Device and system for controlled collapse of exoskeleton

Abstract

The present disclosure relates to apparatus and systems for controlled collapse of an exoskeleton. Embodiments of apparatus, methods, and systems for collapsing / lowering an exoskeleton device including at least one motor and at least one component are disclosed. In some embodiments, the device is configured to be moved by at least one motor. When at least one of a plurality of faults including a power fault (such as a low power fault and a power outage fault), an electrical fault, a software fault, and a mechanical fault is detected in the power supply of the exoskeleton device, one or more components of the device can be decelerated by the at least one motor.

Description

[0001] This application is a divisional application of the invention patent application with application date of April 13, 2017, application number 201780023625.1, and invention name “Device and system for controlled collapse of exoskeleton”. Technical Field

[0002] Embodiments of the present disclosure are directed to exoskeleton devices for providing gait / mobility assistance and, more particularly, to apparatus and systems for controlling the unpowered collapse of such devices. Background Art

[0003] Various conditions cause disabilities in individuals that limit or eliminate the individual's ability to stand and / or move steadily, examples of which include neurological and physical injuries. Exoskeletons ("external skeletons") have been used to allow such individuals to regain some or all of their ability to stand and / or move despite their disability with little or no additional support. Summary of the invention

[0004] Some embodiments of apparatus, methods, and systems for facilitating controlled collapse of an exoskeleton device including a motor are disclosed herein. Such methods may include the steps of receiving an indication of one or more of a power failure, an electrical failure, a software failure, and a mechanical failure of the exoskeleton device that initiates the descent of the exoskeleton device or a component thereof to the ground; and establishing a low impedance circuit between a positive terminal and a negative terminal of the motor to cause an electromagnetic force to be generated to resist or slow the descent of the exoskeleton device or a component thereof.

[0005] In some embodiments, the received indication may be generated by the power failure detection circuit in response to receiving information related to the performance and / or status of the exoskeleton device or component from one or more sensors operably coupled to the exoskeleton device or component. The one or more sensors may include a temperature sensor configured to measure the temperature of a power supply of the exoskeleton device and generate information if the temperature measurement indicates a faulty power supply. In some embodiments, the one or more sensors may include a power meter configured to collect data regarding the availability of power at the power supply of the exoskeleton device and generate information if the collected data indicates a shortage or insufficiency of power supply at the power supply powering the exoskeleton device or component, wherein the power meter may be configured to generate the information after noise is filtered out of the data. In some embodiments, the one or more sensors include a voltmeter and / or an ammeter configured to provide voltage and / or current data, respectively, at one or more points along the electrical circuit system of the exoskeleton device and generate information when the collected data indicates one or more of a power failure, an electrical failure, a software failure, and a mechanical failure.

[0006] In some embodiments, a low impedance between the positive terminal and the negative terminal may be established by a collapse circuit configured to close a low impedance switch between the positive terminal and the negative terminal, wherein the collapse circuit comprises an opto-isolated power driver configured to open or close the low impedance switch.

[0007] In some embodiments of the present disclosure, a collapse circuit for facilitating controlled collapse of an exoskeleton device including a motor is disclosed. The circuit may include: a processor configured to receive an indication of one or more of a power failure, an electrical failure, a software failure, and a mechanical failure of the exoskeleton device, the indication causing the exoskeleton device or a component thereof to initiate a descent to the ground; and a power driver configured to establish a low impedance between the positive and negative terminals of the motor to cause an electromagnetic force to be generated to resist or slow the descent of the exoskeleton device or component thereof.

[0008] In some embodiments, the circuitry further comprises a power failure detection circuit configured to generate an indication in response to receiving information related to the performance and / or status of the exoskeleton device or component from one or more sensors operably coupled to the exoskeleton device or component. The one or more sensors may include a temperature sensor configured to measure the temperature of a power supply of the exoskeleton device and to generate information if the temperature measurement indicates a faulty power supply. In some embodiments, the one or more sensors may include a power meter configured to provide data regarding the availability of power at the power supply of the exoskeleton device and to generate information when the collected data indicates one or more of a power failure, an electrical failure, a software failure, and a mechanical failure. In some embodiments, the one or more sensors may include a voltmeter and / or an ammeter configured to provide voltage and / or current data, respectively, at one or more points along the electrical circuitry of the exoskeleton device and to generate information when the collected data indicates one or more of a power failure, an electrical failure, a software failure, and a mechanical failure.

[0009] In some embodiments, the circuit may include a filter configured to filter noise from the data before the information is generated by the power meter. In some embodiments, the power driver includes an opto-isolated power driver configured to open or close a low impedance switch to establish a low impedance between the positive terminal and the negative terminal of the motor.

[0010] In some embodiments of the present disclosure, a method for facilitating collapse of an exoskeleton device including a motor used by a user is disclosed. The method includes the steps of: receiving an indication of one or more of a power failure, an electrical failure, a software failure, and a mechanical failure of the exoskeleton device, the indication causing the exoskeleton device to initiate a descent to the ground; determining an amount of electromagnetic force sufficient to resist or slow the descent of the exoskeleton device such that during at least a portion of the descent, a collapse rate of the exoskeleton device is substantially constant in time; and establishing a low impedance between a positive terminal and a negative terminal of the motor to cause the generation of the determined amount of electromagnetic force to resist or slow the descent of the exoskeleton device.

[0011] In some embodiments, the rate of collapse of the exoskeleton device is configured such that the total time of at least a portion of the descent is substantially constant relative to the weight of the user. In some embodiments, establishing a low impedance between the positive terminal and the negative terminal comprises varying a time period during which a low impedance switch between the positive terminal and the negative terminal is opened or closed, wherein the varying time period is configured such that the total time of at least a portion of the descent is substantially constant relative to the weight of the user. In some embodiments, the time period may be varied by varying a duty cycle of a power width modulation (PWM) control signal configured to control the opening or closing of the low impedance switch.

[0012] It should be understood that all combinations of the foregoing concepts and additional concepts discussed in more detail below (assuming that these concepts are not mutually inconsistent) are considered to be part of the inventive subject matter disclosed herein. In particular, all combinations of the claimed subject matter appearing at the end of this disclosure are considered to be part of the inventive subject matter disclosed herein. It should also be understood that terms explicitly adopted herein may also appear in any disclosure incorporated by reference, and the terms should be given the meaning most consistent with the specific concepts disclosed herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The skilled artisan will appreciate that the figures are primarily for illustrative purposes and are not intended to limit the scope of the inventive subject matter described herein. The figures are not necessarily to scale; in some cases, various aspects of the inventive subject matter disclosed herein may be shown exaggerated or enlarged in the figures to facilitate understanding of the different features. In the figures, like reference characters generally refer to similar features (e.g., functionally similar and / or structurally similar elements).

[0014] Figure 1A -B shows a schematic diagram of a brushed motor for controlling the motion of an exoskeleton according to some embodiments;

[0015] Figure 2A -B shows a schematic diagram of a brushed motor incorporating a low impedance switch for managing controlled collapse of an exoskeleton according to some embodiments;

[0016] Figure 3An example circuit including a power failure detection circuit for an exoskeleton motor operably coupled to a low impedance switch is shown according to some embodiments;

[0017] Figure 4 details of an example power failure detection circuit for generating an output to a low impedance switch operably coupled to a motor of an exoskeleton according to some embodiments are described;

[0018] Figure 5A shows an example flow chart depicting a protocol for evaluating activation of a controlled collapse of an exoskeleton in accordance with some embodiments;

[0019] Figure 5B An example circuit of a three-phase bridge driver for a brushless motor according to some embodiments is shown;

[0020] Fig. 6A -B shows an example P-channel based H-bridge circuit that may be used as a low impedance switch configured to manage a controlled collapse of an exoskeleton, according to some embodiments;

[0021] Fig. 7A -B shows an example N-channel based H-bridge circuit that may be used as a low impedance switch configured to manage a controlled collapse of an exoskeleton, according to some embodiments;

[0022] Figure 8 shows an example circuit including a self-test circuit for a low impedance motor configured to manage a controlled collapse of an exoskeleton according to some embodiments;

[0023] Fig. 9 An example flow chart illustrating performance of a controlled collapse of a self-testing exoskeleton according to some embodiments is shown;

[0024] Fig.10 shows an exemplary flow chart illustrating activation of adaptive body weight for controlled collapse of an exoskeleton according to some embodiments;

[0025] Fig.11 shows an example diagram illustrating a control mode for controlling a body weight adapted controlled collapse of an exoskeleton according to some embodiments;

[0026] Fig.12 shows an example diagram illustrating a control mode for individually controlling segments of an exoskeleton during a body weight adapted (or adapted collapse mode) controlled collapse of the exoskeleton, according to some embodiments;

[0027] Fig.13An example circuit is shown according to some embodiments, including an energy harvesting circuit for a low impedance motor configured to manage a controlled collapse of an exoskeleton;

[0028] Fig.14 An example set of control modes for controlling four segments of an exoskeleton is illustrated. DETAILED DESCRIPTION

[0029] In some embodiments of the present disclosure, apparatus and systems including exoskeleton devices for providing gait / mobility assistance are provided, and more specifically, apparatus and systems for controlling the unpowered collapse of such devices are provided. Specific embodiments are described herein to illustrate the principles and features of the present invention by way of example and not limitation, but the present invention can withstand the test of various applications.

[0030] In some embodiments, operation of the exoskeleton, including movement (translation, rotation, etc.), maintaining and / or acquiring position (e.g., standing, sitting, maintaining an upright position, etc.), may be powered by one or more motors embedded within or operably coupled to the exoskeleton structure. However, in some circumstances, the exoskeleton may malfunction during use. For example, the exoskeleton's processor may lose the ability to control the motors that operate the exoskeleton, the motors may lose access to the exoskeleton's power source, etc. Failures (particularly those that include the exoskeleton becoming unresponsive or power being withdrawn from the motors) may result in potential injury, such as a rapid descent of the exoskeleton and / or the user to the ground.

[0031] In some embodiments, a controlled collapse circuit is proposed, which is configured to place a short circuit across the motor terminals to create a path for a high current to flow through the motor during the collapse phase. The motor, acting as a generator, can face a low resistance load (i.e., a short circuit) during collapse, while the high current through the motor generates a counter-electromagnetic force (back-EMF) that can resist the movement of the motor, counteracting the rapid descent and resulting in a slower (and therefore, at least in most cases, safer) descent of the exoskeleton and user. In the event of a fault that would normally render the exoskeleton unusable and expose the user to a rapid descent (such as a dead / disconnected battery, a system malfunction or freeze, etc.), the controlled collapse allows the exoskeleton device to support the user's weight while slowly lowering the user to a seat or the ground.

[0032] refer to Figure 1A-B, in some embodiments, a schematic diagram of a brushed motor for controlling the movement of an exoskeleton is shown. The exoskeleton uses motors to power the movement of the user of the exoskeleton, and the motors can be placed in one or more segments (e.g., limbs) of the exoskeleton. For example, the motors can be placed in the lower limbs, upper limbs, torso, midsection area, etc. of the exoskeleton, and they can be used to complete various tasks related to providing gait / movement assistance to the user, such tasks including but not limited to changing the position of the exoskeleton / user (e.g., upright movements such as standing up, sitting down, squatting, etc., rotational movements such as turning around partially or completely, changing orientation, etc.), maintaining position or gait (e.g., maintaining a standing position, maintaining balance when standing up or sitting down, etc.), moving (translating or otherwise changing the position of the user, such as but not limited to walking, running, moving (e.g., side steps), jumping, crawling, etc.).

[0033] In some embodiments, in completing any of the above tasks, the motors located in the various segments of the exoskeleton can act independently or together according to the task. For example, a motor located in one of the lower limbs of the exoskeleton can cause a leg to move in translation, while another motor can rotate the body to allow the user to change direction when walking. Such coordination can be controlled by a central processing module, an example of which is discussed in U.S. Provisional Patent Application Serial No. 62 / 242,780, entitled "Apparatus and Systems for Controlling Exoskeletons" filed on October 16, 2015, which is incorporated herein by reference in its entirety. For example, such a processing module can provide instructions to the motor to control the speed, direction, duration, etc. of the movement of the motor. As discussed above, the control of each motor can be coordinated to cause the exoskeleton to complete any of the above tasks.

[0034] In some embodiments, the motor that can be used to power the movement of the exoskeleton can be a brushed direct current (DC) motor that is both electrically excited and has permanent magnets, an electronically commutated (EC) motor, a brushless DC motor or a switched reluctance motor (SRM), a universal AD-DC motor, an ironless or coreless rotor motor, an axial rotor motor, a servo motor, a stepper motor, an AC motor, and the like. The operation or movement of such a motor can be accomplished by an electronic circuit, an example of which is a so-called H-bridge that allows control of the movement of the motor in each direction. Although the discussion in this application is directed to a brushed DC motor drive, in some embodiments, the same concepts can also be applied to brushless DC motors. Figure 1 depicts an example brushed DC motor with two terminals (labeled as A terminals and B terminals) and includes a stator and a rotor or armature, where the stator is the stationary part (i.e., the housing of the motor) and the rotor or armature is the moving (e.g., rotating) part.

[0035] Table 1 below summarizes the different modes of applying voltages to the two terminals to cause the motor to move in opposite directions (for convenience, we use the terms "right" and "left" to distinguish these two opposite directions).

[0036] Table 1: Effect of terminal voltage on brushed DC motor

[0037]

[0038] In the embodiment of Table 1, voltage application modes 1 and 2 are configured to move the exoskeleton, i.e., the motors can be turned in either direction to allow movement of the exoskeleton (e.g., backward, forward, etc.). High impedance and low impedance in modes 3 and 4 mean high or low impedance or resistance between the terminals, respectively. With respect to mode 3, high impedance or disconnection between the terminals may cause the motors to coast, resulting in uncontrolled movement of the skeleton, including unintentional and rapid collapse that may cause injury to the user. Mode 4, which may be associated with low impedance between the terminals, may also be used to facilitate movement of the exoskeleton. In addition, mode 4 may be used to control (e.g., slow down) the collapse of the exoskeleton by braking the movement of the motors in the collapsing exoskeleton.

[0039] Reference Figure 2A -B, in some embodiments, a schematic diagram of a brushed motor incorporating a low impedance switch for managing a controlled collapse of an exoskeleton is shown. Mode 4 described above can be used to manage a controlled collapse of an exoskeleton and results in a low impedance or resistance corresponding to the closure of the switch, i.e., results in the placement of a "short circuit" (low impedance / resistance) connection between the motor terminals. In some embodiments, this can be achieved by placing the same or substantially the same voltage on both terminals. The voltage can be any amount, including zero voltage (i.e., ground). Opening the switch can accelerate the collapse (e.g., the motor enters Mode 3).

[0040] The following is an example illustrating the use of Mode 4 to effect a controlled collapse of the exoskeleton. When the exoskeleton faces a sudden power failure or a malfunction that results in the user having insufficient control over the exoskeleton, the exoskeleton may begin to collapse uncontrollably under its own and the user's weight, and voltage may be removed from the motor terminals. In such an embodiment, the rotor of the motor may begin to rotate due to the torque caused by gravity, which is transmitted to the rotor by any means capable of transmitting torque, such as gears. If the torque is not balanced by some other source of force, then the rotation caused by these torques can lead to an uncontrolled collapse of the exoskeleton.

[0041] However, in some embodiments, the rotation of the rotor or armature may cause a changing DC current to be generated in the winding rings due to Faraday's law of induction. Since the switch between the two terminals is closed, the generated current can flow freely, generating a back electromagnetic force (back EMF) that counteracts the current causing the back EMF, i.e., a force that causes a motor torque in the opposite direction to the torque caused by gravity.

[0042] In some embodiments, the back EMF may be less than gravity, which may be expressed as follows:

[0043] ε gravitation >ε back EMF

[0044] Such a back EMF can generate a counter torque to the torque attributed to gravity, resulting in braking or deceleration of an uncontrolled descent or collapse of the exoskeleton. Some reasons why the back EMF is less than gravity may be that in addition to losses in the magnetic field, the switches, terminals, and rotor or armature windings may also have resistance, and the resistance from these three elements may result in the loss of at least some (e.g., a small portion) of the power generated by the back EMF force. Therefore, the torque caused by the back EMF can be less than the torque attributed to gravity but in its opposite direction, and the resulting (superimposed) torque acting on the rotor of the motor can be reduced. Therefore, in such an embodiment, the armature can rotate in the direction of the stronger force (e.g., gravity), and the exoskeleton can continue to collapse, resulting in a reduced rate of collapse, i.e., a gentle or controlled collapse. In the absence of such resistance or losses, gravity can be essentially equal to the back EMF, almost completely preventing descent.

[0045] Reference Figure 3 , in some embodiments, an example circuit is shown including a power failure detection circuit for a low impedance motor configured to manage a gentle or controlled collapse of an exoskeleton. As discussed herein, the controlled collapse mechanism of the present application is configured to be used in the event of a malfunction of the exoskeleton, particularly for malfunctions such as a power outage that results in an uncontrolled collapse of the exoskeleton. In such embodiments, a power failure detection circuit configured to detect the removal of voltage or power at the motor can be used to detect such a power outage to activate the controlled collapse circuit described above. Figure 3 A controlled collapse circuit is shown that includes a power failure detection circuit and a low impedance switch that can connect the terminals of the motor once a power failure is detected by the power failure detection circuit as described above.

[0046] Figure 4Details of an exemplary power failure detection circuit are shown, the power failure detection circuit being configured to detect a power failure in an exoskeleton device and generate an output to a low impedance switch, causing the switch (operably coupled to the motor of the exoskeleton) to be triggered and connect the terminals of the motor. In some embodiments, the circuit can include an internal processor configured to receive an external trigger input from an external processor (e.g., a microprocessor of the exoskeleton). For example, an external sensor can observe that the power supply system of the exoskeleton is failing or is about to fail (e.g., a temperature measurement of a battery indicates that the battery is overheating). Another example is the ability of an external sensor to monitor the activity of the main exoskeleton processor and generate data to provide information about the performance of the exoskeleton processor to the internal processor of the power failure detection circuit. Such data can be considered an external trigger to the internal processor of the power failure detection circuit, so that the internal processor can function whenever the main processor is not functioning. In some embodiments, such a sensor can be a component of a power detection circuit capable of obtaining information related to the performance and / or status of a power source (e.g., a DC power supply battery) to provide information such as an external trigger input to the detection circuit.

[0047] In some embodiments, the power failure detection circuit may include or be operably coupled to a DC motor power supply (e.g., a battery) configured to provide information about its performance to the power failure detector so that the detector can determine if there is in fact a power supply failure. In some embodiments, the power failure detection circuit may include a power detector (such as, but not limited to, a power meter) configured to collect data about the availability of power at a power supply (e.g., a battery) of the exoskeleton device and determine if there is a power supply failure. In some embodiments, the circuit may generate an output if the collected data indicates a lack or insufficiency of power supply at a power supply powering the exoskeleton device or its components.

[0048] For example, the power supply may provide data indicating that the state of charge of the power supply is too low, i.e., the power available to operate the exoskeleton is low. In some embodiments, there may be noise on the motor power rails, and such noise may be filtered by a filter before the low power condition information is sent to the detector. An example of such a detector is a voltmeter that receives or measures voltage data associated with the power supply (which may optionally have been filtered) to determine the power condition at the power supply. In another example, an ammeter is provided that measures the current flowing through the exoskeleton wiring or any part of the power system.

[0049] In some embodiments, an external trigger input and / or a detector's determination of a power supply state (e.g., a determination that a power supply (such as a battery) is experiencing a low power condition) may be provided to an internal processor of a power fault detection circuit. The fault detection circuit or the fault detection internal processor may evaluate the input and / or information received from the detector according to trigger selection logic. Figure 5A An example of a low power condition detection algorithm flow is illustrated in . In some embodiments, the logic may specify that during normal operation as determined by external input or detector information (e.g., power at the power source is sufficient and stable), the low impedance switch may be opened, thereby allowing normal operation to continue. However, once the fault detection circuit or internal fault detection processor determines that there is a fault in the exoskeleton system (such as low power availability at the power source), the fault detection circuit or internal processor may cause the switch to close, resulting in low impedance on the motor.

[0050] Come back for reference Figure 4 In some embodiments, the power fault detection circuit may include an opto-isolated power driver configured to drive a low impedance switch to cause the switch to close or open based on instructions received from the fault detection circuit or the fault detection internal processor. For example, upon determining that the exoskeleton is experiencing a low power condition, the opto-isolated power driver may transmit a signal to the low impedance switch to initiate a motor braking mode (e.g., Mode 4 of Table 1) so that the exoskeleton can collapse gracefully. In some embodiments, the power fault detection circuit may generate an isolation status report related to a detected power fault.

[0051] In some embodiments, as described above, the low impedance switch can be configured to conduct when there is no power. Examples of such switches are so-called normally closed (NC) switches, which include electromechanical switches (e.g., conductors, relays) and solid-state switches. Using an electromechanical switch as a low impedance switch can be based on the balance between the low on-resistance established by its isolation and some factors, which can promote conduction when the switch is closed, such as its limited number of switching cycles, noisy switches (bounces), high power levels for driving, larger per-ampere size ratios, low switching speeds, etc. Examples of solid-state NC switches (i.e., solid-state relays) include depletion-type MOSFETs that can also be used as low impedance switches. Solid-state switches may have several useful properties that can be utilized when used as low impedance switches, including their fast and quiet switching, no bounce, low volume, unlimited number of switching cycles, low power switches, minimal or no power requirements for maintaining states, etc. However, these switches may not be isolated according to the design, and the resistance may depend on the current.

[0052] In some embodiments, solid-state switches (such as those comprising solid-state MOSFET transistors) may be implemented in a brushed motor using an H-bridge motor drive configuration. Figure 5B As shown in , in the case of a brushless motor, a three-phase bridge driver structure can be used. All operational aspects of a three-phase motor (brushless motor) are similar to those of a brushed motor. In embodiments where an H-bridge is used to brake a device such as an exoskeleton, the H-bridge structure can be conceived so that it is consistent with one of the specific cases of a failed exoskeleton (i.e., the exoskeleton has no power or energy, such as energy that can be used to keep a specific transistor open or closed). Figure 6B An H-bridge configuration switch is shown that can be used as a low impedance switch for managing the controlled collapse of an exoskeleton device.

[0053] refer to Fig. 6A In some embodiments, the H-bridge can be constructed from enhancement mode N-channel (lower pair) and P-channel (upper pair) MOSFET transistors. N-channel MOSFET transistors have a positive drive voltage (the voltage V between the gate (G) and the source (S) GS ), and the P-channel MOSFET has a negative drive voltage. Whenever there is no voltage V applied between the gate (G) and the source (S), GS When the enhancement mode MOSFET (both P-channel and N-channel) is not conducting (closed), and whenever it is above |V GS threshold | is applied between the same terminals, the enhancement mode MOSFET can be turned on. However, whenever V GS = zero, the depletion-mode MOSFETS can be turned on, that is, by, for example, when the power is off and the transistor control voltage (V GS ) is zero, the transistors can be turned on when no power is supplied and / or no driver is present, facilitating their use in controlled collapse of the exoskeleton. In some embodiments, conduction can be stopped, i.e., when the voltage V GS Higher than |V GS threshold | These are conditions for normal exoskeleton operation (not a relaxed or controlled collapse).

[0054] Figure 6B An exemplary H-bridge configuration switch for a motor drive is shown, which can be used to manage the controlled collapse of an exoskeleton. Figure 6B middle, Fig. 6A The two upper P-channel enhancement-mode transistors are replaced by two N-channel depletion-mode transistors, and the control polarity should be reversed. In such an embodiment, an additional inverter can be added to the depletion-mode transistor gates, because depletion-mode MOSFETs require V to operate. GS<0. Compared to the classic solution of including N-channel enhancement transistors in the upper part of the H-bridge, an inverter may have to be included in the above embodiment because the enhancement N-channel transistors are driven by the positive V GS In some embodiments, whenever a power failure occurs, the driver is powered off and both upper transistors can start conducting. This arrangement closes the circuit where the two upper transistors, the motor and the upper part of the H-bridge are connected to V BUS , facilitating the flow of current and allowing motor braking. Similarly, in a three-phase drive the three upper P-channel enhancement-mode transistors can be replaced with three N-channel depletion-mode MOSFETs. This change can allow motor disconnection for brushless motors.

[0055] exist Fig. 7A Another example of an H-bridge switch for motor drive that can be used to manage the controlled collapse of an exoskeleton is shown in FIG. Figure 7B As shown in , the two lower enhancement-mode MOSFETs can be modified by replacing them with N-channel depletion-mode transistors. Fig. 7A An H-bridge structure based on N-channel MOSFETs. In such an embodiment, no additional inverter is required because the control polarity remains unchanged. As in the above case, when a power failure occurs, the two lower transistors can start to conduct (contrary to the two upper transistors in the case where the two upper transistors are replaced above), facilitating the flow of current and allowing braking of the motor. In a three-phase bridge, all three lower MOSFETs can be modified from package type to depletion type N-channel transistors. After equivalent replacement, they can act similarly to H-bridge transistors, that is, they can allow the brushless motor to be disconnected (soothing or controlled collapse) whenever a power failure occurs.

[0056] By replacing enhancement mode transistors (both P-channel and N-channel) with (for example) P-channel depletion mode transistors, the Fig. 6A and 6B .

[0057] The use of depletion-mode MOSFETs as part of an H-bridge driving a motor in an exoskeleton illustrates the integration of a low-resistance switch within an H-bridge structure that is already part of the exoskeleton, as opposed to using separate low-resistance switches. This overall implementation facilitates a reduction in the number of electronic circuit components by allowing dual use of two of the four MOSFET transistors comprising the H-bridge.

[0058] Reference Figure 8 , in some embodiments, an example circuit is shown including a self-test circuit for a low impedance switch configured to manage a controlled collapse of an exoskeleton. In some embodiments, in addition to Figure 3In addition to the components of the controlled collapse circuit shown in FIG. 1 (such as a separate motor driver, a DC motor power supply, a low impedance switch, etc.), the self-test circuit can include an isolated current sensor capable of withstanding large amounts of current (e.g., up to 4 times, 3 times, 2 times, etc., of the maximum motor current). Additionally, a noise filter configured to adjust the motor current measurements during the self-test can also be part of the self-test circuit. Furthermore, even when the exoskeleton is fully operational without a power failure, an isolated switch trigger can be used to trigger a controlled collapse condition for testing purposes that activates a gentle or controlled collapse function.

[0059] One feature of the self-test circuit is its ability to detect the presence of a controlled collapse circuit on the exoskeleton device, allowing the self-test circuit to distinguish between an exoskeleton that includes a controlled collapse circuit and an exoskeleton that does not have a controlled collapse circuit. The self-test algorithm may be executed during a built-in test (BIT) whenever the system is turned on (such as during a Fig. 9 Alternatively, the self-test algorithm may be initiated when the exoskeleton is in a safe position (e.g. when the user is not present, or if present, when the user is sitting). In some embodiments, the proposed self-test algorithm may not be intended to be executed when the exoskeleton is in a standing position or whenever it is in motion.

[0060] In some embodiments, execution of the self-test algorithm may include minimal movement of some or all of the exoskeleton segments (e.g., movement of approximately 1, 2, 3 degrees, etc. in some specific direction), movement that is not approved by or controlled by the user of the exoskeleton. For example, movement may be performed only within the range of human limb movement. In addition, if actually available, a controlled collapse function of the exoskeleton may be activated. For example, an isolated switch trigger control may provide a controlled collapse condition that is configured to trigger the controlled collapse function. Upon engaging the controlled collapse, a low impedance switch placed in parallel with both the motor and the drive may begin to conduct, causing the switch to draw a large portion of the current from the drive due to the low impedance of the switch.

[0061] In some embodiments, a current sensor that may be in series with the switch may measure current when the controlled collapse circuit and the self-test circuit (STC) are activated. The magnitude of the current may provide an indication as to whether the controlled collapse circuit and / or the self-test circuit are functioning properly or malfunctioning, and a report may be generated indicating the performance of both circuits. For example, if, for example, a current exceeding 10% of the maximum drive rated current is measured, this may be interpreted as indicating that the controlled collapse circuit and / or the self-test circuit (STC) are functioning properly, and an internal or controlling processor may disengage both the motor drive and the controlled collapse circuit, and a report may be generated indicating the functional operation of the controlled collapse. The amount of current measured is limited by, among other factors, the power supply of the exoskeleton (such as a battery) and the drive current supply capabilities.

[0062] In some embodiments, as the exoskeleton completes a maneuver, little or no current may be measured, which may be interpreted by the controlled collapse circuit and / or STC as an indication of a fault, and a corresponding report may be generated indicating the fault. In some embodiments, a high current may not have been detected or the maneuver may not have been completed. In this case, the motor drive may have to be checked and an appropriate report may be generated.

[0063] refer to Fig.10 In some embodiments, an example flow chart illustrating activation of a controlled collapse adapted to body weight of an exoskeleton is provided. As described above, gravity due to the body weight of the user affects the controlled collapse function of the exoskeleton, and for this reason, it is desirable to have a controlled collapse function adapted to body weight. In fact, the controlled collapse feature can be configured to adapt to a wide range of user demographics, so that the exoskeleton (including the controlled collapse function) can adapt to various user parameters, such as but not limited to weight, height, gender, specific user physical characteristics. In some embodiments, the controlled collapse adapted to body weight can allow the controlled collapse time interval to remain at least substantially unchanged by the user's weight. That is, by adjusting the weight of the user of the exoskeleton, the time period of collapse (e.g., the total time required to lower to the ground) can be made at least substantially independent of the weight of the user of the exoskeleton. In some embodiments, adaptation to various user weights can be achieved by designing the controlled collapse function to the highest possible weight, and then programmatically reducing the controlled collapse intensity (e.g., increasing the collapse speed) with the actual user's weight. In other words, a desired collapse speed can be first established for the highest body weight that the exoskeleton is designed to support, and the collapse speeds for any other body weights can be calibrated so that the time interval during their controlled collapse is substantially the same as that of the highest body weight.

[0064] exist Fig.10In the invention, a controlled collapse adapted to body weight is activated by controlling a low impedance switch based at least in part on an analysis of the height and / or speed of collapse of the exoskeleton. Fig.10 An embodiment is shown in which temporary deactivation of controlled collapse is used during controlled collapse of the exoskeleton to adapt to body weight. Depending on the collapse speed and / or the height of the descent, the controlled collapse feature of the exoskeleton can be activated or deactivated to reduce or increase the collapse speed, respectively. For example, the duty cycle of the PWM control signal can be increased or decreased to indicate a determination to reduce or increase the collapse speed, respectively. These switch control signals can then be provided to the low impedance switch. In some embodiments, the signal can be analog. An internal control processor (e.g., a dedicated controlled collapse processor) can control the speed of the controlled collapse to allow the duration of the collapse (from a vertical position to a ground position) to be constant. As described below with respect to Fig.11 This effect may be achieved as described in the example embodiment of FIG. 1 by keeping the low impedance switch closed for a variable period of time that is dependent on the user's weight.

[0065] Fig.11 An example embodiment is shown that illustrates the use of a PWM control mode to control the body weight-adapted controlled collapse of an exoskeleton. Fig.11 In this example embodiment described in , the control signal is active LOW (i.e., the controlled collapse is activated whenever the control signal is zero, and is deactivated whenever the signal is high). The height above the surface can be measured by an inertial sensor / altimeter, a proximity sensor, by using absolute / incremental encoders embedded in the joints of the exoskeleton portions, etc. During normal operation (assuming the exoskeleton is in a stable standing position (Phase A)), the height and collapse speed are stable. The height is nominal and the collapse speed is zero. At point (1), a power failure is detected and a controlled collapse is activated. During Phase B, the height begins to decrease at point (1), while the speed increases due to acceleration. At point (2), the control microprocessor can analyze the height change, speed, and acceleration data to determine that the collapse may be too fast (e.g., the calculated or estimated collapse time exceeds a threshold). Based on this determination, the microprocessor can decide to reduce the PWM duty cycle to reduce the collapse speed. During phase C, the collapse speed is strictly controlled, the acceleration is reduced (e.g., to an infinitesimal value), and the collapse speed is kept at an almost constant value. During phase C, the height decreases almost linearly. Phase C ends at point (3), whenever the exoskeleton reaches the surface (ground). This is the beginning of phase D. The speed is zero and the control signal is stopped. In this way, the controlled collapse adapted to the body weight ends.

[0066] refer to Fig.12, in some embodiments, an example diagram illustrating a control mode for individually controlling segments of an exoskeleton during a controlled collapse of the exoskeleton adapted to body weight is shown. During a controlled collapse, there may be multiple factors that affect the speed of collapse of each segment of the exoskeleton, including friction between the joints of different segments, the initial position of the exoskeleton prior to the controlled collapse, user behavior, etc., which may affect the speed of collapse of the various segments of the exoskeleton. In some embodiments, because the various segments may experience different controlled collapse conditions, it may be desirable to establish a controlled collapse mechanism that is able to balance the possible different collapse speeds of the various segments of the exoskeleton during collapse. Example situations where different segments may experience different controlled collapse conditions include sports (e.g., sports like skating and figure skating, where descent (collapse) may be an integral part of the activity and athletes are instructed how to descend). In some situations, students may be taught safe descent techniques where the descent is not necessarily balanced / symmetrical, i.e., different segments of the exoskeleton may be descended under different conditions.

[0067] Fig.14 An example set of control modes for controlling 4 segments of an exoskeleton is illustrated. In this exemplary embodiment, the segments are controlled separately during the controlled collapse of the exoskeleton. The curves in the figure are divided into six stages:

[0068] Phase A: Exoskeleton operating normally (stationary). Altitude constant, no electrical failure detected.

[0069] Phase B: A power failure is detected at point (1). The exoskeleton enters a controlled collapse. All segments are controlled by the same pattern except segment 2. Segment 2 collapses too fast and the controller decides to slow down the descent by reducing the PWM control duty cycle.

[0070] Phase C: The large acceleration achieved during the previous phase causes the controller to slow down all segments except segment 4. Segment 4 collapses at the correct speed and thus the controller retains the same control duty cycle for that segment.

[0071] Phase D: During collapse, all segments begin to slow down. Segments 1 and 3 are controlled with low duty cycle PWM. Segments 2 and 4 are completely off with zero duty cycle.

[0072] Phase E: Towards the end of the controlled collapse, the controller decides to contract segment 3 (100% duty cycle without engine disconnect). Segments 1 and 2 are controlled by a low duty cycle PWM signal, and only segment 4 is controlled by a high duty cycle signal.

[0073] Phase F: At point (2) the body's center of mass reaches the surface and collapse is complete. All control signals are deactivated.

[0074] about Fig.12 The above examples illustrate controlled collapse mechanisms that separately control the controlled collapse of different segments of the exoskeleton by evaluating information such as height, velocity, acceleration, directional proximity, etc. for each controlled segment. Data may be obtained by sensors strategically positioned throughout the exoskeleton. For example, absolute encoders and incremental encoders embedded in the joints of the exoskeleton may provide at least some of the above information. Fig.11 As described in more detail, analysis of the above information for all segments may allow the control processor to determine how to affect the collapse of each segment (e.g., by varying duty cycle, etc.). By employing PWM-based control of low-resistance switches, giving the exoskeleton the ability to independently increase or decrease the collapse speed of each segment, the disclosed embodiments allow the exoskeleton to collapse to accommodate a variety of user controlled collapse behaviors, initial controlled collapse positions, and provide a means to execute a customized safe collapse procedure following a predefined collapse pattern.

[0075] refer to Fig.13 , in some embodiments, an exemplary controlled collapse circuit is shown, the controlled collapse circuit including an energy harvesting circuit for a low impedance motor configured to manage the controlled collapse of the exoskeleton. As discussed in detail above, at least one cause of engaging in a controlled collapse may be a power failure at the exoskeleton device (where the energy supply may be dappled within milliseconds), which may seem contradictory because a control processor managing the controlled collapse may consume power to complete tasks related to controlling or managing the controlled collapse (e.g., generating PWM, analyzing data, etc.), facilitating the opening and closing of low impedance switches, and the like. In some embodiments, there may be at least two sources of power in the exoskeleton system, the power source that fails: a backup energy storage system designed for controlled collapse and an energy harvesting system, or a combination thereof.

[0076] An example of a backup energy storage system may be a supercapacitor, which may have low weight, high energy availability, and low recharge time. In some embodiments, the recharging of such a supercapacitor may be controlled to avoid inrush current during power-up of the exoskeleton. With respect to the energy harvesting circuit, a regenerative braking technique may be used that harvests the potential or energy generated by the flow of a large current at a low impedance switch closure. Due to Lenz's law, the flow of a large current through an inductor of the energy harvesting circuit may generate a magnetic flux Φ, which results in the generation of a voltage potential across the inductor, which may be converted to a voltage suitable for the system electronics and memory (e.g., at a supercapacitor).

[0077] In some embodiments, given multiple energy sources (e.g., memories and harvesting systems), a controlled collapse circuit including an energy harvesting circuit may include a power selector configured to select one or more power sources to use during controlled collapse. The selector may be based on a simple ORing diode or a more complex power path controller may be used. For example, the selection of the power source may depend on a variety of factors, such as the energy availability at the power source, the amount of energy required to perform the controlled collapse, and the like.

[0078] In some embodiments, the controlled collapse circuit may also include a sensor module configured to sense voltage and height, orientation, and position of the exoskeleton. The sensor module provides data to the low resistance switch controller and driver. The sensed voltage may coordinate the switch control strategy of the exoskeleton.

[0079] In some embodiments, once a power source is selected by the energy source selector, power may be supplied to the low resistance switch controller and driver from the selected source. When receiving power and data from the sensor module, the switch controller and driver may make an evaluation to determine if any parameters of the controlled collapse of the exoskeleton should be changed. For example, in some embodiments, the switch controller and driver may reduce the PWM control duty cycle of only selected segments of the exoskeleton based on the availability of power from the power source, the height of the exoskeleton above the ground, and the segment position obtained by the sensor module. As another example, if the power source is low, the controlled collapse control adapted to body weight is suspended and the exoskeleton enters a simple, uncontrolled lowering routine.

[0080] Although various inventive embodiments have been described and illustrated herein, a person of ordinary skill in the art will readily envision various other means and / or structures for performing the functions described herein and / or obtaining the results and / or one or more advantages described herein, and each such variation and / or modification is considered to be within the scope of the inventive embodiments described herein. More generally, it will be readily understood by those skilled in the art that all parameters, dimensions, materials, components, and configurations described herein are intended to be examples, and that actual parameters, dimensions, materials, and / or configurations will depend on the specific application or application using the teachings of the invention. Those skilled in the art will recognize or be able to determine the equivalents of many specific inventive embodiments described herein using no more than routine experiments. Therefore, it should be understood that the above embodiments are presented only by way of example, and within the scope of the appended claims and their equivalents, other inventive embodiments may be practiced in addition to those specifically described and claimed. The inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and / or method described herein. In addition, if these features, systems, articles, materials, kits, and / or methods are not mutually inconsistent, any combination of two or more such features, systems, articles, materials, and / or methods is included within the scope of the invention disclosed herein. Furthermore, some embodiments disclosed herein are distinguishable from prior art references by the specific lack of one or more features disclosed in the prior art; that is, the claims to these embodiments may include negative limitations in order to distinguish from the prior art.

[0081] Various inventive concepts may also be embodied as one or more methods, an example of which is provided. The actions performed as part of a method may be ordered in any suitable manner. Thus, even though shown as sequential actions in an illustrative embodiment, it is also possible to construct such embodiments in which the actions are performed in an order different from that illustrated, which may include performing some actions simultaneously.

[0082] Any and all references to publications or other documents (including, but not limited to, patents, patent applications, articles, web pages, books, etc.) cited anywhere in this application are hereby incorporated by reference in their entirety. In addition, all definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0083] The indefinite articles "a" and "an" as used in this specification and the claims should be understood to mean "at least one", unless explicitly indicated to the contrary.

[0084] The phrase "and / or" as used in this specification and claims should be understood to mean "either or both" of the elements so combined, i.e., elements that are present jointly in some cases and separately in other cases. Multiple elements listed with "and / or" should be interpreted in the same manner, i.e., "one or more" of the elements so combined. In addition to the elements specifically identified with the "and / or" phrase, other elements may optionally be present, whether or not they are related to the specifically identified elements. Thus, as a non-limiting example, when used in conjunction with open language such as "comprising," a reference to "A and / or B" may refer to only A (optionally including elements other than B) in one embodiment; to only B (optionally including elements other than A) in another embodiment; to both A and B (optionally including other elements) in yet another embodiment, and so on.

[0085] As used in this specification and claims, "or" should be understood to have the same meaning as "and / or" defined above. For example, when separating items in a list, "or" or "and / or" should be interpreted as including, i.e., including at least one of the elements or at least one of the list of elements (but also including more than one), and optionally including additional unlisted items. Only when the term clearly indicates the opposite, such as "only one" or "exactly one", or, when "consisting of..." is used in the claims, it will refer to the inclusion of exactly one element or exactly one element in the list of elements. In general, the term "or" as used herein should be interpreted as indicating exclusive substitution (i.e., "one or the other but not both") only when it is preceded by an exclusive term (such as "either of the two", "one", "only one" or "exactly one"). "Mainly consisting of...", when used in the claims, should have the ordinary meaning as used in the field of patent law.

[0086] As used in this specification and claims, the phrase "at least one" with respect to a list of one or more elements should be understood to mean at least one element selected from any one or more elements in the list of elements, but not necessarily including at least one of each element specifically listed in the list of elements, and not excluding any combination of elements in the list of elements. This definition also allows elements to be selectively present in addition to the elements specifically identified in the list of elements to which the phrase "at least one" refers, regardless of whether the elements are related or unrelated to the specifically identified elements. Thus, as a non-limiting example, in one embodiment, "at least one of A and B" (or equivalently "at least one of A or B", or equivalently "at least one of A and / or B") may refer to at least one, optionally including more than one A, without B (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one B, without A (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one A, and at least one, optionally including more than one B (and optionally including other elements), and so on.

[0087] In the claims and the foregoing specification, all transitional phrases such as "comprises," "comprising," "carrying," "having," "containing," "involving," "maintaining," "comprising," etc. shall be understood as open-ended, i.e., meaning including but not limited to. As provided in Section 211.03 of the U.S. Patent Office Manual of Patent Examining Procedures, only the transitional phrases "consisting of" and "consisting essentially of" shall be closed or semi-closed transitional phrases, respectively.

Claims

1. A method of facilitating controlled collapse of an exoskeleton device comprising a motor, the method comprising: receiving an indication of one or more of a power failure, an electrical failure, a software failure, and a mechanical failure of the exoskeleton device, the indication initiating a descent of the exoskeleton device to the ground; as well as A low impedance circuit is established between the positive and negative terminals of the motor such that an electromagnetic force is generated to slow the descent of the exoskeleton device such that a collapse velocity of the exoskeleton device is substantially constant in time during at least a portion of the descent.

2. The method of claim 1, wherein the received indication is generated by one or more sensors operably coupled to the exoskeleton device.

3. The method of claim 2, wherein the one or more sensors include a temperature sensor configured to measure a temperature of a power source of the exoskeleton device.

4. The method of claim 2, wherein the one or more sensors include a power meter, the power meter being configured to: collecting data regarding the availability of electrical power at a power source of the exoskeleton device, and If the collected data indicates a power supply shortage or insufficiency at a power source powering the exoskeleton device, a message is generated.

5. The method of claim 4, wherein the power meter is configured to generate the information after filtering noise from the data.

6. The method of claim 2, wherein the one or more sensors include a voltmeter and / or an ammeter configured to: Voltage and / or current data are provided separately at one or more points along the electrical circuitry of the exoskeleton device.

7. The method of claim 1, wherein a low impedance is established between the positive terminal and the negative terminal of the motor.

8. The method of claim 7, wherein the low impedance is established via a controlled collapse circuit, the controlled collapse circuit comprising an opto-isolated power driver configured to open or close a low impedance switch.

9. A collapse circuit for facilitating controlled collapse of an exoskeleton device comprising a motor, the circuit comprising: a processor or circuit configured to receive an indication of one or more of a power failure, an electrical failure, a software failure, and a mechanical failure of the exoskeleton device, the indication causing the exoskeleton device to initiate a descent to the ground; as well as A driver is configured to establish a low impedance between the positive terminal and the negative terminal of the motor so as to cause an electromagnetic force to be generated to resist or slow the descent of the exoskeleton device so that the collapse speed of the exoskeleton device is substantially constant in time during at least a portion of the descent.

10. The circuit of claim 9, further comprising a power fault detection circuit configured to generate an indication in response to receiving information related to the performance and / or status of the exoskeleton device, the indication from one or more sensors operably coupled to the exoskeleton device.

11. The circuit of claim 10, further comprising one or more sensors, the one or more sensors comprising a temperature sensor configured to measure a temperature of the power supply indicative of a fault.

12. The circuit of claim 10, further comprising one or more sensors, the one or more sensors comprising a power meter, the power meter being configured to: providing data regarding the availability of electrical power at a power source of the exoskeleton device, and When the collected data indicates one or more of a power failure, an electrical failure, a software failure, and a mechanical failure, information is generated.

13. The circuit of claim 12, further comprising a filter configured to filter noise from the data before the information is generated by the power meter.

14. The circuit of claim 10, further comprising one or more sensors, the one or more sensors comprising a voltmeter and / or an ammeter, the voltmeter and / or ammeter being configured to: providing voltage and / or current data at one or more points along the electrical circuitry of the exoskeleton device, respectively, and Information is generated when the collected data indicates one or more of a power failure, an electrical failure, a software failure, and a mechanical failure.

15. The circuit of claim 9, wherein the power driver comprises an opto-isolated power driver configured to open or close the low impedance switch to establish a low impedance between the positive terminal and the negative terminal of the motor.

16. A method for facilitating collapse of an exoskeleton device used by a user, the exoskeleton device comprising a motor, the method comprising: receiving an indication of one or more of a power failure, an electrical failure, a software failure, and a mechanical failure of the exoskeleton device, the indication causing the exoskeleton device to initiate a descent to the ground; determining an amount of electromagnetic force sufficient to resist or slow the descent of the exoskeleton device such that a collapse velocity of the exoskeleton device during at least a portion of the descent is established such that the collapse velocity of the exoskeleton device during at least a portion of the descent is substantially constant over time; as well as A low impedance is established between the positive and negative terminals of the motor such that an electromagnetic force is generated to resist or slow the descent of the exoskeleton device.

17. The method of claim 16, wherein the rate of collapse of the exoskeleton device is configured such that a total time of at least a portion of the descent is substantially constant relative to the weight of the user.

18. The method of claim 16, wherein establishing a low impedance between the positive terminal and the negative terminal of the motor comprises varying a time period during which a low impedance switch between the positive terminal and the negative terminal is opened or closed.

19. The method of claim 18, wherein the changing of the time period is configured such that a total time of at least a portion of the descent is substantially constant relative to a weight of the user.

20. The method of claim 18, wherein the time period is varied by varying a duty cycle of a power width modulation (PWM) control signal configured to control the opening or closing of the low impedance switch.

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