cable is outside of a set of reference examples for expected return acceleration.

[0051] According to some examples of the presently described subject matter, the controller is configured to: access data indicative of swinging of the tension cable; determine a phase and / or period of the swinging, using the data; and adjust tension in the tension cable, according to the phase and / or period, wherein timing of the tension adjustment is selected to damp swinging of the tension cable.

[0052] According to an aspect of some examples of the presently described subject matter, there is provided a method of operating a controller to vary resistance force applied to a tension cable of an exercise machine during a decrease in extension distance of the tension cable, the method comprising: determining, by the controller, that the decrease in extension distance satisfies a fast tension cable return criterion; and in accordance with the determining, commanding a resistance motor of the exercise equipment to reduce a velocity at which the extension distance of the tension cable decreases.

[0053] According to some examples of the presently described subject matter, the fast tension cable return criterion comprises movements of the tension cable indicative of release of the tension cable by a user while the tension cable is in an extended state.

[0054] According to some examples of the presently described subject matter, in accordance with the determining, the controller applies a brake to the tension cable.

[0055] According to some examples of the presently described subject matter, satisfying the fast tension cable return criterion is indicative of a safety risk due to increased and / or increasing velocity of the tension cable.

[0056] According to some examples of the presently described subject matter, the fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied.

[0057] According to some examples of the presently described subject matter, the threshold velocity reduces along with the extension distance.

[0058] According to an aspect of some examples of the presently described subject matter, there is provided a method of damping control of resistance force applied by a resistance motor to a tension cable of an exercise machine, the method comprising: accessing, by a controller of the exercise machine, data indicative that a user end of the tension cable is moving at a distance within a homing distance from a home position for the user end; and in accordance with the data, automatically adjusting signals from the controller, the signals governing application of the resistance force by the resistance motor; wherein the resistance force is controlled to perform a damped transition through a plurality of resistance force levels between and in addition to a first resistance force and a second resistance force, the resistance force levels and timing of the damped transition being determined in accordance with the data; and wherein the second resistance force is at least double the first resistance force.

[0059] According to some examples of the presently described subject matter, the resistance force levels of the damped transition are determined in accordance with at least one of: a change in the distance of the user end from the home position, and an elapsed time after the user end passes a threshold distance while within the homing distance.

[0060] According to some examples of the presently described subject matter, the change in distance comprises an increase in extension distance of the tension cable, and the damped transition is to the second resistance force from the first resistance force.

[0061] According to some examples of the presently described subject matter, the controller lengthens the damped transition to occur over a larger change in distance of the user end from the home position, when a rate of change in distance of the user end from the home position exceeds a speed threshold.

[0062] According to some examples of the presently described subject matter, the change in distance comprises a decrease in extension distance of the tension cable, and the damped transition is to the first resistance force from the second resistance force.

[0063] According to some examples of the presently described subject matter, the signals governing application of the resistance force by the resistance motor are configured to limit an unloaded equilibrium velocity of the motor to a damping velocity limit, the damping velocity limit being adjusted to be relatively lower within the homing distance, compared to an unloaded equilibrium velocity of the motor beyond the homing distance.

[0064] According to some examples of the presently described subject matter, the damped transition occurs over at least 10 msec.

[0065] According to some examples of the presently described subject matter, the damped transition occurs over at least 0.5 cm.

[0066] According to some examples of the presently described subject matter, the method comprises, when the damped transition reduces the resistance force: determining, by the controller, whether the data indicate that the user end of the tension cable will reach the home position before a targeted minimum transition time elapses; and selecting between a distance-dependent reduction in resistance force and a time-dependent reduction in resistance force in accordance with the determining.

[0067] According to some examples of the presently described subject matter, the homing zone within which the damped transition occurs is extends no more than 25 cm from the home position.

[0068] According to some examples of the presently described subject matter, the controller governs the damped transition both: from the first resistance force to the second resistance force while the user end extends, resulting in an average extension-phase resistance force as a function of position between the home position and the homing distance, and from the second resistance force to the first resistance force while the user end returns to the home position, resulting in an average return-phase resistance force as a function of position between the home position and the homing distance; and wherein the average extension-phase resistance force is larger than the average return-phase resistance.

[0069] According to some examples of the presently described subject matter, the extension-phase damped transition begins at a distance closer to the home position than the end of the return-phase damped transition.

[0070] According to some examples of the presently described subject matter, the return-phase damped transition begins at a distance farther from the home position than the end of the extension-phase damped transition.

[0071] According to some examples of the presently described subject matter, a total distance of the extension-phase damped transition is different than a total distance of the return-phase damped transition.

[0072] According to some examples of the presently described subject matter, the return-phase damped transition occurs over a shorter distance than the extension-phase damped transition.

[0073] According to some examples of the presently described subject matter, the controller imposes hysteresis on the resistance force as a function of distance, in accordance with a direction of movement of the user end of the resistance cable while moving between the homing distance and the home position.

[0074] According to some examples of the presently described subject matter, the second resistance force is a setting force selected for operation of the exercise machine during a set of reps.

[0075] According to some examples of the presently described subject matter, the first resistance force is a quiescent state force which holds the user end in place while waiting for a user to engage with the tension cable.

[0076] According to some examples of the presently described subject matter, the method comprises: accessing, by the controller, data indicative of velocity of the tension cable; determining, by the controller, that the velocity of the tension cable satisfies a fast tension cable return criterion; and in accordance with the determining, at least one of: automatically adjusting signals from the controller governing the resistance motor to reduce force applied to the tension cable, and activating a brake to slow the velocity of the tension cable.

[0077] According to some examples of the presently described subject matter, the fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied.

[0078] According to some examples of the presently described subject matter, the threshold velocity reduces along with distance from the home position.

[0079] According to some examples of the presently described subject matter, the second resistance force is at least 25 pounds.

[0080] According to some examples of the presently described subject matter, the second resistance force is at least 100 pounds.

[0081] According to an aspect of some examples of the presently described subject matter, there is provided an exercise machine comprising: a resistance motor; a tension cable coupled to receive resistance force applied by the resistance motor; and a controller, coupled to control the applied resistance force; wherein the controller comprises processing circuitry configured to: access ongoing data indicative that a user end of the tension cable is moving at a distance within a homing distance from a home position for the user end; and in accordance with the data, automatically adjust signals from the controller governing application of the resistance force by the resistance motor; wherein the resistance force is controlled to transition between a first resistance force and a second resistance force in accordance with the ongoing data indicative of movement of the user end of the tension cable; and wherein the second resistance force is at least double the first resistance force.

[0082] According to some examples of the presently described subject matter, the resistance motor comprises a rotary electric motor.

[0083] According to some examples of the presently described subject matter, the exercise machine comprises one or more sensors which sense the sensed indications, and are coupled to provide the sensed indications to the controller.

[0084] According to an aspect of some examples of the presently described subject matter, there is provided a method of controlling a tension cable of an exercise machine operating to provide resistance at a resistance force, the method comprising: determining that extension distance of the tension cable is changing while a user end of the tension cable is within a homing distance from a home position of the user end; and in accordance with the determining, selecting force applied by a resistance motor to use a specified damping force level, in place of the resistance force.

[0085] According to some examples of the presently described subject matter, the damping force level is initially lower than the resistance force, and rises to meet the resistance force as the extension distance of the tension cable increases.

[0086] According to some examples of the presently described subject matter, the damping force level reduces as the extension distance of the tension cable reduces.

[0087] According to some examples of the presently described subject matter, the damping force level is different at different extension distances of the tension cable, and also different for same extension distances depending on whether the extension distance of the tension cable is increasing or decreasing.

[0088] According to an aspect of some examples of the presently described subject matter, there is provided an exercise machine configured to apply damped transitions of resistance force to a tension cable near a home position for a user end of the tension cable, the exercise machine comprising: a resistance motor; a controller, coupled to control resistance force produced by the resistance motor; and the tension cable, coupled to receive the resistance force produced by the resistance motor; wherein the controller comprises processing circuitry configured to: access data indicative that the user end of the tension cable is moving at a distance within a homing distance from the home position for the user end; and in accordance with the data, automatically adjust signals from the controller, the signals governing application of the resistance force by the resistance motor; wherein the resistance force is controlled to perform a damped transition through a plurality of levels between a first resistance force and a second resistance force in accordance with at least one of a change in the distance of the user end from the home position and an elapsed time after the user end passes a threshold distance while within the homing distance; and wherein the second resistance force is at least double the first resistance force.

[0089] According to some examples of the presently described subject matter, the resistance motor comprises a rotary electric motor.

[0090] According to some examples of the presently described subject matter, the exercise machine comprises one or more sensors coupled to provide the controller with sensed indications of tension cable movement, used to determine that the extension distance of the tension cable is changing while within the home position zone of extension.

[0091] According to some examples of the presently described subject matter, when the damped transition is in a direction reducing the resistance force, the controller is configured to: determine whether the data indicate that the user end of the tension cable will reach the home position before a targeted minimum transition time elapses; and select between a distance-dependent reduction in resistance force and a time-dependent reduction in resistance force in accordance with the determination.

[0092] According to some examples of the presently described subject matter, upon selecting the distance-dependent reduction in resistance force, the controller continues to access data indicative of movements of the user end of tension cable, and to control the damped transition accordingly as a function of distance of the movements.

[0093] According to some examples of the presently described subject matter, the controller is configured to: access data indicative of velocity of the tension cable; determine that the velocity of the tension cable satisfies a fast tension cable return criterion; and in accordance with the determination, perform at least one of: automatically adjusting signals governing the resistance motor to reduce force applied to the tension cable, and activate a brake to slow the velocity of the tension cable.

[0094] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, exemplary methods and / or materials are described below. In case of conflict, the patent specification, including definitions, controls. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

[0095] As will be appreciated by one skilled in the art, aspects of the present disclosure may be embodied as a system, method, or computer program product. Accordingly, aspects of the present disclosure, as appropriate to the disclosure and to the state of technology, may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, microcode, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,”“module” or “system” (e.g., a method may be implemented using “computer circuitry” or “processing circuitry”).

[0096] Furthermore, aspects of some examples of the present disclosure may take the form of a computer program product embodied in one or more computer-readable medium(s) having computer-readable program code embodied thereon. Implementation of the method and / or system of some examples of the present disclosure can involve performing and / or completing selected tasks manually, automatically, or a combination thereof. Moreover, in accordance with instrumentation and equipment provided for implementation of some examples of the method(s) and / or system(s) of the present disclosure, selected operations of these methods ( ) and / or system(s) could be variously implemented by hardware, by software, by firmware, and / or by a combination thereof.

[0097] For example, hardware for performing selected operations in accordance with some examples of the present disclosure is optionally implemented as a chip or a circuit. As software, selected operations in accordance with some examples of the present disclosure is optionally implemented as a plurality of software instructions. Optionally, implementation aspects are built on a general-purpose computing device, e.g., making use of the services of an operating system.

[0098] In some examples of the present disclosure, one or more operations performed in method(s) and / or by system(s) are performed by a data processor, such as a computing platform configured to execute pluralities of instructions in sequence and / or concurrently. Such a data processor may be alternatively referred to herein, e.g., as a “digital processor”, in reference to data processors which operate using groups of digital bits, and / or as “processing circuitry” in reference to the use of electronic circuitry in data processing applications.

[0099] Instruction executing elements of a data processor may comprise, for example, one or more microprocessor chips, ASICs, and / or FPGAs. Optionally, the data processor includes a volatile memory for storing instructions and / or data; and / or a non-volatile storage, for example, a magnetic hard-disk and / or removable media, for storing instructions and / or data. The terms “non-transitory memory” and “non-transitory storage medium”, where they may be used herein, should be expansively construed to cover any volatile or non-volatile computer memory suitable to the presently disclosed subject matter.

[0100] Optionally, a network connection conferring data communication capabilities is provided. A display and / or a user input device such as a keyboard or mouse are optionally provided. Any of these implementations are referred to herein more generally as instances and / or elements of, e.g., computer circuitry and / or processing circuitry.

[0101] Any combination of one or more computer-readable medium(s) may be used by some examples of the present disclosure. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. Without limitation, a computer-readable storage medium may comprise, for example, an electronic-, magnetic-, optical-, electromagnetic-, infrared-, and / or semiconductor-implemented system, apparatus, or device; in any suitable combination.

[0102] A non-exhaustive list of further examples of computer-readable storage medium(s) includes: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device. Any suitable combination of the foregoing is optionally provided.

[0103] In the context of this document, a computer-readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. A computer-readable storage medium may also contain or store information for use by such a program; for example, data structured in the way it is recorded by the computer-readable storage medium so that a computer program can access it as, for example, one or more tables, lists, arrays, data trees, and / or another data structure. Herein a computer-readable storage medium which records data in a form retrievable as groups of digital bits is also referred to as a digital memory. It should be understood that a computer-readable storage medium, in some examples, is optionally also used as a computer writable storage medium, in the case of a computer-readable storage medium which is not read-only in nature, and / or in a read-only state.

[0104] A “data structure” may include any collection of data values and relationships among them. The data may be stored, for example: linearly, horizontally, hierarchically, relationally, non-relationally, unidimensionally, multidimensionally, operationally, in an ordered manner, in an unordered manner, in an object-oriented manner, in a centralized manner, in a decentralized manner, in a distributed manner, in a custom manner, or in another manner enabling data access. A data structure may include, for example, one or more arrays, associative arrays, linked lists, binary trees, balanced trees, heaps, stacks, queues, sets, hash tables, records, tagged unions, ER models, and / or graphs. With particular (but not exclusive) reference to data storage for search retrieval, a data structure may comprise and / or form a part of, for example: an XML database, an RDBMS database, an SQL database, and / or an alternative implemented using MongoDB, Redis, Couchbase, Datastax Enterprise Graph, Elastic Search, Splunk, Solr, Cassandra, Amazon DynamoDB, Scylla, HBase, and / or Neo4J.

[0105] A data structure may be a component of disclosed examples which is stored, as appropriate: locally along with other system components described (e.g., in the same component package, device enclosure and / or room), and / or by a remotely-sited computing component (e.g., a cloud-based data structure). Data in the data structure may be stored in contiguous or non-contiguous memory. Moreover, a data structure, as the term is used herein, does not require information to be co-located. It may be distributed across multiple servers, for example, which may themselves be owned or operated by the same or different entities. The term “data structure” as used herein in the singular is inclusive of plural data structures. In particular, but not exclusively, it may be understood that a data structure itself may be at least partially composed of other data structures and / or portions thereof. As appropriate, limits of the extent of a data structure may determined according to its internal structure (e.g., internal patterns and / or self-references), its use, its providing storage media, the nature of the data stored (e.g., what the stored data are understood to refer to outside of the data structure and / or outside of the realm of data-as-such), and / or other suitable criteria associated with its instantiation. As appropriate, the term “data structure” may be understood as extending to include hardware, software, firmware, and / or any combination thereof for storing and / or facilitating the retrieval of information in a data structure characterized by its data values and relationships among them.

[0106] Certain data are optionally referred to herein as being derived from one or more sensors, e.g., as “sensed data” and / or “sensor data”. Such data comprise one or more physical effects transduced into a machine-readable form, e.g., one or more of the computer readable medium(s) described herein. Sensed / sensor data optionally represent physical quantities and / or objects, e.g., measurements and / or images. The sensed data typically are converted to a digital form used in data processing. However, transmitting, maintaining and / or processing sensed data in analog form (e.g., as amplitudes, frequencies, and / or phase encodings of voltage and / or current using suitable analog circuitry; e.g., for operations of comparison and / or combination) is not excluded.

[0107] Sensed data may be referenced as “indicative of” a certain aspect of a physical state. The scope of an “indicative of” relationship may include, but is not limited to, sensed data which measure the aspect of the physical state as such. More particularly, the scope of an “indicative of” relationship may include, but is not limited to sensed data which reasonably allow and / or are show to allow estimating a past, present, and / or predicted measurement of the aspect of the physical state as such. Estimated measurements are optionally (but not necessarily) calibrated. Estimated measurements are optionally absolute or relative (e.g., relative to an initial state, an average, or another baseline condition; and / or relative in the sense of showing a direction of changing magnitude).

[0108] An “indicative of” relationship is sufficiently characterized, in some examples, by correlations between sensed data and the aspect of the physical state such that the sensed data provide information about the aspect of the physical state. In examples including control and / or modification of the aspect of physical state, an “indicative of” relationship may be characterized by results showing that the sensed data provide information suitable for such control and / or modification; and / or by a reasonable expectation that the sensed data provide information suitable for such control and / or modification. Additionally or alternatively, an “indicative of” relationship may be used as a basis for estimating, controlling, and / or modifying some further physical state.

[0109] Relatedly, it should be understood that data (e.g., sensed data and / or data of a data structure) can be “indicative of” a state encoded by other data. As appropriate, the relationship “indicative of” in such cases may be understood as evidenced by the provision of suitable programming instructions making use of the relationship; not necessarily associated with full or partial reconstruction of the indicated data from the indicating data. Evidence of such an “indicative of” relationship may be gathered, for example, in the context of industrially applicable use of the relationship by a device or method. These examples explaining the “indicative of” relationship are not exclusive of other reasonable uses of the term; e.g., physical states such as lights, sounds, and / or mechanical positions of components which serve as indicators. The relationship “indicative of” as such does not restrict to a particular direction of causation, or, as such, require mutual causation in either direction. It should be understood that two entities can be mutually indicative; the relationship is not necessarily symmetric, however.

[0110] Herein, a data processor (optionally referred to, e.g., as processing circuitry and / or computer circuitry) is said to be “configured” to perform data processing actions (e.g.), accessing and / or manipulation of stored and / or streamed data according to one or more algorithmic operations) insofar as it is coupled to a computer-readable medium to access and / or receive instructions and / or data thereupon and / or therefrom, process them, and / or store processing results in the same or another computer-readable medium. As appropriate (e.g., when performing analog data processing) the term “processing circuitry” may be understood as encompassing data processing hardware which does not necessarily rely on instructions in the form of digitally encoded values. In such cases, the processing circuitry is “configured” in virtue of its construction and / or state.

[0111] The processing performed (e.g., using the stored and / or streamed data) is specified by the instructions (and / or other configured state), with the effect that the processor operates according to the instructions and / or configured state. The act of processing may be referred to additionally or alternatively by one or more other terms; for example: comparing, estimating, determining, calculating, computing, comparing, encrypting, decrypting, identifying, associating, storing, accessing, receiving, obtaining, analyzing, selecting, and / or transforming. For example, in some examples, a processing circuitry accesses and / or receives instructions and data stored in volatile and / or non-volatile memory and / or provided over a communication link, processes the data according to the instructions, stores processing results in volatile and / or non-volatile memory, and / or provides processing results. In some examples, “providing” processing results comprises one or more of transmitting, storing and / or presenting processing results. Presenting optionally comprises showing on a display, indicating by sound, printing on a printout, or otherwise producing results in a form accessible to human sensory capabilities.

[0112] Data may be referred to herein as being “accessed”. This optionally but not necessarily includes being “received”; e.g., by transmission of the data to suitable processing circuitry. Optionally, data is accessed at its original place of storage. Accessed data is optionally but not necessarily transmitted, copied, and / or stored in association with the accessing as such, in whole or in part. Except as otherwise indicated, it is neither required nor excluded that access produces destruction and / or degradation of stored data. Indications applicable in this case may be recognized in such technical aspects as the nature of the data's storage and / or transmission, and / or the mechanism(s) of access (e.g., states of quantum computers may be degraded by access). In the case of processing circuitry in particular, accessing of data may be characterized by changes in physical and / or processing state of the processing circuitry corresponding to one or more aspects of the accessed data. The one or more aspects can include, for example, values of certain data, presence of certain data, and / or other information associated with the accessed data such as its checksum validity and / or memory address. Accordingly, the term “access” is also not limited to full inspection of the referenced data. For example, when a database is accessed, optionally the whole or any part of its data, including metadata depending on fully yet not completely encoding such whole or part, is brought into further effect with respect to an accessing device and / or method.

[0113] In cases where a component of accessing includes “receiving” or “being granted” access (e.g., in the sense of “permission to access”), it should be understood that this establishes a “potential for accessing” separate from access as such. This potential may indeed be associated with access as such (e.g., as can be demonstrated by information to which access was granted being put to further use). However, it should be recognized that there is a potential for a meaningful distinction that can be resolved in the context of the term's use.

[0114] A computer-readable signal medium optionally includes a propagated data signal with computer-readable program code embodied therein; for example, in baseband and / or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to: electro-magnetic, optical, or any suitable combination thereof. A computer-readable signal medium may be any computer-readable medium that is not a computer-readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

[0115] Program code embodied on a computer-readable medium and / or data used thereby is optionally transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination thereof.

[0116] Computer program code for carrying out operations for some examples of the present disclosure is optionally written in any combination of one or more programming languages; for example, an object-programming, procedural and / or functional programming language. Non-limiting examples include C, Java, Smalltalk, C++, Python, ECMAScript (e.g., JavaScript), and Rust, among many other programming languages known to persons of ordinary skill in the art. As is known to persons of ordinary skill in the art, programs written in such languages specify logical operations which may be variously converted to computer instructions suitable for direct use by particular instances of processing circuitry, before and / or during processing.

[0117] Additionally or alternatively, sequences of logical operations (e.g., in the form of instructions from a machine instruction set supported by processing circuitry) may be embedded in the design of an ASIC and / or in the configuration of an FPGA device. The program code may execute entirely on the user's computer, partly on the user's computer (e.g., as a stand-alone software package), partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), and / or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some examples, a user's computer is more particularly specified, e.g., as a “personal communications device”, “personal computing device”, “smartphone”, “tablet”, “laptop computer, or “portable computer”. Except as otherwise described, each of these terms may be understood as relating to a device which is ordinarily operable for an extended period (e.g., an hour or more) while disconnected from a fixed source of electrical power such as a wall outlet (although commonly the device may be connected, e.g., for charging and / or for extended sessions of use). Commonly, such devices are operable in various ad hoc circumstances with various respective degrees of ease, e.g., while in public seating, while standing, and / or while moving around on foot or in a vehicle. Except as otherwise indicated, a “desktop computer” or “workstation” refers to a device which ordinarily operates from a fixed power connection. General-purpose computing devices operated by a user are optionally of either type; and the type is not necessarily fixed (e.g., a “laptop” may be operated while connected with a desk display, and / or have its battery removed). Communications capabilities allowing connection to a general-purpose data network (e.g., a wide area network and / or a local area network) should be generally understood to be available except as explicitly described otherwise. Mention of using any of these types of computing device may be understood as associated with an envisioned equivalent use of the other, except insofar as the context of the mention clearly disclaims this, and / or clearly indicates reliance on the special properties of portability, power requirements, connectivity, and / or display / input capabilities of the mentioned device type.

[0118] Some examples of the present disclosure may be described below with reference to one or more flowchart illustrations and / or block diagrams of methods, apparatus (systems) and / or computer program products. For such examples, it will be understood by persons of ordinary skill in the art that each block of the flowchart illustrations and / or block diagrams, along with combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented, to apply teachings provided herein, through use of suitable computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus (e.g., processing circuitry) to produce a machine; such that the instructions, upon their execution, carry out the functions and / or operations specified in the flowchart and / or block diagram block or blocks.

[0119] These computer program instructions may also be stored in a computer-readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer-readable medium produce an article of manufacture including instructions which implement the function / act specified in the flowchart and / or block diagram block or blocks.

[0120] The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0121] Some of the methods described herein are generally designed only for use by a computer; and may not be feasible or practical for performing purely manually by a human expert. A human expert who wanted to manually perform similar tasks, if feasible (e.g., such as inspecting objects, and / or making determinations from data), might be expected to use completely different methods, e.g., making use of human expert knowledge and / or the pattern recognition capabilities of the human brain.BRIEF DESCRIPTION OF THE DRAWINGS

[0122] Some embodiments of the present disclosure are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example, and for purposes of illustrative discussion of embodiments of the present disclosure. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the present disclosure may be practiced.

[0123] In the drawings:

[0124] FIGS. 1A-1B schematically illustrate examples of an exercise machine, according to some examples of the present disclosure;

[0125] FIG. 1C is a block diagram of an exercise machine, according to some examples of the present disclosure;

[0126] FIG. 2 schematically represents slack compensation through use of a velocity-dependent added resistance force commanded by exercise machine controller circuitry, according to some examples of the present disclosure;

[0127] FIGS. 3A-3B schematically represent scenarios potentially benefiting from slack compensation, according to some examples of the present disclosure;

[0128] FIG. 4A schematically graphs adjustments determined by exercise machine controller circuitry to prevent development of excessive slack distance in a cable operated exercise machine, according to some examples of the present disclosure;

[0129] FIG. 4B is a schematic graph comparing linear and quadratic dependencies of added resistance force on velocity, according to some examples of the present disclosure;

[0130] FIG. 5 schematically illustrates use by exercise equipment controller circuitry of hysteresis in the determination of a slack compensation force, according to some examples of the present disclosure;

[0131] FIG. 6 schematically represents control of cable return velocity by exercise equipment controller circuitry in response to loss of user control, according to some examples of the present disclosure;

[0132] FIG. 7A schematically illustrates damping control of resistance force with hysteresis in a homing zone near a home position of tension cable, according to some examples of the present disclosure;

[0133] FIG. 7B is a schematic flowchart of a method of damping control of resistance force in a homing zone near a home position of tension cable, according to some examples of the present disclosure;

[0134] FIGS. 7C-7D represent other parameter options for use with control of resistance force in a homing zone near a home position of tension cable, according to some examples of the present disclosure;

[0135] FIG. 7E is a schematic graph illustrating variable parameter home position damping, according to some examples of the present disclosure;

[0136] FIG. 8 is a schematic flowchart of a method of slack compensation, according to some examples of the present disclosure; and

[0137] FIG. 9 is a schematic flowchart of a method of operating a controller of an exercise machine to prevent overly dynamic homing of a tension cable, according to some examples of the present disclosure.DETAILED DESCRIPTION

[0138] The present disclosure, in some embodiments thereof, relates to the field of exercise equipment and more particularly, but not exclusively, to resistance cable operated exercise equipment.

[0139] A broad aspect of some examples of the present disclosure relates to the dynamic control of resistance forces to prevent and / or mitigate potentially device-damaging and / or user-disturbing tension cable movements in electronically controlled resistance training exercise machines. Herein, this is also referred to as “protective management” of tension cable dynamics. More broadly, this is an aspect of what is referred to herein as “utility management” of tension cable resistance force; that is, control of tension cable resistance force for purposes such as protection, safety, storage, calibration, and / or device self-diagnosis.

[0140] Utility management of tension cable resistance force is distinguished from (although often simultaneously with) resistance force specified by exercising parameters of the exercise machine. The exercise parameter-defined resistance force is referred to herein as the “setting force” Fsetting. In some examples, the setting force comprises a user-selected and predetermined level of exercise force which the controller signals to the resistance motor along with the adjustment.

[0141] In some examples, tension cable resistance force is further adjusted for another reason; e.g., to communicate haptic signals, and / or to provide strong vibrations with potential effects, e.g., on muscle tension and / or another physiological parameter.

[0142] More particularly, in some examples, protective management of tension cable dynamics comprises dynamic adjustments of force (increasing and / or decreasing) applied to the tension cable by a motor of an exercise machine to reduce and / or avoid one or more of the following:

[0143] Tension cable slack can develop, e.g., when tension cable movements coupled to forces and momentum of the exercise machine become decoupled from movements of a user end of the tension cable operated by the user's grip. Sufficient tension cable slack can lead to device malfunction, e.g., tangling and / or internal misalignments of the tension cable. Potentially, cable slack leads to a sudden jerk transmitted to the user when the tension cable re-tensions after a period of decoupling. This is further discussed in overview below under the heading Aspect of Slack Compensation. FIGS. 2-5 and 8 and their associated descriptions relate specifically but not exclusively to tension cable slack.

[0144] Free acceleration of a tension cable can potentially result from sudden cable release by the user. This may produce whipping (fast uncontrolled movements of the tension cable through the air) and / or slamming (a sudden stop of the user end of the tension cable when it reaches the frame of the exercise device). This is further discussed in overview under the heading Aspect of Recovery from Sudden Tension Cable Release. FIGS. 6 and 9 their associated descriptions relate specifically but not exclusively to mitigation of free acceleration in response to sudden tension cable release.

[0145] Abrupt dynamic transitions in the homing zone of a tension cable include, e.g., slamming into a frame of the exercise machine which could result from homing (returning) the user end of the tension cable too quickly (even without cable release by the user), and / or force discontinuities (e.g., “sticking”) which potentially disturb and / or confuse the user while pulling to extend the tension cable from its stored home position. This is further discussed in overview under the heading Aspect of Home Position Damping of Tension Cable, that is, damping of transitions between forces in a homing zone near a home position of the user end of the cable. FIGS. 7A-7D and their associated descriptions relate specifically but not exclusively to tension cable damping near the home position.

[0146] Forces exerted for purposes of controlling these issues are also referred to herein as “protective management forces”.

[0147] Protective management forces exchange with (i.e., follow / precede) and / or superimpose upon (i.e., are simultaneous with) the setting force governing how much exertion is needed to perform exercises with the exercise machine. Typically, setting force is user-selected.

[0148] In some examples of the present disclosure, the resistance training exercise equipment is electronically controlled, and electrically powered. Accordingly, device resistance is generated according to controller commands which operate a force generator, e.g., a rotary motor capable of developing several hundred watts (e.g., up to about a kilowatt) of power. Optionally, a more powerful motor is used; e.g., a motor of 1-10 kilowatts or greater. Herein, the force generator is also referred to as a “resistance motor” or “main resistance motor”. Optionally a plurality of individual motors are provided, which together act as the resistance motor imparting resistance force to the tension cable. In some examples, the resistance motor comprises a rotary motor, including a rotor (which rotates) and a stator (which remains rotationally stationary). Electrical power induces electromagnetic fields in a pattern which induces the rotor to turn relative to the stator. The force of this also imparts mechanical motion to the tension cable, which is directly or indirectly coupled to the movements of the resistance motor. Hereinbelow, FIGS. 1A-1C further relate specifically but not exclusively to components and / or structure of examples of electronic cable-operated exercise machines, under the heading Implementation of Resistance Motor Control

[0149] Optionally, device-generated resistance forces are electronically controlled to produce a pull force profile implementing the setting force Fsetting. In some embodiments, the pull force profile comprises a constant or varying force selected to be applied to the tension cable by the resistance motor. Along with the pull force profile, other intrinsic and / or electronically applied forces are provided.

[0150] In particular, along with the commanded pull force profile, the exercise machine includes intrinsic inertial properties. While the pull force profile is determined by machine settings, it is the user that determines how hard, and more particularly, how fast they perform a particular pull. Accordingly, the effects of intrinsic inertial properties vary according to user input forces, with the result that actual force experienced by the user is typically different than the pull force profile itself, e.g., due to inertial resistance to acceleration and / or deceleration.

[0151] In some examples, the pull force profile itself is simply a constant force. In some examples, the pull force profile is more complicated, e.g., designed to simulate (at least approximately) a weight with an inertia other than the device's true intrinsic inertia. For example, the pull force profile optionally simulates a constant weight along with the mass inertia of that weight. In some examples, the pull force profile simulates a stretching spring and / or elastic band (e.g., behaving according to Hooke's law), and / or another pull force profile. The targeted value of these forces, at any given moment of a rep, is what is referred to herein as the “setting force” Fsetting.

[0152] When not otherwise adjusted, this targeted value also defines the “commanded” force, that is, the force which the exercise machine's controller circuitry instructs the resistance motor to provide. In some examples, however, commanded force (also referred to herein as Ftotal is subject to modification by further forces, so that it is different from Fsetting. In some examples, protective management forces provide a portion (optionally all) of the difference between Ftotal and Fsetting.

[0153] Typically, protective management forces are automatically determined, although automatic determination may take setting force into account. When applied simultaneously with setting force, protective management forces may be understood as positive or negative (increasing or decreasing).

[0154] Some disclosed embodiments provide an advantage of applying the dynamic adjustments in a manner which avoids disturbing the user's sense that the setting force itself is stable and predictable. It is noted that the user sense may be of an “underlying” setting force; moreover the setting force itself is not necessarily itself constant (e.g., the setting force optionally simulates an elastic band, increasing with increasing extension distance). For the sake of understanding: a “user sense” of setting force stability is optionally understood as including acceptance of variations in resistance force analogous to (although not necessarily simulating) those that might be present in a completely mechanical resistance device, e.g., forces due to linear and / or rotational inertias of flywheels and / or masses used to provide resistance, elasticity in linkages and / or the cable itself, friction, and / or drag (e.g., fluid resistance). For example, a user may readily accept easing in of resistance force within a homing zone near a home position of a user end of the tension cable as “part of the mechanics” of the device, even when the ramping of forces is actually generated as an artifact of electronic control, e.g., a gradually increasing motor current.

[0155] In some examples, “user sense” for the application of a dynamic adjustment is linked to a user's own simultaneous adjustment of motion and / or force. To a user, this may feel analogous, e.g., to effort-dependent effects of mass inertia, rotational inertia, and / or fluid resistance. Potentially, the user is even unaware of the adjustment, e.g., since their own movements and / or efforts are changing, and the adjustment may itself be below a threshold at which the user notices a difference. In some examples, the dynamic adjustment in resistance force is applied as a function of a some measured aspect of tension cable movement, e.g., it may be applied as a function of velocity and / or acceleration of tension cable extension.

[0156] A principle of adjustment applied in some examples of the present disclosure is to adjust for prevention of certain outcomes, e.g., rather than according to constant and absolute thresholds of position, velocity, and / or acceleration alone. For example, in some examples, a homing zone within which resistance forces are eased between holding force and setting force is “normally” defined in terms of changing distance. But when a returning velocity of the user end of the tension cable is high enough, the easing optionally starts sooner (at a greater distance from the home position), e.g., to compensate for limits on sensor performance and / or motor control response time. This provides a potential advantage by allowing the application of “just enough” protective management force (in this case, application within an expandable, but normally more restricted zone), reducing potential interference with the user's sense of a stable and predictable setting force.

[0157] Another principle of adjustment applied in some examples of the present disclosure is to make adjustments in a manner which is relatively insensitive to sensing error, control error, and / or control lag. For example, adjustments are applied monotonically and / or with hysteresis as a function of some measured value, e.g., to avoid producing oscillations as a result of measurement noise and / or control lag. In some examples, adjustments based on measured velocity (first order derivative of position) are used to approximate inertial effects of acceleration (second order derivative of position), noting that acceleration calculations based on position measurements are potentially lagging and / or subject to greater relative error.

[0158] An aspect of some examples of the present disclosure relates to providing slack compensation forces in a tension cable used to operate electronically controlled resistance training exercise equipment (“exercise machines”), according to some examples of the present disclosure.

[0159] Using such a cable-operated, electronically controlled exercise machine, the user begins a rep (“repetition”; the shortened form “rep” being in common use) by pulling on the tension cable against machine-generated resistance forces, thereby increasing cable extension. During a return phase of the rep, it is expected that the user continues to control the cable while allowing it to shorten again.

[0160] Slack potentially results when movements applied by a user to the user end of the tension cable becomes decoupled from movements of the rest of the cable. This is typically associated with a sudden reduction of tension applied by a user to a user end of the tension cable while performing a rep, particularly during cable extension (during a “pull”). For example, such a sudden reduction of tension may occur due to a sudden stop or slow-down in initially rapid pulling by a user. To some extent, momentum (of the tension cable itself and / or of components coupled to its motion such as spool, motor, and / or pulley components) then carries the tension cable forward, resulting in the slack itself-a certain amount of “extra” tension cable which has played out from the exercise machine, beyond what spans the actual distance between the user end of the tension cable and the arm or other anchor location from which the tension cable exits the exercise machine.

[0161] During the development of slack, any resistance force exerted by the motor on the tension cable acts to decelerate it, and then accelerate it in the opposite direction. When all the slack is again removed, a user who has retained their grip on the user end is subjected to a sudden jerk as their grip again become coupled to the movements of the rest of the tension cable. Effects may include, e.g., straining joints and / or throwing the user off balance.

[0162] In some examples of the present disclosure, slack compensation forces are provided to prevent excessive slack from developing in the tension cable in such conditions, and / or to mitigate potential adverse effects due to the development of slack in the tension cable. Accordingly, slack compensation is a form of protective management force which comprises modulation of the commanded force, the modulation being directed at preventing and / or limiting the development of slack in the tension cable. The modulation magnitude is selected, e.g., based on measured dynamics of the motor itself, measured dynamics of the tension cable, measured force applied by the user to the tension cable, and / or another measurement indicative of the dynamic state of the rep and / or the exercise equipment.

[0163] In some embodiments, modulation of force comprises introduction of variable resistance forces into the operation of an exercise machine, the variable resistance forces being selected to keep operation of the machine out of potentially disturbing, damaging, and / or unsafe regimes. Herein, prevention and / or mitigation of slack is equivalently referred to as “slack protection” or “slack compensation”.

[0164] In some examples, variable resistance forces are introduced so as to feel predictable to a user (that is, to avoid the user feeling that force generated by the exercise machine is unstable and / or unpredictable). In some examples, variation in resistance force is introduced as a linear function of velocity. Additionally or alternatively another function shape and / or dynamic parameter indicative of cable movement is used, for example as described below. Force modulations used to protect against slack in a tension cable are also referred to herein as “deslacking” force Fdeslack. In some examples, “feeling predictable to a user” comprises making changes in force modulation (changes to commanded force so that it differs from Fsetting) suitably gradual, while still providing adequate slack protection. However, when the user is operating the device without much risk of slack developing, it is a potential advantage to be able to omit, reduce, and / or discontinue modulation, e.g., so that the resistance which the user senses feels closer to their selected resistance setting. In some examples, the controller's processing circuitry is used to manage transitions in resistance modulation, so that dynamically changing slack protection does not interfere with the user's sense of an underlying mechanical consistency.

[0165] Among the technical problems arising when managing the joint set of concerns mentioned in the previous paragraph (user's sense of consistency vs. slack protection) is that posed by operating constraints on servo feedback capabilities. On the sensing side of the servo loop, applicable constraints potentially include, for example, sensing lag and / or calculation lag (i.e., lag in determining what feedback should be given). On the response side of the servo loop, applicable constraints potentially include, for example, transmission lag and activation lag (i.e., lag in effectively developing the feedback force that has been selected). There can also be errors (e.g., sensing noise) in measurements themselves, and / or errors (e.g., control noise) in providing feedback force. In some examples (e.g., when operating with approximating assumptions), there are potentially systematic errors in the calculations themselves. During a rep (e.g., as the tension cable is accelerated), a certain amount of device kinetic energy (and, correspondingly, momentum) is built up. How much momentum / kinetic energy is present depends on the velocity of the pull (i.e., the rate of tension cable extension / return), which is largely under the direct control of the user. For examples using a rotary motor as the main resistance motor, much of the momentum / kinetic energy is associated with rotation of the motor's rotor, and / or of a spool upon which the tension cable is wound. Masses and velocities of other moving components such as the grip accessory (e.g., a pull bar) and the tension cable itself also contribute. It is noted that for a given pull velocity, device momentum / kinetic energy in an electronically regulated cable-operated exercise machine commonly (though not necessarily) remains about the same throughout a range of resistance force settings (that is, resistance force as set by the user). This contrasts, e.g., with gravity weight resistance training exercise equipment, wherein adding more weights (as sources of resistance force) also adds in their inherently coupled inertias.

[0166] Given a substantially fixed momentum / kinetic energy (at some velocity), there is potentially a greater opportunity to produce slack when a separately controlled resistance force is relatively lowered. More particularly, the pull resistance force Fsetting, when proportionally lower (compared to the kinetic energy), does not slow down the motor as quickly as it does when Fsetting is proportionally higher.

[0167] Focusing on user experience, a pull may become slack as the user slows down the pull near its end, particularly when the user decelerates their body quickly. The tendency to develop slack potentially increases especially when the force of Fsetting is light, and / or when the user performs the pull with higher velocities. This is because the motor's rotor (and / or a spool which it controls) builds up more momentum when velocities are high, while relatively light resistance forces do not overcome this momentum (or its kinetic energy) as quickly. The momentum of the rotor and / or spool can thus act as a “buffer” which partially decouples pull forces exerted by the motor, and the pull force actually sensed by the user. With heavier resistance (a larger value of Fsetting), the ratio of resistance force to kinetic energy rises, and a user potentially experiences less of the “buffering” effect, and / or a lowered risk of slack. There is also potentially a converse effect, wherein the user invests a proportionally greater amount of their overall effort (relative to the baseline pull force profile itself) to accelerate a pull against light resistance than against heavy resistance. The user potentially senses effects of system inertia (or its lack) most when trying to speed it up (e.g., accelerating at the beginning of a pull) or slow it down (e.g., decelerating near the end of a pull). During periods of constant velocity, buffering by the inertia of the system is potentially reduced, allowing the user to sense the commanded force more directly. Risk of slack decoupling in particular concentrates to periods when the user is slowing a pull. During the return phase after a pull, inertia builds again, but this time in the direction of motion which the user is also restraining. Slack is then possible, but potentially less of a concern.

[0168] As a result, resistance force to a pull motion at some speed can feel relatively consistent (and in particular, relatively unaffected by inertial buffering) when resistance is heavy; the user does not ordinarily slow the pull fast enough to be distracted by slack. The resistance force due to Fsetting itself quickly dissipates what inertia there is. But at the same speed, when resistance is light, resistance can feel inconsistent, “light”, or otherwise strange; e.g., with felt resistance forces increasing more significantly (relative to baseline pull force profile) during acceleration, then dropping precipitously during deceleration.

[0169] Furthermore, there is potential risk of user discomfort, injury and / or damage to the device due to sudden “jerks” when built-up reverse momentum again takes up the slack. For example, after a brief period of slack, the user and / or device may experience resistance force added to built-up return momentum applied suddenly. Slack of a sufficient amount also potentially leads to entanglement and / or mis-winding of the tension cable.

[0170] Additionally or alternatively, mismatches between resistance force and inertially buffered “feel” can potentially confuse a user's sense of what pull speed to use when switching among different resistance forces. For example, the user might paradoxically experience a need to slow down (relatively and / or absolutely) when pulling against lighter resistances, so as not to over-accelerate a weakly resisting rotor. The user might feel frustration in trying to avoid overtaxing the machine, potentially losing confidence in its performance.

[0171] In some examples of the present disclosure, an exercise machine controller controls the resistance motor to increase resistance force at least in part as a function of increasing velocity to provide the slack compensation force Fdeslack. Optionally, the function of velocity is linear; i.e., resistance force is added in a ratio-defined proportion as velocity increases, optionally with a threshold offset. Being a lower-order derivative of position than acceleration, velocity is potentially easier to measure and predict. For example, velocity will rise and fall at least once (and commonly although not necessarily exactly once each) during a single extension of the tension cable (during a pull), according to forces applied by a user to a user end of the tension cable. Furthermore, with greater velocity, there is a potentially greater chance of generating slack due to a sudden stop. This makes velocity potentially useful as a proxy for calculating slack compensation forces. By translating velocity changes into corresponding gradual and regular changes to resistance force, slack compensation forces are potentially more easily accepted (and / or less-easily noticed) by a user.

[0172] For example, during a pull, an appropriately selected velocity-based function for resistance increase can be considered to roughly counterbalance the effects of added kinetic energy (and potentially changes in resistance while velocity is changing). Other parts of the increase may be experienced similarly to friction, and / or otherwise be experienced as a “predictable” change to Ftotal. A velocity-based function can be selected which reduces amplitudes of adjustment during slower motions, so that user exertions are correspondingly less perturbed during the periods when they are potentially exerting less force to control motions of the device, and / or themselves making fewer adjustments to the dynamics of tension cable movements.

[0173] In some examples, the function of velocity used to determine Fdeslack is itself adjusted as a function of a selected resistance force governing the pull (the “setting force” F″se∈g). For example, the rate at which force is added as a function of velocity is reduced for higher selected resistances, at least over some portion of the overall pulling distance. This may be justified since as the setting force increases, the mass-equivalent of resistance force can eventually come to far exceed the mass-equivalent of the device inertia. As a result, there is a faster baseline deceleration that occurs should the user suddenly stop exerting pull force. Potentially, this is fast enough that the disadvantages of slack do not develop.

[0174] Optionally, resistance force as a function of velocity inverts at some level of resistance force setting, so that it is removed instead of added. For example, this could be used to reduce a potentially exaggerated deceleration during deceleration of a pull, and / or make the device feel more like an elastic band by canceling out inertia of the motor which resists acceleration.

[0175] Optionally, reductions / increases in resistance during a rep are divided into phases, according to an estimated risk that slack is generated during a particular phase of the rep. A potential advantage of using phases is a potentially reduced likelihood of introducing oscillations into control outputs, as well as potentially reducing interference with user-selected resistance force levels outside of conditions where slack is a particular risk.

[0176] A “vulnerable to slack” phase of a rep can be initiated, for example, based on when a certain velocity threshold is crossed, optionally during an increase in velocity or a decrease in velocity. Optionally, the slack compensation force is delivered according to one function as pull velocity accelerates, and a second function as pull velocity decelerates. In some examples, the transition between the two functions is managed to occur only in one direction. This gives the system some hysteresis, potentially making it less prone to oscillation near threshold values. Threshold values governing the transition are not necessarily based on velocity, or on velocity alone. For example, elapsed time, distance and / or acceleration are optionally used in determining phase transition thresholds. In particular, time and / or distance may be used to control transitions between phases. For example, transitioning from an initial velocity / resistance change function to a new velocity / resistance change function may be limited to occur over a predetermined period of time (e.g., 10-500 msec or 10-1000 msec), and / or over a certain distance (e.g., 0.5-10 cm of continuing movement, or 0.5-50 cm of continuing movement).

[0177] An aspect of some examples of the present disclosure relates to recovering from a sudden loss of user control of a grip accessory at a user end of an electronic cable-operated exercise machine, according to some examples of the present disclosure.

[0178] During operation of an electronic cable-operated exercise machine, a potential for device damage and / or injury arises in case a user operating the exercise machine loses control of the tension cable during a rep (e.g., loses their grip on a grip accessory used to operate the tension cable). During a rep, a controller of the exercise machine typically commands the resistance motor to provide significant force, e.g., potentially comprising 100 pounds or more of force exerted through the tension cable. If (e.g., due to loss of grip) the user suddenly stops exerting a counteracting force, the tension cable and any attached grip accessory begin to rapidly accelerate toward the exercise machine.

[0179] Two general concerns of significance in such cases are to avoid injury to the user and / or anyone standing nearby, and to avoid damage to the exercise machine itself. Furthermore, since such an incident comprises an exception to normal use, the exercise machine should reset itself, and optionally perform self-checks (e.g., in case the dynamics of the incident could have caused device damage).

[0180] In some examples, controller circuitry of the exercise machine accesses sensing data indicative of a current return velocity of the tension cable. Using the sensing data, the controller determines whether a fast tension cable return criterion for the tension cable is met. The fast tension cable return criterion comprises, for example, one or more of: an inherently excessive return velocity (e.g., a return velocity beyond normal and / or intended operating parameters), a period of acceleration indicative of a loss of user input force (e.g., acceleration consistent with unopposed acceleration due to resistance forces which are being commanded for the resistance motor), and a joint return velocity and distance of tension cable extension which create an imminent risk that a user end of the tension cable will return to the home position at an unacceptably high velocity.

[0181] Upon determining that one or more of the faster return velocity criteria are met, the controller the acts to reduce a velocity at which the extension distance of the tension cable is decreasing. In cases where velocity is already sufficiently extreme and / or the available distance to bring the tension cable to a halt is sufficiently short, this optionally comprises activation of a cable brake to bring the tension cable to a full stop and / or shutdown of the resistance motor. Optionally, recovery continues after this point, e.g., by bringing cable return back up to a recovery velocity

[0182] In cases where detection is in time to allow a more graceful recovery, no or partial braking is applied, while the controller changes commands to the resistance motor so that the tension cable is brought to a safe recovery velocity. Optionally, during further retrieval of the tension cable, velocity and / or force is adjusted to avoid inducing dangerous swinging in the tension cable and / or grip accessory. Optionally, the adjustments are timed to reduce swinging, e.g., by reducing tension particularly when sensing indications show that tension changes due to swinging motions have reached a peak.

[0183] As the user end of the tension cable approaches the end of its travel (its home position), velocity is optionally reduced again to a velocity slow enough to avoid damage as the end of the tension cable and / or its terminal accessory connector reach their home position. Optionally, reaching the home position is accompanied by final braking and / or decreasing forces, so that a collision is avoided, and / or occurs under conditions gentle enough to avoid damaging the exercise machine.

[0184] An aspect of some examples of the present disclosure relates to control of forces and / or movements of a tension cable while a user end of the cable is in a homing zone near a home position of the tension cable, according to some examples of the present disclosure. Herein this control is referred to both as “damping” and as “casing”; the two terms each refer to managing the control of transitions in resistance force and / or velocity between relatively high and relatively low values in a gradual fashion, e.g., involving a plurality of intermediate resistance force levels. Although gradual in this sense, the damping is optionally somewhat rapid perceptually (for the user); e.g., occurring in a period of between 10 msec and 500 msec. A maximum slew rate of force reduction is, for example, at least 100 pounds per 100 msec.

[0185] In some examples, the damping applied comprises a component of control exercised on the resistance motor to reduce its unloaded equilibrium velocity while the tension cable is within the homing zone. Herein, this is also referred to as “control-limiting the motor velocity”—that is, the motor velocity is limited so that it does not increase to exceed a certain velocity which is its present controlled limit. Under load, actual motor velocity is generally reduced still further, e.g., as torque and (rotational) speed of the motor are in part converted to perform work. It should be understood that whether loaded or unloaded, the motor potentially takes time to accelerate or decelerate following a change in the controlled limit of its velocity.

[0186] Commonly, the control-limited motor velocity is adjusted by adjusting electrical voltage, while the resistance force applied by the motor is adjusted by adjusting electrical current. Commonly, applying a load to a motor itself elicits an increase in current. Motor driving circuitry may actively or passively modify either or both of current and voltage. Some motor and / or control circuitry designs allow voltage and current to be adjusted independently; in other designs, there is at least some correlation and / or reverse correlation in adjustments to voltage and current.

[0187] In an exercise device, reduction of the controlled velocity limit at least somewhat separately from the resistance force provides a potential advantage by allowing the resistance force of the device to be modified less and / or less abruptly, while still biasing the tension cable toward slower movement. If the user is performing sufficiently slow and careful movements, they can potentially work with the device near to the end of the tension cable's return travel while still experiencing high resistance-yet the motor will also tend to avoid rapidly slamming the handle into its home position should the user's control slip. Furthermore, the motor itself will tend to encourage user care, by limiting the speed to which the tension cable can be accelerated. Homing zone reduction in control-limited velocity does not necessarily prevent a “slam return” under all conditions, but does potentially contribute to reducing compromises between consistency of user experience, and comfort and / or safety.

[0188] In some examples, operation at the setting force of a cable-operated weight machine is eased in (during cable extension) and / or eased out (during cable return) over a short distance and / or period of time as tension cable is pulled away from and / or returned to its home position.

[0189] Use of an easing distance and / or time period for setting force provides potential advantages by allowing users to gauge their movements and / or application of force according to a gradually changing force. For example, rather than eliciting no movement at all until finally pulling as hard as the setting force requires, a user is provided with feedback that helps them gain a more gradual bodily sense of how much additional force is needed for the current resistance force settings of the exercise machine. Optionally, the easing distance provides a short distance of easier resistance than that of the resistance force setting used for exercising. This allows the user to accelerate / decelerate their gripping limb(s) with more control and / or more gradually. This potentially helps the user when starting a first rep (for the case of tension cable extension), and / or helps them to end a set without a harsh final stop (for the case of tension cable return).

[0190] Easing transitions occur within a distance of the home position of the user end of the cable referred to herein as the “homing distance”, which itself defines a region up to the homing position itself referred to herein as the “homing zone”. The homing distance, in some examples, comprises a distance of 25 cm or less. In some examples, the homing distance is 10 cm or less; in some examples, the homing distance is 5 cm or less, e.g., 1 cm, 2 cm, 3 cm, 4 cm, or 5 cm. For the sake of comparing resistance force profiles during extension of the tension cable and during return of the tension cable, the homing distance is considered to be the same in both directions, e.g., the homing distance is optionally considered as the largest distance from the home position at which either transition is underway; optionally a slightly larger distance, e.g., 1-5 cm more distant still. The distance of the transition itself is also referred to herein as a “damping range”.

[0191] In some examples, profiles of the resistance force transitions as a function of distance are different from each other. The differences are selected, in some examples, so that average resistance force throughout the region between the home position and the homing distance is larger for extension of the tension cable than for return of the tension cable. In some examples, the difference in average resistance force is exemplified by a hysteresis in the distances at which accelerations / deceleration begins / ends. In some examples, the difference in average resistance force is exemplified by differences in the shapes of the functions which transition from high to low force vs. from low to high force. Additionally or alternatively, in some examples, target forces are set differently to produce the difference.

[0192] This difference in average resistance has the potential advantage of promoting a safer slowdown during return of the tension cable to its resting (quiescent force) state, when the user is potentially tired, and when the direction of motion is such that there is a risk of hard contact and / or a jarringly sudden stop.

[0193] On the other hand, activating resistance forces more quickly during extension allows rapid stabilization to the resistance levels that the user will be exercising with. This also potentially enhances the sense that the exercise machine has a consistent behavior. For example, the user may experience the ease-in distance as due to elasticity and / or looseness in the tension cable and / or its linkages. While a small amount of this may feel normal and “physical” to the user (even if in fact there is no meaningful level of either, except as attributed by the user), it is a potential advantage to avoid exaggerating such effects.

[0194] Optionally, for example, resistance forces begin increasing toward the resistance setting force as soon as extension is initially detected. Optionally a short delay distance (e.g., 1-5 cm) and / or time (e.g., 10-500 msec) is introduced. In the reverse (returning-phase) direction, resistance forces optionally reach a low baseline level while the user end is still several mm or several cm away from (e.g., 1-10 cm away from) its home position. This allows, e.g., time for the user end to decelerate, and / or makes it easier for the user to return the user end to its home position without reaching a jarring stop.

[0195] The distance at which the extension-phase increase in resistance force to reach the setting force ends (e.g., plateaus and / or finishes transitioning to a resistance force function determined by the setting force) is optionally different than the distance at which the complementary return-phase decrease in resistance force begins. For example, the transition is optionally completed closer to the home position during extension phase than it begins during return phase. As well, rates of change in force as a function of distance and / or as a function of time are optionally different. Changes in force are optionally monotonic (that is, unidirectional) for a given direction of movement; and according to any suitable linear or non-linear function.

[0196] Some disclosed embodiments involve controlling resistance forces during damping. In some examples, the system is configured to provide (when feasible) a gradual-in-time reduction of pulling force as the user end of the tension cable nears the home position, e.g., a period of time of at least 10 msec, at least 25 msec, at least 50 msec, or another preferred minimum period. The preferred minimum period is selected, e.g., to avoid a disturbingly sudden drop in force that could feel to a user as if a weight had suddenly been dropped from the end of the cable which they are exerting pulling force to restrain. A more gradual reduction in force potentially warns the user in time to avoid being thrown off balance; e.g., helping them to avoid stumbling backward when the force the user has been resisting is removed. The preferred minimum period is optionally selected assuming a time-linear decrease in resistance force; non-linear cases are briefly discussed below. In conditions under which the preferred minimum period is unavailable (because the cable is moving too fast), reduction of force is optionally switched to be as a function of distance instead.

[0197] Insofar as the user is either easing into or out of an ongoing exercise session during damped transitions in resistance force, the transition typically (but not necessarily) rises to or falls from the same resistance force (i.e., the resistance setting force). On the transition side near the home position, the quiescent state holding force is commonly the same as well. Optionally, the holding force is the minimum weight setting that the exercise machine can operate with. A relatively lower holding force has the potential advantage of relatively reducing heating of the motor and / or stress / strain on components. Accordingly, the range of the transition optionally ranges from a minimum and / or holding force of, e.g., 1-5 pounds up to an operating setting, e.g., of 50 pounds, 75 pounds, 100 points, 125 pounds, or another setting force. The targeted and / or de facto distance over which this transition occurs is, e.g., about 5 cm, or another distance (e.g., a distance between 0.5-10 cm).

[0198] There are optionally differences in final force targets. For example, a set of reps can begin with one resistance setting, and end with another. Optionally, the holding force in the quiescent state changes over time as well. For example, the final retrieval force during the return phase is optionally lowered below the eventual holding force for a period of time to reduce collision speeds. Once the user end is at the home position, holding force optionally increases somewhat, e.g., to help make sure that the user end is neatly stowed. Optionally, holding force is allowed to droop over time. Optionally, e.g., to counteract spontaneous extension due to the weight of the tension cable and / or its grip accessory, holding force is periodically renewed. These scenarios are examples, and should be considered non-limiting.

[0199] Some disclosed embodiments involve control of damping transitions. In some examples, resistance force is adjusted at least in part (e.g., depending on circumstances) as a function of time. In some examples, the transitions are optionally controlled to happen within and / or not faster than certain duration(s), the durations being selected so that the associated movements of the user end typically also happen within (that is, along a distance not greater than) a limited distance range referred to herein as the “homing zone”. In some examples, measurements of duration and distance are used jointly to control resistance force transitions. For example, a transition to a higher resistance force may be constrained to occur not more quickly than some period of time (e.g., at least 10 msec, 25 msec, 50 msec, 75 msec, 100 msec, 250 msec, 500 msec, or another period of time), even if the user manages to move the user end beyond the normally targeted distance for completing the transition. Optionally, there is an upper time limit; e.g., once the user begins moving the tension cable, the tension is optionally raised to its limit within some period (e.g., within 100-500 msec) whether the user pulls for a short distance (e.g., 0.5 cm) or a longer one (e.g., 10 cm). Alternatively, distances are used to limit time; e.g., a transition time is optionally hurried to keep distances shorter when the user moves the user end quickly enough.

[0200] Some disclosed embodiments involve mixed-mode control of damping transitions during cable return. During a return-phase, distance available within the homing zone optionally plays a limiting role insofar as, on one hand, it is a goal to prevent a hard collision, while on the other, it is potentially advantageous to keep the homing zone within which the homing routine takes over resistance force small, so that the user's workout is not interfered with. However, when velocity of the tension cable is low enough that reduction of resistance force is not limited by available distance, force reduction is optionally controlled to occur gradually and over a preferred minimum time, e.g., about linearly over the period of at least 10 msec, 25 msec, 50 msec, 100 msec, 250 msec, or 500 msec mentioned above.

[0201] When the tension cable is being returned to the home position quickly (at a sufficiently high velocity), the preferred minimum time is not necessarily available, unless the reduction of resistance force also starts while a greater distance separates the user end from its home position. This, however, can have the effect of interfering with a user's workout, e.g., when the user is performing exercises which include deliberately rapid deceleration of the user end of the cable toward a stopping position just beyond the homing zone of the user end. While relatively small adjustments in homing distance may be accepted by users, it could be confusing to a user if the homing zone were sometimes much larger and sometimes much smaller, depending on how they operated the equipment. In some examples, e.g., rather than unduly extending the length of the homing zone, the system instead applies more rapid deceleration once the homing zone is entered, even when this results in a relative excess of deceleration (e.g., linear deceleration over a period shorter than the preferred minimum period for linear deceleration).

[0202] In some examples, velocity is control-limited to a reduced value within the homing zone; that is, the motor is operated with parameters that reduce the velocity to which the motor can accelerate the tension cable. If the user returns the tension cable at a velocity below the velocity limit, this potentially makes no change in what the user senses. If the user attempts to return the tension cable at a velocity above the velocity limit, the control limit on velocity acts to damp the development of excessive return velocity.

[0203] Additionally or alternatively, velocity is limited by application of a brake (e.g., a friction brake, and / or a motor holding force brake) when it is found to exceed a certain threshold. Braking forces act to slow the tension cable. Assuming that the user is maintaining some level of user force, they may initially feel a drop in resistance forces; however, a brake also acts to counteract user forces once the tension cable is stopped.

[0204] In some examples of the present disclosure, a portion of the variability in starting velocity and / or velocity deceleration is handled by switching between control modes used to decrease resistance force, according to the situation. For lower starting velocities, a semi-open loop control method is used, in which resistance force is simply reduced over a predetermined period of time to a target. This mode is selected, e.g., when it is reasonable to assume that counteracting user force will work in time to sufficiently decelerate the user end of the tension cable before it reaches its home position. This mode has potential advantages already mentioned, e.g., a force-reduction duration can be selected which is long enough to give the user time to adjust; it is also “smooth”, and so avoids disturbing the user experience with potential problems such as feedback oscillation and / or sensing errors.

[0205] This mode reaches limits, however, when the rate of approach to the home position is too fast. In some examples, use of a fixed (minimum) length of force reduction time is then discarded, and resistance force is instead ramped down as a function of distance to the home position (e.g., sensing-indicated distance of the user end of the tension cable from its home position). This can be described as “choosing the fastest mode”. If the targeted time to ramp down resistance force is longer than the time which appears available (because the tension cable is moving too fast), then the distance-dependent control mode is selected instead. Optionally, the determination of which mode to use is made upon entering the homing zone, without expectation of a change. Alternatively, control transitions between the modes according to whichever control mode is currently fastest.

[0206] Insofar as velocity is under user control (that is, actual velocity, distinct from the concept of “control-limited” velocity described above), it should be understood that zeroing out resistance force upon and / or before reaching the home position does not by itself guarantee that return velocity is canceled out, or even returned to some particular level. The effect of removing positive resistance force, and / or of control-limiting the velocity such resistance force can develop, “smooths the way” to an eased-in return of the user end to its home position for a user who is also consciously targeting a safe return of the device, and also reduces forces involved (should there be a collision) to those of the (relatively light) inherent mass and momentum of the unpowered moving parts of the system. For example, reduction of resistance force to zero helps reduce a potential for pinching and / or trapping of body parts during the user end return to its home position.

[0207] Some disclosed embodiments involve variations of home position damping of the tension cable. During cable return, the homing zone is optionally allowed to increase in size somewhat as a function of tension cable velocity. In some examples, the increase is by an amount less than what is proportionally needed to entirely avoid dropping below the “preferred minimum” time period of resistance force down-ramping, but large enough to maintain the ramping-down period above some still-shorter predetermined time period. In some examples, dynamic increase of the homing zone is further limited, e.g., by taking into account a current measured and / or estimated deceleration of the user end. This potentially helps to improve the balance between device safety, and avoiding interference with the user's workout. If—e.g., at some checkpoint distance—the current rate at which the user is decelerating the user end is projected to slow the user end enough to avoid disruptive intervention, then the system optionally partially or entirely avoids increasing the size of the homing zone. If the projection turns out to be wrong, the system still retains the option of enforcing rapid deceleration, resistance force reduction, and / or control-limited velocity upon the user end of the tension cable entering the unadjusted or less-adjusted (e.g., default-sized) homing zone.

[0208] Noting that the overall period of deceleration can in principle be lengthened arbitrarily by applying a tapering (non-linear) deceleration, the “preferred minimum time” may optionally be understood as associated with a corresponding “preferred maximum rate of resistance force reduction”. From a given starting point and starting velocity, extending the time of force reduction to reach a some low-valued target may then be understood to involve some (e.g., initial) period of even faster decline. As a result, the user would then potentially experience even greater “suddenness” in the changing dynamics of the tension cable, but this would carry through for only a portion of the whole range of resistance force reduction.

[0209] It is again noted that the while the system generally has greater control of return velocity (e.g., to limit its maximum value) than of extension velocity, there is a potential for erratic user input to affect motion in either direction. Accordingly, it is a potential advantage for the system to be configured generally to “look ahead” in time based on its current dynamic state, together with assumptions about sudden changes in force input that a user could plausibly make. Where the controller determines that it potentially cannot otherwise guarantee, e.g., a suitably low-velocity return of the tension cable to its home position, the controller optionally intervenes with increasingly aggressive parameters and / or mechanisms.

[0210] Accordingly, where return velocities are high enough, and / or positions near enough the home position, a controller optionally intervenes more aggressively to shorten the transition time, as appropriate to prevent and / or reduce forces of a collision (which itself would result in a very short transition). For example, the controller limits pull speed and / or decreases pull resistance when the end of the tension cable is within a homing zone distance from its home position, e.g., within 25 cm, within 10 cm, within 5 cm, or within another distance which leaves the system with enough lead time and distance to react, and avoid the user end of the cable hitting the machine's arm with excessive (e.g., potentially damaging) force and / or velocity. This also potentially helps avoid communicating a jarring deceleration to the user.

[0211] Resistance force reduction, for example, is optionally implemented as a function of one or both of distance and time. If the user allows the tension cable to retract slowly, the system optionally “uses time” to reduce the weight (again, “using time” here may be understood as a proxy for “avoiding excessive suddenness of force reduction” during, e.g., linear force reduction). If the cable is moving faster than time-based force reduction allows for, however, the system optionally reduces the weight based on the distance traveled; e.g., lowering it as fast as needed to reach a target when the user end reaches a certain position. Where velocity is sufficiently high, velocity is optionally reduced more aggressively, e.g., by control-limitation (to prevent accelerating to an excessive velocity) and / or by applying a brake. The brake is optionally applied to the tension cable itself, to the motor, and / or to a spool upon which the tension cable is wound.

[0212] If necessary to help avoid a high velocity collision, resistance force applied by the motor is optionally simply turned off, or even applied (briefly, e.g., not past the point of creating return direction motion) in the opposite direction. In this case, the temporal discontinuity in resistance force this creates is potentially less disturbing than the imminent collision.

[0213] Before explaining at least one embodiment of the present disclosure in detail, it is to be understood that the present disclosure is not necessarily limited in its application to the details of construction and the arrangement of the components and / or methods set forth in the following description and / or illustrated in the drawings and / or given in the Examples. drawings. Features described in the current disclosure, including features of the disclosure, are capable of other embodiments or of being practiced or carried out in various ways.

[0214] Some disclosed embodiments involve resistance motor control of exercise equipment. Reference is now made to FIGS. 1A-1B, which schematically illustrate examples of an exercise machine 100, according to some examples of the present disclosure. FIG. 1A emphasizes externally visible features. FIG. 1B illustrates certain internal features of an example corresponding also to the example of FIG. 1A. Reference is also made to FIG. 1C, which is a block diagram of an exercise machine 100, according to some examples of the present disclosure.

[0215] The example of FIG. 1C includes the examples of FIGS. 1A-1B. It should be understood that sensor 145 is an optional feature of FIG. 1C; provided, for example, to sense one or more of tension force and / or strain in tension cable 105, and / or dynamic movements of tension cable 105, e.g., velocity, acceleration, and / or extension distance.

[0216] In the example shown, exercise machine 100 comprises a power section 120. Tension cable 105 extends from power section 120 through frame 110, and connects at its terminal end (e.g., via accessory connector 107B) to a grip accessory 107. In some examples (e.g., as shown in the examples of FIGS. 1B and 2A), power section 120 comprises motor 125 and spool 121, linked via belt 122. Optionally, belt 122 comprises a v-belt or timing belt. Optionally, power is transmitted from motor 125 to spool 121 by gears. Optionally, motor 125 drives spool 121 directly. In some examples, at least a portion of controller 129 is housed within housing 120A. Additionally or alternatively, a portion of controller 129 is housed in user interface 130, along beam 111 (e.g., within beam housing 111A), and / or elsewhere. In some examples, functional interconnection between controller 129 and motor 125 includes feedback that allows controller 129 to determine one or more dynamic parameters of motor operation, e.g., sensing data from a position encoder, and / or data indicative of voltage, current, and / or power. Optionally, controller 129 receives position data sensed directly from spool 121. This has potential advantages for managing backlash and / or slippage which may potentially occur in the driving mechanisms used to couple motor 125 to spool 121.

[0217] In some examples, controller 129 comprises processing circuitry (e.g., one or more microprocessors and / or other processing circuitry) which accesses data and instructions stored in a memory of controller 129 in order to determine motor control commands to send to motor 125 during user of exercise machine 100 by a user. In some examples, controller 129 comprises communications interface 133, and is configured to receive and / or transmit data through communications interface 133 for use in configuration and / or real-time operation. In some examples, communications interface 133 is optionally used to receive software updates and / or parameter updates. In some examples, communications interface 133 is optionally used to transmit monitoring data, e.g., device operational data allowing diagnosis of situations in which unexpected tension cable dynamics are encountered.

[0218] Frame 110 comprises structural support elements along and / or through which tension cable 105 is routed between power section 120 and exit aperture 112A or another last point of contact between frame 110 and tension cable 105. In some examples, frame 110 comprises arm 112, optionally configured to swivel around swivel joint 114). Optionally, swivel joint 114 is loosened and tightened using locking knob 115. Swivel joint 114 comprises one or more degrees of rotational freedom; for example, it swivels to allow arm 112 to be stored in a vertical position.

[0219] In some examples, arm 112 is furthermore mounted (e.g., via trolley 113) to a beam 111, along which its position can be adjusted. Beam housing 111A is optionally provided to at least partially enclose a track 111B extending along beam 111. Trolley 113 travels vertically along track 111B to adjust a vertical position of swivel joint 114 and arm 112 along track 111B. Optionally, locking knob 115 also acts to loosen and lock this travelling movement; optionally, a separate mechanism is provided.

[0220] Optionally, a user can adjust swivel joint 114 so that pulling from exit aperture 112A aligns more nearly parallel to the orientation of arm 112 and the direction of trolley 113 and / or swivel joint 114, or otherwise as convenient; e.g., according to the exercise performed, the size of the user, and / or the position of trolley 113 along track 111B. Optionally, one or more additional or alternative positioning mechanisms are provided as part of frame 110.

[0221] Frame 110, in some examples, is configured to be mounted to a wall; e.g., anchored to a wall stud, bricks and / or blocks, and / or another structural element of a building. In some examples, one wall attachment comprises attachment at a lower end, e.g., at the position of housing 120A. In some examples, a second wall attachment comprises attachment at an upper end, e.g., brace 116.

[0222] It should be understood that some in examples of the present disclosure, frame 110 comprises any suitable arrangement of structural elements serving to route tension cable 105 to a position that designates the location which the user experiences as the direction from which resistance forces are generated. For example, a user pulling on accessory connector 107B (e.g., using a grip accessory 107) from below arm 112 experiences resistance forces from an upward direction; a user pulling on grip accessory 107 from above arm 112 experiences resistance forces from a downward direction. In some examples, frame 110 comprises a seating arrangement.

[0223] It is not excluded that portions of power section 120 (e.g., spool 121 itself) are moved as part of a mechanism which adjusts the position of exit aperture 112A. Nor is it excluded that power section 120 itself serves as frame 110 (e.g., exit aperture 112A is optionally provided directly from a housing 120A of power section 120).

[0224] In some examples, tension cable 105 is coupled to power section 120 through spool 121 (e.g., FIG. 1B), from which a portion of tension cable 105 unwinds when grip accessory 107 is pulled away from frame 110 (e.g., away from an exit aperture 112A of arm 112), and onto which tension cable 105 re-winds when grip accessory 107 is released. Between exit aperture 112A and power section 120, Tension cable 105 optionally passes through a plurality of cable sections 105A, 105B, 105C articulated from each other by arrangements of one or more pulleys 106A, 106B, 106C. It should be understood that the configuration of power section 120 to comprise a separate spool 121 and motor 125 (e.g., as shown in FIG. 1C) is optional. For example, tension cable 105 optionally winds onto a portion of motor 125 itself. In other examples, tension cable 105 is anchored to a system of pulleys, and motor 125 controls forces on tension cable 105 by movement of the pulleys. In other examples, tension cable 105 is anchored by a plurality of windings to a motor-powered capstan (in any suitable orientation), with one portion of tension cable 105 leading from the capstan to the user end of the tension cable 105, and a portion leading to the other end also leading away from the capstan.

[0225] In some examples, there is provided a user interface 130, through which a user can control settings of exercise machine 100, and / or receive visual, haptic, and / or auditory feedback. In some examples, user interface 130 comprises a rotary knob 131 with embedded screen 132. User input is provided, for example, by rotating and / or pressing (“clicking”) the rotary knob 131. Optionally, embedded screen 132 comprises a touch-receptive surface and can itself be used as an input device. Optionally, exercise machine 100 is configured to establish a data connection with a user-provided personal computing device such as a smart phone or tablet, which can itself be used as a part of user interface 130.

[0226] Some disclosed embodiments involve auxiliary sensing. In some examples, one or more optional sensors 145, 145A-145C is provided to record data indicative of forces and / or motions experienced by tension cable 105 during use. Data from these sensors is optionally used to confirm, augment, and / or replace measurements of the motions and / or operating parameters of motor 125 and / or spool 121.

[0227] Sensors are optionally placed at any location suitable for their measurement task. A strain sensor, for example, may be placed inline along tension cable 105, coupled to the mountings of one or more pulleys 106A-106C, and / or coupled to the mountings of spool 121 and / or motor 125. In some examples, a sensor is positioned where it can measure movements of tension cable 105 optically. In some examples, amplitudes and / or frequencies of sound generated during movements of tension cable 105 are used to measure movement dynamics, e.g., velocity and / or acceleration.

[0228] In FIG. 1B, indicated options for sensor locations include attached on device-internal location of tension cable 105 (e.g., sensor 145A), at the exit of tension cable 105 from arm 112 (e.g., sensor 145C), and integrated into accessory connector 107B (e.g., sensor 145B). Other options include sensors positioned on grip accessory 107, sensors integrated elsewhere along arm 112 (e.g., at a place a structural member of frame 110 vibrates in correlation movements of tension cable 105), and / or sensors integrated into one or more of pulleys 106A-106C and / or the elements that support them.

[0229] In examples using sound sensing to help assess tension cable 105 dynamics, sensed sounds are optionally sounds produced incidentally; e.g., as a result of bearing movements as any of pulleys 106A-106C rotate, and / or due to movements of surfaces of tension cable 105 in contact with other surfaces of exercise machine 100. Optionally, sensed sounds are produced using mechanisms deliberately provided as sound generators; e.g., gently contacting elements making clicks, “zipping” sounds, or another vibrating indication as tension cable 105 is operated. Such vibrations are optionally measured and used as indications of tension cable 105 velocity, position, and / or acceleration. Even when this information is also available from, e.g., a motor encoder, sound recording data provides a sensing channel which can potentially provide high-frequency feedback (e.g., a typical audio recording frequency is 44.1 KHz) allowing interpolated estimates of acceleration values between encoder positions.

[0230] Some disclosed embodiments involve slack compensation. More particularly, some disclosed embodiments involve momentum-dependent resistive force adjustment to prevent and / or reduce slack. Reference is now made to FIG. 2, which schematically represents slack compensation through use of a momentum-dependent added resistance force commanded by exercise machine controller circuitry, according to some examples of the present disclosure. Reference is also made to FIG. 8, which is a schematic flowchart of a method of slack compensation, according to some examples of the present disclosure.

[0231] The horizontal axis of FIG. 2 represents momentum (that is, momentum of components of exercise machine 100 coupled to movement of tension cable 105). Arbitrary units are used. The coupled momentum comprises, e.g., linear and / or angular momentum, e.g., angular momentum of motor 125 and / or spool 121, and optionally at least a portion of the linear momentum of tension cable 105. With specific respect to compensation for slack, momentum is considered to be momentum developed during extension of tension cable 105, e.g., as a user exerts pulling force on it.

[0232] Momentum is considered proportional to velocity, e.g., according to the well-known equation of linear momentum p=mv, where p is momentum, m is mass, and v is velocity. Similarly, the equation of angular momentum defines a rotational analog of linear momentum proportional to rate of rotation. Accordingly, additionally or alternatively to representing momentum, the horizontal axis can be measured and / or represented in terms of a linear velocity of tension cable 105, revolutions per minute of spool 121 and / or motor 125, and / or another measure of velocity.

[0233] Horizontal dotted line 201 represents a certain setting force Fsetting for exercise machine 100 used during a rep (repetition of an exercise cycle). While this is not necessarily a constant force, it is shown as constant here for the sake of description.

[0234] At block 810, in some examples (FIG. 8), controller 129 accesses data indicative of a current momentum coupled to extension of tension cable 105. “Indicative” should be understood as including indicative in conjunction with suitable calculations, and / or jointly indicative, e.g., indicative based on the use of two or more data sources. In some examples, at least a portion of the data indicative of the current momentum is provided by a motion encoder on one or both of spool 121 and motor 125. Optionally velocity and / or momentum is calculated from these measurements. Other than velocity, the main variable aspect of the momentum coupled to movement of tension cable 105 is the disposition of the mass of tension cable 105 itself. Optionally, this is modeled as a function of extension distance. Optionally, this variation is treated as negligible for purposes of slack compensation, allowing the momentum to be treated substantially as having a constant proportion to velocity, according to baseline conditions regarding the mass values and mass distributions of the relevant moving components of exercise machine 100. In some examples, another sensor type is used, e.g., current sensing of electrical current provided to motor 125, and / or one of sensors 145A-145C. Optionally, for example, one or more of sensors 145A-145C measures tension exerted on tension cable 105. It should be understood that insofar as the output of the next block of operations (block 812) is an adjustment, calculations using the data indicative of momentum do not necessarily calculate momentum as such; e.g., an intermediate and / or partial calculation may be accepted as having a relationship to slack risk which is sufficiently correlated to the relevant coupled momentum as to allow the determination of block 812.

[0235] At block 812, in some examples, controller 129 determines an adjustment to resistance force Fdeslack, the adjustment depending on the momentum indicated by the data of block 810.

[0236] For example, as shown in FIG. 2, vertical dotted line 202 represents a threshold momentum threshold pthreshold, and / or velocity threshold vthreshold, above which the rising slope of commanded resistance force 210B increases as a function of velocity. The difference of this value from the value of Fsetting is labeled as Fdeslack.

[0237] For lower momentums / velocities, the value of commanded resistance force 210A is equal to Fsetting. The commanded resistance force 210 over the full range of, e.g., v (where v is, e.g., the linear velocity of a portion of tension cable 105 and / or the rotational velocity of spool 121 and / or motor 125) is defined by the combination of these two partial functions (and likewise for momentum p). Herein, it should be understood that resistance forces referred to as “commanded” are produced through signaling by a controller to an adjustable force generator such as an electrical motor.

[0238] Forces felt by the user may be different if the user is trying to accelerate or decelerate the tension cable. Optionally, acceleration is compensated for, although it is again noted that this potentially could produce errors due to a range of factors related to lags and / or imprecision in sensing and / or control feedback. Where these errors are large enough to disturb the user experience, slack compensation based on velocity measurement is optionally preferred. In some examples, partial slack compensation acceleration compensation is used, with the magnitude of this compensation being kept low enough that users are unlikely to be disturbed by unexpected changes in tension, at least within normal operating parameters.

[0239] In the illustrated example, increase in Fdeslack is linear (beyond vthreshold) as a function of both velocity and momentum. The increase is, for example, according to a predetermined slope value a having units, e.g., of force added per meter per second of velocity of tension cable 105, spool 121, and / or motor 125. Accordingly, the total motor-commanded resistance force Ftotal is optionally described by:Ftotal={if⁢ v≤vthreshold:Fsettingelse:Fsetting+a⁡(v-vthreshold)A similar equation may be written substituting momentum for velocity. It should be understood that a different and velocity-related function is optionally chosen. In particular, the velocity-related function is optionally determined for reducing a risk of the generation of a certain “unacceptable” slack distance during operation of exercise machine 100. A level of this “risk” is optionally assessed according to a first factor corresponding to the greatest allowable slack distance generated, and a second factor corresponding to an estimate of the greatest amount of slack distance that reasonably could be generated under certain circumstances. Where the distance of the second factor is larger than the distance of the first, slack compensation force (Fdeslack is optionally applied. While overcompensation is not excluded (e.g., for simplicity of calculation or another reasons), it is a potential advantage to maintain slack compensation adjustments near their minimum level so as to reduce interference with the user-selected setting force. Application of a threshold such as pthreshold and / or vthreshold below which no correction is applied is suitable, e.g., with lower values of momentum at which the risk of slack development is associated with only very short “unwinding” distances due to the existing momentum of moving components of exercise machine 100. Beyond the threshold, the slope of the adjustment (rate of increase of Fdeslack) is optionally lower for larger values of Fsetting, since the larger resistance force this represents will potentially overcome the momentum more quickly and reduce the runout distance. Optionally, the threshold at which the onset of the adjustment occurs is adjusted upward in accordance with the reduced risk of slack developing, also as a result of the more rapid overcoming of momentum.

[0241] At least while the user is gripping the grip accessory, “slack distance” may be understood as the difference (when tension cable 105 is loose) between the actual distance of the user's grip from the position on exercise machine 100 to which tension cable 105 extends from the user, and an increased distance of the user's grip at which tension in tension cable 105 would be restored. Slack compensation is potentially most important under conditions in which there is sufficient resistance force applied to tension cable 105 to produce tension cable acceleration in the return direction, but not with such speed that users find it difficult to decouple their movements from movement of the tension cable while also retaining their grip on it.

[0242] Additional discussion of slack distance (for example, if the user's grip is lost), and considerations for making the determination of an appropriate momentum- and / or velocity-related function to manage, mitigate, and / or prevent it is presented, e.g., in relation to FIGS. 3A-4B. The “lost grip” condition is of specific concern also with respect to the aspect of recovery from sudden tension cable release, described, e.g., in relation to FIGS. 6 and 9. For conditions in which grip is lost completely, the distance of runout before overcoming momentum coupled to tension cable 105 is of more particular importance as the metric of slack risk, since this is what may lead to internal misalignments and tangling. However, in the “lost grip” scenario, the user will generally not be pulled around when suddenly re-coupled to the momentum of the system, since they are no longer holding on to tension cable tension cable 105.

[0243] In some examples, a distance of potential slack which is considered “unacceptable” is selected with respect to the assumption that the user has managed to reduce cable tension to substantially nothing, and substantially immediately. In this case, potentially the whole runout distance of the system's current momentum (e.g., the distance the cable would unwind from its spool with nothing to stop it but the motor's resistance force) could create slack distance. Optionally there is additional mitigation implemented that increases resistance force quickly after a sensed loss of user force to reduce the runout distance, but then again reduces resistance force before this can become an over-acceleration in the return direction of the tension cable.

[0244] In some examples, the slope value a represents a function of Fsetting, i.e., a=f(Fsetting) For example, with an increasing value of Fsetting, the value of a optionally decreases.

[0245] In some examples, the value of 1 threshold is a function of Fsetting, e.g., vthreshold=g(Fsetting). For example, with an increasing value of Fsetting, the value of vthreshold optionally increases.

[0246] As a more particular example, vthreshold is optionally defined as vthreshold=βFsetting, and a is optionally defined as a=αFsetting, where α and β are proportionality constants. Accordingly, in this case:Ftotal={if⁢ v≤β⁢FsettingFsettingelseα⁢Fsetting(v-β⁢ Fsetting)

[0247] It should be understood that either or both of α and β is optionally set to 1. It is not excluded that function dependencies on Fsetting include a constant offset value. It is not excluded that function dependencies on Fsetting are non-linear, e.g., exponential according to a value larger than one or less than one, and / or polynomial. It is not excluded that function dependencies include factors other than Fsetting and v.

[0248] For example, in some examples, the dynamic acceleration of tension cable 105, spool 121, and / or motor 125 is taken into account. One way of doing this is to calculate vthreshold differently during different accelerations. For example, during acceleration, there is a “built-in” addition to Fsetting due to the portion of the inertia of exercise machine 100 that resists the acceleration. Optionally, the value of Fdeslack is reduced in correspondence with this value by a term that causes vthreshold to be increased. Alternatively, the estimate of, e.g., v itself is reduced, and / or another compensating adjustment is made, e.g., to the slope value a. Optionally, estimation of acceleration forces is directly calculated and used to adjust the value of Fdeslack. Noting that certain methods of making higher-order dynamics measurements (e.g., of acceleration) are potentially more vulnerable to sensing and / or compensation errors and / or lags, the adjustment magnitude is optionally filtered (e.g., low-pass filtered) to avoid introducing changes to Fdeslack which are too sudden for the user.

[0249] Concluding the flowchart of FIG. 8: at block 814, in some examples, the determined adjustment to resistance force Fdeslack is signaled to the resistance motor.

[0250] Reference is now made to FIGS. 3A-3B, which schematically represent scenarios potentially benefiting from slack compensation, according to some examples of the present disclosure. FIG. 3B represents a magnified view of region 300A of FIG. 3A. Curve 301 of FIGS. 3A-3B represents an example relationship of tension cable extension distance (vertical axis) over time (horizontal axis) during a pulling portion of a rep. The slope of this line may be understood as approximately proportional to momentum.

[0251] Dotted line 302 (extending horizontally), represents an extension distance at which user input forces (in the examples of this figure) suddenly decline from the typical case of curve 301; for example, if the user just dropped their hold on the tension cable, or otherwise deviated from their normal form. For purposes of discussion, this deviation in form is assumed to be large enough to potentially generate slack distance.

[0252] Curve 303 represents an example of how cable extension distance could continue to change due to the combined influences of motor-powered resistance forces and inertia of the system (e.g., linear and / or rotational inertia) in a period after the user has moved enough to decouple their force inputs from the dynamic movements of (at least part of) tension cable 105. Since user inputs are removed, curve 303 is generally lower than curve 301 at times after the extension distance marked by dotted line 302 is crossed. At first, tension cable 105 continues to extend (e.g., unwind from its stored position on spool 121), as forward velocity reduces over time due to the resistance forces provided, e.g., by the motor 125. Beyond a peak extension represented at peak 303A, velocity reverses. The tension cable 105 begins to retract, and then accelerates in its speed of retraction.

[0253] In some examples, the “natural” course of curve 303 is interrupted upon detection of the change in user-input forces. For example, at point 304, exercise machine 100 optionally detects that there is a loss of user inputs, and switches to another cable retrieval function 305, e.g., using a return velocity which is smoothed towards zero as the cable nears zero extension distance again. This is discussed more centrally, e.g., as the subject of FIGS. 6 and 9.

[0254] As already discussed, one potential adverse “slack” effect comes from the tension cable not fully extending from exercise machine 100 according to its unwinding distance. Instead (since the user is no longer drawing the tension cable 105 out from its pulling end), tension cable 105 may become internally caught, tangled, and / or displaced within the structure of exercise machine 100. Accordingly, the vertical distance between dotted line 302 and peak 303A indicates a potential for development of slack in the tension cable which it is a potential advantage to reduce.

[0255] Another potential adverse “slack” effect occurs if the user actually has maintained control of the end of tension cable 105, even while reducing their input force. For example, the user might have placed their grip (i.e., their hands) so that the extension distance when tension cable 105 again becomes taut (regains tension) corresponds to the position of dotted line 302. Regaining tension would then occur at the time when curve 303 re-crosses dotted line 302. By this time (in this example), a significant reverse velocity has built up, as indicated by the downward slope of curve 303 at this point. In consequence, the user experiences a “jerk” as the momentum of exercise machine 100 again becomes coupled to their grip. Depending on circumstances, this can be unpleasant, and potentially injury-causing; e.g., due to the effects of sudden acceleration on the user's body, and / or due to the being thrown off balance and potentially stumbling / falling.

[0256] The example of curve 306 represents an intermediate case, in which the user's form quickly (but not instantly) slows the cable-extending movements of their hands (e.g., along the dotted line of curve 306A). Here again, the system's own intrinsic dynamics (still represented by curve 303) potentially overshoot force input from the user. Slack distance is still generated (although somewhat less than in the first example), and the user may still experience a sudden acceleration onset (again, potentially somewhat less than in the first example). Since the user's own body also has momentum, the example of curve 306 is potentially more representative than the line of dotted line (i.e., extension distance) 302 of what a user can actually manage to do while still retaining control over the pulling end of tension cable 105 (e.g., while still maintaining a grip on grip accessory 107).

[0257] If, before curve 303 reaches its peak at peak 303A, the user's extension distance remains at or above this level, then the user will not experience a strong discontinuous “jerk”, although they may experience a fluctuation in effective resistance as the momentum of the motor system is overcome.

[0258] It should be noted that the free-running development of slack distance would be reduced if the moment of change indicated by the left side of dotted line 302 occurred at a lower velocity, e.g., at the left side of dotted line 302A. In this case, momentum to be overcome is also lower, so the distance between peak 303A and dotted line 302A would be reduced. Due to the lowered velocity, it could be more feasible for the user to move their hands “below” the level which crosses dotted line 302A (that is, closer to the location of exercise machine 100 from which tension cable 105 exits). This change in the scenario is not expected to greatly affect internal tangling, however, since it is unlikely that this would push tension cable 105 back into exercise machine 100.

[0259] It (the just-described change in scenario) could result in enough time for tension cable 105 to develop a significant return velocity (and thus still transmit a strong and sudden jerk to the user's hands). However, it may also be correspondingly easier for the system to determine that something is wrong with the user's input; e.g., because the change in user inputs would be easier to distinguish as inappropriate, compared to the deceleration which would normally be occurring at the level indicated by dotted line 302. In this case, the situation may be considered as relating to the cable recovery aspect, e.g., as described in relation to FIGS. 6 and 9.

[0260] One special aspect of the first scenarios (those beginning after extension distance exceeds dotted line 302) is that the user would normally begin deceleration around this point anyway, creating a greater potential for ambiguity. If the system intervenes incorrectly, it could create for the user a sense of system instability. Since an intervention might combine aspects of both increasing force (e.g., to counter momentum and developing slack distance) followed by decreasing force (e.g., to prevent “jerk”), deviations from the ideal could variably result in sudden force increases and / or sudden force decreases, potentially confusing the user.

[0261] Stated generally, it appears that risk of an adverse effect due to slack tends to be higher during times when the user is pulling at higher velocities. First, there is potential for a greater length of tension cable run-out due to built-up momentum internal to the system. Second, it is potentially more difficult to distinguish (by sensing and / or algorithmically) a normal deceleration after reaching peak velocity from an abnormal deceleration, and then to select and apply a consistent correction.

[0262] The second point is also illustrated by a further example. One type of slack compensation optionally applied by exercise machine 100, in some examples, is to sense “unusually fast” reductions in user force inputs (e.g., unusual in absolute magnitude and / or unusual in context, e.g., unusual for the velocity and / or distance of extension). User force inputs are optionally measured directly (e.g., using a load cell), or indirectly, e.g., inferred from changes in velocity and / or acceleration.

[0263] In response (i.e., additionally or alternatively to velocity dependent increases in vtotal) motor pull force is optionally increased to reduce slack distance buildup. For example, dotted curve 307 (FIG. 3B) optionally represents an example in which reduction of user force is sensed effectively “instantly” at the extension distance of dotted line 302, and motor force rapidly increased accordingly. Assuming curve 306A (which continues as curve 306) is near an assumed limit of suddenly decelerating user movements (at least, if the user does not just drop the cable entirely), there would then be a relatively small difference in velocities when dotted curve 307 intersects curve 306A. However, the user would still thereafter experience a suddenly increased resistance force, unless exercise machine 100 then rapidly shifted back to its original setting force.

[0264] Accordingly, this mode of slack compensation is potentially sensitive to sensing rates and to system response rates. Lags and / or errors in sensing and / or responses could potentially disturb the user experience, e.g., by creating unexpected variability, “hitches”, and / or oscillations in resistance force. This problem is particularly significant when the sensing problem includes distinguishing “normal” deceleration rates from “uncontrolled” deceleration rates. For example, depending on conditions and / or measurement types used, there is potentially an early portion of slack distance development which is practically indistinguishable from something that might occur normally.

[0265] In some examples of the present disclosure, rather than waiting for sensing to determine that the user force input is decreasing, a selected variable level of slack mitigating force is added to the setting force. The descriptions in relation to FIG. 2 above provide examples of this slack compensation approach. In particular, the force is adjusted so that it is stronger during periods when tension cable velocity (and, accordingly, certain risks of slack development) is higher.

[0266] Additionally, in some examples, the added slack mitigating force tapers off as the setting force Fsetting approaches levels that inherently tend to prevent the development of unacceptably large slack distances. In the context of FIG. 2, decreasing a as a function of Fsetting would produce such tapering-off, as would increasing vthreshold as a function of Fsetting.

[0267] To assume reduced maximum slack distance with increasing Fsetting reflects reasonable assumptions about the speed of user movements which are likely while the user maintains control of the end of the tension cable 105. For example, curve 308 optionally represents free movement of tension cable 105 when exercise machine 100 is operated with a larger resistance force Fsetting than is the case for curve 303, but then this larger resistance force is reduced as a function of falling velocity. As a result, not only is the interval of slack time reduced, the acceleration being applied on the return phase is no greater than it would otherwise be. As a result, e.g., curve 306 intersects curve 308 both sooner and with a reduced difference in velocity compared to the intersection of curve 306 with curve 303.

[0268] A potential advantage of the use of a velocity-dependent adjustment to resistance force arises insofar as users are more disturbed by sudden resistance changes than by slower changes (other parameters being equal). For example, a certain amount slow-developing resistance change during a rep is potentially acceptable to users (possibly even unconsciously) as “normal”. The change in resistance, if noted, may be attributed (at least as far as user experience is concerned) to typical physical factors such as internal friction and / or system inertia.

[0269] Since sudden jerks due to motor resistance forces are one of the adverse effects associated with slack, there is potentially a seeming paradox in the choice to mitigate slack by providing even more resistance to the user's pulling, even given that this resistance is reduced when velocity starts to decrease.

[0270] The problem may be recast, however, as that of maintaining coupling between movements of the user and movements of exercise machine 100. Slack-originated risks of user discomfort and / or injury arise, not from increased force alone, but rather when excessive disparity between user movements and tension cable movements develops.

[0271] By increasing pull resistance under certain circumstances, exercise machine 100 can, in effect, reduce the ability of the user to reversibly decouple their movements from the machine's movements under conditions and for periods of time that build up large divergences in velocity. Here, the word “reversibly” should be especially noted. If, for example, the user simply drops tension cable 105, then they will not experience a jerk, because coupling will not be suddenly restored through their grip. The next adverse condition then is that overly fast retraction of the cable will result in damage when the handle reaches the frame of exercise machine 100. There is, however, more time and distance available to detect this condition; moreover the distance at which it occurs is generally more predictable.

[0272] Reference is now made to FIG. 4A, which schematically graphs adjustments determined by exercise machine controller circuitry to prevent development of excessive slack distance in a cable operated exercise machine, according to some examples of the present disclosure. Reference is also made to FIG. 4B, which is a schematic graph comparing linear and quadratic dependencies of added resistance force on velocity, according to some examples of the present disclosure.

[0273] In FIG. 4A, velocity (which is also proportional to momentum) is shown graphed in arbitrary units along the horizontal axis. System (baseline) resistance settings are graphed along the vertical axis, also in arbitrary units. FIG. 4B is drawn to the same horizontal velocity scale, while the vertical axis shows resistance forces optionally added for different velocities along horizontal line 405 of FIG. 4A, as further explained below.

[0274] In some examples, slack is mitigated by the exercise machine controller with respect to one or both of slack distance risk, and of slack retensioning (“user jerk”) risk.

[0275] In some examples, risk of slack distance (e.g., development of slack in the tension cable potentially sufficient to cause mechanical difficulties with the exercise machine 100) is mitigated by adding additional resistance motor force under some circumstances. This is the force referred to already as Fdeslack.

[0276] In FIG. 44, slack maximum threshold 401 shows a threshold curve, drawn as a function of both velocity v and system resistance setting Fsetting. Above threshold 401, the “free run” potential for developing slack distance is considered acceptable. The “free run” slack distance is, for example, the distance of further unwinding of tension cable 105 from spool 121 and / or motor 125 which could result if the user simply dropped the tension cable while it moves at a certain velocity, and with a certain resistance force setting being used. As will further explained, this value (also referred to herein as Dslack_max) is optionally used to help set parameters according to which Fdeslack is adjusted.

[0277] Also indicated in FIG. 4A is an optional “LOW-RISK VELOCITIES” zone 410, in which velocity is low enough that friction and / or sensing is sufficient to avoid developing unacceptable slack. Optional zone 411 (“IMPRACTICAL VELOCITIES”) shows tension cable velocities which are unlikely to be reached by users. Optional zone 412 (“SUBTHRESHOLD RESISTANCE LEVELS”) shows system resistance settings below the intended operating threshold of the system. Selection of Fdeslack optionally accounts for one or more of these zones.

[0278] Slack maximum threshold 401 corresponding to Dslack_max is also labeled s in FIG. 44. Additional curves below it are labeled, e.g., 1.5 s, 2 s, etc. to indicate curves associated with proportionally higher slack runout distances for higher velocities and / or lower resistance forces.

[0279] In some examples, for operating areas of the graph below and / or to the right of the curve of slack maximum threshold 401, exercise machine 100 adds enough force (e.g., Fdeslack as represented by arrow 402) to reduce the slack runout to about the value of s; optionally to a smaller value. It is noted that the magnitude of the adjustment needed decreases moving to the left and to slower velocities, e.g., to arrow 403 and then arrow 404. Thus, from in most and potentially all initial states shown, the tendency, when freely decelerating after loss of user control will be to quickly move into to a regime where the risk of slack distance is acceptable, and optionally allow proceeding without continued addition of decelerating force that could lead to unintentionally increased jerk once the user's grip is re-coupled to movements of the tension cable.

[0280] More generally, a criterion is optionally selected such that that some defined “free run” distance of the tension cable (Dslack) is kept within acceptable limits (Dslack_max, for reasonable assumptions about operating conditions. In some examples, Dslack is the amount of further motor runout distance expected if the user simply “drops” the tension cable, and there is no other adjustment before the baseline resistance setting of the motor overcomes inertia. Optionally, another definition is used, e.g., a definition taking into account capabilities of exercise machine 100 to dynamically sense and correct for losses in user input force, and / or limitations of those capabilities.

[0281] In some examples, the free run distance is calculated, e.g., as proportional to the inherent inertia of the motor / cable system Isystem (e.g., linear and / or rotational inertia), inversely proportional to the setting force Fsetting, and proportional to the square of the tension cable velocity v. Here, velocity appears as a squared term (the double integral of distance) because the runout distance occurs when the initial (“time of dropping”) velocity is decelerated to zero. Accordingly, in some examples.D slack ∝v2·I systemF setting.

[0282] To use a certain Dslack_max as a system performance limit, the system optionally adds additional “deslacking” force Fdeslack, as a function of increasing v to ensure that Dslack≤Dslack_max. For example:F deslack =k⁢v2·I systemDslack⁢_⁢max-F setting

[0283] Optionally, k is the double integration constant ½. It should be understood that adjustments and / or approximations involving k and / or the use of other constants and / or terms are optionally provided, e.g., to account for dynamic adjustments made by exercise machine 100 in response to sensed changes in user force input, and / or to account for friction and / or other mechanical characteristics of exercise machine 100 itself.

[0284] For example, 1 cm of slack may be allowable as the value of Dslack_max, while a larger slack distance could result in enough slack for tension cable 105 to slip over the lip of a spool and / or pulley, and / or buckle so that it contacts another mechanism inadvertently. In some examples, the threshold of allowed slack distance is at least 1 cm. In some examples, the threshold of allowed slack distance Dslack_max is, e.g., a value between 0.5 cm and 10 cm; for example, 1, 2, 3, 4, 5, 6 8 or 10 cm.

[0285] With reference now to FIG. 4B: the points 407 along curve 405A of FIG. 4B represent points at which corresponding line 405 of FIG. 4A crosses the various iso-distance lines indicating added resistances optionally corresponding to Fdeslack. The difference in vertical units between FIGS. 4A and 4B should be noted. FIG. 4A represents slack distance as contours s through 4 s, while the vertical axis of FIG. 4 offsets these distances by the negative value of s in order to represent added resistance force Fdeslack.

[0286] It should be understood that the illustrated dependency on the squared value of v is optional. Optionally, in some examples, a linear dependency of on v is used, as shown by curve 410 of FIG. 4B (and also as shown in FIG. 2). While this potentially results in variation in the “actual” value of Dslack_max, e.g., as a function of velocity, the drawbacks of this (e.g., in terms of effects on user experience) are optionally negligible.

[0287] Use of a linear approximation is reasonable particularly for relatively low values of Fsetting and / or v. Very high velocities are unlikely to be exerted by users, so that at sufficiently high values of Fsetting, it is unlikely that Dslack_max will be exceeded. If users do manage and / or attempt unusually high velocity values, it is in any case potentially acceptable to react more vigorously to prevent slack without excessive regard for “user experience” (e.g., this may be considered outside of designed use parameters). Examples of reasonable values of Fsetting include those values within the rated power capacity of motor 125, e.g., given its particular mechanical advantage within exercise machine 100. As experienced by the user, Fsetting is optionally, e.g., within a range of about 2.2 pounds up to about 440 pounds (e.g., the force equivalent of about 1-200 kg).

[0288] Values of v for which user experience (e.g., smoothness of operation) is prioritized optionally include values from 0 m / sec up to about 2 m / sec; optionally another upper bound is used; e.g., up to pull velocities of around 5 m / sec, 6 m / sec, 8 m / sec, or 10 m / sec.

[0289] In accordance with the above descriptions, it may be understood that there are optionally tension cable velocities (e.g., those of zone 410) below which no additional slack-prevention force is used, because momentum of the system is considered to remain practically within acceptable limits for developing slack. For example, there may be plenty of time to react based on detection of reduced user input force, there may be enough internal friction to counteract the low velocity naturally, and / or exercise machine 100 is not operated with resistance forces so low that unacceptable slack can develop at such velocities.

[0290] Also in accordance with the above descriptions, there are optionally resistance force settings above which no additional slack-prevention force is used. For example, velocities of tension cable 105 high enough to develop unallowable slack (e.g., those corresponding to zone 411) may be considered impractical—e.g., involving unrealistic levels of user strength and / or system component acceleration.

[0291] The above descriptions with respect to mitigating slack distance risk can also be used to understand slack compensation to reduce slack retensioning risk; that is, risk of slack in case the user keeps a grip on the handle while also introducing tension cable slack. As already discussed, unwanted effects of slack retensioning (jerking against the user's grip) arise when there is a period of decoupling that leads to acceleration of the tension cable without corresponding acceleration of the handle (and the user's grip on it).

[0292] Ordinarily, the force magnitude of this risk is roughly independent of the system resistance setting. While the higher the system resistance setting Fsetting, the harder the tension cable accelerates, this also results in a proportionally shorter decoupling period, so that the end-of-decoupling jerk velocity (and corresponding portion of the initial acceleration felt by the user) remains about the same. However, since the resistance force added by Fdeslack is decreased as a function of velocity, there is gained a benefit of a shortened runout, but then “normal” deceleration on the other side of the inflection point.

[0293] Furthermore, other things being equal, decoupling time tends to increase with increasing velocity. This means that there is more time for acceleration. Correspondingly larger re-coupling forces (stronger jerks) are possible if a certain slack distance is created. However, the user will also be moving more quickly, and will need to decelerate the mass of their own limbs correspondingly. This potentially makes it harder to generate slack distance in the first place. Accordingly, preventing excessive slack distance is also a reasonable proxy for mitigating slack retensioning risk, even though the focus of concern is different in the two cases. In effect, adding resistance force in the form of a positive-valued Fdeslack speeds up exercise machine 100, with the result that the inherently slack-limiting effects of the user's own mass inertia become correspondingly more prominent.

[0294] Furthermore, a period of constant rapid deceleration (after decreasing Fdeslack is accounted for) that includes or even heads imminently toward a complete reversal of direction is distinctive. While it is not impossible that a user could imitate such “machine-like” dynamics, doing so rapidly would potentially involve use of unusual form, optionally treated as outside the intended operating parameters of exercise machine 100. Accordingly, when such a trend is noticed, exercise machine 100 optionally initiates more aggressive measures to ensure first that runout is limited (by ramping Fdeslack to a higher values, and second, by reducing force at the plateau of runout, ensuring that the user is not then subjected to a strong jerk due to a high return acceleration.

[0295] It should be understood that while Fsetting is represented in these examples as a constant value, this is not a required condition. In some examples, Fsetting varies during normal operation as a function of extension distance (e.g., to simulate training with an elastic band), and / or as a function of time (e.g., vibrating and / or jerking). In such cases, values of Fsetting should be understood as varying appropriately, with targeted values of Fdeslack optionally adjusted to match. Optionally such dynamic adjustments to Fdeslack itself in response to changing Fsetting during a rep are filtered (e.g., slowed to a moving average of Fsetting and / or suppressed. It should be understood that other force adjustments made for purposes besides those associated with Fdeslack are optionally provided together with Fsetting and Fdeslack; i.e., the use of the term Ftotal in relation to their sum does not exclude their combination with other contributing forces.

[0296] It should be noted that the discussion of slack compensation in relation to FIGS. 2-4B focuses in particular on slack which begins developing during extension of the tension cable. It is possible, however, that the user's grip could be lost during an ongoing return phase of tension cable 105, and / or possible that the user could stumble forward or otherwise advance their grip quickly toward exercise machine 100 to create sudden slack. Optionally, this situation is treated just as it is for the extension phase, e.g., with an increase in Fdeslack as function of increasing return velocity.

[0297] However, while this would tend to minimize decoupling times, it potentially interferes with control to ensure that tension cable 105 is retrieved with minimal risk of damage to exercise machine 100 (e.g., as described in relation to FIG. 6). Furthermore, since it lacks the direction reversal, the risks for jerk in this case are smaller—rather than opposing the motion of the user, the tension cable in this case would simply be hurrying to catch up—but catching up is exactly the point of risk. There is, as a result, a concerning potential that an off balance user (e.g., one stumbling forward) would be accelerated faster into the direction of an accident. Accordingly, the use of Fdeslack, in some examples, is confined to use with positive velocities in the direction of extension of tension cable 105. Other aspects of the topic of returning-phase recovery of the tension cable are discussed, e.g., in relation to FIGS. 6 and 9.

[0298] Reference is now made to FIG. 5, which schematically illustrates use by exercise equipment controller circuitry of hysteresis in the determination of a slack compensation force, according to some examples of the present disclosure. As in FIG. 2, velocity / momentum is shown along the horizontal axis, while commanded resistance force is shown along the vertical axis. Again, arbitrary units are used.

[0299] In some examples, adjustments to Fsetting are applied with hysteresis—e.g., once Fdeslack is increased to some value at a first velocity, it is only again reduced below that value at a second velocity, the second velocity being slower than the first velocity.

[0300] In the example shown, graph line 510A represents the situation where Ftotal=Fsetting until reaching vthreshold (at inflection point 502). While velocity still rises beyond this point, it does so according to line graph line 510B, such that Ftotal=Fsetting+Fdeslack rising. If velocity begins to drop (e.g., near the mid-point of a pulling phase of a rep), the maximum reached value of Fdeslack rising at first remains in effect, e.g., as though moving horizontally along arrow 503 rather than back down along graph line 510B. At the point where arrow 503 crosses graph line 510C, it matches Fdeslack falling, and now slack compensation force is changed according to the values of graph line 510C.

[0301] It is not required that arrow 503 be horizontal, e.g., hysteresis movement is optionally in a partially upward direction, such as that of arrow 504.

[0302] Now that the hysteresis barrier has been passed (e.g., as velocity has generally slowed sufficiently), the situation reverses. For example, movement back toward the right would be along the reversed direction of arrow 503 until again encountering graph line 510B. As a result, the slack compensation force does not again rise beyond successively lower values unless by happenstance the velocity rises again enough to overcome the hysteresis threshold.

[0303] It is emphasized that this all occurs while velocity overall is maintained in a same direction.

[0304] In the example shown, hysteresis applies to the slopes of graph lines 510C, 510B, while vthreshold remains the same. However, hysteresis optionally also applies to vthreshold, e.g., moving it to a lower value while traveling along the reducing-velocity leg of graph lines 510C.

[0305] In either case, the first and second values are optionally distinguished by a great enough difference that measurement noise and / or servo feedback lag does not produce inadvertent oscillations. For example, the hysteresis difference is optionally defined so that the user experiences periods of opposite (but in themselves monotonic) change in Fdeslack on either side of a single inflection point somewhat past the peak velocity of the tension cable during a normal pull.

[0306] Use of control hysteresis provides a potential advantage by allowing determination of Fdeslack to be partially adjusted according to ongoing accelerations and / or higher-order measurements of system dynamics, without necessarily following every variation, which could lead to the introduction of oscillations and / or sudden changes.

[0307] The lowering of 510B relative to 510C optionally represents a partial allowance for the presence of acceleration. While the user is maintaining acceleration, they are also dynamically “further” from most situations which could allow them to introduce slack while maintaining control of tension cable 105.

[0308] For the main exception—the user simply losing their grip—the potential trade-off is a brief period of declining velocity in which the slack runout allowed is larger than it would otherwise be. Optionally, this is partially adjusted for by adjusting the “angle” at which graph line 510C is approached to a more upward direction when the loss of acceleration appears rapidly. This allows shifting more extreme changes in slack compensation forces to situations when the user themselves is generating larger accelerations- or else may have lost control of the grip accessory 107.

[0309] In some examples, hysteresis is applied on the basis of acceleration, rather than (or in addition to) velocity. For example, arrow 505 represents a gradual transition from graph line 510B to graph line 510C during much of which velocity is still rising. The transition is triggered once acceleration (rather than velocity) passes a peak, even though velocity continues to increase.

[0310] Optionally, the transition “angle” used depends more closely on details of how acceleration is decreasing. For example, a rapid decrease may induce a fast shift to higher-resistance graph line 510C, e.g., optionally even before velocity has finished increasing, as indicated by arrow 505. A sufficiently gradual (and optionally more “normal” for the form of the exercise) decrease in velocity optionally initiates transition only after v has started to reduce, e.g., along arrow 504 or along arrow 501. It is noted that the relatively sudden increase in force represented by arrow 505 will be in part absorbed by the built-up momentum of tension cable 105, motor 125 and / or spool 121 (indeed, removing that momentum is in large point the reason for the build-up in the first place). Accordingly, effects of this rise are potentially felt as if it maintains Fsetting, rather than letting it grow light during the decelerating phase of the pull. It is noted again that the increase is transient since a general decline towards Fdeslack=0 remains in effect.

[0311] Furthermore, user experienced differences among the various possibilities are potentially masked at least in part by the user's own activity; e.g., when the user slows quickly, tension cable 105 may seem to slow “even more quickly”, but this is optionally in proportion to what the user is trying to do.

[0312] The transition is maintained as constant and non-reversing by having it follow a declining trend in acceleration (optionally also limited so that it cannot occur too quickly), but never going back along the arrow when acceleration appears to briefly increase. Optionally, the point when acceleration reaches 0 completes the transition, but the transition need not be targeted to that specifically. The transition is optionally eased by curving, e.g., arrow 505 in any suitable manner to make it more difficult for the user to detect the onset of a relatively more sudden change in Fdeslack.

[0313] What these various hysteresis options hold in common is the ability to shift in a gradual and unidirectionally controlled manner among different regimes for exerting slack compensation, without relying strictly on moment-to-moment sensing and / or tight feedback control loops. Thus, these options are potentially relatively immune to noise in sensing and / or imperfect control quality. However, general information about “what is going on” during a rep is available, e.g., a transition from a phase of acceleration toward a phase of deceleration. This allows optionally reducing interference with the basic operation of exercise machine 100 (e.g., keeps Ftotal nearer to the value of Fsetting), while still retaining preventative capabilities to prevent development of excessive slack distance.

[0314] Some disclosed embodiments involve recovery from sudden tension cable release. Reference is now made to FIG. 6, which schematically represents control of cable return velocity by exercise equipment controller circuitry in response to loss of user control, according to some examples of the present disclosure. Reference is also made to FIG. 9, which is a schematic flowchart of a method of operating a controller 129 of an exercise machine 100 to prevent overly dynamic homing of a tension cable 105, according to some examples of the present disclosure.

[0315] Graph line 601 represents cable velocity v (vertical axis) as a function of cable extension distance d (horizontal axis). Again, arbitrary units are used. This is a graph of the return of tension cable 105 to a home position, so in time the upper-right end of 601 is earlier, and the lower-left end is later.

[0316] At block 910, in some examples (FIG. 9), controller 129 accesses data characterizing a current decrease in extension distance of tension cable 105. In some examples, the data are provided by a motion encoder on one or both of spool 121 and motor 125. In some examples, another sensor type is used, e.g., current sensing of electrical current provided to motor 125, and / or one of sensors 145A-145C; e.g., sensing of tension forces applied to tension cable 105 and / or sensing of the movement of tension cable 105.

[0317] At block 912, in some examples (FIG. 9), controller 129 determines that the decrease in extension distance indicated by the data of block 910 satisfies a fast tension cable return criterion.

[0318] For example, section 603 of graph line 601 begins with a constant initial velocity in the return direction, then suddenly begins to accelerate out of user control, e.g., as could happen if the user suddenly loses their grip on grip accessory 107. At inflection point 602, the system “notices” this situation (based on the data characterizing the current decrease in extension distance), and responds by beginning deceleration throughout section 605 to a recovery velocity 604 (or optionally another, e.g., lower velocity, depending on condition specifics).

[0319] “Notice” of the situation optionally comprises a determination that a current decrease in extension distance of the cable corresponds to fast tension cable return criterion. In some examples, the fast tension cable return criterion comprises a profile of changing distance over time consistent with unopposed acceleration in response to the currently commanded motor force, e.g., a constantly accelerating reduction in distance.

[0320] In some examples, the fast tension cable return criterion is met when exercise machine 100 determines that acceleration is outside of a set of reference examples, e.g., examples of normal user interactions and / or known edge cases. Additionally or alternatively, in some examples, the fast tension cable return criterion comprises detection of a return velocity above some safe and / or reasonable threshold.

[0321] In some examples, the system determines that for a current return velocity, a certain threshold distance 611 is at risk of being passed at a velocity above a certain safe velocity threshold 615 unless the system intervenes to reduce the return velocity.

[0322] More generally, one or both of two distinct types of motion / distance profiles optionally trigger a safe-retrieval procedure: profiles in which the current retrieval speed of tension cable 105 is excessive (e.g., poses a risk) no matter what its current position, and profiles in which the current retrieval speed of tension cable 105 is excessive because of how close it currently is to being brought to an excessively sudden stop at its home position.

[0323] At block 914, in some examples (FIG. 9), controller 129 signals to the resistance motor 125 to reduce velocity of tension cable extension decrease.

[0324] In some examples, recovery velocity 604 is set to be at or below a safe velocity threshold 615. In some examples, recovery velocity 604 and / or safe velocity threshold 615 is selected to be low enough to avoid dangerously dragging and / or swinging it into a body part, and / or swinging it dangerously while uncontrolled into other parts of exercise machine 100. It is noted that as tension cable 105 shortens, there is a potential for its angular momentum to be converted into sharper swings. Optionally, exercise machine 100 adjusts recovery velocity 604 according to its current configuration and / or position of tension cable 105, e.g., to avoid creating rapid swings by an overly-fast withdrawal when tension cable 105 is hanging in the air (e.g., especially if being drawn toward head-height), but with a faster velocity optionally allowed, e.g., so long as grip accessory 107 remains in contact with the ground.

[0325] In some examples, recovery velocity 604 is dynamically adjusted to damp and / or avoid amplifying swinging of tension cable 105 and / or the grip accessory 107 attached to it. For example, tension in tension cable 105 is sensed as a function of time to determine its swing, and recovery velocity is adjusted, e.g., to reduce tension at the high points of the swings. In cases where forces consistent with excessive swing are detected, recovery velocity 604 is optionally decreased more than in other cases. Optionally, recovery is halted and / or reversed at appropriate moments during the swing (e.g., near tension peaks) to damp pendulum motions of tension cable 105.

[0326] The speed at which the decline to recovery velocity 604 happens is optionally adjusted based on how much distance is left for the return of tension cable 105. It is a potential advantage to reach the recovery velocity quickly (e.g., so that risk of further accident and / or injury is reduced), while not decelerating so abruptly that built-up momentum of tension cable 105 carries it beyond what spool 121 and / or motor 125 are actively taking up. Avoiding excess wear on braking mechanisms is also optionally taken into account in selecting an appropriate deceleration.

[0327] However, if the remaining return distance is too close to one or more threshold distances 611, one or more of these concerns is optionally discounted and / or ignored in order to ensure that tension cable 105 is safely slowed, e.g., before it can collide with exercise machine 100, and / or to avoid accelerating it into a dangerous swing. For example, emergency braking is optionally deployed in such a case. In the example shown, threshold distance 611 is deemed too close to inflection point 602 considering the current velocity, and so through the period of segment 613 a motor brake is briefly applied. The rest of the distance to recovery velocity 604 occurs with decreased deceleration. Optionally (e.g., in cases where velocity is particularly high and / or there is a lack of certainty of stopping in time), braking is applied sufficiently to bring velocity substantially to a halt.

[0328] In some examples, emergency stopping is accompanied by ceasing operation of motor 125 altogether. Optionally motor 125 is provided with a breaker fuse or other failsafe device which can only operate to halt motor operation.

[0329] Graphical break 607 represents an arbitrary distance of recovery performed at recovery velocity 604.

[0330] At region 609, in some examples, a final recovery phase begins. This is optionally triggered at the same distance used as threshold distance 611, or at another distance, e.g., a distance of 2 cm, 5 cm, 10 cm, or another distance. In some examples, final recovery phase comprises deceleration to a velocity low enough to allow accessory connector 107B to reach its home position at a non-damaging contact speed. Optionally, accessory connector 107B is brought snugly into its home position. Optionally, retrieval force is discontinued within a short distance of the travel limits of accessory connector 107B, so that accessory connector 107B may remain slightly loose and is not necessarily brought into full contact with a stop limiting it from being pulled into the frame 110 of exercise machine 100. Optionally, timed braking is used as accessory connector 107B reaches its home position, so that it is brought to a halt at an appropriate home position. In some examples, the returning-motion homing control procedure described in relation to FIGS. 7A-7D is used.

[0331] Optionally, a user can interrupt a recovery operation which has sufficiently slowed by regaining control of grip accessory 107 and / or tension cable 105 and again exerting force on it. With sufficient force exerted on it, and optionally with associated extension showing that the force is not just do being caught on something, exercise machine 100 optionally enters a controlled recovery phase in which allowed speeds increase nearer to speeds consistent with the normal return phase of a rep. Optionally, full recovery to home position is aborted if it is determined that there is sufficient restraining force on grip accessory 107, e.g., for safety, and / or to allow users to resume exercising.

[0332] In some examples, e.g., after a recovery mode retrieval in which a particularly rapid velocity, acceleration and / or deceleration has occurred, exercise machine 100 engages in and / or requires one or more self-check and / or “re-seating” operations to ensure that tension cable 105 has not moved out of place; e.g., become caught and / or tangled. Such operations optionally comprise one or more slow extensions and recoveries during which exercise machine 100 verifies that operation is normal, e.g., according to responses of motor 125, sensing of forces on tension cable 105, and / or according to user confirmation.

[0333] Some disclosed embodiments involve home position damping of a tension cable. Reference is now made to FIG. 7A, which schematically illustrates damping control of resistance force with hysteresis in a homing zone near a home position of tension cable 105, according to some examples of the present disclosure. Reference is also made to FIG. 7B, which is a schematic flowchart of a method of damping control of resistance force in a homing zone near a home position of tension cable 105, according to some examples of the present disclosure. Further reference is made to FIGS. 7C-7D, which represent other parameter options for use with control of resistance force in a homing zone near a home position of tension cable 105, according to some examples of the present disclosure.

[0334] Graph line 712 of FIG. 7A represents an example relationship of commanded resistance force (vertical access) as a function of extension distance from a home position 702 of tension cable 105 (horizontal axis). Graph line 712 represents resistance force as tension cable 105 is returned by a user allowing it to return to its home position 702. Point 717 represents the furthest extent of a notional “homing zone”, that is, the position of a homing distance within which there is a concern for making large changes in resistance force, e.g., short-distance and / or short-period ramp-ups by a factor of 2 or more.

[0335] Graph line 701 also represents an example relationship of commanded resistance force as a function of extension distance from a home position 702 of tension cable 105, but in this case, graph line 701 represents resistance force as tension cable 105 is extended from its home position. The overview discusses potential advantages of the difference in function shapes between graph line 701 and graph line 712. Other graph shapes and parameter differences are shown in FIGS. 7C-7D. In the case of graph line 721 (FIG. 7C), the initial holding force at home position 702 is notably elevated from the force exerted there in returning phase graph line 728. Both graph line 721 and graph line 728 begin with relatively fast (and then slowing transitions in force levels, but in opposite directions. In FIG. 7D, graph line 731 rises very quickly, but to a somewhat lower level than return-phase graph line 732. Graph line 732 falls quickly, e.g., optionally representing a braking action to ensure that the tension cable's user end does not collide violently with frame 110 at home position home position 702.

[0336] At block 720, in some examples (FIG. 7B), controller 129 accesses data indicative of a current position of tension cable 105, the current position comprising a user end of tension cable 105 (e.g., comprising accessory connector 107B) within a homing zone adjacent to a home position of tension cable 105. In some examples, the homing zone (e.g., limited by the position of homing distance 717) comprises a region extending about 5 cm away from the home position, about 10 cm away from the home position, about 25 cm away, or another distance away from the home position.

[0337] In some examples, the data indicative of the current velocity are provided by a motion encoder on one or both of spool 121 and motor 125. In some examples, another sensor type is used, e.g., current sensing of electrical current provided to motor 125, and / or one of sensors 145A-145C.

[0338] At block 722, in some examples, controller 129 adjusts signals sent to motor 125 to ease (“damp”) a transition in resistance forces between a lower resistance nearer to the home position, and a higher resistance further from the home position.

[0339] It should be noted that any of these resistance force adjusting methods are optionally provided along with control-limiting of motor velocity to a lower velocity than is allowed outside of the homing zone. Control-limiting of motor velocity may cause resistance force to reduce with a different time course, e.g., when the approach velocity of the tension cable exceeds the control limit applied to motor velocity in the homing zone.

[0340] Some disclosed embodiments involve variable parameter home position damping. Reference is now made to FIG. 7E, which is a schematic graph illustrating variable parameter home position damping, according to some examples of the present disclosure.

[0341] The graph is divided vertically into three panels 760, 761, 762, which respectively represent different parameter pairs for two different tension cable return events.

[0342] For each panel, the horizontal axis represents extension distance D in arbitrary units. In the scenario illustrated, extension distance D is decreasing as a function of elapsed time t, which is also the vertical axis of bottom panel 762 (in arbitrary units). In the bottom panel, trace 741B represents a “slow” return event, and trace 742B represents a “fast” return event.

[0343] The vertical axis of top panel 760 is velocity v in arbitrary units, with trace 741 representing the same “slow” return event as trace 741B, and trace 742 likewise corresponding to the fast return event of trace 742B.

[0344] The vertical axis of middle panel 761 is commanded resistance force F in arbitrary units. Here, traces 741A and 742A respectively correspond to traces 741B and 742B. It should be noted that in all examples shown, resistance force transitions through a plurality of levels; i.e., the transition is damped continuously and / or step-wise, not simply “on” or “off”. Optionally, the transition proceeds substantially continuously throughout the periods shown. In this context, “continuously” includes transitioning through a rapidly succeeding sequence of partial steps, noting, e.g., that motor commands are optionally issued discretely at some frequency.

[0345] Vertical dotted line 745 represents the distance Dhoming-zone, left of which the system enters its “homing zone routine”. To the right of this position, tension cable returning movements are substantially under the control of the user, according to how they choose to resist Fsetting, represented as constant and equal or nearly equal for each of traces 741A, 742A. For the sake of illustration, distances and times are relatively compressed on the right side of Dhoming-zone; e.g., they could represent a total distance of 30-150 cm.

[0346] The left side of Dhoming-zone represents parameter changes occurring within the homing zone; e.g., within 5-25 cm of the home position itself, represented at extension distance 0.

[0347] In the illustrated pair of examples, the user who is moving the user end of tension cable 105 along trace 741 (panel 760) has begun deceleration of the tension cable well outside of the homing zone, such that upon entering the homing zone, the user end of the tension cable 105 is below a nominal default maximum (control-limited) velocity 746 (vmax-default). The position of vmax-default represents the largest velocity to which the system will “allow itself” to accelerate the tension cable while within the homing zone.

[0348] In the example of trace 741, the crossing of Dhoming-zone is at a lower velocity (also referred to herein as vcrossing) than vmax-default, so that control-limitation of velocity does not come into effect.

[0349] Velocity declines from there (at about the same slope) until it reaches vhoming. Final homing velocity 747 represents a velocity of the user end as it reaches its home position (and then is stopped by arm 112 or another portion of frame 110). This velocity is not necessarily controlled fully by the system directly, e.g., it is a result of interplay between the resistance force and the user force (e.g., resistance force weakens as the user also “lets” the tension cable return home, the user in this case also potentially lessening their force during the same period). Actual velocity may be higher or lower, and the value may vary according to the finishing movements of the user. However, if the user ceases to act against the declining resistance force at all, then there is still a control limit set by vmax-default, above which vhoming will not rise.

[0350] In the example shown, the declining velocity of trace 741 is initiated by a corresponding decline in the commanded resistance force F, e.g., over the period tdefault, up until reaching inflection point 743. The depicted constant deceleration as a linear function of decreasing commanded resistance force is an example, and should be understood as non-limiting; again, the actual relationship depends, e.g., on user behavior and / or physical characteristics of the moving components involved.

[0351] Residual movements after the period of tdefault (panel 762) are optionally generated by supplying enough resistance force to keep the user end of tension cable 105 moving if it is not being subjected to any substantial user force.

[0352] In the case of trace 742 (panel 760), velocity upon entering the homing zone is significantly higher than vmax-default, and a different optional control scheme is used. With velocity being control-limited, there is potentially no “commanded” resistance force exerted against the user though the motor's torque. Torque may be exerted as a negative braking force, until velocity falls to the level of vmax_default.

[0353] The user may still feel force as their inputs act to decelerate the movement of components such as the tension cable, motor, and spool.

[0354] From the point where the control-limited velocity is reached, e.g., as shown in panel 761, corresponding force vs. distance trace 742A now reaches the value of Fhoming at a certain position (e.g., the homing position itself, in the example shown), rather than after a certain amount of time. Because of the initially faster velocity, overall, the time over which force reduction occurs is shorter, as illustrated by time 752 (trapid), associated with trace 742B of panel 762.

[0355] As for the other example, the actual low velocity vhoming is not necessarily under the full direct control of the system, but rather is illustrated assuming that the user is exerting normal effort to reduce the velocity by applying user force. The examples shown here both remain within the range of velocities that the system treats as “normal”. Again, however, the system control-limits velocity so that it will not again exceed vmax-default, even if the user ceases to act against the motor's resistance force. In some examples, additional limiting is applied comprising operation of a brake, which tends to bring motion of tension cable 105 to a stop, and resists an increase in velocity in either direction.

[0356] Optionally, vmax-default itself changes as a function of time and / or distance. This may occur as an outcome of limits on changing states of electrical components of the system (e.g., delays as stored voltage capacitances and / or inductive currents collapse), and / or deliberately commanded.

[0357] As used herein with reference to quantity or value, the term “about” means “within ±10% of”.

[0358] The terms “comprises”, “comprising”, “includes”, “including”, “having” and their conjugates mean: “including but not limited to”.

[0359] The term “consisting of” means: “including and limited to”.

[0360] The term “consisting essentially of” means that the composition, method or structure may include additional ingredients, steps and / or parts, but only if the additional ingredients, steps and / or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure.

[0361] As used herein, the singular form “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a compound” or “at least one compound” may include a plurality of compounds, including mixtures thereof.

[0362] The words “example” and “exemplary” are used herein to mean “serving as an example, instance or illustration”. Any embodiment described as an “example” or “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments and / or to exclude the incorporation of features from other embodiments.

[0363] The word “optionally” is used herein to mean “is provided in some embodiments and not provided in other embodiments”. Any particular embodiment of the present disclosure may include a plurality of “optional” features except insofar as such features conflict.

[0364] Throughout this application, embodiments may be presented with reference to a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of descriptions of the present disclosure. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as “from 1 to 6” should be considered to have specifically disclosed subranges such as “from 1 to 3”, “from 1 to 4”, “from 1 to 5”, “from 2 to 4”, “from 2 to 6”, “from 3 to 6”, etc.; as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0365] Whenever a numerical range is indicated herein (for example “10-15”, “10 to 15”, or any pair of numbers linked by these another such range indication), it is meant to include any number (fractional or integral) within the indicated range limits, including the range limits, unless the context clearly dictates otherwise. The phrases “range / ranging / ranges between” a first indicate number and a second indicate number and “range / ranging / ranges from” a first indicate number “to”, “up to”, “until” or “through” (or another such range-indicating term) a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numbers therebetween.

[0366] Although descriptions of the present disclosure are provided in conjunction with specific embodiments, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.

[0367] It is appreciated that certain features which are, for clarity, described in the present disclosure in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the present disclosure. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments unless the embodiment is inoperative without those elements.

[0368] It is the intent of the applicant(s) that all publications, patents and patent applications referred to in this specification are to be incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application were specifically and individually noted when referenced that it is to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present disclosure. To the extent that section headings are used, they should not be construed as necessarily limiting. In addition, any priority document(s) of this application is / are hereby incorporated herein by reference in its / their entirety.

[0369] Various example embodiments for exercise machine technologies are articulated below in the form of clauses. It is to be understood the term “technology” refers equally to systems (e.g., exercise machines, computing devices (e.g., processors, non-transitory computer readable media), resistance motors, and methods for operating these systems.

[0370] Clause 1. A cable-operated exercise machine providing slack-compensating control of resistance force applied to a tension cable, the exercise machine comprising: the tension cable, configured to receive user force applied by pulling on a user end of the tension cable; a resistance motor applying the resistance force to a motor-coupled end of the tension cable, in opposition to the user force; and a controller comprising processing circuitry configured to: access data indicative of a momentum of components of the exercise machine, wherein the momentum of the components is coupled to movement of the motor-coupled end of the tension cable; determine an adjustment to the resistance force, wherein a size of the adjustment is determined, in accordance with the indicated momentum, to compensate against slack distance developing along the tension cable consequent to a potential rapid reduction in the user force; and signal the adjustment in resistance force to the resistance motor.

[0371] Clause 2: The technology of clause 1, wherein the components having momentum coupled to movement of the motor-coupled end of the tension cable include at least rotating elements of the motor.

[0372] Clause 3: The technology of each preceding clause alone or in combination, wherein the components having momentum coupled to movement of the motor-coupled end of the tension cable include a spool on which the tension cable is wound.

[0373] Clause 4: The technology of each preceding clause alone or in combination, wherein the size of the determined adjustment to the resistance force varies in magnitude as a function of a setting force, the setting force comprising a user-selected and predetermined level of exercise force which the controller signals to the resistance motor along with the adjustment. Clause: The technology of each preceding clause alone or in combination, wherein the size of the determined adjustment to the resistance force increases in magnitude as the setting force decreases.

[0374] Clause 6: The technology of each preceding clause alone or in combination, wherein the determined adjustment to the resistance force is signaled for exercises performed with the setting force below a threshold, and not applied for exercises performed with the setting force above the threshold.

[0375] Clause 7: The technology of each preceding clause alone or in combination, wherein the determined adjustment to the resistance force increases with increasing momentum of the components of the exercise machine coupled to movement of the motor-coupled end of the tension cable.

[0376] Clause 8: The technology of each preceding clause alone or in combination, wherein the determined adjustment is signaled during extension phases of tension cable movement, and not applied during return phases of tension cable movement.

[0377] Clause 9: The technology of each preceding clause alone or in combination, wherein the determined adjustment changes as a linear function of increasing velocity.

[0378] Clause 10: The technology of each preceding clause alone or in combination, wherein the determined adjustment changes as a non-linear function of increasing velocity.

[0379] Clause 11: The technology of each preceding clause alone or in combination, wherein the controller: determines an ongoing accelerating or decelerating phase of tension cable extension; and determines the adjustment according to the ongoing accelerating or decelerating phase of tension cable extension.

[0380] Clause 12: The technology of each preceding clause alone or in combination, wherein the adjustment increases the resistance force during a decelerating phase of tension cable extension.

[0381] Clause 13: The technology of each preceding clause alone or in combination, wherein the resistance motor comprises a rotary electric motor.

[0382] Clause 14: The technology of each preceding clause alone or in combination, wherein the resistance motor comprises one or more electric motors.

[0383] Clause 15: The technology of each preceding clause alone or in combination, comprising one or more sensors coupled to provide the controller with the data indicative of the momentum of the components of the exercise machine coupled to movement of the motor-coupled end of the tension cable.

[0384] Clause 16: The technology of each preceding clause alone or in combination, wherein the one or more sensors comprise at least one of: a rotary encoder measuring rotation coupled to movement of the tension cable, and a load cell measuring tension in the cable.

[0385] Clause 17: The technology of each preceding clause alone or in combination, wherein the user end of the tension cable comprises an accessory connector configured to connect to one or more accessories through which the user force is applied.

[0386] Clause 18: The technology of each preceding clause alone or in combination, including one or more of the accessories, each configured to be gripped by the user to apply the user force.

[0387] Clause 19: The technology of each preceding clause alone or in combination, wherein the adjustment to the resistance force is determined to prevent, upon sudden removal of user force from the tension cable, a potential distance of more than 2 cm of further runout of the tension cable from the components having momentum coupled to movement of the motor-coupled end of the tension cable.

[0388] Clause 20: The technology of each preceding clause alone or in combination, wherein development of slack distance is compensated against with respect to a potential rapid reduction in the user force which is substantially immediate, and to a reduced level of substantially no user force.

[0389] Clause 21: A method of operating controller processing circuitry providing slack-compensating control of resistance force applied to a tension cable of a cable-operated exercise machine, the method comprising: accessing data indicative of a momentum of components of the exercise machine, wherein said momentum is momentum of components with movements coupled to movement of a motor-coupled end of the tension cable; determining an adjustment to the resistance force, wherein a size of the adjustment is determined, in accordance with the indicated coupled momentum, to compensate against slack distance developing along the tension cable consequent to a potential rapid reduction in user force; and signaling the adjustment in resistance force to the resistance motor as slack compensation.

[0390] Clause 22: The technology of each preceding clause alone or in combination, wherein the components having movements coupled to movement of the motor-coupled end of the tension cable include at least rotating elements of the motor.

[0391] Clause 23: The technology of each preceding clause alone or in combination, wherein the components having movements coupled to movement of the motor-coupled end of the tension cable include a spool on which the tension cable is wound.

[0392] Clause 24: The technology of each preceding clause alone or in combination, wherein the determining sizes the adjustment to the resistance force as a function of a setting force, the setting force comprising a user-selected and predetermined level of exercise force which the controller signals to the resistance motor along with the adjustment.

[0393] Clause 25: The technology of each preceding clause alone or in combination, wherein the determining sizes the adjustment to the resistance force with increasing magnitude as the setting force decreases.

[0394] Clause 26: The technology of each preceding clause alone or in combination, comprising signaling the determined adjustment to the resistance force for exercises performed with the setting force below a threshold; and for exercises performed with the setting force above the threshold, determining not to signal said adjustment.

[0395] Clause 27: The technology of each preceding clause alone or in combination, wherein the determining provides an adjustment to the resistance force which is increasing with increasing momentum of the components of the exercise machine coupled to movement of the motor-coupled end of the tension cable.

[0396] Clause 28: The technology of each preceding clause alone or in combination, wherein the signaling of the determined adjustment is during extension phases of tension cable movement; and comprising determining not to signal the adjustment during return phases of tension cable movement.

[0397] Clause 29: The technology of each preceding clause alone or in combination, comprising determining the adjustment as a linear function of increasing velocity.

[0398] Clause 30: The technology of each preceding clause alone or in combination, comprising determining the adjustment as a non-linear function of increasing velocity.

[0399] Clause 31: The technology of each preceding clause alone or in combination, comprising: determining, automatically, an ongoing accelerating or decelerating phase of tension cable extension; and determining the adjustment according to the ongoing accelerating or decelerating phase of tension cable extension.

[0400] Clause 32: The technology of each preceding clause alone or in combination, comprising increasing the adjustment to the resistance force during a decelerating phase of tension cable extension.

[0401] Clause 33: A method of operating a controller to vary a resistance force applied to a tension cable of an exercise machine during changes in extension distance of the tension cable, the method comprising: estimating, by the controller, an ongoing acceleration of the tension cable; and determining an adjustment to the resistance force, dependent on the ongoing acceleration of the tension cable; and applying the adjustment to modify the ongoing acceleration.

[0402] Clause 34: The technology of each preceding clause alone or in combination, wherein the adjustment is selected to be proportional to a baseline training resistance force.

[0403] Clause 35: The technology of each preceding clause alone or in combination, wherein the adjustment is selected to simulate an inertial mass resistant to changes in acceleration.

[0404] Clause 36: An exercise machine comprising: at least one motor; a tension cable extending from a user end to an attachment to the at least one motor, wherein the motor provides adjustable resistance force resisting force applied from the user end; and a controller controlling the resistance force provided by the motor; wherein the controller comprises processing circuitry configured to: access data indicative of acceleration of the tension cable; determine an adjustment to the resistance force, dependent on the indicated acceleration of the tension cable; and signal the adjustment in resistance force to the resistance motor.

[0405] Clause 37: A tension cable exercise machine comprising a resistance motor, tension cable, and controller, wherein the controller comprises processing circuitry configured to: access data characterizing a decrease in extension distance of the tension cable; determine that the decrease in extension distance satisfies a fast tension cable return criterion; and in accordance with the determination, signal the resistance motor to reduce a velocity at which the extension distance of the tension cable is decreasing.

[0406] Clause 38: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion comprises movements of the tension cable indicative of release of the tension cable by a user while the tension cable is in an extended state.

[0407] Clause 39: The technology of each preceding clause alone or in combination, wherein the resistance motor comprises a rotary electric motor.

[0408] Clause 40: The technology of each preceding clause alone or in combination, comprising one or more sensors coupled to provide the controller with said data characterizing the decrease in extension distance, used to determine that the decrease in extension distance satisfies the fast tension cable return criterion.

[0409] Clause 41: The technology of each preceding clause alone or in combination, comprising a tension cable brake, and wherein the reducing a velocity comprises activating the tension cable brake.

[0410] Clause 42: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion indicates that without activation of the brake, there is insufficient distance at an ongoing velocity to stop a collision between the tension cable and the exercise machine.

[0411] Clause 43: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion satisfied is indicative of a safety risk due to increased and / or increasing velocity of the tension cable.

[0412] Clause 44: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied.

[0413] Clause 45: The technology of each preceding clause alone or in combination, wherein the threshold velocity used is adjusted by reducing the threshold velocity as the extension distance reduces.

[0414] Clause 46: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion comprises a determination that return acceleration of the tension cable is indicative of a loss of user force.

[0415] Clause 47: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion comprises a determination that return acceleration of the tension cable is outside of a set of reference examples for expected return acceleration.

[0416] Clause 48: The technology of each preceding clause alone or in combination, wherein the controller is configured to: access data indicative of swinging of the tension cable; determine a phase and / or period of the swinging, using the data; and adjust tension in the tension cable, according to the phase and / or period, wherein timing of the tension adjustment is selected to damp swinging of the tension cable.

[0417] Clause 49: A method of operating a controller to vary resistance force applied to a tension cable of an exercise machine during a decrease in extension distance of the tension cable, the method comprising: determining, by the controller, that the decrease in extension distance satisfies a fast tension cable return criterion; and in accordance with the determining, commanding a resistance motor of the exercise equipment to reduce a velocity at which the extension distance of the tension cable decreases.

[0418] Clause 50: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion comprises movements of the tension cable indicative of release of the tension cable by a user while the tension cable is in an extended state.

[0419] Clause 51: The technology of each preceding clause alone or in combination, wherein, in accordance with the determining, the controller applies a brake to the tension cable.

[0420] Clause 52: The technology of each preceding clause alone or in combination, wherein satisfying the fast tension cable return criterion is indicative of a safety risk due to increased and / or increasing velocity of the tension cable.

[0421] Clause 33: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied.

[0422] Clause 54: The technology of each preceding clause alone or in combination, wherein the threshold velocity reduces along with the extension distance.

[0423] Clause 55: A method of damping control of resistance force applied by a resistance motor to a tension cable of an exercise machine, the method comprising: accessing, by a controller of the exercise machine, data indicative that a user end of the tension cable is moving at a distance within a homing distance from a home position for the user end; and in accordance with the data, automatically adjusting signals from the controller, said signals governing application of the resistance force by the resistance motor; wherein the resistance force is controlled to perform a damped transition through a plurality of resistance force levels between and in addition to a first resistance force and a second resistance force, the resistance force levels and timing of the damped transition being determined in accordance with the data; and wherein the second resistance force is at least double the first resistance force.

[0424] Clause 56: The technology of each preceding clause alone or in combination, wherein the resistance force levels of the damped transition are determined in accordance with at least one of: a change in the distance of the user end from the home position, and an elapsed time after the user end passes a threshold distance while within the homing distance.

[0425] Clause 57: The technology of each preceding clause alone or in combination, wherein the change in distance comprises an increase in extension distance of the tension cable, and the damped transition is to the second resistance force from the first resistance force.

[0426] Clause 58: The technology of each preceding clause alone or in combination, wherein the controller lengthens the damped transition to occur over a larger change in distance of the user end from the home position, when a rate of change in distance of the user end from the home position exceeds a speed threshold.

[0427] Clause 59: The technology of each preceding clause alone or in combination, wherein the change in distance comprises a decrease in extension distance of the tension cable, and the damped transition is to the first resistance force from the second resistance force.

[0428] Clause 60: The technology of each preceding clause alone or in combination, wherein the signals governing application of the resistance force by the resistance motor are configured to limit an unloaded equilibrium velocity of the motor to a damping velocity limit, the damping velocity limit being adjusted to be relatively lower within the homing distance, compared to an unloaded equilibrium velocity of the motor beyond the homing distance.

[0429] Clause 61: The technology of each preceding clause alone or in combination, wherein the damped transition occurs over at least 10 msec.

[0430] Clause 62: The technology of each preceding clause alone or in combination, wherein the damped transition occurs over at least 0.5 cm.

[0431] Clause 63: The technology of each preceding clause alone or in combination, comprising, when the damped transition reduces the resistance force: determining, by the controller, whether the data indicate that the user end of the tension cable will reach the home position before a targeted minimum transition time elapses; and selecting between a distance-dependent reduction in resistance force and a time-dependent reduction in resistance force in accordance with the determining.

[0432] Clause 64: The technology of each preceding clause alone or in combination, wherein the homing zone within which the damped transition occurs is extends no more than 25 cm from the home position.

[0433] Clause 65: The technology of each preceding clause alone or in combination, wherein: the controller governs the damped transition both: from the first resistance force to the second resistance force while the user end extends, resulting in an average extension-phase resistance force as a function of position between the home position and the homing distance, and from the second resistance force to the first resistance force while the user end returns to the home position, resulting in an average return-phase resistance force as a function of position between the home position and the homing distance; and wherein the average extension-phase resistance force is larger than the average return-phase resistance.

[0434] Clause 66: The technology of each preceding clause alone or in combination, wherein the extension-phase damped transition begins at a distance closer to the home position than the end of the return-phase damped transition.

[0435] Clause 67: The technology of each preceding clause alone or in combination, wherein the return-phase damped transition begins at a distance farther from the home position than the end of the extension-phase damped transition.

[0436] Clause 68: The technology of each preceding clause alone or in combination, wherein a total distance of the extension-phase damped transition is different than a total distance of the return-phase damped transition.

[0437] Clause 69: The technology of each preceding clause alone or in combination, wherein the return-phase damped transition occurs over a shorter distance than the extension-phase damped transition.

[0438] Clause 70: The technology of each preceding clause alone or in combination, wherein the controller imposes hysteresis on the resistance force as a function of distance, in accordance with a direction of movement of the user end of the resistance cable while moving between the homing distance and the home position.

[0439] Clause 71: The technology of each preceding clause alone or in combination, wherein the second resistance force is a setting force selected for operation of the exercise machine during a set of reps.

[0440] Clause 72: The technology of each preceding clause alone or in combination, wherein the first resistance force is a quiescent state force which holds the user end in place while waiting for a user to engage with the tension cable.

[0441] Clause 73: The technology of each preceding clause alone or in combination, comprising: accessing, by the controller, data indicative of velocity of the tension cable; determining, by the controller, that the velocity of the tension cable satisfies a fast tension cable return criterion; and in accordance with the determining, at least one of: automatically adjusting signals from the controller governing the resistance motor to reduce force applied to the tension cable, and activating a brake to slow the velocity of the tension cable.

[0442] Clause 74: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied.

[0443] Clause 75: The technology of each preceding clause alone or in combination, wherein the threshold velocity reduces along with distance from the home position.

[0444] Clause 76: The technology of each preceding clause alone or in combination, wherein the second resistance force is at least 25 pounds.

[0445] Clause 77: The technology of each preceding clause alone or in combination, wherein the second resistance force is at least 100 pounds.

[0446] Clause 78: An exercise machine comprising: a resistance motor; a tension cable coupled to receive resistance force applied by the resistance motor; and a controller, coupled to control the applied resistance force; wherein the controller comprises processing circuitry configured to: access ongoing data indicative that a user end of the tension cable is moving at a distance within a homing distance from a home position for the user end; and in accordance with the data, automatically adjust signals from the controller governing application of the resistance force by the resistance motor; wherein the resistance force is controlled to transition between a first resistance force and a second resistance force in accordance with the ongoing data indicative of movement of the user end of the tension cable; and wherein the second resistance force is at least double the first resistance force.

[0447] Clause 79: The technology of each preceding clause alone or in combination, wherein the resistance motor comprises a rotary electric motor.

[0448] Clause 80: The technology of each preceding clause alone or in combination, comprising one or more sensors which sense the sensed indications, and are coupled to provide the sensed indications to the controller.

[0449] Clause 81: A method of controlling a tension cable of an exercise machine operating to provide resistance at a resistance force, the method comprising: determining that extension distance of the tension cable is changing while a user end of the tension cable is within a homing distance from a home position of the user end; and in accordance with the determining, selecting force applied by a resistance motor to use a specified damping force level, in place of the resistance force.

[0450] Clause 82: The technology of each preceding clause alone or in combination, wherein the damping force level is initially lower than the resistance force, and rises to meet the resistance force as the extension distance of the tension cable increases.

[0451] Clause 83: The technology of each preceding clause alone or in combination, wherein the damping force level reduces as the extension distance of the tension cable reduces.

[0452] Clause 84: The technology of each preceding clause alone or in combination, wherein the damping force level is different at different extension distances of the tension cable, and also different for same extension distances depending on whether the extension distance of the tension cable is increasing or decreasing.

[0453] Clause 85: An exercise machine configured to apply damped transitions of resistance force to a tension cable near a home position for a user end of the tension cable, the exercise machine comprising: a resistance motor; a controller, coupled to control resistance force produced by the resistance motor; and the tension cable, coupled to receive the resistance force produced by the resistance motor; wherein the controller comprises processing circuitry configured to: access data indicative that the user end of the tension cable is moving at a distance within a homing distance from the home position for the user end; and in accordance with the data, automatically adjust signals from the controller, said signals governing application of the resistance force by the resistance motor; wherein the resistance force is controlled to perform a damped transition through a plurality of levels between a first resistance force and a second resistance force in accordance with at least one of a change in the distance of the user end from the home position and an elapsed time after the user end passes a threshold distance while within the homing distance; and wherein the second resistance force is at least double the first resistance force.

[0454] Clause 86: The technology of each preceding clause alone or in combination, wherein the resistance motor comprises a rotary electric motor.

[0455] Clause 87: The technology of each preceding clause alone or in combination, comprising one or more sensors coupled to provide the controller with sensed indications of tension cable movement, used to determine that the extension distance of the tension cable is changing while within the home position zone of extension.

[0456] Clause 88: The technology of each preceding clause alone or in combination, wherein, when the damped transition is in a direction reducing the resistance force, the controller is configured to: determine whether the data indicate that the user end of the tension cable will reach the home position before a targeted minimum transition time elapses; and select between a distance-dependent reduction in resistance force and a time-dependent reduction in resistance force in accordance with the determination.

[0457] Clause 89: The technology of each preceding clause alone or in combination, wherein, upon selecting the distance-dependent reduction in resistance force, the controller continues to access data indicative of movements of the user end of tension cable, and to control the damped transition accordingly as a function of distance of the movements.

[0458] Clause 90: The technology of each preceding clause alone or in combination, wherein the controller is configured to: access data indicative of velocity of the tension cable; determine that the velocity of the tension cable satisfies a fast tension cable return criterion; and in accordance with the determination, perform at least one of: automatically adjusting signals governing the resistance motor to reduce force applied to the tension cable, and activate a brake to slow the velocity of the tension cable.

[0459] Disclosed embodiments may include any one of the following bullet-pointed features alone or in combination with one or more other bullet-pointed features, whether implemented as a system (e.g., an exercise machine, a computing device, a resistance motor) and / or method, by at least one processor or circuitry, and / or stored as executable instructions on non-transitory computer readable media or computer readable media.

[0460] a cable-operated exercise machine providing slack-compensating control of resistance force applied to a tension cable;

[0461] a tension cable, configured to receive user force applied by pulling on a user end of the tension cable;

[0462] a resistance motor applying a resistance force to a motor-coupled end of a tension cable, in opposition to a user force;

[0463] a controller comprising processing circuitry;

[0464] access data indicative of a momentum of components of an exercise machine;

[0465] momentum of components is coupled to movement of a motor-coupled end of a tension cable;

[0466] determine an adjustment to a resistance force;

[0467] a size of an adjustment is determined, in accordance with an indicated momentum, to compensate against slack distance developing along a tension cable consequent to a potential rapid reduction in a user force;

[0468] signal an adjustment in resistance force to a resistance motor;

[0469] components having momentum coupled to movement of a motor-coupled end of a tension cable include at least rotating elements of the motor;

[0470] components having momentum coupled to movement of a motor-coupled end of a tension cable include a spool on which the tension cable is wound;

[0471] a size of a determined adjustment to a resistance force varies in magnitude as a function of a setting force;

[0472] a setting force comprising a user-selected and predetermined level of exercise force which a controller signals to a resistance motor along with an adjustment;

[0473] a size of a determined adjustment to a resistance force increases in magnitude as a setting force decreases;

[0474] a determined adjustment to a resistance force is signaled for exercises performed with a setting force below a threshold, and not applied for exercises performed with the setting force above the threshold;

[0475] a determined adjustment to a resistance force increases with increasing momentum of components of an exercise machine coupled to movement of a motor-coupled end of a tension cable;

[0476] a determined adjustment is signaled during extension phases of tension cable movement, and not applied during return phases of tension cable movement;

[0477] a determined adjustment changes as a linear function of increasing velocity;

[0478] a determined adjustment changes as a non-linear function of increasing velocity;

[0479] a controller: determines an ongoing accelerating or decelerating phase of tension cable extension;

[0480] determines an adjustment according to an ongoing accelerating or decelerating phase of tension cable extension;

[0481] 12. The exercise machine of claim 11, wherein the adjustment increases the resistance force during a decelerating phase of tension cable extension.

[0482] a resistance motor comprises a rotary electric motor;

[0483] a resistance motor comprises one or more electric motors;

[0484] one or more sensors coupled to provide a controller with data indicative of a momentum of components of an exercise machine coupled to movement of a motor-coupled end of a tension cable;

[0485] a rotary encoder measuring rotation coupled to movement of a tension cable;

[0486] a load cell measuring tension in a cable;

[0487] a user end of a tension cable comprises an accessory connector configured to connect to one or more accessories through which a user force is applied;

[0488] one or more of the accessories, each configured to be gripped by a user to apply a user force;

[0489] adjustment to a resistance force is determined to prevent, upon sudden removal of user force from a tension cable, a potential distance of more than 2 cm of further runout of the tension cable from a components having momentum coupled to movement of a motor-coupled end of the tension cable;

[0490] development of slack distance is compensated against with respect to a potential rapid reduction in a user force which is substantially immediate, and to a reduced level of substantially no user force;

[0491] providing slack-compensating control of resistance force applied to a tension cable of a cable-operated exercise machine;

[0492] accessing data indicative of a momentum of components of an exercise machine;

[0493] momentum is momentum of components with movements coupled to movement of a motor-coupled end of a tension cable;

[0494] determining an adjustment to a resistance force;

[0495] a size of an adjustment is determined, in accordance with the indicated coupled momentum, to compensate against slack distance developing along a tension cable consequent to a potential rapid reduction in user force;

[0496] signaling an adjustment in resistance force to a resistance motor as slack compensation;

[0497] components having movements coupled to movement of a motor-coupled end of a tension cable include at least rotating elements of the motor;

[0498] components having movements coupled to movement of a motor-coupled end of a tension cable include a spool on which the tension cable is wound;

[0499] determining sizes adjustment to a resistance force as a function of a setting force;

[0500] a setting force comprising a user-selected and predetermined level of exercise force which a controller signals to a resistance motor along with an adjustment;

[0501] determining sizes an adjustment to a resistance force with increasing magnitude as a setting force decreases;

[0502] signaling a determined adjustment to a resistance force for exercises performed with a setting force below a threshold;

[0503] for exercises performed with a setting force above the threshold, determining not to signal an adjustment;

[0504] determining provides an adjustment to a resistance force which is increasing with increasing momentum of components of an exercise machine coupled to movement of a motor-coupled end of a tension cable;

[0505] signaling of a determined adjustment is during extension phases of tension cable movement;

[0506] determining not to signal the adjustment during return phases of tension cable movement;

[0507] determining an adjustment as a linear function of increasing velocity;

[0508] determining an adjustment as a non-linear function of increasing velocity;

[0509] determining, automatically, an ongoing accelerating or decelerating phase of tension cable extension;

[0510] determining an adjustment according to an ongoing accelerating or decelerating phase of tension cable extension.

[0511] increasing an adjustment to a resistance force during a decelerating phase of tension cable extension;

[0512] operating a controller to vary a resistance force applied to a tension cable of an exercise machine during changes in extension distance of the tension cable;

[0513] estimating, by a controller, an ongoing acceleration of the tension cable;

[0514] determining an adjustment to a resistance force, dependent on an ongoing acceleration of a tension cable;

[0515] applying an adjustment to modify an ongoing acceleration;

[0516] an adjustment is selected to be proportional to a baseline training resistance force;

[0517] an adjustment is selected to simulate an inertial mass resistant to changes in acceleration;

[0518] at least one motor;

[0519] a tension cable extending from a user end to an attachment to at least one motor;

[0520] a motor provides adjustable resistance force resisting force applied from a user end;

[0521] a controller controlling a resistance force provided by a motor;

[0522] a controller comprises processing circuitry;

[0523] access data indicative of acceleration of a tension cable;

[0524] determine an adjustment to a resistance force, dependent on an indicated acceleration of a tension cable;

[0525] signal an adjustment in resistance force to a resistance motor;

[0526] a tension cable exercise machine;

[0527] a resistance motor;

[0528] a tension cable;

[0529] a controller;

[0530] a controller comprises processing circuitry;

[0531] access data characterizing a decrease in extension distance of a tension cable;

[0532] determine that a decrease in extension distance satisfies a fast tension cable return criterion;

[0533] in accordance with the determination, signal a resistance motor to reduce a velocity at which an extension distance of a tension cable is decreasing;

[0534] a fast tension cable return criterion comprises movements of a tension cable indicative of release of the tension cable by a user while the tension cable is in an extended state;

[0535] a resistance motor comprises a rotary electric motor;

[0536] one or more sensors coupled to provide a controller with data characterizing a decrease in extension distance;

[0537] using sensor data to determine that a decrease in extension distance satisfies a fast tension cable return criterion;

[0538] a tension cable brake;

[0539] reducing a velocity comprises activating a tension cable brake;

[0540] a fast tension cable return criterion indicates that without activation of a brake, there is insufficient distance at an ongoing velocity to stop a collision between a tension cable and an exercise machine;

[0541] a fast tension cable return criterion satisfied is indicative of a safety risk due to increased and / or increasing velocity of a tension cable;

[0542] 44. The exercise machine of any one of claims 37-43, wherein the fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied.

[0543] a threshold velocity used is adjusted by reducing the threshold velocity as an extension distance reduces;

[0544] a fast tension cable return criterion comprises a determination that return acceleration of a tension cable is indicative of a loss of user force;

[0545] a fast tension cable return criterion comprises a determination that return acceleration of a tension cable is outside of a set of reference examples for expected return acceleration;

[0546] a controller is configured to access data indicative of swinging of a tension cable;

[0547] determine a phase and / or period of a swinging, using data;

[0548] adjust tension in a tension cable, according to a phase and / or period;

[0549] timing of tension adjustment is selected to damp swinging of a tension cable;

[0550] operating a controller to vary resistance force applied to a tension cable of an exercise machine during a decrease in extension distance of the tension cable;

[0551] determining, by a controller, that a decrease in extension distance satisfies a fast tension cable return criterion;

[0552] in accordance with a determination, commanding a resistance motor of exercise equipment to reduce a velocity at which an extension distance of a tension cable decreases;

[0553] a fast tension cable return criterion comprises movements of a tension cable indicative of release of the tension cable by a user while the tension cable is in an extended state;

[0554] in accordance with a determination, a controller applies a brake to a tension cable;

[0555] satisfying a fast tension cable return criterion is indicative of a safety risk due to increased and / or increasing velocity of a tension cable;

[0556] a fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied;

[0557] a threshold velocity reduces along with an extension distance;

[0558] damping control of resistance force applied by a resistance motor to a tension cable of an exercise machine;

[0559] accessing, by a controller of an exercise machine, data indicative that a user end of a tension cable is moving at a distance within a homing distance from a home position for the user end;

[0560] in accordance with data, automatically adjusting signals from a controller, said signals governing application of a resistance force by a resistance motor;

[0561] a resistance force is controlled to perform a damped transition through a plurality of resistance force levels between and in addition to a first resistance force and a second resistance force;

[0562] resistance force levels and timing of damped transition being determined in accordance with data; and

[0563] a second resistance force is at least double a first resistance force;

[0564] resistance force levels of a damped transition are determined in accordance with at least one of: a change in a distance of a user end from a home position, and an elapsed time after the user end passes a threshold distance while within the homing distance;

[0565] a change in distance comprises an increase in extension distance of a tension cable;

[0566] a damped transition is to a second resistance force from a first resistance force;

[0567] a controller lengthens a damped transition to occur over a larger change in distance of a user end from a home position, when a rate of change in distance of the user end from the home position exceeds a speed threshold;

[0568] a change in distance comprises a decrease in extension distance of the tension cable, and a damped transition is to a first resistance force from a second resistance force;

[0569] signals governing application of a resistance force by a resistance motor are configured to limit an unloaded equilibrium velocity of the motor to a damping velocity limit;

[0570] a damping velocity limit being adjusted to be relatively lower within a homing distance, compared to an unloaded equilibrium velocity of a motor beyond the homing distance;

[0571] a damped transition occurs over at least 10 msec;

[0572] a damped transition occurs over at least 0.5 cm;

[0573] when a damped transition reduces the resistance force: determining, by a controller, whether data indicate that a user end of a tension cable will reach a home position before a targeted minimum transition time elapses;

[0574] selecting between a distance-dependent reduction in resistance force and a time-dependent reduction in resistance force in accordance with a determination;

[0575] a homing zone within which a damped transition occurs is extends no more than 25 cm from a home position;

[0576] a controller governs a damped transition both: from a first resistance force to a second resistance force while a user end extends, resulting in an average extension-phase resistance force as a function of position between the home position and the homing distance, and from the second resistance force to the first resistance force while the user end returns to the home position, resulting in an average return-phase resistance force as a function of position between the home position and the homing distance;

[0577] an average extension-phase resistance force is larger than an average return-phase resistance;

[0578] an extension-phase damped transition begins at a distance closer to a home position than an end of a return-phase damped transition;

[0579] a return-phase damped transition begins at a distance farther from a home position than an end of the extension-phase damped transition;

[0580] a total distance of an extension-phase damped transition is different than a total distance of a return-phase damped transition;

[0581] a return-phase damped transition occurs over a shorter distance than a extension-phase damped transition;

[0582] a controller imposes hysteresis on a resistance force as a function of distance, in accordance with a direction of movement of a user end of a resistance cable while moving between a homing distance and a home position;

[0583] a second resistance force is a setting force selected for operation of an exercise machine during a set of repetitions;

[0584] a first resistance force is a quiescent state force which holds a user end in place while waiting for a user to engage with a tension cable;

[0585] accessing, by a controller, data indicative of velocity of a tension cable;

[0586] determining, by a controller, that a velocity of a tension cable satisfies a fast tension cable return criterion;

[0587] in accordance with a determination, at least one of: automatically adjusting signals from a controller governing a resistance motor to reduce force applied to a tension cable, and

[0588] activating a brake to slow a velocity of a tension cable;

[0589] a fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied;

[0590] a threshold velocity reduces along with distance from a home position;

[0591] a second resistance force is at least 25 pounds;

[0592] a second resistance force is at least 100 pounds;

[0593] an exercise machine;

[0594] a resistance motor;

[0595] a tension cable coupled to receive resistance force applied by a resistance motor;

[0596] a controller, coupled to control an applied resistance force;

[0597] a controller comprises processing circuitry;

[0598] access ongoing data indicative that a user end of a tension cable is moving at a distance within a homing distance from a home position for the user end;

[0599] in accordance with data, automatically adjust signals from a controller governing application of a resistance force by a resistance motor;

[0600] a resistance force is controlled to transition between a first resistance force and a second resistance force in accordance with ongoing data indicative of movement of a user end of a tension cable;

[0601] a second resistance force is at least double a first resistance force;

[0602] a resistance motor comprises a rotary electric motor;

[0603] one or more sensors which sense a sensed indications, and coupled to provide the sensed indications to a controller;

[0604] controlling a tension cable of an exercise machine operating to provide resistance at a resistance force;

[0605] determining that extension distance of a tension cable is changing while a user end of the tension cable is within a homing distance from a home position of the user end;

[0606] in accordance with a determination, selecting force applied by a resistance motor to use a specified damping force level, in place of a resistance force;

[0607] a damping force level is initially lower than a resistance force, and rises to meet a resistance force as an extension distance of a tension cable increases;

[0608] a damping force level reduces as the extension distance of a tension cable reduces;

[0609] a damping force level is different at different extension distances of a tension cable, and also different for same extension distances depending on whether an extension distance of a tension cable is increasing or decreasing.

[0610] an exercise machine configured to apply damped transitions of resistance force to a tension cable near a home position for a user end of the tension cable;

[0611] a resistance motor;

[0612] a controller, coupled to control resistance force produced by a resistance motor;

[0613] a tension cable, coupled to receive a resistance force produced by a resistance motor;

[0614] a controller comprises processing circuitry;

[0615] access data indicative that a user end of a tension cable is moving at a distance within a homing distance from a home position for a user end;

[0616] in accordance with data, automatically adjust signals from a controller;

[0617] signals governing application of a resistance force by a resistance motor;

[0618] a resistance force is controlled to perform a damped transition through a plurality of levels between a first resistance force and a second resistance force in accordance with at least one of a change in a distance of a user end from a home position and an elapsed time after the user end passes a threshold distance while within the homing distance;

[0619] wherein the second resistance force is at least double the first resistance force;

[0620] a resistance motor comprises a rotary electric motor;

[0621] one or more sensors coupled to provide a controller with sensed indications of tension cable movement;

[0622] determine that an extension distance of a tension cable is changing while within a home position zone of extension;

[0623] when a damped transition is in a direction reducing a resistance force, a controller is configured to: determine whether data indicate that a user end of a tension cable will reach a home position before a targeted minimum transition time elapses;

[0624] select between a distance-dependent reduction in resistance force and a time-dependent reduction in resistance force in accordance with a determination;

[0625] upon selecting a distance-dependent reduction in resistance force, a controller continues to access data indicative of movements of a user end of tension cable, and to control a damped transition accordingly as a function of distance of the movements;

[0626] a controller is configured to:

[0627] access data indicative of velocity of a tension cable;

[0628] determine that a velocity of a tension cable satisfies a fast tension cable return criterion;

[0629] in accordance with a determination, perform at least one of:

[0630] automatically adjusting signals governing a resistance motor to reduce force applied to a tension cable; and

[0631] activate a brake to slow the velocity of a tension cable.

Examples

Embodiment Construction

[0138]The present disclosure, in some embodiments thereof, relates to the field of exercise equipment and more particularly, but not exclusively, to resistance cable operated exercise equipment.

[0139]A broad aspect of some examples of the present disclosure relates to the dynamic control of resistance forces to prevent and / or mitigate potentially device-damaging and / or user-disturbing tension cable movements in electronically controlled resistance training exercise machines. Herein, this is also referred to as “protective management” of tension cable dynamics. More broadly, this is an aspect of what is referred to herein as “utility management” of tension cable resistance force; that is, control of tension cable resistance force for purposes such as protection, safety, storage, calibration, and / or device self-diagnosis.

[0140]Utility management of tension cable resistance force is distinguished from (although often simultaneously with) resistance force specified by exercising paramet...

PRIORITY CLAIM

[0001] This application claims the benefit of priority of U.S. Provisional Patent Application No. 63 / 780,328, filed on Mar. 30, 2025, which is incorporated herein by reference in its entirety.TECHNICAL FIELD AND BACKGROUND

[0002] The present disclosure, in some embodiments thereof, relates to the field of exercise equipment and more particularly, but not exclusively, to resistance cable operated exercise equipment.

[0003] Resistance training promotes the building and strengthening of muscles and bone tissue, and burns fat. Some motor-operated resistance training devices transmit resistance forces to users through a cable.SUMMARY

[0004] According to an aspect of some examples of the presently described subject matter, there is provided a cable-operated exercise machine providing slack-compensating control of resistance force applied to a tension cable, the exercise machine comprising: the tension cable, configured to receive user force applied by pulling on a user end of the tension cable; a resistance motor applying the resistance force to a motor-coupled end of the tension cable, in opposition to the user force; and a controller comprising processing circuitry configured to: access data indicative of a momentum of components of the exercise machine, wherein the momentum of the components is coupled to movement of the motor-coupled end of the tension cable; determine an adjustment to the resistance force, wherein a size of the adjustment is determined, in accordance with the indicated momentum, to compensate against slack distance developing along the tension cable consequent to a potential rapid reduction in the user force; and signal the adjustment in resistance force to the resistance motor.

[0005] According to some examples of the presently described subject matter, the components having momentum coupled to movement of the motor-coupled end of the tension cable include at least rotating elements of the motor.

[0006] According to some examples of the presently described subject matter, the components having momentum coupled to movement of the motor-coupled end of the tension cable include a spool on which the tension cable is wound.

[0007] According to some examples of the presently described subject matter, the size of the determined adjustment to the resistance force varies in magnitude as a function of a setting force, the setting force comprising a user-selected and predetermined level of exercise force which the controller signals to the resistance motor along with the adjustment.

[0008] According to some examples of the presently described subject matter, the size of the determined adjustment to the resistance force increases in magnitude as the setting force decreases.

[0009] According to some examples of the presently described subject matter, the determined adjustment to the resistance force is signaled for exercises performed with the setting force below a threshold, and not applied for exercises performed with the setting force above the threshold.

[0010] According to some examples of the presently described subject matter, the determined adjustment to the resistance force increases with increasing momentum of the components of the exercise machine coupled to movement of the motor-coupled end of the tension cable.

[0011] According to some examples of the presently described subject matter, the determined adjustment is signaled during extension phases of tension cable movement, and not applied during return phases of tension cable movement.

[0012] According to some examples of the presently described subject matter, the determined adjustment changes as a linear function of increasing velocity.

[0013] According to some examples of the presently described subject matter, the determined adjustment changes as a non-linear function of increasing velocity.

[0014] According to some examples of the presently described subject matter, the controller: determines an ongoing accelerating or decelerating phase of tension cable extension; and determines the adjustment according to the ongoing accelerating or decelerating phase of tension cable extension.

[0015] According to some examples of the presently described subject matter, the adjustment increases the resistance force during a decelerating phase of tension cable extension.

[0016] According to some examples of the presently described subject matter, the resistance motor comprises a rotary electric motor.

[0017] According to some examples of the presently described subject matter, the resistance motor comprises one or more electric motors.

[0018] According to some examples of the presently described subject matter, the exercise machine comprises one or more sensors coupled to provide the controller with the data indicative of the momentum of the components of the exercise machine coupled to movement of the motor-coupled end of the tension cable.

[0019] According to some examples of the presently described subject matter, the one or more sensors comprise at least one of: a rotary encoder measuring rotation coupled to movement of the tension cable, and a load cell measuring tension in the cable.

[0020] According to some examples of the presently described subject matter, the user end of the tension cable comprises an accessory connector configured to connect to one or more accessories through which the user force is applied.

[0021] According to some examples of the presently described subject matter, the exercise machine includes one or more of the accessories, each configured to be gripped by the user to apply the user force.

[0022] According to some examples of the presently described subject matter, the adjustment to the resistance force is determined to prevent, upon sudden removal of user force from the tension cable, a potential distance of more than 2 cm of further runout of the tension cable from the components having momentum coupled to movement of the motor-coupled end of the tension cable.

[0023] According to some examples of the presently described subject matter, development of slack distance is compensated against with respect to a potential rapid reduction in the user force which is substantially immediate, and to a reduced level of substantially no user force.

[0024] According to an aspect of some examples of the presently described subject matter, there is provided a method of operating controller processing circuitry providing slack-compensating control of resistance force applied to a tension cable of a cable-operated exercise machine, the method comprising: accessing data indicative of a momentum of components of the exercise machine, wherein the momentum is momentum of components with movements coupled to movement of a motor-coupled end of the tension cable; determining an adjustment to the resistance force, wherein a size of the adjustment is determined, in accordance with the indicated coupled momentum, to compensate against slack distance developing along the tension cable consequent to a potential rapid reduction in user force; and signaling the adjustment in resistance force to the resistance motor as slack compensation.

[0025] According to some examples of the presently described subject matter, the components having movements coupled to movement of the motor-coupled end of the tension cable include at least rotating elements of the motor.

[0026] According to some examples of the presently described subject matter, the components having movements coupled to movement of the motor-coupled end of the tension cable include a spool on which the tension cable is wound.

[0027] According to some examples of the presently described subject matter, the determining sizes the adjustment to the resistance force as a function of a setting force, the setting force comprising a user-selected and predetermined level of exercise force which the controller signals to the resistance motor along with the adjustment.

[0028] According to some examples of the presently described subject matter, the determining sizes the adjustment to the resistance force with increasing magnitude as the setting force decreases.

[0029] According to some examples of the presently described subject matter, the method comprises signaling the determined adjustment to the resistance force for exercises performed with the setting force below a threshold; and for exercises performed with the setting force above the threshold, determining not to signal the adjustment.

[0030] According to some examples of the presently described subject matter, the determining provides an adjustment to the resistance force which is increasing with increasing momentum of the components of the exercise machine coupled to movement of the motor-coupled end of the tension cable.

[0031] According to some examples of the presently described subject matter, the signaling of the determined adjustment is during extension phases of tension cable movement; and comprising determining not to signal the adjustment during return phases of tension cable movement.

[0032] According to some examples of the presently described subject matter, the method comprises determining the adjustment as a linear function of increasing velocity.

[0033] According to some examples of the presently described subject matter, the method comprises determining the adjustment as a non-linear function of increasing velocity.

[0034] According to some examples of the presently described subject matter, the method comprises: determining, automatically, an ongoing accelerating or decelerating phase of tension cable extension; and determining the adjustment according to the ongoing accelerating or decelerating phase of tension cable extension.

[0035] According to some examples of the presently described subject matter, the method comprises increasing the adjustment to the resistance force during a decelerating phase of tension cable extension.

[0036] According to an aspect of some examples of the presently described subject matter, there is provided a method of operating a controller to vary a resistance force applied to a tension cable of an exercise machine during changes in extension distance of the tension cable, the method comprising: estimating, by the controller, an ongoing acceleration of the tension cable; and determining an adjustment to the resistance force, dependent on the ongoing acceleration of the tension cable; and applying the adjustment to modify the ongoing acceleration.

[0037] According to some examples of the presently described subject matter, the adjustment is selected to be proportional to a baseline training resistance force.

[0038] According to some examples of the presently described subject matter, the adjustment is selected to simulate an inertial mass resistant to changes in acceleration.

[0039] According to an aspect of some examples of the presently described subject matter, there is provided an exercise machine comprising: at least one motor; a tension cable extending from a user end to an attachment to the at least one motor, wherein the motor provides adjustable resistance force resisting force applied from the user end; and a controller controlling the resistance force provided by the motor; wherein the controller comprises processing circuitry configured to: access data indicative of acceleration of the tension cable; determine an adjustment to the resistance force, dependent on the indicated acceleration of the tension cable; and signal the adjustment in resistance force to the resistance motor.

[0040] According to an aspect of some examples of the presently described subject matter, there is provided a tension cable exercise machine comprising a resistance motor, tension cable, and controller, wherein the controller comprises processing circuitry configured to: access data characterizing a decrease in extension distance of the tension cable; determine that the decrease in extension distance satisfies a fast tension cable return criterion; and in accordance with the determination, signal the resistance motor to reduce a velocity at which the extension distance of the tension cable is decreasing.

[0041] According to some examples of the presently described subject matter, the fast tension cable return criterion comprises movements of the tension cable indicative of release of the tension cable by a user while the tension cable is in an extended state.

[0042] According to some examples of the presently described subject matter, the resistance motor comprises a rotary electric motor.

[0043] According to some examples of the presently described subject matter, the exercise machine comprises one or more sensors coupled to provide the controller with the data characterizing the decrease in extension distance, used to determine that the decrease in extension distance satisfies the fast tension cable return criterion.

[0044] According to some examples of the presently described subject matter, the exercise machine comprises a tension cable brake, and wherein the reducing a velocity comprises activating the tension cable brake.

[0045] According to some examples of the presently described subject matter, the fast tension cable return criterion indicates that without activation of the brake, there is insufficient distance at an ongoing velocity to stop a collision between the tension cable and the exercise machine.

[0046] According to some examples of the presently described subject matter, the fast tension cable return criterion satisfied is indicative of a safety risk due to increased and / or increasing velocity of the tension cable.

[0047] According to some examples of the presently described subject matter, the fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied.

[0048] According to some examples of the presently described subject matter, the threshold velocity used is adjusted by reducing the threshold velocity as the extension distance reduces.

[0049] According to some examples of the presently described subject matter, the fast tension cable return criterion comprises a determination that return acceleration of the tension cable is indicative of a loss of user force.

[0050] According to some examples of the presently described subject matter, the fast tension cable return criterion comprises a determination that return acceleration of the tension cable is outside of a set of reference examples for expected return acceleration.

[0051] According to some examples of the presently described subject matter, the controller is configured to: access data indicative of swinging of the tension cable; determine a phase and / or period of the swinging, using the data; and adjust tension in the tension cable, according to the phase and / or period, wherein timing of the tension adjustment is selected to damp swinging of the tension cable.

[0052] According to an aspect of some examples of the presently described subject matter, there is provided a method of operating a controller to vary resistance force applied to a tension cable of an exercise machine during a decrease in extension distance of the tension cable, the method comprising: determining, by the controller, that the decrease in extension distance satisfies a fast tension cable return criterion; and in accordance with the determining, commanding a resistance motor of the exercise equipment to reduce a velocity at which the extension distance of the tension cable decreases.

[0053] According to some examples of the presently described subject matter, the fast tension cable return criterion comprises movements of the tension cable indicative of release of the tension cable by a user while the tension cable is in an extended state.

[0054] According to some examples of the presently described subject matter, in accordance with the determining, the controller applies a brake to the tension cable.

[0055] According to some examples of the presently described subject matter, satisfying the fast tension cable return criterion is indicative of a safety risk due to increased and / or increasing velocity of the tension cable.

[0056] According to some examples of the presently described subject matter, the fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied.

[0057] According to some examples of the presently described subject matter, the threshold velocity reduces along with the extension distance.

[0058] According to an aspect of some examples of the presently described subject matter, there is provided a method of damping control of resistance force applied by a resistance motor to a tension cable of an exercise machine, the method comprising: accessing, by a controller of the exercise machine, data indicative that a user end of the tension cable is moving at a distance within a homing distance from a home position for the user end; and in accordance with the data, automatically adjusting signals from the controller, the signals governing application of the resistance force by the resistance motor; wherein the resistance force is controlled to perform a damped transition through a plurality of resistance force levels between and in addition to a first resistance force and a second resistance force, the resistance force levels and timing of the damped transition being determined in accordance with the data; and wherein the second resistance force is at least double the first resistance force.

[0059] According to some examples of the presently described subject matter, the resistance force levels of the damped transition are determined in accordance with at least one of: a change in the distance of the user end from the home position, and an elapsed time after the user end passes a threshold distance while within the homing distance.

[0060] According to some examples of the presently described subject matter, the change in distance comprises an increase in extension distance of the tension cable, and the damped transition is to the second resistance force from the first resistance force.

[0061] According to some examples of the presently described subject matter, the controller lengthens the damped transition to occur over a larger change in distance of the user end from the home position, when a rate of change in distance of the user end from the home position exceeds a speed threshold.

[0062] According to some examples of the presently described subject matter, the change in distance comprises a decrease in extension distance of the tension cable, and the damped transition is to the first resistance force from the second resistance force.

[0063] According to some examples of the presently described subject matter, the signals governing application of the resistance force by the resistance motor are configured to limit an unloaded equilibrium velocity of the motor to a damping velocity limit, the damping velocity limit being adjusted to be relatively lower within the homing distance, compared to an unloaded equilibrium velocity of the motor beyond the homing distance.

[0064] According to some examples of the presently described subject matter, the damped transition occurs over at least 10 msec.

[0065] According to some examples of the presently described subject matter, the damped transition occurs over at least 0.5 cm.

[0066] According to some examples of the presently described subject matter, the method comprises, when the damped transition reduces the resistance force: determining, by the controller, whether the data indicate that the user end of the tension cable will reach the home position before a targeted minimum transition time elapses; and selecting between a distance-dependent reduction in resistance force and a time-dependent reduction in resistance force in accordance with the determining.

[0067] According to some examples of the presently described subject matter, the homing zone within which the damped transition occurs is extends no more than 25 cm from the home position.

[0068] According to some examples of the presently described subject matter, the controller governs the damped transition both: from the first resistance force to the second resistance force while the user end extends, resulting in an average extension-phase resistance force as a function of position between the home position and the homing distance, and from the second resistance force to the first resistance force while the user end returns to the home position, resulting in an average return-phase resistance force as a function of position between the home position and the homing distance; and wherein the average extension-phase resistance force is larger than the average return-phase resistance.

[0069] According to some examples of the presently described subject matter, the extension-phase damped transition begins at a distance closer to the home position than the end of the return-phase damped transition.

[0070] According to some examples of the presently described subject matter, the return-phase damped transition begins at a distance farther from the home position than the end of the extension-phase damped transition.

[0071] According to some examples of the presently described subject matter, a total distance of the extension-phase damped transition is different than a total distance of the return-phase damped transition.

[0072] According to some examples of the presently described subject matter, the return-phase damped transition occurs over a shorter distance than the extension-phase damped transition.

[0073] According to some examples of the presently described subject matter, the controller imposes hysteresis on the resistance force as a function of distance, in accordance with a direction of movement of the user end of the resistance cable while moving between the homing distance and the home position.

[0074] According to some examples of the presently described subject matter, the second resistance force is a setting force selected for operation of the exercise machine during a set of reps.

[0075] According to some examples of the presently described subject matter, the first resistance force is a quiescent state force which holds the user end in place while waiting for a user to engage with the tension cable.

[0076] According to some examples of the presently described subject matter, the method comprises: accessing, by the controller, data indicative of velocity of the tension cable; determining, by the controller, that the velocity of the tension cable satisfies a fast tension cable return criterion; and in accordance with the determining, at least one of: automatically adjusting signals from the controller governing the resistance motor to reduce force applied to the tension cable, and activating a brake to slow the velocity of the tension cable.

[0077] According to some examples of the presently described subject matter, the fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied.

[0078] According to some examples of the presently described subject matter, the threshold velocity reduces along with distance from the home position.

[0079] According to some examples of the presently described subject matter, the second resistance force is at least 25 pounds.

[0080] According to some examples of the presently described subject matter, the second resistance force is at least 100 pounds.

[0081] According to an aspect of some examples of the presently described subject matter, there is provided an exercise machine comprising: a resistance motor; a tension cable coupled to receive resistance force applied by the resistance motor; and a controller, coupled to control the applied resistance force; wherein the controller comprises processing circuitry configured to: access ongoing data indicative that a user end of the tension cable is moving at a distance within a homing distance from a home position for the user end; and in accordance with the data, automatically adjust signals from the controller governing application of the resistance force by the resistance motor; wherein the resistance force is controlled to transition between a first resistance force and a second resistance force in accordance with the ongoing data indicative of movement of the user end of the tension cable; and wherein the second resistance force is at least double the first resistance force.

[0082] According to some examples of the presently described subject matter, the resistance motor comprises a rotary electric motor.

[0083] According to some examples of the presently described subject matter, the exercise machine comprises one or more sensors which sense the sensed indications, and are coupled to provide the sensed indications to the controller.

[0084] According to an aspect of some examples of the presently described subject matter, there is provided a method of controlling a tension cable of an exercise machine operating to provide resistance at a resistance force, the method comprising: determining that extension distance of the tension cable is changing while a user end of the tension cable is within a homing distance from a home position of the user end; and in accordance with the determining, selecting force applied by a resistance motor to use a specified damping force level, in place of the resistance force.

[0085] According to some examples of the presently described subject matter, the damping force level is initially lower than the resistance force, and rises to meet the resistance force as the extension distance of the tension cable increases.

[0086] According to some examples of the presently described subject matter, the damping force level reduces as the extension distance of the tension cable reduces.

[0087] According to some examples of the presently described subject matter, the damping force level is different at different extension distances of the tension cable, and also different for same extension distances depending on whether the extension distance of the tension cable is increasing or decreasing.

[0088] According to an aspect of some examples of the presently described subject matter, there is provided an exercise machine configured to apply damped transitions of resistance force to a tension cable near a home position for a user end of the tension cable, the exercise machine comprising: a resistance motor; a controller, coupled to control resistance force produced by the resistance motor; and the tension cable, coupled to receive the resistance force produced by the resistance motor; wherein the controller comprises processing circuitry configured to: access data indicative that the user end of the tension cable is moving at a distance within a homing distance from the home position for the user end; and in accordance with the data, automatically adjust signals from the controller, the signals governing application of the resistance force by the resistance motor; wherein the resistance force is controlled to perform a damped transition through a plurality of levels between a first resistance force and a second resistance force in accordance with at least one of a change in the distance of the user end from the home position and an elapsed time after the user end passes a threshold distance while within the homing distance; and wherein the second resistance force is at least double the first resistance force.

[0089] According to some examples of the presently described subject matter, the resistance motor comprises a rotary electric motor.

[0090] According to some examples of the presently described subject matter, the exercise machine comprises one or more sensors coupled to provide the controller with sensed indications of tension cable movement, used to determine that the extension distance of the tension cable is changing while within the home position zone of extension.

[0091] According to some examples of the presently described subject matter, when the damped transition is in a direction reducing the resistance force, the controller is configured to: determine whether the data indicate that the user end of the tension cable will reach the home position before a targeted minimum transition time elapses; and select between a distance-dependent reduction in resistance force and a time-dependent reduction in resistance force in accordance with the determination.

[0092] According to some examples of the presently described subject matter, upon selecting the distance-dependent reduction in resistance force, the controller continues to access data indicative of movements of the user end of tension cable, and to control the damped transition accordingly as a function of distance of the movements.

[0093] According to some examples of the presently described subject matter, the controller is configured to: access data indicative of velocity of the tension cable; determine that the velocity of the tension cable satisfies a fast tension cable return criterion; and in accordance with the determination, perform at least one of: automatically adjusting signals governing the resistance motor to reduce force applied to the tension cable, and activate a brake to slow the velocity of the tension cable.

[0094] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, exemplary methods and / or materials are described below. In case of conflict, the patent specification, including definitions, controls. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

[0095] As will be appreciated by one skilled in the art, aspects of the present disclosure may be embodied as a system, method, or computer program product. Accordingly, aspects of the present disclosure, as appropriate to the disclosure and to the state of technology, may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, microcode, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,”“module” or “system” (e.g., a method may be implemented using “computer circuitry” or “processing circuitry”).

[0096] Furthermore, aspects of some examples of the present disclosure may take the form of a computer program product embodied in one or more computer-readable medium(s) having computer-readable program code embodied thereon. Implementation of the method and / or system of some examples of the present disclosure can involve performing and / or completing selected tasks manually, automatically, or a combination thereof. Moreover, in accordance with instrumentation and equipment provided for implementation of some examples of the method(s) and / or system(s) of the present disclosure, selected operations of these methods ( ) and / or system(s) could be variously implemented by hardware, by software, by firmware, and / or by a combination thereof.

[0097] For example, hardware for performing selected operations in accordance with some examples of the present disclosure is optionally implemented as a chip or a circuit. As software, selected operations in accordance with some examples of the present disclosure is optionally implemented as a plurality of software instructions. Optionally, implementation aspects are built on a general-purpose computing device, e.g., making use of the services of an operating system.

[0098] In some examples of the present disclosure, one or more operations performed in method(s) and / or by system(s) are performed by a data processor, such as a computing platform configured to execute pluralities of instructions in sequence and / or concurrently. Such a data processor may be alternatively referred to herein, e.g., as a “digital processor”, in reference to data processors which operate using groups of digital bits, and / or as “processing circuitry” in reference to the use of electronic circuitry in data processing applications.

[0099] Instruction executing elements of a data processor may comprise, for example, one or more microprocessor chips, ASICs, and / or FPGAs. Optionally, the data processor includes a volatile memory for storing instructions and / or data; and / or a non-volatile storage, for example, a magnetic hard-disk and / or removable media, for storing instructions and / or data. The terms “non-transitory memory” and “non-transitory storage medium”, where they may be used herein, should be expansively construed to cover any volatile or non-volatile computer memory suitable to the presently disclosed subject matter.

[0100] Optionally, a network connection conferring data communication capabilities is provided. A display and / or a user input device such as a keyboard or mouse are optionally provided. Any of these implementations are referred to herein more generally as instances and / or elements of, e.g., computer circuitry and / or processing circuitry.

[0101] Any combination of one or more computer-readable medium(s) may be used by some examples of the present disclosure. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. Without limitation, a computer-readable storage medium may comprise, for example, an electronic-, magnetic-, optical-, electromagnetic-, infrared-, and / or semiconductor-implemented system, apparatus, or device; in any suitable combination.

[0102] A non-exhaustive list of further examples of computer-readable storage medium(s) includes: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device. Any suitable combination of the foregoing is optionally provided.

[0103] In the context of this document, a computer-readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. A computer-readable storage medium may also contain or store information for use by such a program; for example, data structured in the way it is recorded by the computer-readable storage medium so that a computer program can access it as, for example, one or more tables, lists, arrays, data trees, and / or another data structure. Herein a computer-readable storage medium which records data in a form retrievable as groups of digital bits is also referred to as a digital memory. It should be understood that a computer-readable storage medium, in some examples, is optionally also used as a computer writable storage medium, in the case of a computer-readable storage medium which is not read-only in nature, and / or in a read-only state.

[0104] A “data structure” may include any collection of data values and relationships among them. The data may be stored, for example: linearly, horizontally, hierarchically, relationally, non-relationally, unidimensionally, multidimensionally, operationally, in an ordered manner, in an unordered manner, in an object-oriented manner, in a centralized manner, in a decentralized manner, in a distributed manner, in a custom manner, or in another manner enabling data access. A data structure may include, for example, one or more arrays, associative arrays, linked lists, binary trees, balanced trees, heaps, stacks, queues, sets, hash tables, records, tagged unions, ER models, and / or graphs. With particular (but not exclusive) reference to data storage for search retrieval, a data structure may comprise and / or form a part of, for example: an XML database, an RDBMS database, an SQL database, and / or an alternative implemented using MongoDB, Redis, Couchbase, Datastax Enterprise Graph, Elastic Search, Splunk, Solr, Cassandra, Amazon DynamoDB, Scylla, HBase, and / or Neo4J.

[0105] A data structure may be a component of disclosed examples which is stored, as appropriate: locally along with other system components described (e.g., in the same component package, device enclosure and / or room), and / or by a remotely-sited computing component (e.g., a cloud-based data structure). Data in the data structure may be stored in contiguous or non-contiguous memory. Moreover, a data structure, as the term is used herein, does not require information to be co-located. It may be distributed across multiple servers, for example, which may themselves be owned or operated by the same or different entities. The term “data structure” as used herein in the singular is inclusive of plural data structures. In particular, but not exclusively, it may be understood that a data structure itself may be at least partially composed of other data structures and / or portions thereof. As appropriate, limits of the extent of a data structure may determined according to its internal structure (e.g., internal patterns and / or self-references), its use, its providing storage media, the nature of the data stored (e.g., what the stored data are understood to refer to outside of the data structure and / or outside of the realm of data-as-such), and / or other suitable criteria associated with its instantiation. As appropriate, the term “data structure” may be understood as extending to include hardware, software, firmware, and / or any combination thereof for storing and / or facilitating the retrieval of information in a data structure characterized by its data values and relationships among them.

[0106] Certain data are optionally referred to herein as being derived from one or more sensors, e.g., as “sensed data” and / or “sensor data”. Such data comprise one or more physical effects transduced into a machine-readable form, e.g., one or more of the computer readable medium(s) described herein. Sensed / sensor data optionally represent physical quantities and / or objects, e.g., measurements and / or images. The sensed data typically are converted to a digital form used in data processing. However, transmitting, maintaining and / or processing sensed data in analog form (e.g., as amplitudes, frequencies, and / or phase encodings of voltage and / or current using suitable analog circuitry; e.g., for operations of comparison and / or combination) is not excluded.

[0107] Sensed data may be referenced as “indicative of” a certain aspect of a physical state. The scope of an “indicative of” relationship may include, but is not limited to, sensed data which measure the aspect of the physical state as such. More particularly, the scope of an “indicative of” relationship may include, but is not limited to sensed data which reasonably allow and / or are show to allow estimating a past, present, and / or predicted measurement of the aspect of the physical state as such. Estimated measurements are optionally (but not necessarily) calibrated. Estimated measurements are optionally absolute or relative (e.g., relative to an initial state, an average, or another baseline condition; and / or relative in the sense of showing a direction of changing magnitude).

[0108] An “indicative of” relationship is sufficiently characterized, in some examples, by correlations between sensed data and the aspect of the physical state such that the sensed data provide information about the aspect of the physical state. In examples including control and / or modification of the aspect of physical state, an “indicative of” relationship may be characterized by results showing that the sensed data provide information suitable for such control and / or modification; and / or by a reasonable expectation that the sensed data provide information suitable for such control and / or modification. Additionally or alternatively, an “indicative of” relationship may be used as a basis for estimating, controlling, and / or modifying some further physical state.

[0109] Relatedly, it should be understood that data (e.g., sensed data and / or data of a data structure) can be “indicative of” a state encoded by other data. As appropriate, the relationship “indicative of” in such cases may be understood as evidenced by the provision of suitable programming instructions making use of the relationship; not necessarily associated with full or partial reconstruction of the indicated data from the indicating data. Evidence of such an “indicative of” relationship may be gathered, for example, in the context of industrially applicable use of the relationship by a device or method. These examples explaining the “indicative of” relationship are not exclusive of other reasonable uses of the term; e.g., physical states such as lights, sounds, and / or mechanical positions of components which serve as indicators. The relationship “indicative of” as such does not restrict to a particular direction of causation, or, as such, require mutual causation in either direction. It should be understood that two entities can be mutually indicative; the relationship is not necessarily symmetric, however.

[0110] Herein, a data processor (optionally referred to, e.g., as processing circuitry and / or computer circuitry) is said to be “configured” to perform data processing actions (e.g.), accessing and / or manipulation of stored and / or streamed data according to one or more algorithmic operations) insofar as it is coupled to a computer-readable medium to access and / or receive instructions and / or data thereupon and / or therefrom, process them, and / or store processing results in the same or another computer-readable medium. As appropriate (e.g., when performing analog data processing) the term “processing circuitry” may be understood as encompassing data processing hardware which does not necessarily rely on instructions in the form of digitally encoded values. In such cases, the processing circuitry is “configured” in virtue of its construction and / or state.

[0111] The processing performed (e.g., using the stored and / or streamed data) is specified by the instructions (and / or other configured state), with the effect that the processor operates according to the instructions and / or configured state. The act of processing may be referred to additionally or alternatively by one or more other terms; for example: comparing, estimating, determining, calculating, computing, comparing, encrypting, decrypting, identifying, associating, storing, accessing, receiving, obtaining, analyzing, selecting, and / or transforming. For example, in some examples, a processing circuitry accesses and / or receives instructions and data stored in volatile and / or non-volatile memory and / or provided over a communication link, processes the data according to the instructions, stores processing results in volatile and / or non-volatile memory, and / or provides processing results. In some examples, “providing” processing results comprises one or more of transmitting, storing and / or presenting processing results. Presenting optionally comprises showing on a display, indicating by sound, printing on a printout, or otherwise producing results in a form accessible to human sensory capabilities.

[0112] Data may be referred to herein as being “accessed”. This optionally but not necessarily includes being “received”; e.g., by transmission of the data to suitable processing circuitry. Optionally, data is accessed at its original place of storage. Accessed data is optionally but not necessarily transmitted, copied, and / or stored in association with the accessing as such, in whole or in part. Except as otherwise indicated, it is neither required nor excluded that access produces destruction and / or degradation of stored data. Indications applicable in this case may be recognized in such technical aspects as the nature of the data's storage and / or transmission, and / or the mechanism(s) of access (e.g., states of quantum computers may be degraded by access). In the case of processing circuitry in particular, accessing of data may be characterized by changes in physical and / or processing state of the processing circuitry corresponding to one or more aspects of the accessed data. The one or more aspects can include, for example, values of certain data, presence of certain data, and / or other information associated with the accessed data such as its checksum validity and / or memory address. Accordingly, the term “access” is also not limited to full inspection of the referenced data. For example, when a database is accessed, optionally the whole or any part of its data, including metadata depending on fully yet not completely encoding such whole or part, is brought into further effect with respect to an accessing device and / or method.

[0113] In cases where a component of accessing includes “receiving” or “being granted” access (e.g., in the sense of “permission to access”), it should be understood that this establishes a “potential for accessing” separate from access as such. This potential may indeed be associated with access as such (e.g., as can be demonstrated by information to which access was granted being put to further use). However, it should be recognized that there is a potential for a meaningful distinction that can be resolved in the context of the term's use.

[0114] A computer-readable signal medium optionally includes a propagated data signal with computer-readable program code embodied therein; for example, in baseband and / or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to: electro-magnetic, optical, or any suitable combination thereof. A computer-readable signal medium may be any computer-readable medium that is not a computer-readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

[0115] Program code embodied on a computer-readable medium and / or data used thereby is optionally transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination thereof.

[0116] Computer program code for carrying out operations for some examples of the present disclosure is optionally written in any combination of one or more programming languages; for example, an object-programming, procedural and / or functional programming language. Non-limiting examples include C, Java, Smalltalk, C++, Python, ECMAScript (e.g., JavaScript), and Rust, among many other programming languages known to persons of ordinary skill in the art. As is known to persons of ordinary skill in the art, programs written in such languages specify logical operations which may be variously converted to computer instructions suitable for direct use by particular instances of processing circuitry, before and / or during processing.

[0117] Additionally or alternatively, sequences of logical operations (e.g., in the form of instructions from a machine instruction set supported by processing circuitry) may be embedded in the design of an ASIC and / or in the configuration of an FPGA device. The program code may execute entirely on the user's computer, partly on the user's computer (e.g., as a stand-alone software package), partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), and / or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some examples, a user's computer is more particularly specified, e.g., as a “personal communications device”, “personal computing device”, “smartphone”, “tablet”, “laptop computer, or “portable computer”. Except as otherwise described, each of these terms may be understood as relating to a device which is ordinarily operable for an extended period (e.g., an hour or more) while disconnected from a fixed source of electrical power such as a wall outlet (although commonly the device may be connected, e.g., for charging and / or for extended sessions of use). Commonly, such devices are operable in various ad hoc circumstances with various respective degrees of ease, e.g., while in public seating, while standing, and / or while moving around on foot or in a vehicle. Except as otherwise indicated, a “desktop computer” or “workstation” refers to a device which ordinarily operates from a fixed power connection. General-purpose computing devices operated by a user are optionally of either type; and the type is not necessarily fixed (e.g., a “laptop” may be operated while connected with a desk display, and / or have its battery removed). Communications capabilities allowing connection to a general-purpose data network (e.g., a wide area network and / or a local area network) should be generally understood to be available except as explicitly described otherwise. Mention of using any of these types of computing device may be understood as associated with an envisioned equivalent use of the other, except insofar as the context of the mention clearly disclaims this, and / or clearly indicates reliance on the special properties of portability, power requirements, connectivity, and / or display / input capabilities of the mentioned device type.

[0118] Some examples of the present disclosure may be described below with reference to one or more flowchart illustrations and / or block diagrams of methods, apparatus (systems) and / or computer program products. For such examples, it will be understood by persons of ordinary skill in the art that each block of the flowchart illustrations and / or block diagrams, along with combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented, to apply teachings provided herein, through use of suitable computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus (e.g., processing circuitry) to produce a machine; such that the instructions, upon their execution, carry out the functions and / or operations specified in the flowchart and / or block diagram block or blocks.

[0119] These computer program instructions may also be stored in a computer-readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer-readable medium produce an article of manufacture including instructions which implement the function / act specified in the flowchart and / or block diagram block or blocks.

[0120] The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0121] Some of the methods described herein are generally designed only for use by a computer; and may not be feasible or practical for performing purely manually by a human expert. A human expert who wanted to manually perform similar tasks, if feasible (e.g., such as inspecting objects, and / or making determinations from data), might be expected to use completely different methods, e.g., making use of human expert knowledge and / or the pattern recognition capabilities of the human brain.BRIEF DESCRIPTION OF THE DRAWINGS

[0122] Some embodiments of the present disclosure are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example, and for purposes of illustrative discussion of embodiments of the present disclosure. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the present disclosure may be practiced.

[0123] In the drawings:

[0124] FIGS. 1A-1B schematically illustrate examples of an exercise machine, according to some examples of the present disclosure;

[0125] FIG. 1C is a block diagram of an exercise machine, according to some examples of the present disclosure;

[0126] FIG. 2 schematically represents slack compensation through use of a velocity-dependent added resistance force commanded by exercise machine controller circuitry, according to some examples of the present disclosure;

[0127] FIGS. 3A-3B schematically represent scenarios potentially benefiting from slack compensation, according to some examples of the present disclosure;

[0128] FIG. 4A schematically graphs adjustments determined by exercise machine controller circuitry to prevent development of excessive slack distance in a cable operated exercise machine, according to some examples of the present disclosure;

[0129] FIG. 4B is a schematic graph comparing linear and quadratic dependencies of added resistance force on velocity, according to some examples of the present disclosure;

[0130] FIG. 5 schematically illustrates use by exercise equipment controller circuitry of hysteresis in the determination of a slack compensation force, according to some examples of the present disclosure;

[0131] FIG. 6 schematically represents control of cable return velocity by exercise equipment controller circuitry in response to loss of user control, according to some examples of the present disclosure;

[0132] FIG. 7A schematically illustrates damping control of resistance force with hysteresis in a homing zone near a home position of tension cable, according to some examples of the present disclosure;

[0133] FIG. 7B is a schematic flowchart of a method of damping control of resistance force in a homing zone near a home position of tension cable, according to some examples of the present disclosure;

[0134] FIGS. 7C-7D represent other parameter options for use with control of resistance force in a homing zone near a home position of tension cable, according to some examples of the present disclosure;

[0135] FIG. 7E is a schematic graph illustrating variable parameter home position damping, according to some examples of the present disclosure;

[0136] FIG. 8 is a schematic flowchart of a method of slack compensation, according to some examples of the present disclosure; and

[0137] FIG. 9 is a schematic flowchart of a method of operating a controller of an exercise machine to prevent overly dynamic homing of a tension cable, according to some examples of the present disclosure.DETAILED DESCRIPTION

[0138] The present disclosure, in some embodiments thereof, relates to the field of exercise equipment and more particularly, but not exclusively, to resistance cable operated exercise equipment.

[0139] A broad aspect of some examples of the present disclosure relates to the dynamic control of resistance forces to prevent and / or mitigate potentially device-damaging and / or user-disturbing tension cable movements in electronically controlled resistance training exercise machines. Herein, this is also referred to as “protective management” of tension cable dynamics. More broadly, this is an aspect of what is referred to herein as “utility management” of tension cable resistance force; that is, control of tension cable resistance force for purposes such as protection, safety, storage, calibration, and / or device self-diagnosis.

[0140] Utility management of tension cable resistance force is distinguished from (although often simultaneously with) resistance force specified by exercising parameters of the exercise machine. The exercise parameter-defined resistance force is referred to herein as the “setting force” Fsetting. In some examples, the setting force comprises a user-selected and predetermined level of exercise force which the controller signals to the resistance motor along with the adjustment.

[0141] In some examples, tension cable resistance force is further adjusted for another reason; e.g., to communicate haptic signals, and / or to provide strong vibrations with potential effects, e.g., on muscle tension and / or another physiological parameter.

[0142] More particularly, in some examples, protective management of tension cable dynamics comprises dynamic adjustments of force (increasing and / or decreasing) applied to the tension cable by a motor of an exercise machine to reduce and / or avoid one or more of the following:

[0143] Tension cable slack can develop, e.g., when tension cable movements coupled to forces and momentum of the exercise machine become decoupled from movements of a user end of the tension cable operated by the user's grip. Sufficient tension cable slack can lead to device malfunction, e.g., tangling and / or internal misalignments of the tension cable. Potentially, cable slack leads to a sudden jerk transmitted to the user when the tension cable re-tensions after a period of decoupling. This is further discussed in overview below under the heading Aspect of Slack Compensation. FIGS. 2-5 and 8 and their associated descriptions relate specifically but not exclusively to tension cable slack.

[0144] Free acceleration of a tension cable can potentially result from sudden cable release by the user. This may produce whipping (fast uncontrolled movements of the tension cable through the air) and / or slamming (a sudden stop of the user end of the tension cable when it reaches the frame of the exercise device). This is further discussed in overview under the heading Aspect of Recovery from Sudden Tension Cable Release. FIGS. 6 and 9 their associated descriptions relate specifically but not exclusively to mitigation of free acceleration in response to sudden tension cable release.

[0145] Abrupt dynamic transitions in the homing zone of a tension cable include, e.g., slamming into a frame of the exercise machine which could result from homing (returning) the user end of the tension cable too quickly (even without cable release by the user), and / or force discontinuities (e.g., “sticking”) which potentially disturb and / or confuse the user while pulling to extend the tension cable from its stored home position. This is further discussed in overview under the heading Aspect of Home Position Damping of Tension Cable, that is, damping of transitions between forces in a homing zone near a home position of the user end of the cable. FIGS. 7A-7D and their associated descriptions relate specifically but not exclusively to tension cable damping near the home position.

[0146] Forces exerted for purposes of controlling these issues are also referred to herein as “protective management forces”.

[0147] Protective management forces exchange with (i.e., follow / precede) and / or superimpose upon (i.e., are simultaneous with) the setting force governing how much exertion is needed to perform exercises with the exercise machine. Typically, setting force is user-selected.

[0148] In some examples of the present disclosure, the resistance training exercise equipment is electronically controlled, and electrically powered. Accordingly, device resistance is generated according to controller commands which operate a force generator, e.g., a rotary motor capable of developing several hundred watts (e.g., up to about a kilowatt) of power. Optionally, a more powerful motor is used; e.g., a motor of 1-10 kilowatts or greater. Herein, the force generator is also referred to as a “resistance motor” or “main resistance motor”. Optionally a plurality of individual motors are provided, which together act as the resistance motor imparting resistance force to the tension cable. In some examples, the resistance motor comprises a rotary motor, including a rotor (which rotates) and a stator (which remains rotationally stationary). Electrical power induces electromagnetic fields in a pattern which induces the rotor to turn relative to the stator. The force of this also imparts mechanical motion to the tension cable, which is directly or indirectly coupled to the movements of the resistance motor. Hereinbelow, FIGS. 1A-1C further relate specifically but not exclusively to components and / or structure of examples of electronic cable-operated exercise machines, under the heading Implementation of Resistance Motor Control

[0149] Optionally, device-generated resistance forces are electronically controlled to produce a pull force profile implementing the setting force Fsetting. In some embodiments, the pull force profile comprises a constant or varying force selected to be applied to the tension cable by the resistance motor. Along with the pull force profile, other intrinsic and / or electronically applied forces are provided.

[0150] In particular, along with the commanded pull force profile, the exercise machine includes intrinsic inertial properties. While the pull force profile is determined by machine settings, it is the user that determines how hard, and more particularly, how fast they perform a particular pull. Accordingly, the effects of intrinsic inertial properties vary according to user input forces, with the result that actual force experienced by the user is typically different than the pull force profile itself, e.g., due to inertial resistance to acceleration and / or deceleration.

[0151] In some examples, the pull force profile itself is simply a constant force. In some examples, the pull force profile is more complicated, e.g., designed to simulate (at least approximately) a weight with an inertia other than the device's true intrinsic inertia. For example, the pull force profile optionally simulates a constant weight along with the mass inertia of that weight. In some examples, the pull force profile simulates a stretching spring and / or elastic band (e.g., behaving according to Hooke's law), and / or another pull force profile. The targeted value of these forces, at any given moment of a rep, is what is referred to herein as the “setting force” Fsetting.

[0152] When not otherwise adjusted, this targeted value also defines the “commanded” force, that is, the force which the exercise machine's controller circuitry instructs the resistance motor to provide. In some examples, however, commanded force (also referred to herein as Ftotal is subject to modification by further forces, so that it is different from Fsetting. In some examples, protective management forces provide a portion (optionally all) of the difference between Ftotal and Fsetting.

[0153] Typically, protective management forces are automatically determined, although automatic determination may take setting force into account. When applied simultaneously with setting force, protective management forces may be understood as positive or negative (increasing or decreasing).

[0154] Some disclosed embodiments provide an advantage of applying the dynamic adjustments in a manner which avoids disturbing the user's sense that the setting force itself is stable and predictable. It is noted that the user sense may be of an “underlying” setting force; moreover the setting force itself is not necessarily itself constant (e.g., the setting force optionally simulates an elastic band, increasing with increasing extension distance). For the sake of understanding: a “user sense” of setting force stability is optionally understood as including acceptance of variations in resistance force analogous to (although not necessarily simulating) those that might be present in a completely mechanical resistance device, e.g., forces due to linear and / or rotational inertias of flywheels and / or masses used to provide resistance, elasticity in linkages and / or the cable itself, friction, and / or drag (e.g., fluid resistance). For example, a user may readily accept easing in of resistance force within a homing zone near a home position of a user end of the tension cable as “part of the mechanics” of the device, even when the ramping of forces is actually generated as an artifact of electronic control, e.g., a gradually increasing motor current.

[0155] In some examples, “user sense” for the application of a dynamic adjustment is linked to a user's own simultaneous adjustment of motion and / or force. To a user, this may feel analogous, e.g., to effort-dependent effects of mass inertia, rotational inertia, and / or fluid resistance. Potentially, the user is even unaware of the adjustment, e.g., since their own movements and / or efforts are changing, and the adjustment may itself be below a threshold at which the user notices a difference. In some examples, the dynamic adjustment in resistance force is applied as a function of a some measured aspect of tension cable movement, e.g., it may be applied as a function of velocity and / or acceleration of tension cable extension.

[0156] A principle of adjustment applied in some examples of the present disclosure is to adjust for prevention of certain outcomes, e.g., rather than according to constant and absolute thresholds of position, velocity, and / or acceleration alone. For example, in some examples, a homing zone within which resistance forces are eased between holding force and setting force is “normally” defined in terms of changing distance. But when a returning velocity of the user end of the tension cable is high enough, the easing optionally starts sooner (at a greater distance from the home position), e.g., to compensate for limits on sensor performance and / or motor control response time. This provides a potential advantage by allowing the application of “just enough” protective management force (in this case, application within an expandable, but normally more restricted zone), reducing potential interference with the user's sense of a stable and predictable setting force.

[0157] Another principle of adjustment applied in some examples of the present disclosure is to make adjustments in a manner which is relatively insensitive to sensing error, control error, and / or control lag. For example, adjustments are applied monotonically and / or with hysteresis as a function of some measured value, e.g., to avoid producing oscillations as a result of measurement noise and / or control lag. In some examples, adjustments based on measured velocity (first order derivative of position) are used to approximate inertial effects of acceleration (second order derivative of position), noting that acceleration calculations based on position measurements are potentially lagging and / or subject to greater relative error.

[0158] An aspect of some examples of the present disclosure relates to providing slack compensation forces in a tension cable used to operate electronically controlled resistance training exercise equipment (“exercise machines”), according to some examples of the present disclosure.

[0159] Using such a cable-operated, electronically controlled exercise machine, the user begins a rep (“repetition”; the shortened form “rep” being in common use) by pulling on the tension cable against machine-generated resistance forces, thereby increasing cable extension. During a return phase of the rep, it is expected that the user continues to control the cable while allowing it to shorten again.

[0160] Slack potentially results when movements applied by a user to the user end of the tension cable becomes decoupled from movements of the rest of the cable. This is typically associated with a sudden reduction of tension applied by a user to a user end of the tension cable while performing a rep, particularly during cable extension (during a “pull”). For example, such a sudden reduction of tension may occur due to a sudden stop or slow-down in initially rapid pulling by a user. To some extent, momentum (of the tension cable itself and / or of components coupled to its motion such as spool, motor, and / or pulley components) then carries the tension cable forward, resulting in the slack itself-a certain amount of “extra” tension cable which has played out from the exercise machine, beyond what spans the actual distance between the user end of the tension cable and the arm or other anchor location from which the tension cable exits the exercise machine.

[0161] During the development of slack, any resistance force exerted by the motor on the tension cable acts to decelerate it, and then accelerate it in the opposite direction. When all the slack is again removed, a user who has retained their grip on the user end is subjected to a sudden jerk as their grip again become coupled to the movements of the rest of the tension cable. Effects may include, e.g., straining joints and / or throwing the user off balance.

[0162] In some examples of the present disclosure, slack compensation forces are provided to prevent excessive slack from developing in the tension cable in such conditions, and / or to mitigate potential adverse effects due to the development of slack in the tension cable. Accordingly, slack compensation is a form of protective management force which comprises modulation of the commanded force, the modulation being directed at preventing and / or limiting the development of slack in the tension cable. The modulation magnitude is selected, e.g., based on measured dynamics of the motor itself, measured dynamics of the tension cable, measured force applied by the user to the tension cable, and / or another measurement indicative of the dynamic state of the rep and / or the exercise equipment.

[0163] In some embodiments, modulation of force comprises introduction of variable resistance forces into the operation of an exercise machine, the variable resistance forces being selected to keep operation of the machine out of potentially disturbing, damaging, and / or unsafe regimes. Herein, prevention and / or mitigation of slack is equivalently referred to as “slack protection” or “slack compensation”.

[0164] In some examples, variable resistance forces are introduced so as to feel predictable to a user (that is, to avoid the user feeling that force generated by the exercise machine is unstable and / or unpredictable). In some examples, variation in resistance force is introduced as a linear function of velocity. Additionally or alternatively another function shape and / or dynamic parameter indicative of cable movement is used, for example as described below. Force modulations used to protect against slack in a tension cable are also referred to herein as “deslacking” force Fdeslack. In some examples, “feeling predictable to a user” comprises making changes in force modulation (changes to commanded force so that it differs from Fsetting) suitably gradual, while still providing adequate slack protection. However, when the user is operating the device without much risk of slack developing, it is a potential advantage to be able to omit, reduce, and / or discontinue modulation, e.g., so that the resistance which the user senses feels closer to their selected resistance setting. In some examples, the controller's processing circuitry is used to manage transitions in resistance modulation, so that dynamically changing slack protection does not interfere with the user's sense of an underlying mechanical consistency.

[0165] Among the technical problems arising when managing the joint set of concerns mentioned in the previous paragraph (user's sense of consistency vs. slack protection) is that posed by operating constraints on servo feedback capabilities. On the sensing side of the servo loop, applicable constraints potentially include, for example, sensing lag and / or calculation lag (i.e., lag in determining what feedback should be given). On the response side of the servo loop, applicable constraints potentially include, for example, transmission lag and activation lag (i.e., lag in effectively developing the feedback force that has been selected). There can also be errors (e.g., sensing noise) in measurements themselves, and / or errors (e.g., control noise) in providing feedback force. In some examples (e.g., when operating with approximating assumptions), there are potentially systematic errors in the calculations themselves. During a rep (e.g., as the tension cable is accelerated), a certain amount of device kinetic energy (and, correspondingly, momentum) is built up. How much momentum / kinetic energy is present depends on the velocity of the pull (i.e., the rate of tension cable extension / return), which is largely under the direct control of the user. For examples using a rotary motor as the main resistance motor, much of the momentum / kinetic energy is associated with rotation of the motor's rotor, and / or of a spool upon which the tension cable is wound. Masses and velocities of other moving components such as the grip accessory (e.g., a pull bar) and the tension cable itself also contribute. It is noted that for a given pull velocity, device momentum / kinetic energy in an electronically regulated cable-operated exercise machine commonly (though not necessarily) remains about the same throughout a range of resistance force settings (that is, resistance force as set by the user). This contrasts, e.g., with gravity weight resistance training exercise equipment, wherein adding more weights (as sources of resistance force) also adds in their inherently coupled inertias.

[0166] Given a substantially fixed momentum / kinetic energy (at some velocity), there is potentially a greater opportunity to produce slack when a separately controlled resistance force is relatively lowered. More particularly, the pull resistance force Fsetting, when proportionally lower (compared to the kinetic energy), does not slow down the motor as quickly as it does when Fsetting is proportionally higher.

[0167] Focusing on user experience, a pull may become slack as the user slows down the pull near its end, particularly when the user decelerates their body quickly. The tendency to develop slack potentially increases especially when the force of Fsetting is light, and / or when the user performs the pull with higher velocities. This is because the motor's rotor (and / or a spool which it controls) builds up more momentum when velocities are high, while relatively light resistance forces do not overcome this momentum (or its kinetic energy) as quickly. The momentum of the rotor and / or spool can thus act as a “buffer” which partially decouples pull forces exerted by the motor, and the pull force actually sensed by the user. With heavier resistance (a larger value of Fsetting), the ratio of resistance force to kinetic energy rises, and a user potentially experiences less of the “buffering” effect, and / or a lowered risk of slack. There is also potentially a converse effect, wherein the user invests a proportionally greater amount of their overall effort (relative to the baseline pull force profile itself) to accelerate a pull against light resistance than against heavy resistance. The user potentially senses effects of system inertia (or its lack) most when trying to speed it up (e.g., accelerating at the beginning of a pull) or slow it down (e.g., decelerating near the end of a pull). During periods of constant velocity, buffering by the inertia of the system is potentially reduced, allowing the user to sense the commanded force more directly. Risk of slack decoupling in particular concentrates to periods when the user is slowing a pull. During the return phase after a pull, inertia builds again, but this time in the direction of motion which the user is also restraining. Slack is then possible, but potentially less of a concern.

[0168] As a result, resistance force to a pull motion at some speed can feel relatively consistent (and in particular, relatively unaffected by inertial buffering) when resistance is heavy; the user does not ordinarily slow the pull fast enough to be distracted by slack. The resistance force due to Fsetting itself quickly dissipates what inertia there is. But at the same speed, when resistance is light, resistance can feel inconsistent, “light”, or otherwise strange; e.g., with felt resistance forces increasing more significantly (relative to baseline pull force profile) during acceleration, then dropping precipitously during deceleration.

[0169] Furthermore, there is potential risk of user discomfort, injury and / or damage to the device due to sudden “jerks” when built-up reverse momentum again takes up the slack. For example, after a brief period of slack, the user and / or device may experience resistance force added to built-up return momentum applied suddenly. Slack of a sufficient amount also potentially leads to entanglement and / or mis-winding of the tension cable.

[0170] Additionally or alternatively, mismatches between resistance force and inertially buffered “feel” can potentially confuse a user's sense of what pull speed to use when switching among different resistance forces. For example, the user might paradoxically experience a need to slow down (relatively and / or absolutely) when pulling against lighter resistances, so as not to over-accelerate a weakly resisting rotor. The user might feel frustration in trying to avoid overtaxing the machine, potentially losing confidence in its performance.

[0171] In some examples of the present disclosure, an exercise machine controller controls the resistance motor to increase resistance force at least in part as a function of increasing velocity to provide the slack compensation force Fdeslack. Optionally, the function of velocity is linear; i.e., resistance force is added in a ratio-defined proportion as velocity increases, optionally with a threshold offset. Being a lower-order derivative of position than acceleration, velocity is potentially easier to measure and predict. For example, velocity will rise and fall at least once (and commonly although not necessarily exactly once each) during a single extension of the tension cable (during a pull), according to forces applied by a user to a user end of the tension cable. Furthermore, with greater velocity, there is a potentially greater chance of generating slack due to a sudden stop. This makes velocity potentially useful as a proxy for calculating slack compensation forces. By translating velocity changes into corresponding gradual and regular changes to resistance force, slack compensation forces are potentially more easily accepted (and / or less-easily noticed) by a user.

[0172] For example, during a pull, an appropriately selected velocity-based function for resistance increase can be considered to roughly counterbalance the effects of added kinetic energy (and potentially changes in resistance while velocity is changing). Other parts of the increase may be experienced similarly to friction, and / or otherwise be experienced as a “predictable” change to Ftotal. A velocity-based function can be selected which reduces amplitudes of adjustment during slower motions, so that user exertions are correspondingly less perturbed during the periods when they are potentially exerting less force to control motions of the device, and / or themselves making fewer adjustments to the dynamics of tension cable movements.

[0173] In some examples, the function of velocity used to determine Fdeslack is itself adjusted as a function of a selected resistance force governing the pull (the “setting force” F″se∈g). For example, the rate at which force is added as a function of velocity is reduced for higher selected resistances, at least over some portion of the overall pulling distance. This may be justified since as the setting force increases, the mass-equivalent of resistance force can eventually come to far exceed the mass-equivalent of the device inertia. As a result, there is a faster baseline deceleration that occurs should the user suddenly stop exerting pull force. Potentially, this is fast enough that the disadvantages of slack do not develop.

[0174] Optionally, resistance force as a function of velocity inverts at some level of resistance force setting, so that it is removed instead of added. For example, this could be used to reduce a potentially exaggerated deceleration during deceleration of a pull, and / or make the device feel more like an elastic band by canceling out inertia of the motor which resists acceleration.

[0175] Optionally, reductions / increases in resistance during a rep are divided into phases, according to an estimated risk that slack is generated during a particular phase of the rep. A potential advantage of using phases is a potentially reduced likelihood of introducing oscillations into control outputs, as well as potentially reducing interference with user-selected resistance force levels outside of conditions where slack is a particular risk.

[0176] A “vulnerable to slack” phase of a rep can be initiated, for example, based on when a certain velocity threshold is crossed, optionally during an increase in velocity or a decrease in velocity. Optionally, the slack compensation force is delivered according to one function as pull velocity accelerates, and a second function as pull velocity decelerates. In some examples, the transition between the two functions is managed to occur only in one direction. This gives the system some hysteresis, potentially making it less prone to oscillation near threshold values. Threshold values governing the transition are not necessarily based on velocity, or on velocity alone. For example, elapsed time, distance and / or acceleration are optionally used in determining phase transition thresholds. In particular, time and / or distance may be used to control transitions between phases. For example, transitioning from an initial velocity / resistance change function to a new velocity / resistance change function may be limited to occur over a predetermined period of time (e.g., 10-500 msec or 10-1000 msec), and / or over a certain distance (e.g., 0.5-10 cm of continuing movement, or 0.5-50 cm of continuing movement).

[0177] An aspect of some examples of the present disclosure relates to recovering from a sudden loss of user control of a grip accessory at a user end of an electronic cable-operated exercise machine, according to some examples of the present disclosure.

[0178] During operation of an electronic cable-operated exercise machine, a potential for device damage and / or injury arises in case a user operating the exercise machine loses control of the tension cable during a rep (e.g., loses their grip on a grip accessory used to operate the tension cable). During a rep, a controller of the exercise machine typically commands the resistance motor to provide significant force, e.g., potentially comprising 100 pounds or more of force exerted through the tension cable. If (e.g., due to loss of grip) the user suddenly stops exerting a counteracting force, the tension cable and any attached grip accessory begin to rapidly accelerate toward the exercise machine.

[0179] Two general concerns of significance in such cases are to avoid injury to the user and / or anyone standing nearby, and to avoid damage to the exercise machine itself. Furthermore, since such an incident comprises an exception to normal use, the exercise machine should reset itself, and optionally perform self-checks (e.g., in case the dynamics of the incident could have caused device damage).

[0180] In some examples, controller circuitry of the exercise machine accesses sensing data indicative of a current return velocity of the tension cable. Using the sensing data, the controller determines whether a fast tension cable return criterion for the tension cable is met. The fast tension cable return criterion comprises, for example, one or more of: an inherently excessive return velocity (e.g., a return velocity beyond normal and / or intended operating parameters), a period of acceleration indicative of a loss of user input force (e.g., acceleration consistent with unopposed acceleration due to resistance forces which are being commanded for the resistance motor), and a joint return velocity and distance of tension cable extension which create an imminent risk that a user end of the tension cable will return to the home position at an unacceptably high velocity.

[0181] Upon determining that one or more of the faster return velocity criteria are met, the controller the acts to reduce a velocity at which the extension distance of the tension cable is decreasing. In cases where velocity is already sufficiently extreme and / or the available distance to bring the tension cable to a halt is sufficiently short, this optionally comprises activation of a cable brake to bring the tension cable to a full stop and / or shutdown of the resistance motor. Optionally, recovery continues after this point, e.g., by bringing cable return back up to a recovery velocity

[0182] In cases where detection is in time to allow a more graceful recovery, no or partial braking is applied, while the controller changes commands to the resistance motor so that the tension cable is brought to a safe recovery velocity. Optionally, during further retrieval of the tension cable, velocity and / or force is adjusted to avoid inducing dangerous swinging in the tension cable and / or grip accessory. Optionally, the adjustments are timed to reduce swinging, e.g., by reducing tension particularly when sensing indications show that tension changes due to swinging motions have reached a peak.

[0183] As the user end of the tension cable approaches the end of its travel (its home position), velocity is optionally reduced again to a velocity slow enough to avoid damage as the end of the tension cable and / or its terminal accessory connector reach their home position. Optionally, reaching the home position is accompanied by final braking and / or decreasing forces, so that a collision is avoided, and / or occurs under conditions gentle enough to avoid damaging the exercise machine.

[0184] An aspect of some examples of the present disclosure relates to control of forces and / or movements of a tension cable while a user end of the cable is in a homing zone near a home position of the tension cable, according to some examples of the present disclosure. Herein this control is referred to both as “damping” and as “casing”; the two terms each refer to managing the control of transitions in resistance force and / or velocity between relatively high and relatively low values in a gradual fashion, e.g., involving a plurality of intermediate resistance force levels. Although gradual in this sense, the damping is optionally somewhat rapid perceptually (for the user); e.g., occurring in a period of between 10 msec and 500 msec. A maximum slew rate of force reduction is, for example, at least 100 pounds per 100 msec.

[0185] In some examples, the damping applied comprises a component of control exercised on the resistance motor to reduce its unloaded equilibrium velocity while the tension cable is within the homing zone. Herein, this is also referred to as “control-limiting the motor velocity”—that is, the motor velocity is limited so that it does not increase to exceed a certain velocity which is its present controlled limit. Under load, actual motor velocity is generally reduced still further, e.g., as torque and (rotational) speed of the motor are in part converted to perform work. It should be understood that whether loaded or unloaded, the motor potentially takes time to accelerate or decelerate following a change in the controlled limit of its velocity.

[0186] Commonly, the control-limited motor velocity is adjusted by adjusting electrical voltage, while the resistance force applied by the motor is adjusted by adjusting electrical current. Commonly, applying a load to a motor itself elicits an increase in current. Motor driving circuitry may actively or passively modify either or both of current and voltage. Some motor and / or control circuitry designs allow voltage and current to be adjusted independently; in other designs, there is at least some correlation and / or reverse correlation in adjustments to voltage and current.

[0187] In an exercise device, reduction of the controlled velocity limit at least somewhat separately from the resistance force provides a potential advantage by allowing the resistance force of the device to be modified less and / or less abruptly, while still biasing the tension cable toward slower movement. If the user is performing sufficiently slow and careful movements, they can potentially work with the device near to the end of the tension cable's return travel while still experiencing high resistance-yet the motor will also tend to avoid rapidly slamming the handle into its home position should the user's control slip. Furthermore, the motor itself will tend to encourage user care, by limiting the speed to which the tension cable can be accelerated. Homing zone reduction in control-limited velocity does not necessarily prevent a “slam return” under all conditions, but does potentially contribute to reducing compromises between consistency of user experience, and comfort and / or safety.

[0188] In some examples, operation at the setting force of a cable-operated weight machine is eased in (during cable extension) and / or eased out (during cable return) over a short distance and / or period of time as tension cable is pulled away from and / or returned to its home position.

[0189] Use of an easing distance and / or time period for setting force provides potential advantages by allowing users to gauge their movements and / or application of force according to a gradually changing force. For example, rather than eliciting no movement at all until finally pulling as hard as the setting force requires, a user is provided with feedback that helps them gain a more gradual bodily sense of how much additional force is needed for the current resistance force settings of the exercise machine. Optionally, the easing distance provides a short distance of easier resistance than that of the resistance force setting used for exercising. This allows the user to accelerate / decelerate their gripping limb(s) with more control and / or more gradually. This potentially helps the user when starting a first rep (for the case of tension cable extension), and / or helps them to end a set without a harsh final stop (for the case of tension cable return).

[0190] Easing transitions occur within a distance of the home position of the user end of the cable referred to herein as the “homing distance”, which itself defines a region up to the homing position itself referred to herein as the “homing zone”. The homing distance, in some examples, comprises a distance of 25 cm or less. In some examples, the homing distance is 10 cm or less; in some examples, the homing distance is 5 cm or less, e.g., 1 cm, 2 cm, 3 cm, 4 cm, or 5 cm. For the sake of comparing resistance force profiles during extension of the tension cable and during return of the tension cable, the homing distance is considered to be the same in both directions, e.g., the homing distance is optionally considered as the largest distance from the home position at which either transition is underway; optionally a slightly larger distance, e.g., 1-5 cm more distant still. The distance of the transition itself is also referred to herein as a “damping range”.

[0191] In some examples, profiles of the resistance force transitions as a function of distance are different from each other. The differences are selected, in some examples, so that average resistance force throughout the region between the home position and the homing distance is larger for extension of the tension cable than for return of the tension cable. In some examples, the difference in average resistance force is exemplified by a hysteresis in the distances at which accelerations / deceleration begins / ends. In some examples, the difference in average resistance force is exemplified by differences in the shapes of the functions which transition from high to low force vs. from low to high force. Additionally or alternatively, in some examples, target forces are set differently to produce the difference.

[0192] This difference in average resistance has the potential advantage of promoting a safer slowdown during return of the tension cable to its resting (quiescent force) state, when the user is potentially tired, and when the direction of motion is such that there is a risk of hard contact and / or a jarringly sudden stop.

[0193] On the other hand, activating resistance forces more quickly during extension allows rapid stabilization to the resistance levels that the user will be exercising with. This also potentially enhances the sense that the exercise machine has a consistent behavior. For example, the user may experience the ease-in distance as due to elasticity and / or looseness in the tension cable and / or its linkages. While a small amount of this may feel normal and “physical” to the user (even if in fact there is no meaningful level of either, except as attributed by the user), it is a potential advantage to avoid exaggerating such effects.

[0194] Optionally, for example, resistance forces begin increasing toward the resistance setting force as soon as extension is initially detected. Optionally a short delay distance (e.g., 1-5 cm) and / or time (e.g., 10-500 msec) is introduced. In the reverse (returning-phase) direction, resistance forces optionally reach a low baseline level while the user end is still several mm or several cm away from (e.g., 1-10 cm away from) its home position. This allows, e.g., time for the user end to decelerate, and / or makes it easier for the user to return the user end to its home position without reaching a jarring stop.

[0195] The distance at which the extension-phase increase in resistance force to reach the setting force ends (e.g., plateaus and / or finishes transitioning to a resistance force function determined by the setting force) is optionally different than the distance at which the complementary return-phase decrease in resistance force begins. For example, the transition is optionally completed closer to the home position during extension phase than it begins during return phase. As well, rates of change in force as a function of distance and / or as a function of time are optionally different. Changes in force are optionally monotonic (that is, unidirectional) for a given direction of movement; and according to any suitable linear or non-linear function.

[0196] Some disclosed embodiments involve controlling resistance forces during damping. In some examples, the system is configured to provide (when feasible) a gradual-in-time reduction of pulling force as the user end of the tension cable nears the home position, e.g., a period of time of at least 10 msec, at least 25 msec, at least 50 msec, or another preferred minimum period. The preferred minimum period is selected, e.g., to avoid a disturbingly sudden drop in force that could feel to a user as if a weight had suddenly been dropped from the end of the cable which they are exerting pulling force to restrain. A more gradual reduction in force potentially warns the user in time to avoid being thrown off balance; e.g., helping them to avoid stumbling backward when the force the user has been resisting is removed. The preferred minimum period is optionally selected assuming a time-linear decrease in resistance force; non-linear cases are briefly discussed below. In conditions under which the preferred minimum period is unavailable (because the cable is moving too fast), reduction of force is optionally switched to be as a function of distance instead.

[0197] Insofar as the user is either easing into or out of an ongoing exercise session during damped transitions in resistance force, the transition typically (but not necessarily) rises to or falls from the same resistance force (i.e., the resistance setting force). On the transition side near the home position, the quiescent state holding force is commonly the same as well. Optionally, the holding force is the minimum weight setting that the exercise machine can operate with. A relatively lower holding force has the potential advantage of relatively reducing heating of the motor and / or stress / strain on components. Accordingly, the range of the transition optionally ranges from a minimum and / or holding force of, e.g., 1-5 pounds up to an operating setting, e.g., of 50 pounds, 75 pounds, 100 points, 125 pounds, or another setting force. The targeted and / or de facto distance over which this transition occurs is, e.g., about 5 cm, or another distance (e.g., a distance between 0.5-10 cm).

[0198] There are optionally differences in final force targets. For example, a set of reps can begin with one resistance setting, and end with another. Optionally, the holding force in the quiescent state changes over time as well. For example, the final retrieval force during the return phase is optionally lowered below the eventual holding force for a period of time to reduce collision speeds. Once the user end is at the home position, holding force optionally increases somewhat, e.g., to help make sure that the user end is neatly stowed. Optionally, holding force is allowed to droop over time. Optionally, e.g., to counteract spontaneous extension due to the weight of the tension cable and / or its grip accessory, holding force is periodically renewed. These scenarios are examples, and should be considered non-limiting.

[0199] Some disclosed embodiments involve control of damping transitions. In some examples, resistance force is adjusted at least in part (e.g., depending on circumstances) as a function of time. In some examples, the transitions are optionally controlled to happen within and / or not faster than certain duration(s), the durations being selected so that the associated movements of the user end typically also happen within (that is, along a distance not greater than) a limited distance range referred to herein as the “homing zone”. In some examples, measurements of duration and distance are used jointly to control resistance force transitions. For example, a transition to a higher resistance force may be constrained to occur not more quickly than some period of time (e.g., at least 10 msec, 25 msec, 50 msec, 75 msec, 100 msec, 250 msec, 500 msec, or another period of time), even if the user manages to move the user end beyond the normally targeted distance for completing the transition. Optionally, there is an upper time limit; e.g., once the user begins moving the tension cable, the tension is optionally raised to its limit within some period (e.g., within 100-500 msec) whether the user pulls for a short distance (e.g., 0.5 cm) or a longer one (e.g., 10 cm). Alternatively, distances are used to limit time; e.g., a transition time is optionally hurried to keep distances shorter when the user moves the user end quickly enough.

[0200] Some disclosed embodiments involve mixed-mode control of damping transitions during cable return. During a return-phase, distance available within the homing zone optionally plays a limiting role insofar as, on one hand, it is a goal to prevent a hard collision, while on the other, it is potentially advantageous to keep the homing zone within which the homing routine takes over resistance force small, so that the user's workout is not interfered with. However, when velocity of the tension cable is low enough that reduction of resistance force is not limited by available distance, force reduction is optionally controlled to occur gradually and over a preferred minimum time, e.g., about linearly over the period of at least 10 msec, 25 msec, 50 msec, 100 msec, 250 msec, or 500 msec mentioned above.

[0201] When the tension cable is being returned to the home position quickly (at a sufficiently high velocity), the preferred minimum time is not necessarily available, unless the reduction of resistance force also starts while a greater distance separates the user end from its home position. This, however, can have the effect of interfering with a user's workout, e.g., when the user is performing exercises which include deliberately rapid deceleration of the user end of the cable toward a stopping position just beyond the homing zone of the user end. While relatively small adjustments in homing distance may be accepted by users, it could be confusing to a user if the homing zone were sometimes much larger and sometimes much smaller, depending on how they operated the equipment. In some examples, e.g., rather than unduly extending the length of the homing zone, the system instead applies more rapid deceleration once the homing zone is entered, even when this results in a relative excess of deceleration (e.g., linear deceleration over a period shorter than the preferred minimum period for linear deceleration).

[0202] In some examples, velocity is control-limited to a reduced value within the homing zone; that is, the motor is operated with parameters that reduce the velocity to which the motor can accelerate the tension cable. If the user returns the tension cable at a velocity below the velocity limit, this potentially makes no change in what the user senses. If the user attempts to return the tension cable at a velocity above the velocity limit, the control limit on velocity acts to damp the development of excessive return velocity.

[0203] Additionally or alternatively, velocity is limited by application of a brake (e.g., a friction brake, and / or a motor holding force brake) when it is found to exceed a certain threshold. Braking forces act to slow the tension cable. Assuming that the user is maintaining some level of user force, they may initially feel a drop in resistance forces; however, a brake also acts to counteract user forces once the tension cable is stopped.

[0204] In some examples of the present disclosure, a portion of the variability in starting velocity and / or velocity deceleration is handled by switching between control modes used to decrease resistance force, according to the situation. For lower starting velocities, a semi-open loop control method is used, in which resistance force is simply reduced over a predetermined period of time to a target. This mode is selected, e.g., when it is reasonable to assume that counteracting user force will work in time to sufficiently decelerate the user end of the tension cable before it reaches its home position. This mode has potential advantages already mentioned, e.g., a force-reduction duration can be selected which is long enough to give the user time to adjust; it is also “smooth”, and so avoids disturbing the user experience with potential problems such as feedback oscillation and / or sensing errors.

[0205] This mode reaches limits, however, when the rate of approach to the home position is too fast. In some examples, use of a fixed (minimum) length of force reduction time is then discarded, and resistance force is instead ramped down as a function of distance to the home position (e.g., sensing-indicated distance of the user end of the tension cable from its home position). This can be described as “choosing the fastest mode”. If the targeted time to ramp down resistance force is longer than the time which appears available (because the tension cable is moving too fast), then the distance-dependent control mode is selected instead. Optionally, the determination of which mode to use is made upon entering the homing zone, without expectation of a change. Alternatively, control transitions between the modes according to whichever control mode is currently fastest.

[0206] Insofar as velocity is under user control (that is, actual velocity, distinct from the concept of “control-limited” velocity described above), it should be understood that zeroing out resistance force upon and / or before reaching the home position does not by itself guarantee that return velocity is canceled out, or even returned to some particular level. The effect of removing positive resistance force, and / or of control-limiting the velocity such resistance force can develop, “smooths the way” to an eased-in return of the user end to its home position for a user who is also consciously targeting a safe return of the device, and also reduces forces involved (should there be a collision) to those of the (relatively light) inherent mass and momentum of the unpowered moving parts of the system. For example, reduction of resistance force to zero helps reduce a potential for pinching and / or trapping of body parts during the user end return to its home position.

[0207] Some disclosed embodiments involve variations of home position damping of the tension cable. During cable return, the homing zone is optionally allowed to increase in size somewhat as a function of tension cable velocity. In some examples, the increase is by an amount less than what is proportionally needed to entirely avoid dropping below the “preferred minimum” time period of resistance force down-ramping, but large enough to maintain the ramping-down period above some still-shorter predetermined time period. In some examples, dynamic increase of the homing zone is further limited, e.g., by taking into account a current measured and / or estimated deceleration of the user end. This potentially helps to improve the balance between device safety, and avoiding interference with the user's workout. If—e.g., at some checkpoint distance—the current rate at which the user is decelerating the user end is projected to slow the user end enough to avoid disruptive intervention, then the system optionally partially or entirely avoids increasing the size of the homing zone. If the projection turns out to be wrong, the system still retains the option of enforcing rapid deceleration, resistance force reduction, and / or control-limited velocity upon the user end of the tension cable entering the unadjusted or less-adjusted (e.g., default-sized) homing zone.

[0208] Noting that the overall period of deceleration can in principle be lengthened arbitrarily by applying a tapering (non-linear) deceleration, the “preferred minimum time” may optionally be understood as associated with a corresponding “preferred maximum rate of resistance force reduction”. From a given starting point and starting velocity, extending the time of force reduction to reach a some low-valued target may then be understood to involve some (e.g., initial) period of even faster decline. As a result, the user would then potentially experience even greater “suddenness” in the changing dynamics of the tension cable, but this would carry through for only a portion of the whole range of resistance force reduction.

[0209] It is again noted that the while the system generally has greater control of return velocity (e.g., to limit its maximum value) than of extension velocity, there is a potential for erratic user input to affect motion in either direction. Accordingly, it is a potential advantage for the system to be configured generally to “look ahead” in time based on its current dynamic state, together with assumptions about sudden changes in force input that a user could plausibly make. Where the controller determines that it potentially cannot otherwise guarantee, e.g., a suitably low-velocity return of the tension cable to its home position, the controller optionally intervenes with increasingly aggressive parameters and / or mechanisms.

[0210] Accordingly, where return velocities are high enough, and / or positions near enough the home position, a controller optionally intervenes more aggressively to shorten the transition time, as appropriate to prevent and / or reduce forces of a collision (which itself would result in a very short transition). For example, the controller limits pull speed and / or decreases pull resistance when the end of the tension cable is within a homing zone distance from its home position, e.g., within 25 cm, within 10 cm, within 5 cm, or within another distance which leaves the system with enough lead time and distance to react, and avoid the user end of the cable hitting the machine's arm with excessive (e.g., potentially damaging) force and / or velocity. This also potentially helps avoid communicating a jarring deceleration to the user.

[0211] Resistance force reduction, for example, is optionally implemented as a function of one or both of distance and time. If the user allows the tension cable to retract slowly, the system optionally “uses time” to reduce the weight (again, “using time” here may be understood as a proxy for “avoiding excessive suddenness of force reduction” during, e.g., linear force reduction). If the cable is moving faster than time-based force reduction allows for, however, the system optionally reduces the weight based on the distance traveled; e.g., lowering it as fast as needed to reach a target when the user end reaches a certain position. Where velocity is sufficiently high, velocity is optionally reduced more aggressively, e.g., by control-limitation (to prevent accelerating to an excessive velocity) and / or by applying a brake. The brake is optionally applied to the tension cable itself, to the motor, and / or to a spool upon which the tension cable is wound.

[0212] If necessary to help avoid a high velocity collision, resistance force applied by the motor is optionally simply turned off, or even applied (briefly, e.g., not past the point of creating return direction motion) in the opposite direction. In this case, the temporal discontinuity in resistance force this creates is potentially less disturbing than the imminent collision.

[0213] Before explaining at least one embodiment of the present disclosure in detail, it is to be understood that the present disclosure is not necessarily limited in its application to the details of construction and the arrangement of the components and / or methods set forth in the following description and / or illustrated in the drawings and / or given in the Examples. drawings. Features described in the current disclosure, including features of the disclosure, are capable of other embodiments or of being practiced or carried out in various ways.

[0214] Some disclosed embodiments involve resistance motor control of exercise equipment. Reference is now made to FIGS. 1A-1B, which schematically illustrate examples of an exercise machine 100, according to some examples of the present disclosure. FIG. 1A emphasizes externally visible features. FIG. 1B illustrates certain internal features of an example corresponding also to the example of FIG. 1A. Reference is also made to FIG. 1C, which is a block diagram of an exercise machine 100, according to some examples of the present disclosure.

[0215] The example of FIG. 1C includes the examples of FIGS. 1A-1B. It should be understood that sensor 145 is an optional feature of FIG. 1C; provided, for example, to sense one or more of tension force and / or strain in tension cable 105, and / or dynamic movements of tension cable 105, e.g., velocity, acceleration, and / or extension distance.

[0216] In the example shown, exercise machine 100 comprises a power section 120. Tension cable 105 extends from power section 120 through frame 110, and connects at its terminal end (e.g., via accessory connector 107B) to a grip accessory 107. In some examples (e.g., as shown in the examples of FIGS. 1B and 2A), power section 120 comprises motor 125 and spool 121, linked via belt 122. Optionally, belt 122 comprises a v-belt or timing belt. Optionally, power is transmitted from motor 125 to spool 121 by gears. Optionally, motor 125 drives spool 121 directly. In some examples, at least a portion of controller 129 is housed within housing 120A. Additionally or alternatively, a portion of controller 129 is housed in user interface 130, along beam 111 (e.g., within beam housing 111A), and / or elsewhere. In some examples, functional interconnection between controller 129 and motor 125 includes feedback that allows controller 129 to determine one or more dynamic parameters of motor operation, e.g., sensing data from a position encoder, and / or data indicative of voltage, current, and / or power. Optionally, controller 129 receives position data sensed directly from spool 121. This has potential advantages for managing backlash and / or slippage which may potentially occur in the driving mechanisms used to couple motor 125 to spool 121.

[0217] In some examples, controller 129 comprises processing circuitry (e.g., one or more microprocessors and / or other processing circuitry) which accesses data and instructions stored in a memory of controller 129 in order to determine motor control commands to send to motor 125 during user of exercise machine 100 by a user. In some examples, controller 129 comprises communications interface 133, and is configured to receive and / or transmit data through communications interface 133 for use in configuration and / or real-time operation. In some examples, communications interface 133 is optionally used to receive software updates and / or parameter updates. In some examples, communications interface 133 is optionally used to transmit monitoring data, e.g., device operational data allowing diagnosis of situations in which unexpected tension cable dynamics are encountered.

[0218] Frame 110 comprises structural support elements along and / or through which tension cable 105 is routed between power section 120 and exit aperture 112A or another last point of contact between frame 110 and tension cable 105. In some examples, frame 110 comprises arm 112, optionally configured to swivel around swivel joint 114). Optionally, swivel joint 114 is loosened and tightened using locking knob 115. Swivel joint 114 comprises one or more degrees of rotational freedom; for example, it swivels to allow arm 112 to be stored in a vertical position.

[0219] In some examples, arm 112 is furthermore mounted (e.g., via trolley 113) to a beam 111, along which its position can be adjusted. Beam housing 111A is optionally provided to at least partially enclose a track 111B extending along beam 111. Trolley 113 travels vertically along track 111B to adjust a vertical position of swivel joint 114 and arm 112 along track 111B. Optionally, locking knob 115 also acts to loosen and lock this travelling movement; optionally, a separate mechanism is provided.

[0220] Optionally, a user can adjust swivel joint 114 so that pulling from exit aperture 112A aligns more nearly parallel to the orientation of arm 112 and the direction of trolley 113 and / or swivel joint 114, or otherwise as convenient; e.g., according to the exercise performed, the size of the user, and / or the position of trolley 113 along track 111B. Optionally, one or more additional or alternative positioning mechanisms are provided as part of frame 110.

[0221] Frame 110, in some examples, is configured to be mounted to a wall; e.g., anchored to a wall stud, bricks and / or blocks, and / or another structural element of a building. In some examples, one wall attachment comprises attachment at a lower end, e.g., at the position of housing 120A. In some examples, a second wall attachment comprises attachment at an upper end, e.g., brace 116.

[0222] It should be understood that some in examples of the present disclosure, frame 110 comprises any suitable arrangement of structural elements serving to route tension cable 105 to a position that designates the location which the user experiences as the direction from which resistance forces are generated. For example, a user pulling on accessory connector 107B (e.g., using a grip accessory 107) from below arm 112 experiences resistance forces from an upward direction; a user pulling on grip accessory 107 from above arm 112 experiences resistance forces from a downward direction. In some examples, frame 110 comprises a seating arrangement.

[0223] It is not excluded that portions of power section 120 (e.g., spool 121 itself) are moved as part of a mechanism which adjusts the position of exit aperture 112A. Nor is it excluded that power section 120 itself serves as frame 110 (e.g., exit aperture 112A is optionally provided directly from a housing 120A of power section 120).

[0224] In some examples, tension cable 105 is coupled to power section 120 through spool 121 (e.g., FIG. 1B), from which a portion of tension cable 105 unwinds when grip accessory 107 is pulled away from frame 110 (e.g., away from an exit aperture 112A of arm 112), and onto which tension cable 105 re-winds when grip accessory 107 is released. Between exit aperture 112A and power section 120, Tension cable 105 optionally passes through a plurality of cable sections 105A, 105B, 105C articulated from each other by arrangements of one or more pulleys 106A, 106B, 106C. It should be understood that the configuration of power section 120 to comprise a separate spool 121 and motor 125 (e.g., as shown in FIG. 1C) is optional. For example, tension cable 105 optionally winds onto a portion of motor 125 itself. In other examples, tension cable 105 is anchored to a system of pulleys, and motor 125 controls forces on tension cable 105 by movement of the pulleys. In other examples, tension cable 105 is anchored by a plurality of windings to a motor-powered capstan (in any suitable orientation), with one portion of tension cable 105 leading from the capstan to the user end of the tension cable 105, and a portion leading to the other end also leading away from the capstan.

[0225] In some examples, there is provided a user interface 130, through which a user can control settings of exercise machine 100, and / or receive visual, haptic, and / or auditory feedback. In some examples, user interface 130 comprises a rotary knob 131 with embedded screen 132. User input is provided, for example, by rotating and / or pressing (“clicking”) the rotary knob 131. Optionally, embedded screen 132 comprises a touch-receptive surface and can itself be used as an input device. Optionally, exercise machine 100 is configured to establish a data connection with a user-provided personal computing device such as a smart phone or tablet, which can itself be used as a part of user interface 130.

[0226] Some disclosed embodiments involve auxiliary sensing. In some examples, one or more optional sensors 145, 145A-145C is provided to record data indicative of forces and / or motions experienced by tension cable 105 during use. Data from these sensors is optionally used to confirm, augment, and / or replace measurements of the motions and / or operating parameters of motor 125 and / or spool 121.

[0227] Sensors are optionally placed at any location suitable for their measurement task. A strain sensor, for example, may be placed inline along tension cable 105, coupled to the mountings of one or more pulleys 106A-106C, and / or coupled to the mountings of spool 121 and / or motor 125. In some examples, a sensor is positioned where it can measure movements of tension cable 105 optically. In some examples, amplitudes and / or frequencies of sound generated during movements of tension cable 105 are used to measure movement dynamics, e.g., velocity and / or acceleration.

[0228] In FIG. 1B, indicated options for sensor locations include attached on device-internal location of tension cable 105 (e.g., sensor 145A), at the exit of tension cable 105 from arm 112 (e.g., sensor 145C), and integrated into accessory connector 107B (e.g., sensor 145B). Other options include sensors positioned on grip accessory 107, sensors integrated elsewhere along arm 112 (e.g., at a place a structural member of frame 110 vibrates in correlation movements of tension cable 105), and / or sensors integrated into one or more of pulleys 106A-106C and / or the elements that support them.

[0229] In examples using sound sensing to help assess tension cable 105 dynamics, sensed sounds are optionally sounds produced incidentally; e.g., as a result of bearing movements as any of pulleys 106A-106C rotate, and / or due to movements of surfaces of tension cable 105 in contact with other surfaces of exercise machine 100. Optionally, sensed sounds are produced using mechanisms deliberately provided as sound generators; e.g., gently contacting elements making clicks, “zipping” sounds, or another vibrating indication as tension cable 105 is operated. Such vibrations are optionally measured and used as indications of tension cable 105 velocity, position, and / or acceleration. Even when this information is also available from, e.g., a motor encoder, sound recording data provides a sensing channel which can potentially provide high-frequency feedback (e.g., a typical audio recording frequency is 44.1 KHz) allowing interpolated estimates of acceleration values between encoder positions.

[0230] Some disclosed embodiments involve slack compensation. More particularly, some disclosed embodiments involve momentum-dependent resistive force adjustment to prevent and / or reduce slack. Reference is now made to FIG. 2, which schematically represents slack compensation through use of a momentum-dependent added resistance force commanded by exercise machine controller circuitry, according to some examples of the present disclosure. Reference is also made to FIG. 8, which is a schematic flowchart of a method of slack compensation, according to some examples of the present disclosure.

[0231] The horizontal axis of FIG. 2 represents momentum (that is, momentum of components of exercise machine 100 coupled to movement of tension cable 105). Arbitrary units are used. The coupled momentum comprises, e.g., linear and / or angular momentum, e.g., angular momentum of motor 125 and / or spool 121, and optionally at least a portion of the linear momentum of tension cable 105. With specific respect to compensation for slack, momentum is considered to be momentum developed during extension of tension cable 105, e.g., as a user exerts pulling force on it.

[0232] Momentum is considered proportional to velocity, e.g., according to the well-known equation of linear momentum p=mv, where p is momentum, m is mass, and v is velocity. Similarly, the equation of angular momentum defines a rotational analog of linear momentum proportional to rate of rotation. Accordingly, additionally or alternatively to representing momentum, the horizontal axis can be measured and / or represented in terms of a linear velocity of tension cable 105, revolutions per minute of spool 121 and / or motor 125, and / or another measure of velocity.

[0233] Horizontal dotted line 201 represents a certain setting force Fsetting for exercise machine 100 used during a rep (repetition of an exercise cycle). While this is not necessarily a constant force, it is shown as constant here for the sake of description.

[0234] At block 810, in some examples (FIG. 8), controller 129 accesses data indicative of a current momentum coupled to extension of tension cable 105. “Indicative” should be understood as including indicative in conjunction with suitable calculations, and / or jointly indicative, e.g., indicative based on the use of two or more data sources. In some examples, at least a portion of the data indicative of the current momentum is provided by a motion encoder on one or both of spool 121 and motor 125. Optionally velocity and / or momentum is calculated from these measurements. Other than velocity, the main variable aspect of the momentum coupled to movement of tension cable 105 is the disposition of the mass of tension cable 105 itself. Optionally, this is modeled as a function of extension distance. Optionally, this variation is treated as negligible for purposes of slack compensation, allowing the momentum to be treated substantially as having a constant proportion to velocity, according to baseline conditions regarding the mass values and mass distributions of the relevant moving components of exercise machine 100. In some examples, another sensor type is used, e.g., current sensing of electrical current provided to motor 125, and / or one of sensors 145A-145C. Optionally, for example, one or more of sensors 145A-145C measures tension exerted on tension cable 105. It should be understood that insofar as the output of the next block of operations (block 812) is an adjustment, calculations using the data indicative of momentum do not necessarily calculate momentum as such; e.g., an intermediate and / or partial calculation may be accepted as having a relationship to slack risk which is sufficiently correlated to the relevant coupled momentum as to allow the determination of block 812.

[0235] At block 812, in some examples, controller 129 determines an adjustment to resistance force Fdeslack, the adjustment depending on the momentum indicated by the data of block 810.

[0236] For example, as shown in FIG. 2, vertical dotted line 202 represents a threshold momentum threshold pthreshold, and / or velocity threshold vthreshold, above which the rising slope of commanded resistance force 210B increases as a function of velocity. The difference of this value from the value of Fsetting is labeled as Fdeslack.

[0237] For lower momentums / velocities, the value of commanded resistance force 210A is equal to Fsetting. The commanded resistance force 210 over the full range of, e.g., v (where v is, e.g., the linear velocity of a portion of tension cable 105 and / or the rotational velocity of spool 121 and / or motor 125) is defined by the combination of these two partial functions (and likewise for momentum p). Herein, it should be understood that resistance forces referred to as “commanded” are produced through signaling by a controller to an adjustable force generator such as an electrical motor.

[0238] Forces felt by the user may be different if the user is trying to accelerate or decelerate the tension cable. Optionally, acceleration is compensated for, although it is again noted that this potentially could produce errors due to a range of factors related to lags and / or imprecision in sensing and / or control feedback. Where these errors are large enough to disturb the user experience, slack compensation based on velocity measurement is optionally preferred. In some examples, partial slack compensation acceleration compensation is used, with the magnitude of this compensation being kept low enough that users are unlikely to be disturbed by unexpected changes in tension, at least within normal operating parameters.

[0239] In the illustrated example, increase in Fdeslack is linear (beyond vthreshold) as a function of both velocity and momentum. The increase is, for example, according to a predetermined slope value a having units, e.g., of force added per meter per second of velocity of tension cable 105, spool 121, and / or motor 125. Accordingly, the total motor-commanded resistance force Ftotal is optionally described by:Ftotal={if⁢ v≤vthreshold:Fsettingelse:Fsetting+a⁡(v-vthreshold)A similar equation may be written substituting momentum for velocity. It should be understood that a different and velocity-related function is optionally chosen. In particular, the velocity-related function is optionally determined for reducing a risk of the generation of a certain “unacceptable” slack distance during operation of exercise machine 100. A level of this “risk” is optionally assessed according to a first factor corresponding to the greatest allowable slack distance generated, and a second factor corresponding to an estimate of the greatest amount of slack distance that reasonably could be generated under certain circumstances. Where the distance of the second factor is larger than the distance of the first, slack compensation force (Fdeslack is optionally applied. While overcompensation is not excluded (e.g., for simplicity of calculation or another reasons), it is a potential advantage to maintain slack compensation adjustments near their minimum level so as to reduce interference with the user-selected setting force. Application of a threshold such as pthreshold and / or vthreshold below which no correction is applied is suitable, e.g., with lower values of momentum at which the risk of slack development is associated with only very short “unwinding” distances due to the existing momentum of moving components of exercise machine 100. Beyond the threshold, the slope of the adjustment (rate of increase of Fdeslack) is optionally lower for larger values of Fsetting, since the larger resistance force this represents will potentially overcome the momentum more quickly and reduce the runout distance. Optionally, the threshold at which the onset of the adjustment occurs is adjusted upward in accordance with the reduced risk of slack developing, also as a result of the more rapid overcoming of momentum.

[0241] At least while the user is gripping the grip accessory, “slack distance” may be understood as the difference (when tension cable 105 is loose) between the actual distance of the user's grip from the position on exercise machine 100 to which tension cable 105 extends from the user, and an increased distance of the user's grip at which tension in tension cable 105 would be restored. Slack compensation is potentially most important under conditions in which there is sufficient resistance force applied to tension cable 105 to produce tension cable acceleration in the return direction, but not with such speed that users find it difficult to decouple their movements from movement of the tension cable while also retaining their grip on it.

[0242] Additional discussion of slack distance (for example, if the user's grip is lost), and considerations for making the determination of an appropriate momentum- and / or velocity-related function to manage, mitigate, and / or prevent it is presented, e.g., in relation to FIGS. 3A-4B. The “lost grip” condition is of specific concern also with respect to the aspect of recovery from sudden tension cable release, described, e.g., in relation to FIGS. 6 and 9. For conditions in which grip is lost completely, the distance of runout before overcoming momentum coupled to tension cable 105 is of more particular importance as the metric of slack risk, since this is what may lead to internal misalignments and tangling. However, in the “lost grip” scenario, the user will generally not be pulled around when suddenly re-coupled to the momentum of the system, since they are no longer holding on to tension cable tension cable 105.

[0243] In some examples, a distance of potential slack which is considered “unacceptable” is selected with respect to the assumption that the user has managed to reduce cable tension to substantially nothing, and substantially immediately. In this case, potentially the whole runout distance of the system's current momentum (e.g., the distance the cable would unwind from its spool with nothing to stop it but the motor's resistance force) could create slack distance. Optionally there is additional mitigation implemented that increases resistance force quickly after a sensed loss of user force to reduce the runout distance, but then again reduces resistance force before this can become an over-acceleration in the return direction of the tension cable.

[0244] In some examples, the slope value a represents a function of Fsetting, i.e., a=f(Fsetting) For example, with an increasing value of Fsetting, the value of a optionally decreases.

[0245] In some examples, the value of 1 threshold is a function of Fsetting, e.g., vthreshold=g(Fsetting). For example, with an increasing value of Fsetting, the value of vthreshold optionally increases.

[0246] As a more particular example, vthreshold is optionally defined as vthreshold=βFsetting, and a is optionally defined as a=αFsetting, where α and β are proportionality constants. Accordingly, in this case:Ftotal={if⁢ v≤β⁢FsettingFsettingelseα⁢Fsetting(v-β⁢ Fsetting)

[0247] It should be understood that either or both of α and β is optionally set to 1. It is not excluded that function dependencies on Fsetting include a constant offset value. It is not excluded that function dependencies on Fsetting are non-linear, e.g., exponential according to a value larger than one or less than one, and / or polynomial. It is not excluded that function dependencies include factors other than Fsetting and v.

[0248] For example, in some examples, the dynamic acceleration of tension cable 105, spool 121, and / or motor 125 is taken into account. One way of doing this is to calculate vthreshold differently during different accelerations. For example, during acceleration, there is a “built-in” addition to Fsetting due to the portion of the inertia of exercise machine 100 that resists the acceleration. Optionally, the value of Fdeslack is reduced in correspondence with this value by a term that causes vthreshold to be increased. Alternatively, the estimate of, e.g., v itself is reduced, and / or another compensating adjustment is made, e.g., to the slope value a. Optionally, estimation of acceleration forces is directly calculated and used to adjust the value of Fdeslack. Noting that certain methods of making higher-order dynamics measurements (e.g., of acceleration) are potentially more vulnerable to sensing and / or compensation errors and / or lags, the adjustment magnitude is optionally filtered (e.g., low-pass filtered) to avoid introducing changes to Fdeslack which are too sudden for the user.

[0249] Concluding the flowchart of FIG. 8: at block 814, in some examples, the determined adjustment to resistance force Fdeslack is signaled to the resistance motor.

[0250] Reference is now made to FIGS. 3A-3B, which schematically represent scenarios potentially benefiting from slack compensation, according to some examples of the present disclosure. FIG. 3B represents a magnified view of region 300A of FIG. 3A. Curve 301 of FIGS. 3A-3B represents an example relationship of tension cable extension distance (vertical axis) over time (horizontal axis) during a pulling portion of a rep. The slope of this line may be understood as approximately proportional to momentum.

[0251] Dotted line 302 (extending horizontally), represents an extension distance at which user input forces (in the examples of this figure) suddenly decline from the typical case of curve 301; for example, if the user just dropped their hold on the tension cable, or otherwise deviated from their normal form. For purposes of discussion, this deviation in form is assumed to be large enough to potentially generate slack distance.

[0252] Curve 303 represents an example of how cable extension distance could continue to change due to the combined influences of motor-powered resistance forces and inertia of the system (e.g., linear and / or rotational inertia) in a period after the user has moved enough to decouple their force inputs from the dynamic movements of (at least part of) tension cable 105. Since user inputs are removed, curve 303 is generally lower than curve 301 at times after the extension distance marked by dotted line 302 is crossed. At first, tension cable 105 continues to extend (e.g., unwind from its stored position on spool 121), as forward velocity reduces over time due to the resistance forces provided, e.g., by the motor 125. Beyond a peak extension represented at peak 303A, velocity reverses. The tension cable 105 begins to retract, and then accelerates in its speed of retraction.

[0253] In some examples, the “natural” course of curve 303 is interrupted upon detection of the change in user-input forces. For example, at point 304, exercise machine 100 optionally detects that there is a loss of user inputs, and switches to another cable retrieval function 305, e.g., using a return velocity which is smoothed towards zero as the cable nears zero extension distance again. This is discussed more centrally, e.g., as the subject of FIGS. 6 and 9.

[0254] As already discussed, one potential adverse “slack” effect comes from the tension cable not fully extending from exercise machine 100 according to its unwinding distance. Instead (since the user is no longer drawing the tension cable 105 out from its pulling end), tension cable 105 may become internally caught, tangled, and / or displaced within the structure of exercise machine 100. Accordingly, the vertical distance between dotted line 302 and peak 303A indicates a potential for development of slack in the tension cable which it is a potential advantage to reduce.

[0255] Another potential adverse “slack” effect occurs if the user actually has maintained control of the end of tension cable 105, even while reducing their input force. For example, the user might have placed their grip (i.e., their hands) so that the extension distance when tension cable 105 again becomes taut (regains tension) corresponds to the position of dotted line 302. Regaining tension would then occur at the time when curve 303 re-crosses dotted line 302. By this time (in this example), a significant reverse velocity has built up, as indicated by the downward slope of curve 303 at this point. In consequence, the user experiences a “jerk” as the momentum of exercise machine 100 again becomes coupled to their grip. Depending on circumstances, this can be unpleasant, and potentially injury-causing; e.g., due to the effects of sudden acceleration on the user's body, and / or due to the being thrown off balance and potentially stumbling / falling.

[0256] The example of curve 306 represents an intermediate case, in which the user's form quickly (but not instantly) slows the cable-extending movements of their hands (e.g., along the dotted line of curve 306A). Here again, the system's own intrinsic dynamics (still represented by curve 303) potentially overshoot force input from the user. Slack distance is still generated (although somewhat less than in the first example), and the user may still experience a sudden acceleration onset (again, potentially somewhat less than in the first example). Since the user's own body also has momentum, the example of curve 306 is potentially more representative than the line of dotted line (i.e., extension distance) 302 of what a user can actually manage to do while still retaining control over the pulling end of tension cable 105 (e.g., while still maintaining a grip on grip accessory 107).

[0257] If, before curve 303 reaches its peak at peak 303A, the user's extension distance remains at or above this level, then the user will not experience a strong discontinuous “jerk”, although they may experience a fluctuation in effective resistance as the momentum of the motor system is overcome.

[0258] It should be noted that the free-running development of slack distance would be reduced if the moment of change indicated by the left side of dotted line 302 occurred at a lower velocity, e.g., at the left side of dotted line 302A. In this case, momentum to be overcome is also lower, so the distance between peak 303A and dotted line 302A would be reduced. Due to the lowered velocity, it could be more feasible for the user to move their hands “below” the level which crosses dotted line 302A (that is, closer to the location of exercise machine 100 from which tension cable 105 exits). This change in the scenario is not expected to greatly affect internal tangling, however, since it is unlikely that this would push tension cable 105 back into exercise machine 100.

[0259] It (the just-described change in scenario) could result in enough time for tension cable 105 to develop a significant return velocity (and thus still transmit a strong and sudden jerk to the user's hands). However, it may also be correspondingly easier for the system to determine that something is wrong with the user's input; e.g., because the change in user inputs would be easier to distinguish as inappropriate, compared to the deceleration which would normally be occurring at the level indicated by dotted line 302. In this case, the situation may be considered as relating to the cable recovery aspect, e.g., as described in relation to FIGS. 6 and 9.

[0260] One special aspect of the first scenarios (those beginning after extension distance exceeds dotted line 302) is that the user would normally begin deceleration around this point anyway, creating a greater potential for ambiguity. If the system intervenes incorrectly, it could create for the user a sense of system instability. Since an intervention might combine aspects of both increasing force (e.g., to counter momentum and developing slack distance) followed by decreasing force (e.g., to prevent “jerk”), deviations from the ideal could variably result in sudden force increases and / or sudden force decreases, potentially confusing the user.

[0261] Stated generally, it appears that risk of an adverse effect due to slack tends to be higher during times when the user is pulling at higher velocities. First, there is potential for a greater length of tension cable run-out due to built-up momentum internal to the system. Second, it is potentially more difficult to distinguish (by sensing and / or algorithmically) a normal deceleration after reaching peak velocity from an abnormal deceleration, and then to select and apply a consistent correction.

[0262] The second point is also illustrated by a further example. One type of slack compensation optionally applied by exercise machine 100, in some examples, is to sense “unusually fast” reductions in user force inputs (e.g., unusual in absolute magnitude and / or unusual in context, e.g., unusual for the velocity and / or distance of extension). User force inputs are optionally measured directly (e.g., using a load cell), or indirectly, e.g., inferred from changes in velocity and / or acceleration.

[0263] In response (i.e., additionally or alternatively to velocity dependent increases in vtotal) motor pull force is optionally increased to reduce slack distance buildup. For example, dotted curve 307 (FIG. 3B) optionally represents an example in which reduction of user force is sensed effectively “instantly” at the extension distance of dotted line 302, and motor force rapidly increased accordingly. Assuming curve 306A (which continues as curve 306) is near an assumed limit of suddenly decelerating user movements (at least, if the user does not just drop the cable entirely), there would then be a relatively small difference in velocities when dotted curve 307 intersects curve 306A. However, the user would still thereafter experience a suddenly increased resistance force, unless exercise machine 100 then rapidly shifted back to its original setting force.

[0264] Accordingly, this mode of slack compensation is potentially sensitive to sensing rates and to system response rates. Lags and / or errors in sensing and / or responses could potentially disturb the user experience, e.g., by creating unexpected variability, “hitches”, and / or oscillations in resistance force. This problem is particularly significant when the sensing problem includes distinguishing “normal” deceleration rates from “uncontrolled” deceleration rates. For example, depending on conditions and / or measurement types used, there is potentially an early portion of slack distance development which is practically indistinguishable from something that might occur normally.

[0265] In some examples of the present disclosure, rather than waiting for sensing to determine that the user force input is decreasing, a selected variable level of slack mitigating force is added to the setting force. The descriptions in relation to FIG. 2 above provide examples of this slack compensation approach. In particular, the force is adjusted so that it is stronger during periods when tension cable velocity (and, accordingly, certain risks of slack development) is higher.

[0266] Additionally, in some examples, the added slack mitigating force tapers off as the setting force Fsetting approaches levels that inherently tend to prevent the development of unacceptably large slack distances. In the context of FIG. 2, decreasing a as a function of Fsetting would produce such tapering-off, as would increasing vthreshold as a function of Fsetting.

[0267] To assume reduced maximum slack distance with increasing Fsetting reflects reasonable assumptions about the speed of user movements which are likely while the user maintains control of the end of the tension cable 105. For example, curve 308 optionally represents free movement of tension cable 105 when exercise machine 100 is operated with a larger resistance force Fsetting than is the case for curve 303, but then this larger resistance force is reduced as a function of falling velocity. As a result, not only is the interval of slack time reduced, the acceleration being applied on the return phase is no greater than it would otherwise be. As a result, e.g., curve 306 intersects curve 308 both sooner and with a reduced difference in velocity compared to the intersection of curve 306 with curve 303.

[0268] A potential advantage of the use of a velocity-dependent adjustment to resistance force arises insofar as users are more disturbed by sudden resistance changes than by slower changes (other parameters being equal). For example, a certain amount slow-developing resistance change during a rep is potentially acceptable to users (possibly even unconsciously) as “normal”. The change in resistance, if noted, may be attributed (at least as far as user experience is concerned) to typical physical factors such as internal friction and / or system inertia.

[0269] Since sudden jerks due to motor resistance forces are one of the adverse effects associated with slack, there is potentially a seeming paradox in the choice to mitigate slack by providing even more resistance to the user's pulling, even given that this resistance is reduced when velocity starts to decrease.

[0270] The problem may be recast, however, as that of maintaining coupling between movements of the user and movements of exercise machine 100. Slack-originated risks of user discomfort and / or injury arise, not from increased force alone, but rather when excessive disparity between user movements and tension cable movements develops.

[0271] By increasing pull resistance under certain circumstances, exercise machine 100 can, in effect, reduce the ability of the user to reversibly decouple their movements from the machine's movements under conditions and for periods of time that build up large divergences in velocity. Here, the word “reversibly” should be especially noted. If, for example, the user simply drops tension cable 105, then they will not experience a jerk, because coupling will not be suddenly restored through their grip. The next adverse condition then is that overly fast retraction of the cable will result in damage when the handle reaches the frame of exercise machine 100. There is, however, more time and distance available to detect this condition; moreover the distance at which it occurs is generally more predictable.

[0272] Reference is now made to FIG. 4A, which schematically graphs adjustments determined by exercise machine controller circuitry to prevent development of excessive slack distance in a cable operated exercise machine, according to some examples of the present disclosure. Reference is also made to FIG. 4B, which is a schematic graph comparing linear and quadratic dependencies of added resistance force on velocity, according to some examples of the present disclosure.

[0273] In FIG. 4A, velocity (which is also proportional to momentum) is shown graphed in arbitrary units along the horizontal axis. System (baseline) resistance settings are graphed along the vertical axis, also in arbitrary units. FIG. 4B is drawn to the same horizontal velocity scale, while the vertical axis shows resistance forces optionally added for different velocities along horizontal line 405 of FIG. 4A, as further explained below.

[0274] In some examples, slack is mitigated by the exercise machine controller with respect to one or both of slack distance risk, and of slack retensioning (“user jerk”) risk.

[0275] In some examples, risk of slack distance (e.g., development of slack in the tension cable potentially sufficient to cause mechanical difficulties with the exercise machine 100) is mitigated by adding additional resistance motor force under some circumstances. This is the force referred to already as Fdeslack.

[0276] In FIG. 44, slack maximum threshold 401 shows a threshold curve, drawn as a function of both velocity v and system resistance setting Fsetting. Above threshold 401, the “free run” potential for developing slack distance is considered acceptable. The “free run” slack distance is, for example, the distance of further unwinding of tension cable 105 from spool 121 and / or motor 125 which could result if the user simply dropped the tension cable while it moves at a certain velocity, and with a certain resistance force setting being used. As will further explained, this value (also referred to herein as Dslack_max) is optionally used to help set parameters according to which Fdeslack is adjusted.

[0277] Also indicated in FIG. 4A is an optional “LOW-RISK VELOCITIES” zone 410, in which velocity is low enough that friction and / or sensing is sufficient to avoid developing unacceptable slack. Optional zone 411 (“IMPRACTICAL VELOCITIES”) shows tension cable velocities which are unlikely to be reached by users. Optional zone 412 (“SUBTHRESHOLD RESISTANCE LEVELS”) shows system resistance settings below the intended operating threshold of the system. Selection of Fdeslack optionally accounts for one or more of these zones.

[0278] Slack maximum threshold 401 corresponding to Dslack_max is also labeled s in FIG. 44. Additional curves below it are labeled, e.g., 1.5 s, 2 s, etc. to indicate curves associated with proportionally higher slack runout distances for higher velocities and / or lower resistance forces.

[0279] In some examples, for operating areas of the graph below and / or to the right of the curve of slack maximum threshold 401, exercise machine 100 adds enough force (e.g., Fdeslack as represented by arrow 402) to reduce the slack runout to about the value of s; optionally to a smaller value. It is noted that the magnitude of the adjustment needed decreases moving to the left and to slower velocities, e.g., to arrow 403 and then arrow 404. Thus, from in most and potentially all initial states shown, the tendency, when freely decelerating after loss of user control will be to quickly move into to a regime where the risk of slack distance is acceptable, and optionally allow proceeding without continued addition of decelerating force that could lead to unintentionally increased jerk once the user's grip is re-coupled to movements of the tension cable.

[0280] More generally, a criterion is optionally selected such that that some defined “free run” distance of the tension cable (Dslack) is kept within acceptable limits (Dslack_max, for reasonable assumptions about operating conditions. In some examples, Dslack is the amount of further motor runout distance expected if the user simply “drops” the tension cable, and there is no other adjustment before the baseline resistance setting of the motor overcomes inertia. Optionally, another definition is used, e.g., a definition taking into account capabilities of exercise machine 100 to dynamically sense and correct for losses in user input force, and / or limitations of those capabilities.

[0281] In some examples, the free run distance is calculated, e.g., as proportional to the inherent inertia of the motor / cable system Isystem (e.g., linear and / or rotational inertia), inversely proportional to the setting force Fsetting, and proportional to the square of the tension cable velocity v. Here, velocity appears as a squared term (the double integral of distance) because the runout distance occurs when the initial (“time of dropping”) velocity is decelerated to zero. Accordingly, in some examples.D slack ∝v2·I systemF setting.

[0282] To use a certain Dslack_max as a system performance limit, the system optionally adds additional “deslacking” force Fdeslack, as a function of increasing v to ensure that Dslack≤Dslack_max. For example:F deslack =k⁢v2·I systemDslack⁢_⁢max-F setting

[0283] Optionally, k is the double integration constant ½. It should be understood that adjustments and / or approximations involving k and / or the use of other constants and / or terms are optionally provided, e.g., to account for dynamic adjustments made by exercise machine 100 in response to sensed changes in user force input, and / or to account for friction and / or other mechanical characteristics of exercise machine 100 itself.

[0284] For example, 1 cm of slack may be allowable as the value of Dslack_max, while a larger slack distance could result in enough slack for tension cable 105 to slip over the lip of a spool and / or pulley, and / or buckle so that it contacts another mechanism inadvertently. In some examples, the threshold of allowed slack distance is at least 1 cm. In some examples, the threshold of allowed slack distance Dslack_max is, e.g., a value between 0.5 cm and 10 cm; for example, 1, 2, 3, 4, 5, 6 8 or 10 cm.

[0285] With reference now to FIG. 4B: the points 407 along curve 405A of FIG. 4B represent points at which corresponding line 405 of FIG. 4A crosses the various iso-distance lines indicating added resistances optionally corresponding to Fdeslack. The difference in vertical units between FIGS. 4A and 4B should be noted. FIG. 4A represents slack distance as contours s through 4 s, while the vertical axis of FIG. 4 offsets these distances by the negative value of s in order to represent added resistance force Fdeslack.

[0286] It should be understood that the illustrated dependency on the squared value of v is optional. Optionally, in some examples, a linear dependency of on v is used, as shown by curve 410 of FIG. 4B (and also as shown in FIG. 2). While this potentially results in variation in the “actual” value of Dslack_max, e.g., as a function of velocity, the drawbacks of this (e.g., in terms of effects on user experience) are optionally negligible.

[0287] Use of a linear approximation is reasonable particularly for relatively low values of Fsetting and / or v. Very high velocities are unlikely to be exerted by users, so that at sufficiently high values of Fsetting, it is unlikely that Dslack_max will be exceeded. If users do manage and / or attempt unusually high velocity values, it is in any case potentially acceptable to react more vigorously to prevent slack without excessive regard for “user experience” (e.g., this may be considered outside of designed use parameters). Examples of reasonable values of Fsetting include those values within the rated power capacity of motor 125, e.g., given its particular mechanical advantage within exercise machine 100. As experienced by the user, Fsetting is optionally, e.g., within a range of about 2.2 pounds up to about 440 pounds (e.g., the force equivalent of about 1-200 kg).

[0288] Values of v for which user experience (e.g., smoothness of operation) is prioritized optionally include values from 0 m / sec up to about 2 m / sec; optionally another upper bound is used; e.g., up to pull velocities of around 5 m / sec, 6 m / sec, 8 m / sec, or 10 m / sec.

[0289] In accordance with the above descriptions, it may be understood that there are optionally tension cable velocities (e.g., those of zone 410) below which no additional slack-prevention force is used, because momentum of the system is considered to remain practically within acceptable limits for developing slack. For example, there may be plenty of time to react based on detection of reduced user input force, there may be enough internal friction to counteract the low velocity naturally, and / or exercise machine 100 is not operated with resistance forces so low that unacceptable slack can develop at such velocities.

[0290] Also in accordance with the above descriptions, there are optionally resistance force settings above which no additional slack-prevention force is used. For example, velocities of tension cable 105 high enough to develop unallowable slack (e.g., those corresponding to zone 411) may be considered impractical—e.g., involving unrealistic levels of user strength and / or system component acceleration.

[0291] The above descriptions with respect to mitigating slack distance risk can also be used to understand slack compensation to reduce slack retensioning risk; that is, risk of slack in case the user keeps a grip on the handle while also introducing tension cable slack. As already discussed, unwanted effects of slack retensioning (jerking against the user's grip) arise when there is a period of decoupling that leads to acceleration of the tension cable without corresponding acceleration of the handle (and the user's grip on it).

[0292] Ordinarily, the force magnitude of this risk is roughly independent of the system resistance setting. While the higher the system resistance setting Fsetting, the harder the tension cable accelerates, this also results in a proportionally shorter decoupling period, so that the end-of-decoupling jerk velocity (and corresponding portion of the initial acceleration felt by the user) remains about the same. However, since the resistance force added by Fdeslack is decreased as a function of velocity, there is gained a benefit of a shortened runout, but then “normal” deceleration on the other side of the inflection point.

[0293] Furthermore, other things being equal, decoupling time tends to increase with increasing velocity. This means that there is more time for acceleration. Correspondingly larger re-coupling forces (stronger jerks) are possible if a certain slack distance is created. However, the user will also be moving more quickly, and will need to decelerate the mass of their own limbs correspondingly. This potentially makes it harder to generate slack distance in the first place. Accordingly, preventing excessive slack distance is also a reasonable proxy for mitigating slack retensioning risk, even though the focus of concern is different in the two cases. In effect, adding resistance force in the form of a positive-valued Fdeslack speeds up exercise machine 100, with the result that the inherently slack-limiting effects of the user's own mass inertia become correspondingly more prominent.

[0294] Furthermore, a period of constant rapid deceleration (after decreasing Fdeslack is accounted for) that includes or even heads imminently toward a complete reversal of direction is distinctive. While it is not impossible that a user could imitate such “machine-like” dynamics, doing so rapidly would potentially involve use of unusual form, optionally treated as outside the intended operating parameters of exercise machine 100. Accordingly, when such a trend is noticed, exercise machine 100 optionally initiates more aggressive measures to ensure first that runout is limited (by ramping Fdeslack to a higher values, and second, by reducing force at the plateau of runout, ensuring that the user is not then subjected to a strong jerk due to a high return acceleration.

[0295] It should be understood that while Fsetting is represented in these examples as a constant value, this is not a required condition. In some examples, Fsetting varies during normal operation as a function of extension distance (e.g., to simulate training with an elastic band), and / or as a function of time (e.g., vibrating and / or jerking). In such cases, values of Fsetting should be understood as varying appropriately, with targeted values of Fdeslack optionally adjusted to match. Optionally such dynamic adjustments to Fdeslack itself in response to changing Fsetting during a rep are filtered (e.g., slowed to a moving average of Fsetting and / or suppressed. It should be understood that other force adjustments made for purposes besides those associated with Fdeslack are optionally provided together with Fsetting and Fdeslack; i.e., the use of the term Ftotal in relation to their sum does not exclude their combination with other contributing forces.

[0296] It should be noted that the discussion of slack compensation in relation to FIGS. 2-4B focuses in particular on slack which begins developing during extension of the tension cable. It is possible, however, that the user's grip could be lost during an ongoing return phase of tension cable 105, and / or possible that the user could stumble forward or otherwise advance their grip quickly toward exercise machine 100 to create sudden slack. Optionally, this situation is treated just as it is for the extension phase, e.g., with an increase in Fdeslack as function of increasing return velocity.

[0297] However, while this would tend to minimize decoupling times, it potentially interferes with control to ensure that tension cable 105 is retrieved with minimal risk of damage to exercise machine 100 (e.g., as described in relation to FIG. 6). Furthermore, since it lacks the direction reversal, the risks for jerk in this case are smaller—rather than opposing the motion of the user, the tension cable in this case would simply be hurrying to catch up—but catching up is exactly the point of risk. There is, as a result, a concerning potential that an off balance user (e.g., one stumbling forward) would be accelerated faster into the direction of an accident. Accordingly, the use of Fdeslack, in some examples, is confined to use with positive velocities in the direction of extension of tension cable 105. Other aspects of the topic of returning-phase recovery of the tension cable are discussed, e.g., in relation to FIGS. 6 and 9.

[0298] Reference is now made to FIG. 5, which schematically illustrates use by exercise equipment controller circuitry of hysteresis in the determination of a slack compensation force, according to some examples of the present disclosure. As in FIG. 2, velocity / momentum is shown along the horizontal axis, while commanded resistance force is shown along the vertical axis. Again, arbitrary units are used.

[0299] In some examples, adjustments to Fsetting are applied with hysteresis—e.g., once Fdeslack is increased to some value at a first velocity, it is only again reduced below that value at a second velocity, the second velocity being slower than the first velocity.

[0300] In the example shown, graph line 510A represents the situation where Ftotal=Fsetting until reaching vthreshold (at inflection point 502). While velocity still rises beyond this point, it does so according to line graph line 510B, such that Ftotal=Fsetting+Fdeslack rising. If velocity begins to drop (e.g., near the mid-point of a pulling phase of a rep), the maximum reached value of Fdeslack rising at first remains in effect, e.g., as though moving horizontally along arrow 503 rather than back down along graph line 510B. At the point where arrow 503 crosses graph line 510C, it matches Fdeslack falling, and now slack compensation force is changed according to the values of graph line 510C.

[0301] It is not required that arrow 503 be horizontal, e.g., hysteresis movement is optionally in a partially upward direction, such as that of arrow 504.

[0302] Now that the hysteresis barrier has been passed (e.g., as velocity has generally slowed sufficiently), the situation reverses. For example, movement back toward the right would be along the reversed direction of arrow 503 until again encountering graph line 510B. As a result, the slack compensation force does not again rise beyond successively lower values unless by happenstance the velocity rises again enough to overcome the hysteresis threshold.

[0303] It is emphasized that this all occurs while velocity overall is maintained in a same direction.

[0304] In the example shown, hysteresis applies to the slopes of graph lines 510C, 510B, while vthreshold remains the same. However, hysteresis optionally also applies to vthreshold, e.g., moving it to a lower value while traveling along the reducing-velocity leg of graph lines 510C.

[0305] In either case, the first and second values are optionally distinguished by a great enough difference that measurement noise and / or servo feedback lag does not produce inadvertent oscillations. For example, the hysteresis difference is optionally defined so that the user experiences periods of opposite (but in themselves monotonic) change in Fdeslack on either side of a single inflection point somewhat past the peak velocity of the tension cable during a normal pull.

[0306] Use of control hysteresis provides a potential advantage by allowing determination of Fdeslack to be partially adjusted according to ongoing accelerations and / or higher-order measurements of system dynamics, without necessarily following every variation, which could lead to the introduction of oscillations and / or sudden changes.

[0307] The lowering of 510B relative to 510C optionally represents a partial allowance for the presence of acceleration. While the user is maintaining acceleration, they are also dynamically “further” from most situations which could allow them to introduce slack while maintaining control of tension cable 105.

[0308] For the main exception—the user simply losing their grip—the potential trade-off is a brief period of declining velocity in which the slack runout allowed is larger than it would otherwise be. Optionally, this is partially adjusted for by adjusting the “angle” at which graph line 510C is approached to a more upward direction when the loss of acceleration appears rapidly. This allows shifting more extreme changes in slack compensation forces to situations when the user themselves is generating larger accelerations- or else may have lost control of the grip accessory 107.

[0309] In some examples, hysteresis is applied on the basis of acceleration, rather than (or in addition to) velocity. For example, arrow 505 represents a gradual transition from graph line 510B to graph line 510C during much of which velocity is still rising. The transition is triggered once acceleration (rather than velocity) passes a peak, even though velocity continues to increase.

[0310] Optionally, the transition “angle” used depends more closely on details of how acceleration is decreasing. For example, a rapid decrease may induce a fast shift to higher-resistance graph line 510C, e.g., optionally even before velocity has finished increasing, as indicated by arrow 505. A sufficiently gradual (and optionally more “normal” for the form of the exercise) decrease in velocity optionally initiates transition only after v has started to reduce, e.g., along arrow 504 or along arrow 501. It is noted that the relatively sudden increase in force represented by arrow 505 will be in part absorbed by the built-up momentum of tension cable 105, motor 125 and / or spool 121 (indeed, removing that momentum is in large point the reason for the build-up in the first place). Accordingly, effects of this rise are potentially felt as if it maintains Fsetting, rather than letting it grow light during the decelerating phase of the pull. It is noted again that the increase is transient since a general decline towards Fdeslack=0 remains in effect.

[0311] Furthermore, user experienced differences among the various possibilities are potentially masked at least in part by the user's own activity; e.g., when the user slows quickly, tension cable 105 may seem to slow “even more quickly”, but this is optionally in proportion to what the user is trying to do.

[0312] The transition is maintained as constant and non-reversing by having it follow a declining trend in acceleration (optionally also limited so that it cannot occur too quickly), but never going back along the arrow when acceleration appears to briefly increase. Optionally, the point when acceleration reaches 0 completes the transition, but the transition need not be targeted to that specifically. The transition is optionally eased by curving, e.g., arrow 505 in any suitable manner to make it more difficult for the user to detect the onset of a relatively more sudden change in Fdeslack.

[0313] What these various hysteresis options hold in common is the ability to shift in a gradual and unidirectionally controlled manner among different regimes for exerting slack compensation, without relying strictly on moment-to-moment sensing and / or tight feedback control loops. Thus, these options are potentially relatively immune to noise in sensing and / or imperfect control quality. However, general information about “what is going on” during a rep is available, e.g., a transition from a phase of acceleration toward a phase of deceleration. This allows optionally reducing interference with the basic operation of exercise machine 100 (e.g., keeps Ftotal nearer to the value of Fsetting), while still retaining preventative capabilities to prevent development of excessive slack distance.

[0314] Some disclosed embodiments involve recovery from sudden tension cable release. Reference is now made to FIG. 6, which schematically represents control of cable return velocity by exercise equipment controller circuitry in response to loss of user control, according to some examples of the present disclosure. Reference is also made to FIG. 9, which is a schematic flowchart of a method of operating a controller 129 of an exercise machine 100 to prevent overly dynamic homing of a tension cable 105, according to some examples of the present disclosure.

[0315] Graph line 601 represents cable velocity v (vertical axis) as a function of cable extension distance d (horizontal axis). Again, arbitrary units are used. This is a graph of the return of tension cable 105 to a home position, so in time the upper-right end of 601 is earlier, and the lower-left end is later.

[0316] At block 910, in some examples (FIG. 9), controller 129 accesses data characterizing a current decrease in extension distance of tension cable 105. In some examples, the data are provided by a motion encoder on one or both of spool 121 and motor 125. In some examples, another sensor type is used, e.g., current sensing of electrical current provided to motor 125, and / or one of sensors 145A-145C; e.g., sensing of tension forces applied to tension cable 105 and / or sensing of the movement of tension cable 105.

[0317] At block 912, in some examples (FIG. 9), controller 129 determines that the decrease in extension distance indicated by the data of block 910 satisfies a fast tension cable return criterion.

[0318] For example, section 603 of graph line 601 begins with a constant initial velocity in the return direction, then suddenly begins to accelerate out of user control, e.g., as could happen if the user suddenly loses their grip on grip accessory 107. At inflection point 602, the system “notices” this situation (based on the data characterizing the current decrease in extension distance), and responds by beginning deceleration throughout section 605 to a recovery velocity 604 (or optionally another, e.g., lower velocity, depending on condition specifics).

[0319] “Notice” of the situation optionally comprises a determination that a current decrease in extension distance of the cable corresponds to fast tension cable return criterion. In some examples, the fast tension cable return criterion comprises a profile of changing distance over time consistent with unopposed acceleration in response to the currently commanded motor force, e.g., a constantly accelerating reduction in distance.

[0320] In some examples, the fast tension cable return criterion is met when exercise machine 100 determines that acceleration is outside of a set of reference examples, e.g., examples of normal user interactions and / or known edge cases. Additionally or alternatively, in some examples, the fast tension cable return criterion comprises detection of a return velocity above some safe and / or reasonable threshold.

[0321] In some examples, the system determines that for a current return velocity, a certain threshold distance 611 is at risk of being passed at a velocity above a certain safe velocity threshold 615 unless the system intervenes to reduce the return velocity.

[0322] More generally, one or both of two distinct types of motion / distance profiles optionally trigger a safe-retrieval procedure: profiles in which the current retrieval speed of tension cable 105 is excessive (e.g., poses a risk) no matter what its current position, and profiles in which the current retrieval speed of tension cable 105 is excessive because of how close it currently is to being brought to an excessively sudden stop at its home position.

[0323] At block 914, in some examples (FIG. 9), controller 129 signals to the resistance motor 125 to reduce velocity of tension cable extension decrease.

[0324] In some examples, recovery velocity 604 is set to be at or below a safe velocity threshold 615. In some examples, recovery velocity 604 and / or safe velocity threshold 615 is selected to be low enough to avoid dangerously dragging and / or swinging it into a body part, and / or swinging it dangerously while uncontrolled into other parts of exercise machine 100. It is noted that as tension cable 105 shortens, there is a potential for its angular momentum to be converted into sharper swings. Optionally, exercise machine 100 adjusts recovery velocity 604 according to its current configuration and / or position of tension cable 105, e.g., to avoid creating rapid swings by an overly-fast withdrawal when tension cable 105 is hanging in the air (e.g., especially if being drawn toward head-height), but with a faster velocity optionally allowed, e.g., so long as grip accessory 107 remains in contact with the ground.

[0325] In some examples, recovery velocity 604 is dynamically adjusted to damp and / or avoid amplifying swinging of tension cable 105 and / or the grip accessory 107 attached to it. For example, tension in tension cable 105 is sensed as a function of time to determine its swing, and recovery velocity is adjusted, e.g., to reduce tension at the high points of the swings. In cases where forces consistent with excessive swing are detected, recovery velocity 604 is optionally decreased more than in other cases. Optionally, recovery is halted and / or reversed at appropriate moments during the swing (e.g., near tension peaks) to damp pendulum motions of tension cable 105.

[0326] The speed at which the decline to recovery velocity 604 happens is optionally adjusted based on how much distance is left for the return of tension cable 105. It is a potential advantage to reach the recovery velocity quickly (e.g., so that risk of further accident and / or injury is reduced), while not decelerating so abruptly that built-up momentum of tension cable 105 carries it beyond what spool 121 and / or motor 125 are actively taking up. Avoiding excess wear on braking mechanisms is also optionally taken into account in selecting an appropriate deceleration.

[0327] However, if the remaining return distance is too close to one or more threshold distances 611, one or more of these concerns is optionally discounted and / or ignored in order to ensure that tension cable 105 is safely slowed, e.g., before it can collide with exercise machine 100, and / or to avoid accelerating it into a dangerous swing. For example, emergency braking is optionally deployed in such a case. In the example shown, threshold distance 611 is deemed too close to inflection point 602 considering the current velocity, and so through the period of segment 613 a motor brake is briefly applied. The rest of the distance to recovery velocity 604 occurs with decreased deceleration. Optionally (e.g., in cases where velocity is particularly high and / or there is a lack of certainty of stopping in time), braking is applied sufficiently to bring velocity substantially to a halt.

[0328] In some examples, emergency stopping is accompanied by ceasing operation of motor 125 altogether. Optionally motor 125 is provided with a breaker fuse or other failsafe device which can only operate to halt motor operation.

[0329] Graphical break 607 represents an arbitrary distance of recovery performed at recovery velocity 604.

[0330] At region 609, in some examples, a final recovery phase begins. This is optionally triggered at the same distance used as threshold distance 611, or at another distance, e.g., a distance of 2 cm, 5 cm, 10 cm, or another distance. In some examples, final recovery phase comprises deceleration to a velocity low enough to allow accessory connector 107B to reach its home position at a non-damaging contact speed. Optionally, accessory connector 107B is brought snugly into its home position. Optionally, retrieval force is discontinued within a short distance of the travel limits of accessory connector 107B, so that accessory connector 107B may remain slightly loose and is not necessarily brought into full contact with a stop limiting it from being pulled into the frame 110 of exercise machine 100. Optionally, timed braking is used as accessory connector 107B reaches its home position, so that it is brought to a halt at an appropriate home position. In some examples, the returning-motion homing control procedure described in relation to FIGS. 7A-7D is used.

[0331] Optionally, a user can interrupt a recovery operation which has sufficiently slowed by regaining control of grip accessory 107 and / or tension cable 105 and again exerting force on it. With sufficient force exerted on it, and optionally with associated extension showing that the force is not just do being caught on something, exercise machine 100 optionally enters a controlled recovery phase in which allowed speeds increase nearer to speeds consistent with the normal return phase of a rep. Optionally, full recovery to home position is aborted if it is determined that there is sufficient restraining force on grip accessory 107, e.g., for safety, and / or to allow users to resume exercising.

[0332] In some examples, e.g., after a recovery mode retrieval in which a particularly rapid velocity, acceleration and / or deceleration has occurred, exercise machine 100 engages in and / or requires one or more self-check and / or “re-seating” operations to ensure that tension cable 105 has not moved out of place; e.g., become caught and / or tangled. Such operations optionally comprise one or more slow extensions and recoveries during which exercise machine 100 verifies that operation is normal, e.g., according to responses of motor 125, sensing of forces on tension cable 105, and / or according to user confirmation.

[0333] Some disclosed embodiments involve home position damping of a tension cable. Reference is now made to FIG. 7A, which schematically illustrates damping control of resistance force with hysteresis in a homing zone near a home position of tension cable 105, according to some examples of the present disclosure. Reference is also made to FIG. 7B, which is a schematic flowchart of a method of damping control of resistance force in a homing zone near a home position of tension cable 105, according to some examples of the present disclosure. Further reference is made to FIGS. 7C-7D, which represent other parameter options for use with control of resistance force in a homing zone near a home position of tension cable 105, according to some examples of the present disclosure.

[0334] Graph line 712 of FIG. 7A represents an example relationship of commanded resistance force (vertical access) as a function of extension distance from a home position 702 of tension cable 105 (horizontal axis). Graph line 712 represents resistance force as tension cable 105 is returned by a user allowing it to return to its home position 702. Point 717 represents the furthest extent of a notional “homing zone”, that is, the position of a homing distance within which there is a concern for making large changes in resistance force, e.g., short-distance and / or short-period ramp-ups by a factor of 2 or more.

[0335] Graph line 701 also represents an example relationship of commanded resistance force as a function of extension distance from a home position 702 of tension cable 105, but in this case, graph line 701 represents resistance force as tension cable 105 is extended from its home position. The overview discusses potential advantages of the difference in function shapes between graph line 701 and graph line 712. Other graph shapes and parameter differences are shown in FIGS. 7C-7D. In the case of graph line 721 (FIG. 7C), the initial holding force at home position 702 is notably elevated from the force exerted there in returning phase graph line 728. Both graph line 721 and graph line 728 begin with relatively fast (and then slowing transitions in force levels, but in opposite directions. In FIG. 7D, graph line 731 rises very quickly, but to a somewhat lower level than return-phase graph line 732. Graph line 732 falls quickly, e.g., optionally representing a braking action to ensure that the tension cable's user end does not collide violently with frame 110 at home position home position 702.

[0336] At block 720, in some examples (FIG. 7B), controller 129 accesses data indicative of a current position of tension cable 105, the current position comprising a user end of tension cable 105 (e.g., comprising accessory connector 107B) within a homing zone adjacent to a home position of tension cable 105. In some examples, the homing zone (e.g., limited by the position of homing distance 717) comprises a region extending about 5 cm away from the home position, about 10 cm away from the home position, about 25 cm away, or another distance away from the home position.

[0337] In some examples, the data indicative of the current velocity are provided by a motion encoder on one or both of spool 121 and motor 125. In some examples, another sensor type is used, e.g., current sensing of electrical current provided to motor 125, and / or one of sensors 145A-145C.

[0338] At block 722, in some examples, controller 129 adjusts signals sent to motor 125 to ease (“damp”) a transition in resistance forces between a lower resistance nearer to the home position, and a higher resistance further from the home position.

[0339] It should be noted that any of these resistance force adjusting methods are optionally provided along with control-limiting of motor velocity to a lower velocity than is allowed outside of the homing zone. Control-limiting of motor velocity may cause resistance force to reduce with a different time course, e.g., when the approach velocity of the tension cable exceeds the control limit applied to motor velocity in the homing zone.

[0340] Some disclosed embodiments involve variable parameter home position damping. Reference is now made to FIG. 7E, which is a schematic graph illustrating variable parameter home position damping, according to some examples of the present disclosure.

[0341] The graph is divided vertically into three panels 760, 761, 762, which respectively represent different parameter pairs for two different tension cable return events.

[0342] For each panel, the horizontal axis represents extension distance D in arbitrary units. In the scenario illustrated, extension distance D is decreasing as a function of elapsed time t, which is also the vertical axis of bottom panel 762 (in arbitrary units). In the bottom panel, trace 741B represents a “slow” return event, and trace 742B represents a “fast” return event.

[0343] The vertical axis of top panel 760 is velocity v in arbitrary units, with trace 741 representing the same “slow” return event as trace 741B, and trace 742 likewise corresponding to the fast return event of trace 742B.

[0344] The vertical axis of middle panel 761 is commanded resistance force F in arbitrary units. Here, traces 741A and 742A respectively correspond to traces 741B and 742B. It should be noted that in all examples shown, resistance force transitions through a plurality of levels; i.e., the transition is damped continuously and / or step-wise, not simply “on” or “off”. Optionally, the transition proceeds substantially continuously throughout the periods shown. In this context, “continuously” includes transitioning through a rapidly succeeding sequence of partial steps, noting, e.g., that motor commands are optionally issued discretely at some frequency.

[0345] Vertical dotted line 745 represents the distance Dhoming-zone, left of which the system enters its “homing zone routine”. To the right of this position, tension cable returning movements are substantially under the control of the user, according to how they choose to resist Fsetting, represented as constant and equal or nearly equal for each of traces 741A, 742A. For the sake of illustration, distances and times are relatively compressed on the right side of Dhoming-zone; e.g., they could represent a total distance of 30-150 cm.

[0346] The left side of Dhoming-zone represents parameter changes occurring within the homing zone; e.g., within 5-25 cm of the home position itself, represented at extension distance 0.

[0347] In the illustrated pair of examples, the user who is moving the user end of tension cable 105 along trace 741 (panel 760) has begun deceleration of the tension cable well outside of the homing zone, such that upon entering the homing zone, the user end of the tension cable 105 is below a nominal default maximum (control-limited) velocity 746 (vmax-default). The position of vmax-default represents the largest velocity to which the system will “allow itself” to accelerate the tension cable while within the homing zone.

[0348] In the example of trace 741, the crossing of Dhoming-zone is at a lower velocity (also referred to herein as vcrossing) than vmax-default, so that control-limitation of velocity does not come into effect.

[0349] Velocity declines from there (at about the same slope) until it reaches vhoming. Final homing velocity 747 represents a velocity of the user end as it reaches its home position (and then is stopped by arm 112 or another portion of frame 110). This velocity is not necessarily controlled fully by the system directly, e.g., it is a result of interplay between the resistance force and the user force (e.g., resistance force weakens as the user also “lets” the tension cable return home, the user in this case also potentially lessening their force during the same period). Actual velocity may be higher or lower, and the value may vary according to the finishing movements of the user. However, if the user ceases to act against the declining resistance force at all, then there is still a control limit set by vmax-default, above which vhoming will not rise.

[0350] In the example shown, the declining velocity of trace 741 is initiated by a corresponding decline in the commanded resistance force F, e.g., over the period tdefault, up until reaching inflection point 743. The depicted constant deceleration as a linear function of decreasing commanded resistance force is an example, and should be understood as non-limiting; again, the actual relationship depends, e.g., on user behavior and / or physical characteristics of the moving components involved.

[0351] Residual movements after the period of tdefault (panel 762) are optionally generated by supplying enough resistance force to keep the user end of tension cable 105 moving if it is not being subjected to any substantial user force.

[0352] In the case of trace 742 (panel 760), velocity upon entering the homing zone is significantly higher than vmax-default, and a different optional control scheme is used. With velocity being control-limited, there is potentially no “commanded” resistance force exerted against the user though the motor's torque. Torque may be exerted as a negative braking force, until velocity falls to the level of vmax_default.

[0353] The user may still feel force as their inputs act to decelerate the movement of components such as the tension cable, motor, and spool.

[0354] From the point where the control-limited velocity is reached, e.g., as shown in panel 761, corresponding force vs. distance trace 742A now reaches the value of Fhoming at a certain position (e.g., the homing position itself, in the example shown), rather than after a certain amount of time. Because of the initially faster velocity, overall, the time over which force reduction occurs is shorter, as illustrated by time 752 (trapid), associated with trace 742B of panel 762.

[0355] As for the other example, the actual low velocity vhoming is not necessarily under the full direct control of the system, but rather is illustrated assuming that the user is exerting normal effort to reduce the velocity by applying user force. The examples shown here both remain within the range of velocities that the system treats as “normal”. Again, however, the system control-limits velocity so that it will not again exceed vmax-default, even if the user ceases to act against the motor's resistance force. In some examples, additional limiting is applied comprising operation of a brake, which tends to bring motion of tension cable 105 to a stop, and resists an increase in velocity in either direction.

[0356] Optionally, vmax-default itself changes as a function of time and / or distance. This may occur as an outcome of limits on changing states of electrical components of the system (e.g., delays as stored voltage capacitances and / or inductive currents collapse), and / or deliberately commanded.

[0357] As used herein with reference to quantity or value, the term “about” means “within ±10% of”.

[0358] The terms “comprises”, “comprising”, “includes”, “including”, “having” and their conjugates mean: “including but not limited to”.

[0359] The term “consisting of” means: “including and limited to”.

[0360] The term “consisting essentially of” means that the composition, method or structure may include additional ingredients, steps and / or parts, but only if the additional ingredients, steps and / or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure.

[0361] As used herein, the singular form “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a compound” or “at least one compound” may include a plurality of compounds, including mixtures thereof.

[0362] The words “example” and “exemplary” are used herein to mean “serving as an example, instance or illustration”. Any embodiment described as an “example” or “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments and / or to exclude the incorporation of features from other embodiments.

[0363] The word “optionally” is used herein to mean “is provided in some embodiments and not provided in other embodiments”. Any particular embodiment of the present disclosure may include a plurality of “optional” features except insofar as such features conflict.

[0364] Throughout this application, embodiments may be presented with reference to a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of descriptions of the present disclosure. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as “from 1 to 6” should be considered to have specifically disclosed subranges such as “from 1 to 3”, “from 1 to 4”, “from 1 to 5”, “from 2 to 4”, “from 2 to 6”, “from 3 to 6”, etc.; as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0365] Whenever a numerical range is indicated herein (for example “10-15”, “10 to 15”, or any pair of numbers linked by these another such range indication), it is meant to include any number (fractional or integral) within the indicated range limits, including the range limits, unless the context clearly dictates otherwise. The phrases “range / ranging / ranges between” a first indicate number and a second indicate number and “range / ranging / ranges from” a first indicate number “to”, “up to”, “until” or “through” (or another such range-indicating term) a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numbers therebetween.

[0366] Although descriptions of the present disclosure are provided in conjunction with specific embodiments, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.

[0367] It is appreciated that certain features which are, for clarity, described in the present disclosure in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the present disclosure. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments unless the embodiment is inoperative without those elements.

[0368] It is the intent of the applicant(s) that all publications, patents and patent applications referred to in this specification are to be incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application were specifically and individually noted when referenced that it is to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present disclosure. To the extent that section headings are used, they should not be construed as necessarily limiting. In addition, any priority document(s) of this application is / are hereby incorporated herein by reference in its / their entirety.

[0369] Various example embodiments for exercise machine technologies are articulated below in the form of clauses. It is to be understood the term “technology” refers equally to systems (e.g., exercise machines, computing devices (e.g., processors, non-transitory computer readable media), resistance motors, and methods for operating these systems.

[0370] Clause 1. A cable-operated exercise machine providing slack-compensating control of resistance force applied to a tension cable, the exercise machine comprising: the tension cable, configured to receive user force applied by pulling on a user end of the tension cable; a resistance motor applying the resistance force to a motor-coupled end of the tension cable, in opposition to the user force; and a controller comprising processing circuitry configured to: access data indicative of a momentum of components of the exercise machine, wherein the momentum of the components is coupled to movement of the motor-coupled end of the tension cable; determine an adjustment to the resistance force, wherein a size of the adjustment is determined, in accordance with the indicated momentum, to compensate against slack distance developing along the tension cable consequent to a potential rapid reduction in the user force; and signal the adjustment in resistance force to the resistance motor.

[0371] Clause 2: The technology of clause 1, wherein the components having momentum coupled to movement of the motor-coupled end of the tension cable include at least rotating elements of the motor.

[0372] Clause 3: The technology of each preceding clause alone or in combination, wherein the components having momentum coupled to movement of the motor-coupled end of the tension cable include a spool on which the tension cable is wound.

[0373] Clause 4: The technology of each preceding clause alone or in combination, wherein the size of the determined adjustment to the resistance force varies in magnitude as a function of a setting force, the setting force comprising a user-selected and predetermined level of exercise force which the controller signals to the resistance motor along with the adjustment. Clause: The technology of each preceding clause alone or in combination, wherein the size of the determined adjustment to the resistance force increases in magnitude as the setting force decreases.

[0374] Clause 6: The technology of each preceding clause alone or in combination, wherein the determined adjustment to the resistance force is signaled for exercises performed with the setting force below a threshold, and not applied for exercises performed with the setting force above the threshold.

[0375] Clause 7: The technology of each preceding clause alone or in combination, wherein the determined adjustment to the resistance force increases with increasing momentum of the components of the exercise machine coupled to movement of the motor-coupled end of the tension cable.

[0376] Clause 8: The technology of each preceding clause alone or in combination, wherein the determined adjustment is signaled during extension phases of tension cable movement, and not applied during return phases of tension cable movement.

[0377] Clause 9: The technology of each preceding clause alone or in combination, wherein the determined adjustment changes as a linear function of increasing velocity.

[0378] Clause 10: The technology of each preceding clause alone or in combination, wherein the determined adjustment changes as a non-linear function of increasing velocity.

[0379] Clause 11: The technology of each preceding clause alone or in combination, wherein the controller: determines an ongoing accelerating or decelerating phase of tension cable extension; and determines the adjustment according to the ongoing accelerating or decelerating phase of tension cable extension.

[0380] Clause 12: The technology of each preceding clause alone or in combination, wherein the adjustment increases the resistance force during a decelerating phase of tension cable extension.

[0381] Clause 13: The technology of each preceding clause alone or in combination, wherein the resistance motor comprises a rotary electric motor.

[0382] Clause 14: The technology of each preceding clause alone or in combination, wherein the resistance motor comprises one or more electric motors.

[0383] Clause 15: The technology of each preceding clause alone or in combination, comprising one or more sensors coupled to provide the controller with the data indicative of the momentum of the components of the exercise machine coupled to movement of the motor-coupled end of the tension cable.

[0384] Clause 16: The technology of each preceding clause alone or in combination, wherein the one or more sensors comprise at least one of: a rotary encoder measuring rotation coupled to movement of the tension cable, and a load cell measuring tension in the cable.

[0385] Clause 17: The technology of each preceding clause alone or in combination, wherein the user end of the tension cable comprises an accessory connector configured to connect to one or more accessories through which the user force is applied.

[0386] Clause 18: The technology of each preceding clause alone or in combination, including one or more of the accessories, each configured to be gripped by the user to apply the user force.

[0387] Clause 19: The technology of each preceding clause alone or in combination, wherein the adjustment to the resistance force is determined to prevent, upon sudden removal of user force from the tension cable, a potential distance of more than 2 cm of further runout of the tension cable from the components having momentum coupled to movement of the motor-coupled end of the tension cable.

[0388] Clause 20: The technology of each preceding clause alone or in combination, wherein development of slack distance is compensated against with respect to a potential rapid reduction in the user force which is substantially immediate, and to a reduced level of substantially no user force.

[0389] Clause 21: A method of operating controller processing circuitry providing slack-compensating control of resistance force applied to a tension cable of a cable-operated exercise machine, the method comprising: accessing data indicative of a momentum of components of the exercise machine, wherein said momentum is momentum of components with movements coupled to movement of a motor-coupled end of the tension cable; determining an adjustment to the resistance force, wherein a size of the adjustment is determined, in accordance with the indicated coupled momentum, to compensate against slack distance developing along the tension cable consequent to a potential rapid reduction in user force; and signaling the adjustment in resistance force to the resistance motor as slack compensation.

[0390] Clause 22: The technology of each preceding clause alone or in combination, wherein the components having movements coupled to movement of the motor-coupled end of the tension cable include at least rotating elements of the motor.

[0391] Clause 23: The technology of each preceding clause alone or in combination, wherein the components having movements coupled to movement of the motor-coupled end of the tension cable include a spool on which the tension cable is wound.

[0392] Clause 24: The technology of each preceding clause alone or in combination, wherein the determining sizes the adjustment to the resistance force as a function of a setting force, the setting force comprising a user-selected and predetermined level of exercise force which the controller signals to the resistance motor along with the adjustment.

[0393] Clause 25: The technology of each preceding clause alone or in combination, wherein the determining sizes the adjustment to the resistance force with increasing magnitude as the setting force decreases.

[0394] Clause 26: The technology of each preceding clause alone or in combination, comprising signaling the determined adjustment to the resistance force for exercises performed with the setting force below a threshold; and for exercises performed with the setting force above the threshold, determining not to signal said adjustment.

[0395] Clause 27: The technology of each preceding clause alone or in combination, wherein the determining provides an adjustment to the resistance force which is increasing with increasing momentum of the components of the exercise machine coupled to movement of the motor-coupled end of the tension cable.

[0396] Clause 28: The technology of each preceding clause alone or in combination, wherein the signaling of the determined adjustment is during extension phases of tension cable movement; and comprising determining not to signal the adjustment during return phases of tension cable movement.

[0397] Clause 29: The technology of each preceding clause alone or in combination, comprising determining the adjustment as a linear function of increasing velocity.

[0398] Clause 30: The technology of each preceding clause alone or in combination, comprising determining the adjustment as a non-linear function of increasing velocity.

[0399] Clause 31: The technology of each preceding clause alone or in combination, comprising: determining, automatically, an ongoing accelerating or decelerating phase of tension cable extension; and determining the adjustment according to the ongoing accelerating or decelerating phase of tension cable extension.

[0400] Clause 32: The technology of each preceding clause alone or in combination, comprising increasing the adjustment to the resistance force during a decelerating phase of tension cable extension.

[0401] Clause 33: A method of operating a controller to vary a resistance force applied to a tension cable of an exercise machine during changes in extension distance of the tension cable, the method comprising: estimating, by the controller, an ongoing acceleration of the tension cable; and determining an adjustment to the resistance force, dependent on the ongoing acceleration of the tension cable; and applying the adjustment to modify the ongoing acceleration.

[0402] Clause 34: The technology of each preceding clause alone or in combination, wherein the adjustment is selected to be proportional to a baseline training resistance force.

[0403] Clause 35: The technology of each preceding clause alone or in combination, wherein the adjustment is selected to simulate an inertial mass resistant to changes in acceleration.

[0404] Clause 36: An exercise machine comprising: at least one motor; a tension cable extending from a user end to an attachment to the at least one motor, wherein the motor provides adjustable resistance force resisting force applied from the user end; and a controller controlling the resistance force provided by the motor; wherein the controller comprises processing circuitry configured to: access data indicative of acceleration of the tension cable; determine an adjustment to the resistance force, dependent on the indicated acceleration of the tension cable; and signal the adjustment in resistance force to the resistance motor.

[0405] Clause 37: A tension cable exercise machine comprising a resistance motor, tension cable, and controller, wherein the controller comprises processing circuitry configured to: access data characterizing a decrease in extension distance of the tension cable; determine that the decrease in extension distance satisfies a fast tension cable return criterion; and in accordance with the determination, signal the resistance motor to reduce a velocity at which the extension distance of the tension cable is decreasing.

[0406] Clause 38: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion comprises movements of the tension cable indicative of release of the tension cable by a user while the tension cable is in an extended state.

[0407] Clause 39: The technology of each preceding clause alone or in combination, wherein the resistance motor comprises a rotary electric motor.

[0408] Clause 40: The technology of each preceding clause alone or in combination, comprising one or more sensors coupled to provide the controller with said data characterizing the decrease in extension distance, used to determine that the decrease in extension distance satisfies the fast tension cable return criterion.

[0409] Clause 41: The technology of each preceding clause alone or in combination, comprising a tension cable brake, and wherein the reducing a velocity comprises activating the tension cable brake.

[0410] Clause 42: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion indicates that without activation of the brake, there is insufficient distance at an ongoing velocity to stop a collision between the tension cable and the exercise machine.

[0411] Clause 43: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion satisfied is indicative of a safety risk due to increased and / or increasing velocity of the tension cable.

[0412] Clause 44: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied.

[0413] Clause 45: The technology of each preceding clause alone or in combination, wherein the threshold velocity used is adjusted by reducing the threshold velocity as the extension distance reduces.

[0414] Clause 46: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion comprises a determination that return acceleration of the tension cable is indicative of a loss of user force.

[0415] Clause 47: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion comprises a determination that return acceleration of the tension cable is outside of a set of reference examples for expected return acceleration.

[0416] Clause 48: The technology of each preceding clause alone or in combination, wherein the controller is configured to: access data indicative of swinging of the tension cable; determine a phase and / or period of the swinging, using the data; and adjust tension in the tension cable, according to the phase and / or period, wherein timing of the tension adjustment is selected to damp swinging of the tension cable.

[0417] Clause 49: A method of operating a controller to vary resistance force applied to a tension cable of an exercise machine during a decrease in extension distance of the tension cable, the method comprising: determining, by the controller, that the decrease in extension distance satisfies a fast tension cable return criterion; and in accordance with the determining, commanding a resistance motor of the exercise equipment to reduce a velocity at which the extension distance of the tension cable decreases.

[0418] Clause 50: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion comprises movements of the tension cable indicative of release of the tension cable by a user while the tension cable is in an extended state.

[0419] Clause 51: The technology of each preceding clause alone or in combination, wherein, in accordance with the determining, the controller applies a brake to the tension cable.

[0420] Clause 52: The technology of each preceding clause alone or in combination, wherein satisfying the fast tension cable return criterion is indicative of a safety risk due to increased and / or increasing velocity of the tension cable.

[0421] Clause 33: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied.

[0422] Clause 54: The technology of each preceding clause alone or in combination, wherein the threshold velocity reduces along with the extension distance.

[0423] Clause 55: A method of damping control of resistance force applied by a resistance motor to a tension cable of an exercise machine, the method comprising: accessing, by a controller of the exercise machine, data indicative that a user end of the tension cable is moving at a distance within a homing distance from a home position for the user end; and in accordance with the data, automatically adjusting signals from the controller, said signals governing application of the resistance force by the resistance motor; wherein the resistance force is controlled to perform a damped transition through a plurality of resistance force levels between and in addition to a first resistance force and a second resistance force, the resistance force levels and timing of the damped transition being determined in accordance with the data; and wherein the second resistance force is at least double the first resistance force.

[0424] Clause 56: The technology of each preceding clause alone or in combination, wherein the resistance force levels of the damped transition are determined in accordance with at least one of: a change in the distance of the user end from the home position, and an elapsed time after the user end passes a threshold distance while within the homing distance.

[0425] Clause 57: The technology of each preceding clause alone or in combination, wherein the change in distance comprises an increase in extension distance of the tension cable, and the damped transition is to the second resistance force from the first resistance force.

[0426] Clause 58: The technology of each preceding clause alone or in combination, wherein the controller lengthens the damped transition to occur over a larger change in distance of the user end from the home position, when a rate of change in distance of the user end from the home position exceeds a speed threshold.

[0427] Clause 59: The technology of each preceding clause alone or in combination, wherein the change in distance comprises a decrease in extension distance of the tension cable, and the damped transition is to the first resistance force from the second resistance force.

[0428] Clause 60: The technology of each preceding clause alone or in combination, wherein the signals governing application of the resistance force by the resistance motor are configured to limit an unloaded equilibrium velocity of the motor to a damping velocity limit, the damping velocity limit being adjusted to be relatively lower within the homing distance, compared to an unloaded equilibrium velocity of the motor beyond the homing distance.

[0429] Clause 61: The technology of each preceding clause alone or in combination, wherein the damped transition occurs over at least 10 msec.

[0430] Clause 62: The technology of each preceding clause alone or in combination, wherein the damped transition occurs over at least 0.5 cm.

[0431] Clause 63: The technology of each preceding clause alone or in combination, comprising, when the damped transition reduces the resistance force: determining, by the controller, whether the data indicate that the user end of the tension cable will reach the home position before a targeted minimum transition time elapses; and selecting between a distance-dependent reduction in resistance force and a time-dependent reduction in resistance force in accordance with the determining.

[0432] Clause 64: The technology of each preceding clause alone or in combination, wherein the homing zone within which the damped transition occurs is extends no more than 25 cm from the home position.

[0433] Clause 65: The technology of each preceding clause alone or in combination, wherein: the controller governs the damped transition both: from the first resistance force to the second resistance force while the user end extends, resulting in an average extension-phase resistance force as a function of position between the home position and the homing distance, and from the second resistance force to the first resistance force while the user end returns to the home position, resulting in an average return-phase resistance force as a function of position between the home position and the homing distance; and wherein the average extension-phase resistance force is larger than the average return-phase resistance.

[0434] Clause 66: The technology of each preceding clause alone or in combination, wherein the extension-phase damped transition begins at a distance closer to the home position than the end of the return-phase damped transition.

[0435] Clause 67: The technology of each preceding clause alone or in combination, wherein the return-phase damped transition begins at a distance farther from the home position than the end of the extension-phase damped transition.

[0436] Clause 68: The technology of each preceding clause alone or in combination, wherein a total distance of the extension-phase damped transition is different than a total distance of the return-phase damped transition.

[0437] Clause 69: The technology of each preceding clause alone or in combination, wherein the return-phase damped transition occurs over a shorter distance than the extension-phase damped transition.

[0438] Clause 70: The technology of each preceding clause alone or in combination, wherein the controller imposes hysteresis on the resistance force as a function of distance, in accordance with a direction of movement of the user end of the resistance cable while moving between the homing distance and the home position.

[0439] Clause 71: The technology of each preceding clause alone or in combination, wherein the second resistance force is a setting force selected for operation of the exercise machine during a set of reps.

[0440] Clause 72: The technology of each preceding clause alone or in combination, wherein the first resistance force is a quiescent state force which holds the user end in place while waiting for a user to engage with the tension cable.

[0441] Clause 73: The technology of each preceding clause alone or in combination, comprising: accessing, by the controller, data indicative of velocity of the tension cable; determining, by the controller, that the velocity of the tension cable satisfies a fast tension cable return criterion; and in accordance with the determining, at least one of: automatically adjusting signals from the controller governing the resistance motor to reduce force applied to the tension cable, and activating a brake to slow the velocity of the tension cable.

[0442] Clause 74: The technology of each preceding clause alone or in combination, wherein the fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied.

[0443] Clause 75: The technology of each preceding clause alone or in combination, wherein the threshold velocity reduces along with distance from the home position.

[0444] Clause 76: The technology of each preceding clause alone or in combination, wherein the second resistance force is at least 25 pounds.

[0445] Clause 77: The technology of each preceding clause alone or in combination, wherein the second resistance force is at least 100 pounds.

[0446] Clause 78: An exercise machine comprising: a resistance motor; a tension cable coupled to receive resistance force applied by the resistance motor; and a controller, coupled to control the applied resistance force; wherein the controller comprises processing circuitry configured to: access ongoing data indicative that a user end of the tension cable is moving at a distance within a homing distance from a home position for the user end; and in accordance with the data, automatically adjust signals from the controller governing application of the resistance force by the resistance motor; wherein the resistance force is controlled to transition between a first resistance force and a second resistance force in accordance with the ongoing data indicative of movement of the user end of the tension cable; and wherein the second resistance force is at least double the first resistance force.

[0447] Clause 79: The technology of each preceding clause alone or in combination, wherein the resistance motor comprises a rotary electric motor.

[0448] Clause 80: The technology of each preceding clause alone or in combination, comprising one or more sensors which sense the sensed indications, and are coupled to provide the sensed indications to the controller.

[0449] Clause 81: A method of controlling a tension cable of an exercise machine operating to provide resistance at a resistance force, the method comprising: determining that extension distance of the tension cable is changing while a user end of the tension cable is within a homing distance from a home position of the user end; and in accordance with the determining, selecting force applied by a resistance motor to use a specified damping force level, in place of the resistance force.

[0450] Clause 82: The technology of each preceding clause alone or in combination, wherein the damping force level is initially lower than the resistance force, and rises to meet the resistance force as the extension distance of the tension cable increases.

[0451] Clause 83: The technology of each preceding clause alone or in combination, wherein the damping force level reduces as the extension distance of the tension cable reduces.

[0452] Clause 84: The technology of each preceding clause alone or in combination, wherein the damping force level is different at different extension distances of the tension cable, and also different for same extension distances depending on whether the extension distance of the tension cable is increasing or decreasing.

[0453] Clause 85: An exercise machine configured to apply damped transitions of resistance force to a tension cable near a home position for a user end of the tension cable, the exercise machine comprising: a resistance motor; a controller, coupled to control resistance force produced by the resistance motor; and the tension cable, coupled to receive the resistance force produced by the resistance motor; wherein the controller comprises processing circuitry configured to: access data indicative that the user end of the tension cable is moving at a distance within a homing distance from the home position for the user end; and in accordance with the data, automatically adjust signals from the controller, said signals governing application of the resistance force by the resistance motor; wherein the resistance force is controlled to perform a damped transition through a plurality of levels between a first resistance force and a second resistance force in accordance with at least one of a change in the distance of the user end from the home position and an elapsed time after the user end passes a threshold distance while within the homing distance; and wherein the second resistance force is at least double the first resistance force.

[0454] Clause 86: The technology of each preceding clause alone or in combination, wherein the resistance motor comprises a rotary electric motor.

[0455] Clause 87: The technology of each preceding clause alone or in combination, comprising one or more sensors coupled to provide the controller with sensed indications of tension cable movement, used to determine that the extension distance of the tension cable is changing while within the home position zone of extension.

[0456] Clause 88: The technology of each preceding clause alone or in combination, wherein, when the damped transition is in a direction reducing the resistance force, the controller is configured to: determine whether the data indicate that the user end of the tension cable will reach the home position before a targeted minimum transition time elapses; and select between a distance-dependent reduction in resistance force and a time-dependent reduction in resistance force in accordance with the determination.

[0457] Clause 89: The technology of each preceding clause alone or in combination, wherein, upon selecting the distance-dependent reduction in resistance force, the controller continues to access data indicative of movements of the user end of tension cable, and to control the damped transition accordingly as a function of distance of the movements.

[0458] Clause 90: The technology of each preceding clause alone or in combination, wherein the controller is configured to: access data indicative of velocity of the tension cable; determine that the velocity of the tension cable satisfies a fast tension cable return criterion; and in accordance with the determination, perform at least one of: automatically adjusting signals governing the resistance motor to reduce force applied to the tension cable, and activate a brake to slow the velocity of the tension cable.

[0459] Disclosed embodiments may include any one of the following bullet-pointed features alone or in combination with one or more other bullet-pointed features, whether implemented as a system (e.g., an exercise machine, a computing device, a resistance motor) and / or method, by at least one processor or circuitry, and / or stored as executable instructions on non-transitory computer readable media or computer readable media.

[0460] a cable-operated exercise machine providing slack-compensating control of resistance force applied to a tension cable;

[0461] a tension cable, configured to receive user force applied by pulling on a user end of the tension cable;

[0462] a resistance motor applying a resistance force to a motor-coupled end of a tension cable, in opposition to a user force;

[0463] a controller comprising processing circuitry;

[0464] access data indicative of a momentum of components of an exercise machine;

[0465] momentum of components is coupled to movement of a motor-coupled end of a tension cable;

[0466] determine an adjustment to a resistance force;

[0467] a size of an adjustment is determined, in accordance with an indicated momentum, to compensate against slack distance developing along a tension cable consequent to a potential rapid reduction in a user force;

[0468] signal an adjustment in resistance force to a resistance motor;

[0469] components having momentum coupled to movement of a motor-coupled end of a tension cable include at least rotating elements of the motor;

[0470] components having momentum coupled to movement of a motor-coupled end of a tension cable include a spool on which the tension cable is wound;

[0471] a size of a determined adjustment to a resistance force varies in magnitude as a function of a setting force;

[0472] a setting force comprising a user-selected and predetermined level of exercise force which a controller signals to a resistance motor along with an adjustment;

[0473] a size of a determined adjustment to a resistance force increases in magnitude as a setting force decreases;

[0474] a determined adjustment to a resistance force is signaled for exercises performed with a setting force below a threshold, and not applied for exercises performed with the setting force above the threshold;

[0475] a determined adjustment to a resistance force increases with increasing momentum of components of an exercise machine coupled to movement of a motor-coupled end of a tension cable;

[0476] a determined adjustment is signaled during extension phases of tension cable movement, and not applied during return phases of tension cable movement;

[0477] a determined adjustment changes as a linear function of increasing velocity;

[0478] a determined adjustment changes as a non-linear function of increasing velocity;

[0479] a controller: determines an ongoing accelerating or decelerating phase of tension cable extension;

[0480] determines an adjustment according to an ongoing accelerating or decelerating phase of tension cable extension;

[0481] 12. The exercise machine of claim 11, wherein the adjustment increases the resistance force during a decelerating phase of tension cable extension.

[0482] a resistance motor comprises a rotary electric motor;

[0483] a resistance motor comprises one or more electric motors;

[0484] one or more sensors coupled to provide a controller with data indicative of a momentum of components of an exercise machine coupled to movement of a motor-coupled end of a tension cable;

[0485] a rotary encoder measuring rotation coupled to movement of a tension cable;

[0486] a load cell measuring tension in a cable;

[0487] a user end of a tension cable comprises an accessory connector configured to connect to one or more accessories through which a user force is applied;

[0488] one or more of the accessories, each configured to be gripped by a user to apply a user force;

[0489] adjustment to a resistance force is determined to prevent, upon sudden removal of user force from a tension cable, a potential distance of more than 2 cm of further runout of the tension cable from a components having momentum coupled to movement of a motor-coupled end of the tension cable;

[0490] development of slack distance is compensated against with respect to a potential rapid reduction in a user force which is substantially immediate, and to a reduced level of substantially no user force;

[0491] providing slack-compensating control of resistance force applied to a tension cable of a cable-operated exercise machine;

[0492] accessing data indicative of a momentum of components of an exercise machine;

[0493] momentum is momentum of components with movements coupled to movement of a motor-coupled end of a tension cable;

[0494] determining an adjustment to a resistance force;

[0495] a size of an adjustment is determined, in accordance with the indicated coupled momentum, to compensate against slack distance developing along a tension cable consequent to a potential rapid reduction in user force;

[0496] signaling an adjustment in resistance force to a resistance motor as slack compensation;

[0497] components having movements coupled to movement of a motor-coupled end of a tension cable include at least rotating elements of the motor;

[0498] components having movements coupled to movement of a motor-coupled end of a tension cable include a spool on which the tension cable is wound;

[0499] determining sizes adjustment to a resistance force as a function of a setting force;

[0500] a setting force comprising a user-selected and predetermined level of exercise force which a controller signals to a resistance motor along with an adjustment;

[0501] determining sizes an adjustment to a resistance force with increasing magnitude as a setting force decreases;

[0502] signaling a determined adjustment to a resistance force for exercises performed with a setting force below a threshold;

[0503] for exercises performed with a setting force above the threshold, determining not to signal an adjustment;

[0504] determining provides an adjustment to a resistance force which is increasing with increasing momentum of components of an exercise machine coupled to movement of a motor-coupled end of a tension cable;

[0505] signaling of a determined adjustment is during extension phases of tension cable movement;

[0506] determining not to signal the adjustment during return phases of tension cable movement;

[0507] determining an adjustment as a linear function of increasing velocity;

[0508] determining an adjustment as a non-linear function of increasing velocity;

[0509] determining, automatically, an ongoing accelerating or decelerating phase of tension cable extension;

[0510] determining an adjustment according to an ongoing accelerating or decelerating phase of tension cable extension.

[0511] increasing an adjustment to a resistance force during a decelerating phase of tension cable extension;

[0512] operating a controller to vary a resistance force applied to a tension cable of an exercise machine during changes in extension distance of the tension cable;

[0513] estimating, by a controller, an ongoing acceleration of the tension cable;

[0514] determining an adjustment to a resistance force, dependent on an ongoing acceleration of a tension cable;

[0515] applying an adjustment to modify an ongoing acceleration;

[0516] an adjustment is selected to be proportional to a baseline training resistance force;

[0517] an adjustment is selected to simulate an inertial mass resistant to changes in acceleration;

[0518] at least one motor;

[0519] a tension cable extending from a user end to an attachment to at least one motor;

[0520] a motor provides adjustable resistance force resisting force applied from a user end;

[0521] a controller controlling a resistance force provided by a motor;

[0522] a controller comprises processing circuitry;

[0523] access data indicative of acceleration of a tension cable;

[0524] determine an adjustment to a resistance force, dependent on an indicated acceleration of a tension cable;

[0525] signal an adjustment in resistance force to a resistance motor;

[0526] a tension cable exercise machine;

[0527] a resistance motor;

[0528] a tension cable;

[0529] a controller;

[0530] a controller comprises processing circuitry;

[0531] access data characterizing a decrease in extension distance of a tension cable;

[0532] determine that a decrease in extension distance satisfies a fast tension cable return criterion;

[0533] in accordance with the determination, signal a resistance motor to reduce a velocity at which an extension distance of a tension cable is decreasing;

[0534] a fast tension cable return criterion comprises movements of a tension cable indicative of release of the tension cable by a user while the tension cable is in an extended state;

[0535] a resistance motor comprises a rotary electric motor;

[0536] one or more sensors coupled to provide a controller with data characterizing a decrease in extension distance;

[0537] using sensor data to determine that a decrease in extension distance satisfies a fast tension cable return criterion;

[0538] a tension cable brake;

[0539] reducing a velocity comprises activating a tension cable brake;

[0540] a fast tension cable return criterion indicates that without activation of a brake, there is insufficient distance at an ongoing velocity to stop a collision between a tension cable and an exercise machine;

[0541] a fast tension cable return criterion satisfied is indicative of a safety risk due to increased and / or increasing velocity of a tension cable;

[0542] 44. The exercise machine of any one of claims 37-43, wherein the fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied.

[0543] a threshold velocity used is adjusted by reducing the threshold velocity as an extension distance reduces;

[0544] a fast tension cable return criterion comprises a determination that return acceleration of a tension cable is indicative of a loss of user force;

[0545] a fast tension cable return criterion comprises a determination that return acceleration of a tension cable is outside of a set of reference examples for expected return acceleration;

[0546] a controller is configured to access data indicative of swinging of a tension cable;

[0547] determine a phase and / or period of a swinging, using data;

[0548] adjust tension in a tension cable, according to a phase and / or period;

[0549] timing of tension adjustment is selected to damp swinging of a tension cable;

[0550] operating a controller to vary resistance force applied to a tension cable of an exercise machine during a decrease in extension distance of the tension cable;

[0551] determining, by a controller, that a decrease in extension distance satisfies a fast tension cable return criterion;

[0552] in accordance with a determination, commanding a resistance motor of exercise equipment to reduce a velocity at which an extension distance of a tension cable decreases;

[0553] a fast tension cable return criterion comprises movements of a tension cable indicative of release of the tension cable by a user while the tension cable is in an extended state;

[0554] in accordance with a determination, a controller applies a brake to a tension cable;

[0555] satisfying a fast tension cable return criterion is indicative of a safety risk due to increased and / or increasing velocity of a tension cable;

[0556] a fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied;

[0557] a threshold velocity reduces along with an extension distance;

[0558] damping control of resistance force applied by a resistance motor to a tension cable of an exercise machine;

[0559] accessing, by a controller of an exercise machine, data indicative that a user end of a tension cable is moving at a distance within a homing distance from a home position for the user end;

[0560] in accordance with data, automatically adjusting signals from a controller, said signals governing application of a resistance force by a resistance motor;

[0561] a resistance force is controlled to perform a damped transition through a plurality of resistance force levels between and in addition to a first resistance force and a second resistance force;

[0562] resistance force levels and timing of damped transition being determined in accordance with data; and

[0563] a second resistance force is at least double a first resistance force;

[0564] resistance force levels of a damped transition are determined in accordance with at least one of: a change in a distance of a user end from a home position, and an elapsed time after the user end passes a threshold distance while within the homing distance;

[0565] a change in distance comprises an increase in extension distance of a tension cable;

[0566] a damped transition is to a second resistance force from a first resistance force;

[0567] a controller lengthens a damped transition to occur over a larger change in distance of a user end from a home position, when a rate of change in distance of the user end from the home position exceeds a speed threshold;

[0568] a change in distance comprises a decrease in extension distance of the tension cable, and a damped transition is to a first resistance force from a second resistance force;

[0569] signals governing application of a resistance force by a resistance motor are configured to limit an unloaded equilibrium velocity of the motor to a damping velocity limit;

[0570] a damping velocity limit being adjusted to be relatively lower within a homing distance, compared to an unloaded equilibrium velocity of a motor beyond the homing distance;

[0571] a damped transition occurs over at least 10 msec;

[0572] a damped transition occurs over at least 0.5 cm;

[0573] when a damped transition reduces the resistance force: determining, by a controller, whether data indicate that a user end of a tension cable will reach a home position before a targeted minimum transition time elapses;

[0574] selecting between a distance-dependent reduction in resistance force and a time-dependent reduction in resistance force in accordance with a determination;

[0575] a homing zone within which a damped transition occurs is extends no more than 25 cm from a home position;

[0576] a controller governs a damped transition both: from a first resistance force to a second resistance force while a user end extends, resulting in an average extension-phase resistance force as a function of position between the home position and the homing distance, and from the second resistance force to the first resistance force while the user end returns to the home position, resulting in an average return-phase resistance force as a function of position between the home position and the homing distance;

[0577] an average extension-phase resistance force is larger than an average return-phase resistance;

[0578] an extension-phase damped transition begins at a distance closer to a home position than an end of a return-phase damped transition;

[0579] a return-phase damped transition begins at a distance farther from a home position than an end of the extension-phase damped transition;

[0580] a total distance of an extension-phase damped transition is different than a total distance of a return-phase damped transition;

[0581] a return-phase damped transition occurs over a shorter distance than a extension-phase damped transition;

[0582] a controller imposes hysteresis on a resistance force as a function of distance, in accordance with a direction of movement of a user end of a resistance cable while moving between a homing distance and a home position;

[0583] a second resistance force is a setting force selected for operation of an exercise machine during a set of repetitions;

[0584] a first resistance force is a quiescent state force which holds a user end in place while waiting for a user to engage with a tension cable;

[0585] accessing, by a controller, data indicative of velocity of a tension cable;

[0586] determining, by a controller, that a velocity of a tension cable satisfies a fast tension cable return criterion;

[0587] in accordance with a determination, at least one of: automatically adjusting signals from a controller governing a resistance motor to reduce force applied to a tension cable, and

[0588] activating a brake to slow a velocity of a tension cable;

[0589] a fast tension cable return criterion comprises a threshold velocity, above which the fast tension cable return criterion is satisfied;

[0590] a threshold velocity reduces along with distance from a home position;

[0591] a second resistance force is at least 25 pounds;

[0592] a second resistance force is at least 100 pounds;

[0593] an exercise machine;

[0594] a resistance motor;

[0595] a tension cable coupled to receive resistance force applied by a resistance motor;

[0596] a controller, coupled to control an applied resistance force;

[0597] a controller comprises processing circuitry;

[0598] access ongoing data indicative that a user end of a tension cable is moving at a distance within a homing distance from a home position for the user end;

[0599] in accordance with data, automatically adjust signals from a controller governing application of a resistance force by a resistance motor;

[0600] a resistance force is controlled to transition between a first resistance force and a second resistance force in accordance with ongoing data indicative of movement of a user end of a tension cable;

[0601] a second resistance force is at least double a first resistance force;

[0602] a resistance motor comprises a rotary electric motor;

[0603] one or more sensors which sense a sensed indications, and coupled to provide the sensed indications to a controller;

[0604] controlling a tension cable of an exercise machine operating to provide resistance at a resistance force;

[0605] determining that extension distance of a tension cable is changing while a user end of the tension cable is within a homing distance from a home position of the user end;

[0606] in accordance with a determination, selecting force applied by a resistance motor to use a specified damping force level, in place of a resistance force;

[0607] a damping force level is initially lower than a resistance force, and rises to meet a resistance force as an extension distance of a tension cable increases;

[0608] a damping force level reduces as the extension distance of a tension cable reduces;

[0609] a damping force level is different at different extension distances of a tension cable, and also different for same extension distances depending on whether an extension distance of a tension cable is increasing or decreasing.

[0610] an exercise machine configured to apply damped transitions of resistance force to a tension cable near a home position for a user end of the tension cable;

[0611] a resistance motor;

[0612] a controller, coupled to control resistance force produced by a resistance motor;

[0613] a tension cable, coupled to receive a resistance force produced by a resistance motor;

[0614] a controller comprises processing circuitry;

[0615] access data indicative that a user end of a tension cable is moving at a distance within a homing distance from a home position for a user end;

[0616] in accordance with data, automatically adjust signals from a controller;

[0617] signals governing application of a resistance force by a resistance motor;

[0618] a resistance force is controlled to perform a damped transition through a plurality of levels between a first resistance force and a second resistance force in accordance with at least one of a change in a distance of a user end from a home position and an elapsed time after the user end passes a threshold distance while within the homing distance;

[0619] wherein the second resistance force is at least double the first resistance force;

[0620] a resistance motor comprises a rotary electric motor;

[0621] one or more sensors coupled to provide a controller with sensed indications of tension cable movement;

[0622] determine that an extension distance of a tension cable is changing while within a home position zone of extension;

[0623] when a damped transition is in a direction reducing a resistance force, a controller is configured to: determine whether data indicate that a user end of a tension cable will reach a home position before a targeted minimum transition time elapses;

[0624] select between a distance-dependent reduction in resistance force and a time-dependent reduction in resistance force in accordance with a determination;

[0625] upon selecting a distance-dependent reduction in resistance force, a controller continues to access data indicative of movements of a user end of tension cable, and to control a damped transition accordingly as a function of distance of the movements;

[0626] a controller is configured to:

[0627] access data indicative of velocity of a tension cable;

[0628] determine that a velocity of a tension cable satisfies a fast tension cable return criterion;

[0629] in accordance with a determination, perform at least one of:

[0630] automatically adjusting signals governing a resistance motor to reduce force applied to a tension cable; and

[0631] activate a brake to slow the velocity of a tension cable.

Examples

Embodiment Construction

[0138]The present disclosure, in some embodiments thereof, relates to the field of exercise equipment and more particularly, but not exclusively, to resistance cable operated exercise equipment.

[0139]A broad aspect of some examples of the present disclosure relates to the dynamic control of resistance forces to prevent and / or mitigate potentially device-damaging and / or user-disturbing tension cable movements in electronically controlled resistance training exercise machines. Herein, this is also referred to as “protective management” of tension cable dynamics. More broadly, this is an aspect of what is referred to herein as “utility management” of tension cable resistance force; that is, control of tension cable resistance force for purposes such as protection, safety, storage, calibration, and / or device self-diagnosis.

[0140]Utility management of tension cable resistance force is distinguished from (although often simultaneously with) resistance force specified by exercising paramet...

Claims

1. A cable-operated exercise machine providing slack-compensating control of resistance force applied to a tension cable, the exercise machine comprising:the tension cable, configured to receive user force applied by pulling on a user end of the tension cable;a resistance motor applying the resistance force to a motor-coupled end of the tension cable, in opposition to the user force; anda controller comprising processing circuitry configured to:access data indicative of a momentum of components of the exercise machine, wherein the momentum of the components is coupled to movement of the motor-coupled end of the tension cable;determine an adjustment to the resistance force, wherein a size of the adjustment is determined, in accordance with the indicated momentum, to compensate against slack distance developing along the tension cable consequent to a potential rapid reduction in the user force; andsignal the adjustment in resistance force to the resistance motor.

2. The exercise machine of claim 1, wherein the components having momentum coupled to movement of the motor-coupled end of the tension cable include at least rotating elements of the motor.

3. The exercise machine of claim 2, wherein the components having momentum coupled to movement of the motor-coupled end of the tension cable include a spool on which the tension cable is wound.

4. The exercise machine of claim 1, wherein the size of the determined adjustment to the resistance force varies in magnitude as a function of a setting force, the setting force comprising a user-selected and predetermined level of exercise force which the controller signals to the resistance motor along with the adjustment.

5. The exercise machine of claim 4, wherein the size of the determined adjustment to the resistance force increases in magnitude as the setting force decreases.

6. The exercise machine of claim 5, wherein the determined adjustment to the resistance force is signaled for exercises performed with the setting force below a threshold, and not applied for exercises performed with the setting force above the threshold.

7. The exercise machine of claim 1, wherein the determined adjustment to the resistance force increases with increasing momentum of the components of the exercise machine coupled to movement of the motor-coupled end of the tension cable.

8. The exercise machine of claim 1, wherein the determined adjustment is signaled during extension phases of tension cable movement, and not applied during return phases of tension cable movement.

9. The exercise machine of claim 1, wherein the determined adjustment changes as a linear function of increasing velocity.

10. The exercise machine of claim 1, wherein the determined adjustment changes as a non-linear function of increasing velocity.

11. The exercise machine of claim 1, wherein the controller:determines an ongoing accelerating or decelerating phase of tension cable extension; anddetermines the adjustment according to the ongoing accelerating or decelerating phase of tension cable extension.

12. The exercise machine of claim 11, wherein the adjustment increases the resistance force during a decelerating phase of tension cable extension.

13. The exercise machine of claim 1, wherein the resistance motor comprises a rotary electric motor.

14. The exercise machine of claim 1, wherein the resistance motor comprises one or more electric motors.

15. The exercise machine of claim 1, comprising one or more sensors coupled to provide the controller with the data indicative of the momentum of the components of the exercise machine coupled to movement of the motor-coupled end of the tension cable.

16. The exercise machine of claim 15, wherein the one or more sensors comprise at least one of:a rotary encoder measuring rotation coupled to movement of the tension cable, anda load cell measuring tension in the cable.

17. The exercise machine of claim 1, wherein the user end of the tension cable comprises an accessory connector configured to connect to one or more accessories through which the user force is applied.

18. The exercise machine of claim 17, including one or more of the accessories, each configured to be gripped by the user to apply the user force.

19. The exercise machine of claim 1, wherein the adjustment to the resistance force is determined to prevent, upon sudden removal of user force from the tension cable, a potential distance of more than 2 cm of further runout of the tension cable from the components having momentum coupled to movement of the motor-coupled end of the tension cable.

20. The exercise machine of claim 1, wherein development of slack distance is compensated against with respect to a potential rapid reduction in the user force which is substantially immediate, and to a reduced level of substantially no user force.

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