Power machines and methods of operating power machines

Abstract

A power machine can include a frame, a lift arm, and one or more electrical devices for controlling one or more work elements. The electrical devices can be controlled to improve positional accuracy for the work elements during a work operation, in order to improve power management and customer experience (e.g., in order to provide a smoother ride during drive operations), and in order to provide float functionality for the work elements.

Description

[0001] This application is a divisional application, based on the PCT national phase application with an international filing date of January 20, 2023, which entered into China on July 19, 2024, with national application number 202380017974.8 and invention title "Power Machinery and Method of Operating Power Machinery". The corresponding PCT international application number is PCT / US2023 / 060985.

[0002] Cross-references to related applications

[0003] This application claims priority to U.S. Provisional Patent Application No. 63 / 301,462, filed January 20, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0004] This disclosure relates to powered machinery. More specifically, this disclosure relates to powered machinery that operates wholly or partially under electric power. For the purposes of this disclosure, powered machinery includes any type of machinery that generates power for the purpose of performing a particular task or a variety of tasks. One type of powered machinery is a work vehicle. For example, a work vehicle for a loader is typically a self-propelled vehicle with a work device such as a lifting boom (although some work vehicles may have other work devices), which can be manipulated to perform work functions. Several examples include loaders, excavators, multi-purpose vehicles, tractors, and trenchers. Background Technology

[0005] Conventional power machinery may include hydraulic systems and related components configured to perform various operational functions using output from a power source (e.g., an internal combustion engine). More specifically, hydraulic motors may be configured to power the movement of the power machinery, and hydraulic actuators (e.g., hydraulic cylinders) may be used to move a lifting arm structure attached to the power machinery to tilt or otherwise move implements connected to the lifting arm structure, or to perform other operations.

[0006] The above discussion is provided only for general background information and is not intended to help determine the scope of the subject matter for which protection is sought. Summary of the Invention

[0007] Some examples of this disclosure provide a power machinery for mobile operation of implements or other operations. The power machinery may include a main frame supporting an operator station and a lifting arm structure.

[0008] Some examples provide a power machine comprising: a main frame; a power source supported by the main frame; a drive system configured to be powered by the power source to provide traction to move the main frame over terrain; and a lifting arm structure supported by the main frame. The lifting arm structure may include a lifting arm, a implement carrier supported by the lifting arm, and one or more electric actuators configured to be powered by the power source to perform one or more of the following: moving the lifting arm relative to the main frame, or moving the implement carrier relative to the lifting arm. The control system may include one or more control devices configured to, during the start-up mode of the power machinery: receive operator input for moving at least one of the one or more electric actuators in a first predetermined direction; based on the received operator input, command the at least one electric actuator to move in the first predetermined direction until at least one of the following is achieved: the at least one electric actuator reaches a predetermined reference position, or the control system no longer receives the operator input; and in response to the at least one electric actuator reaching the predetermined reference position, determine the actual position of the at least one electric actuator based on the predetermined reference position.

[0009] In some examples, receiving additional operator input can prompt the control system to command the at least one electric actuator to perform additional movement. The one or more control devices can be configured to determine the actual position of the at least one electric actuator corresponding to the additional movement based on the sensed movement relative to the predetermined reference position.

[0010] In some examples, commanding the at least one electric actuator to make the movement in the first predetermined direction may include commanding the movement to be made at a speed less than or equal to a predetermined speed, which may be slower than the rated operating speed of the at least one electric actuator.

[0011] In some examples, commanding the at least one electric actuator to make the movement in the first predetermined direction may include commanding the movement to be less than or equal to the predetermined speed, regardless of a requested speed exceeding the predetermined speed as indicated by the operator input.

[0012] In some examples, the control system may include a resolver that communicates with the at least one electric actuator to track the relative movement of the at least one electric actuator. One or more control devices may be configured to further determine the actual position based on the tracking of the relative movement of the at least one electric actuator by the resolver.

[0013] In some examples, the received operator input may correspond to a lifting arm command, and the first predetermined direction may correspond to the lowering of the lifting arm.

[0014] In some examples, the received operator input may correspond to a machine carrier command, and the first predetermined direction may correspond to the retraction of the machine carrier.

[0015] In some examples, the one or more control devices may be configured to, after determining that the physical state conditions of the power machinery can be satisfied, and further based on the determination that the physical state conditions of the power machinery can be satisfied, command the at least one electric actuator to make the movement in the first predetermined direction.

[0016] Some examples provide a method for operating a powered machine. Operator input for moving at least one electric actuator of the powered machine can be received. A component of the operator input corresponding to the return direction can be determined. Based on the powered machine being in a start-up mode, and upon determining that the component is non-zero: while the component remains non-zero, the at least one electric actuator can be commanded to move in the return direction at a return speed until the at least one electric actuator reaches a predetermined reference position; and subsequent commanded movements of the at least one electric actuator can be tracked based on the relative movement from the predetermined reference position.

[0017] In some examples, based on the power machinery being in the start-up mode and when the component is determined to be zero, the at least one electric actuator can be commanded to move in a direction corresponding to the operator input, and the movement of the at least one electric actuator can be tracked based on the relative movement from the predicted reference position.

[0018] In some examples, the shutdown position of the at least one electric actuator can be determined during a shutdown period of the power machinery prior to the start-up mode. During the start-up mode, the predicted reference position can be determined based on the determined shutdown position.

[0019] Some examples provide a power machine having a main frame, a power source supported by the main frame, and a lifting arm structure supported by the main frame. The lifting arm structure may include a lifting arm, a tool carrier supported by the lifting arm, and one or more electric actuators configured to raise and lower the lifting arm relative to the main frame. The control system may include one or more control devices configured to operate the lifting arm structure in a floating mode, whereby the one or more electric actuators allow the lifting arm structure to move relative to the main frame in response to external forces.

[0020] In some examples, operating the lifting arm structure in the floating mode may include: the one or more control devices selectively supplying power to the one or more electric actuators to resist but not stop the movement of the lifting arm structure in response to the external force.

[0021] In some examples, the external force includes gravity.

[0022] In some examples, selectively powering one or more electric actuators to resist but not stop the movement of the lifting arm may include controlling the one or more electric actuators to prevent the lifting arm from moving at a speed exceeding a threshold speed due to the external force.

[0023] In some examples, selectively powering one or more electric actuators to resist but not stop the movement of the lifting arm may include providing zero operating power to the one or more electric actuators when the current speed of the lifting arm can be zero.

[0024] Some examples provide a method for controlling the lifting arm of a powered machine using an electronic control system. A floating mode can be determined as an active operating mode for the powered machine. Based on the fact that the floating mode is the active operating mode, the operation of one or more electric actuators can be controlled to raise and lower the lifting arm of the powered machine such that: the current speed of the lifting arm remains below a threshold floating speed for operation of the lifting arm; and the one or more electric actuators are not supplied with power to actively move the lifting arm.

[0025] Some examples include: controlling the operation of one or more electric actuators based on the floating mode being the active operating mode, such that the one or more electric actuators are not supplied with power to maintain the position of the lifting arm.

[0026] Some examples include: based on the floating mode being the active operating mode, controlling the operation of the one or more electric actuators such that the one or more electric actuators can be powered to resist gravity and maintain the position of the lifting arm.

[0027] Some examples include: based on the floating mode being the active operating mode, controlling the operation of the one or more electric actuators such that the one or more electric actuators are not provided with power to maintain the position of the lifting arm against a net external force exceeding gravity in the direction of gravity.

[0028] In some examples, the floating mode can be determined as the active operation mode based on user input corresponding to the mode selection received by the electronic control system.

[0029] Some examples provide a power machine including a main frame, an electrical source supported by the main frame, and a drive system. The drive system may include: one or more drive motors powered by the electrical source and operatively coupled to a traction element to provide traction power for travel over terrain; and a suspension system that anchors the traction element to the main frame. The control system may include one or more control devices configured to control the drive speed of the one or more drive motors according to a first mode to perform precise operation, and to control the drive speed of the one or more drive motors according to a second mode to compensate for oscillations caused by travel on the suspension system. In the second mode, the control system may control the drive speed with an integral gain that is substantially reduced compared to the first mode.

[0030] In some examples, in the second mode, the control system can control the drive speed by implementing proportional control without an integral control term.

[0031] In some examples, in the second mode, the control system can use a proportional-integral-derivative (PID) control loop that may include an effective zero integral gain to control the drive speed.

[0032] In some examples, the control system can be configured to implement the PID control loop with an effective non-zero integral gain in the first mode.

[0033] In some examples, the control system can be configured to implement the PID control loop with zero integral gain in the first mode.

[0034] In some examples, the control system may be configured to selectively operate in either the first mode or the second mode in response to an operator input indicating a selection of the first mode or the second mode.

[0035] In some examples, the control system may be configured to selectively operate in either the first mode or the second mode based on monitoring the operation of one or more actuators of the power machinery.

[0036] In some examples, the traction element may be a tracked traction element.

[0037] Some examples provide a method for controlling the drive operation of a power machine. A selection of a first drive mode or a second drive mode can be received. The power machine can be operated according to the selected first or second drive mode. In the first drive mode, speed control of one or more electric drive motors of the power machine can be implemented using a proportional-integral-derivative (PID) control loop. In the second drive mode, speed control of the one or more electric drive motors can be implemented using a proportional control loop.

[0038] In some examples, the first drive mode may be a precision control drive mode.

[0039] In some examples, the second drive mode may be a hydraulic simulation drive mode.

[0040] In some examples, the second drive mode may not include a proportional-integral-derivative control loop.

[0041] In some examples, the proportional control loop may correspond to the PID control loop of the first drive mode implemented with effective zero integral gain.

[0042] Some examples provide a method for controlling the drive operation of powered machinery. A selection of a precise control drive mode or a hydraulic simulation drive mode can be received. One or more drive motors, which can be powered by an electrical source and operatively coupled to a traction element, can be electronically controlled to provide traction power for movement across terrain. In response to receiving the selection of the precise control drive mode, the one or more drive motors can be electronically controlled with an effective non-zero integral gain. In response to receiving the selection of the hydraulic simulation drive mode, the one or more drive motors can be electronically controlled with an effective zero integral gain.

[0043] In some examples, in response to the selection of the precise drive mode, the one or more drive motors can be controlled by a first control loop with effective non-zero integral gain, and in response to the selection of the hydraulic simulation drive mode, the one or more drive motors can be controlled by a first control loop with effective zero integral gain.

[0044] In some examples, in response to the selection of the hydraulic simulation drive mode, the one or more drive motors can be controlled using the first control loop with zero integral gain.

[0045] In some examples, in response to receiving the selection of the hydraulic simulation drive mode, the one or more drive motors can be controlled with zero integral gain.

[0046] In some examples, in response to receiving the selection of the hydraulic simulation drive mode, the one or more drive motors can be controlled using a proportional-integral-derivative (PID) control loop with the effective zero integral gain.

[0047] In some examples, receiving the selection may include receiving user input indicating the commanded driving mode.

[0048] In some examples, receiving the selection may include automatically identifying the selection based on the commanded movement or actual movement of the non-traction actuator of the power machinery.

[0049] The summary and abstract are provided to present the selected concepts in a simplified form, which will be further described in the detailed description below. The summary and abstract are not intended to identify key or essential features of the claimed subject matter, nor are they intended to help determine the scope of the claimed subject matter. Attached Figure Description

[0050] Figure 1 This is a block diagram illustrating a representative power machinery functional system that can advantageously practice examples of the present disclosure.

[0051] Figure 2 It is a perspective view generally showing the front of a powered machine on which the examples disclosed in this specification can be advantageously practiced.

[0052] Figure 3 It is roughly shown Figure 2 The rear perspective view of the power machinery shown.

[0053] Figure 4 For example, the illustration is shown. Figure 2 and Figure 3 A block diagram of the components of the power system of a loader.

[0054] Figure 5 This is a side elevation view showing certain components of a power machine in the form of an electrically powered, compact tracked loader, according to an example of this disclosure.

[0055] Figures 6 to 8 This is a flowchart illustrating a method for controlling one or more actuators of an electrically powered machine according to an example of this disclosure. Detailed Implementation

[0056] The concepts disclosed in this discussion are described and illustrated with reference to exemplary arrangements. However, these concepts are not limited in their application to the construction details and component arrangements of the illustrated embodiments and can be practiced or performed in a variety of other ways. The terminology in this document is used for descriptive purposes and should not be considered limiting. As used herein, words such as “including,” “comprising,” and “having,” and variations thereof, mean to encompass the items listed thereafter, their equivalents, and additional items.

[0057] Although the power machinery disclosed herein may be embodied in many different forms, several specific embodiments are discussed herein, and it is understood that the embodiments described in this disclosure are merely considered as examples of the principles described herein, and the disclosed technology is not intended to be limited to the illustrated examples.

[0058] Some of the discussions below describe components and configurations for improved power machinery, including those that use electric (e.g., as opposed to hydraulic) power to operate certain power machinery components or otherwise implement certain power machinery functions. In some examples, electric components may be mounted to the frame of the power machinery to selectively move the working elements of the power machinery, including booms or implement carriers. In some examples, electric components may provide prime movers for the power machinery, including providing prime movers for tracked power machinery (e.g., compact tracked loaders).

[0059] Correspondingly, some examples can provide improvements to conventional power machinery, including power machinery that uses hydraulic components to perform certain operations and other machinery with conventionally controlled electric actuators. For example, in conventional methods, accurately tracking the position of electronically controlled working elements may require complex or expensive position sensors or calibration operations, which may be incompatible in the context of loaders or other work vehicles. In this regard, some examples of this disclosure may include systems and methods for controlling the homing operation of a boom or other working element, including calibrating the boom position during a start-up operation with homing movement based on specific operator input.

[0060] As another example, some configurations can improve ride control for power machinery, thereby correspondingly improving operator comfort and battery life. During the driving operation of power machinery, conventional control of the drive motor speed can sometimes lead to relatively large or otherwise undesirable oscillations in power demand and the physical structure of the power machinery. For example, relatively fine control of the motor speed of power machinery with a torsional (or other) suspension system can result in relatively large oscillating movements of the suspension system and correspondingly large variations in power delivery from the power source (e.g., rapid oscillations between fully discharged and fully charged power). Some examples of this disclosure may include systems and methods for selectively eliminating integral control from the control loop used for drive speed control to reduce these types of oscillations and thus help reduce wear on electrical system components and improve operator comfort.

[0061] As yet another example, some configurations can provide floating operation for electric booms. For instance, when the power machinery is operating in floating mode, the electric actuators used to raise and lower the boom can be controlled to allow the boom to move under external forces (e.g., gravity or ground contact) but not to actively move the boom (i.e., not to induce the boom to move in a direction corresponding to the power direction of the associated actuator). In some examples, the electric lifting actuators can be controlled to provide a back force to ensure that the boom does not move at excessive speeds during floating operation (e.g., under the influence of gravity on a loaded bucket) so that power is not provided to hold the boom in its current position and to prevent active movement of the boom.

[0062] As will be described below, these concepts can be implemented in a variety of powered machines. Figure 1 The diagram illustrates representative power machinery on which practical examples can be implemented, and... Figures 2 to 3 An example of such a powered machine is illustrated and described below before any other examples are disclosed. For the sake of brevity, only one powered machine is illustrated and discussed as a representative powered machine. However, as mentioned above, the examples below can be practiced on any of a number of powered machines, including those with... Figures 2 to 3 The examples shown represent different types of power machinery. For the purposes of this discussion, power machinery includes a frame, at least one working element, and a power source capable of providing power to the working element to complete a work task. One type of power machinery is a self-propelled work vehicle. A self-propelled work vehicle is a type of power machinery that includes a frame, a working element, and a power source capable of providing power to the working element. At least one of the working elements is a prime mover system for moving the power machinery under power.

[0063] Figure 1This is a block diagram illustrating the basic system of power machinery 100, which can be any of many different types of power machinery. The examples discussed below can be advantageously incorporated into power machinery 100. Figure 1 The block diagram illustrates the various systems on the power machinery 100 and the relationships between the various components and systems. As mentioned above, at the most basic level, the power machinery used for the purposes of this discussion includes a frame, a power source, and working elements. The power machinery 100 has a frame 110, a power source 120, and working elements 130. Because Figure 1 The power machinery 100 shown is a self-propelled work vehicle, and therefore also includes a traction element 140 and an operator station 150. The traction element 140 itself is a work element configured to move the power machinery above a support surface, and the operator station 150 provides operating positions for controlling the work elements of the power machinery. A control system 160 is provided to interact with other systems to perform various work tasks, at least in part, in response to control signals provided by the operator.

[0064] Some work vehicles have working elements capable of performing specialized tasks. For example, some work vehicles have a lifting arm, to which a implement (e.g., a bucket) is attached, for example, via a pin-attachment arrangement. The working element (i.e., the lifting arm) can be manipulated to position the implement for performing the task. In some examples, the implement can be positioned relative to the working element, for example, by rotating the bucket relative to the lifting arm, to further position the implement. Under normal operation of such a work vehicle, the bucket is intended to be attached and in use. Such a work vehicle can accommodate other implements by disassembling the implement / working element combination and reassembling another implement in place of the original bucket. However, other work vehicles are intended to be used with a wide variety of implements and have implement interfaces, such as... Figure 1 The tool interface 170 shown is, in its most basic form, a connection mechanism between the frame 110 or the working element 130 and the tool. This connection mechanism can be as simple as a connection point for directly attaching the tool to the frame 110 or the working element 130, or more complex, as discussed below.

[0065] In some power machinery, the implement interface 170 may include an implement carrier, which is a physical structure movably attached to a working element. The implement carrier has engagement and locking features to receive and secure any one of a plurality of different implements to the working element. A characteristic of such an implement carrier is that once an implement is attached to it, it is fixed to the implement (i.e., cannot move relative to the implement), and when the implement carrier moves relative to the working element, the implement moves with the implement carrier. The term implement carrier, as used herein, is not merely a pivoting connection point, but specifically intended to refer to a dedicated device for receiving and securing various different implements. The implement carrier itself may be mounted to the working element 130, such as a boom or frame 110. The implement interface 170 may also include one or more power sources for supplying power to one or more working elements on the implement. Some power machinery may have multiple working elements with implement interfaces, each of which may, but does not need, have an implement carrier for receiving implements. Some other power machinery may have working elements with multiple tool interfaces, allowing a single working element to accommodate multiple tools simultaneously. Each of these tool interfaces may, but does not need to, have a tool carrier.

[0066] Frame 110 includes a physical structure that can support various other components attached to or positioned thereon. Frame 110 may include any number of individual components. Some powered machinery has a rigid frame; that is, no part of the frame can move relative to another part of the frame. Other powered machinery has at least one part that can move relative to another part of the frame. For example, an excavator may have an upper frame portion that rotates relative to a lower frame portion. Other work vehicles have an articulated frame, such that one part of the frame pivots relative to another part for steering purposes.

[0067] Frame 110 supports power source 120, which is configured to power one or more working elements 130, including one or more traction elements 140, and in some examples, via implement interface 170 for use by attached implements. Power from power source 120 can be directly supplied to any of the working elements 130, traction elements 140, and implement interface 170. Alternatively, power from power source 120 can be supplied to control system 160, which in turn selectively supplies power to elements capable of using it to perform working functions. Power sources for power machinery typically include engines (e.g., internal combustion engines) and power conversion systems (e.g., mechanical transmissions or hydraulic systems) configured to convert output from the engine into a form of power usable by the working elements. Other types of power sources can be incorporated into power machinery, including power sources or combinations of power sources, often referred to as hybrid power sources.

[0068] Figure 1 A single working element designated as working element 130 is shown, but various power machines can have any number of working elements. Working elements are typically attached to the frame of the power machine and are movable relative to the frame when performing a work task. For example, the power machine can be a lawnmower with a mower stand or other mower component as a working element, which is movable relative to the mower's frame. Additionally, traction elements 140 are a special case of working elements because their working function is typically to move the power machine 100 above a support surface. Traction elements 140 are shown separate from working element 130 because many power machines have additional working elements in addition to traction elements, although this is not always the case. The power machine can have any number of traction elements, some or all of which can receive power from power source 120 to propel the power machine 100. Traction elements can be, for example, track assemblies, wheels attached to axles, and the like. The traction element can be mounted to the frame such that the movement of the traction element is restricted to rotation about the axle (so that steering is accomplished by sliding action), or alternatively, it can be pivotally mounted to the frame to accomplish steering by pivoting the traction element relative to the frame.

[0069] Power machinery 100 includes an operator station 150, which includes an operating position from which an operator can control the operation of the power machinery. In some power machinery, the operator station 150 is defined by an enclosed or partially enclosed cab. Some power machinery on which the disclosed examples can be practiced may not have a cab or operator's cab of the type described above. For example, a walk-behind loader may not have a cab or operator's cab, but instead has an operating position serving as an operator station from which the power machinery is properly operated. More broadly, power machinery that is not a work vehicle may have an operator station that is not necessarily similar to the operating position and operator's cab referenced above. Furthermore, some power machinery (e.g., power machinery 100 and others), whether or not they have an operator's cab or operator's position, may be able to operate remotely (i.e., from a remotely located operator station) in place of an operator station adjacent to or on the power machinery, or other than an operator station adjacent to or on the power machinery. This may include applications in which at least some of the operator-controlled functions of the power machinery can be operated from an operating position associated with an implement connected to the power machinery. Alternatively, in the case of some power machinery, a remote control device (i.e., remote from both the power machinery and any implements connected to it) may be provided, which is capable of controlling at least some of the operator-controlled functions on the power machinery.

[0070] Figures 2 to 3 The diagram shows a loader 200. A loader 200 is... Figure 1 The illustration shows a specific example of a type of power machinery, in which the examples discussed below can be advantageously employed. Loader 200 is a skid-steer loader, which is a loader having traction elements (in this case, four wheels) mounted to the loader's frame via rigid axles. Here, the phrase "rigid axle" refers to the fact that skid-steer loader 200 does not have any traction elements that can rotate or steer to assist the loader in turning. Instead, the skid-steer loader has a drive system that independently powers one or more traction elements on each side of the loader, such that by providing different traction signals to each side, the machinery will tend to skid above the support surface. These varying signals can even include: powering the traction elements(s) on one side of the loader to move the loader in the forward direction; and powering the traction elements(s) on the other side of the loader to move the loader in the opposite direction, such that the loader will rotate about a radius centered within the loader's own footprint. The term "skid steering" has traditionally referred to loaders with skid steering as described above, where wheels serve as traction elements. However, it should be noted that many tracked loaders also achieve turning via skid and are technically skid-steering loaders, even if they do not have wheels. For the purposes of this discussion, unless otherwise stated, the term skid steering should not be considered as limiting the scope of the discussion to loaders where wheels serve as traction elements. Correspondingly, although some exemplary power machines discussed herein are presented as skid-steering power machines, some examples disclosed herein can be implemented on a variety of other power machines. For example, some configurations can be implemented on compact loaders or compact excavators that do not achieve turning via skid.

[0071] Loader 200 is Figure 1 The diagram is broadly illustrated and is a specific example of the power machinery 100 discussed above. For that purpose, the features of the loader 200 described below include those related to... Figure 1The reference numerals used herein are generally similar. For example, loader 200 is described as having a frame 210, just as power machine 100 has a frame 110. A skid-steer loader 200 is described herein to provide a reference for understanding an environment on which examples described below relating to track assemblies and mounting elements for mounting track assemblies to power machines can be practiced. Loader 200 should not be considered limiting, particularly regarding the description of features that may have been described herein, which are not essential to the disclosed examples and can therefore be included or may not be excluded from power machines other than loader 200, on which the examples disclosed below can be advantageously practiced. Unless otherwise specifically indicated, the examples disclosed below can be practiced on a variety of power machines, of which loader 200 is only one. For example, some or all of the concepts discussed below can be practiced on many other types of work vehicles (e.g., various other loaders, excavators, trenchers, and bulldozers, to name just a few).

[0072] The loader 200 includes a frame 210 supporting a power system 220 capable of generating or otherwise providing power to operate various functions on the power machinery. The power system 220 is shown in block diagram form but is located within the frame 210. The frame 210 also supports a working element in the form of a boom assembly 230, powered by the power system 220 and capable of performing various work tasks. When the loader 200 is a work vehicle, the frame 210 also supports a traction system 240, also powered by the power system 220, which can propel the power machinery above a support surface. The boom assembly 230, in turn, supports a implement interface 270, which includes: an implement carrier 272 capable of receiving and securing various implements to the loader 200 for performing various work tasks; and a power coupling 274 to which implements can be coupled for selectively providing power to implements that may be connected to the loader. The power coupling 274 can provide a hydraulic power source, an electrical power source, or both. The loader 200 includes a cab 250 defining an operator station 255 from which the operator can operate various control devices 260 to cause the powered machinery to perform various operational functions. The cab 250 can pivot rearward about an axis extending through the mounting 254 to provide access to the power system components as needed for maintenance and repair.

[0073] Operator station 255 includes operator seat 258 and multiple operation input devices, including a lever 260 that the operator can manipulate to control various mechanical functions. Operator input devices may include buttons, switches, levers, sliders, pedals, and the like, which may be standalone devices (e.g., manually operated levers or foot pedals) or integrated into handles or display panels (including programmable input devices). Actuation of the operator input devices may generate signals in the form of electrical, hydraulic, and / or mechanical signals. Signals generated in response to the operator input devices are provided to various components on the power machinery for controlling various functions on the power machinery. Functions controlled via the operator input devices on power machinery 200 include control of traction element 219, lifting arm assembly 230, implement carrier 272, and providing signals to any implements that can be operatively coupled to implements.

[0074] The loader may include a human-machine interface (HMI) comprising a display device disposed in a cab 250 to provide indications of information relevant to the operation of the power machinery in a form perceptible to the operator (e.g., auditory and / or visual indications). Auditory indications may be in the form of buzzers, bells, and the like, or via verbal communication. Visual indications may be in the form of graphics, lights, icons, gauges, alphanumeric characters, and the like. The display may provide dedicated indications, such as warning lights or gauges, or dynamically provide programmable information, including programmable display devices, such as monitors of various sizes and capacities. The display device may provide diagnostic information, troubleshooting information, instruction information, and various other types of information assisting the operator in operating the power machinery or implements connected to it. Other information that may be useful to the operator may also be provided. Other power machinery (e.g., walk-behind loaders) may not have a cab, operator's cab, or seat. The operator's position on such loaders is typically defined relative to the position most suitable for the operator to manipulate operator input devices.

[0075] Various power machines, including and / or interacting with the examples discussed below, may have various different frame components supporting various working elements. The elements of frame 210 discussed herein are provided for illustrative purposes, and frame 210 is not the only type of frame that power machines on which the examples can be practiced may adopt. The frame 210 of loader 200 includes a base frame or lower portion 211 of the frame and a main frame or upper portion 212 of the frame supported by the base frame. In some examples, the main frame 212 of loader 200 is attached to the base frame 211, for example, by fasteners or by welding the base frame to the main frame. Alternatively, the main frame and the base frame may be integrally formed. The main frame 212 includes a pair of upright portions 214A and 214B located on either side of the main frame and facing the rear of the main frame, the pair of upright portions 214A and 214B supporting the lifting arm assembly 230, and the lifting arm assembly 230 being pivotally attached to the pair of upright portions 214A and 214B. The lifting arm assembly 230 is illustratedly pinned to each of the upright portions 214A and 214B. For the purposes of this discussion, the combination of upright portions 214A and 214B, the lifting arm assembly 230, and mounting features on the mounting hardware (including pins used to pin the lifting arm assembly to the main frame 212) is collectively referred to as joints 216A and 216B (one located on each of the upright portions 214). Joints 216A and 216B are aligned along axis 218 such that the lifting arm assembly can pivot relative to the frame 210 about axis 218, as discussed below. Other power machinery may not include an upright portion on either side of the frame, or may not have a lifting arm assembly that can be mounted to an upright portion on either side of the frame and facing the rear of the frame. For example, some power machinery may have a single arm mounted to a single side of the power machinery or to the front or rear end of the power machinery. Other machinery may have multiple working elements, including multiple lifting arms, each of which is mounted to the machinery in its own configuration. The frame 210 also supports a pair of traction elements in the form of wheels 219A-D on either side of the loader 200.

[0076] Figures 2 to 3The lifting arm assembly 230 shown is one example of many different types of lifting arm assemblies that can be attached to power machinery, such as loader 200, or other power machinery on which the examples discussed herein can be practiced. Lifting arm assembly 230 is a so-called vertical lifting arm, meaning that it is movable relative to frame 210 along a lifting path 237 forming a generally vertical path under the control of loader 200 (i.e., the lifting arm assembly can be raised and lowered). Other lifting arm assemblies can have different geometries and can be coupled to the loader frame in various ways to provide a lifting path different from the radial path of lifting arm assembly 230. For example, some lifting paths on other loaders provide radial lifting paths. Other lifting arm assemblies can have extendable or telescopic portions. Other power machinery can have multiple lifting arm assemblies attached to its frame, each lifting arm assembly being independent of the other lifting arm assemblies. Unless otherwise specifically stated, the inventive concepts set forth in this discussion are not limited to the type or number of lifting arm assemblies coupled to a particular power machinery.

[0077] The lifting arm assembly 230 has a pair of lifting arms 234 disposed on opposite sides of the frame 210. A first end 232A of each of the lifting arms 234 is pivotally coupled to a power mechanism at a joint 216, and when in a position such as Figure 2 In the lowered position shown, the second end 232B of each of the lifting arms is positioned in front of the frame 210. The connector 216 is positioned toward the rear of the loader 200 such that the lifting arms extend along the side of the frame 210. As the lifting arm assembly 230 moves between its minimum and maximum height, the lifting path 237 is defined by the travel path of the second end 232B of the lifting arms 234.

[0078] Each of the lifting arms 234 has a first portion 234A, the first portion 234A of each lifting arm 234 being pivotally coupled to the frame 210 at one of the joints 216, and a second portion 234B extending from its connection with the first portion 234A to a second end 232B of the lifting arm assembly 230. Each lifting arm 234 is coupled to a transverse member 236 attached to the first portion 234A. The transverse member 236 provides increased structural stability to the lifting arm assembly 230. On the loader 200, a pair of actuators 238, hydraulic cylinders configured to receive pressurized fluid from the power system 220, are pivotally coupled to both the frame 210 and the lifting arms 234 at pivotable joints 238A and 238B located on either side of the loader 200. The actuators 238 are sometimes referred to individually and collectively as lifting cylinders. Actuation of actuator 238 (i.e., extension and retraction) causes lifting arm assembly 230 to pivot about joint 216, thereby raising and lowering it along a fixed path illustrated by arrow 237. Each of a pair of control links 217 is pivotally mounted to frame 210 and one of the lifting arms 232 on either side of frame 210. Control links 217 help define the fixed lifting path of lifting arm assembly 230.

[0079] Some lifting arms, most notably those on excavators but also those on loaders, may have a section that can be controlled to pivot relative to another section, rather than as... Figure 2 The lifting boom assembly 230 shown in the illustration moves in a coordinated manner (i.e., along a predetermined path). Some power machinery has a lifting boom assembly with a single lifting boom, as is known in excavators or even some loaders and other power machinery. Other power machinery may have multiple lifting boom assemblies, each independent of the others.

[0080] A tool interface 270 is located near the second end 232B of the lifting arm assembly 234. The tool interface 270 includes a tool carrier 272 capable of receiving and securing various tools to the lifting arm 230. Such tools have complementary mechanical interfaces configured to engage with the tool carrier 272. The tool carrier 272 is pivotally mounted at the second end 232B of the arm 234. A tool carrier actuator 235 is operatively coupled to the lifting arm assembly 230 and the tool carrier 272, and is operable to rotate the tool carrier relative to the lifting arm assembly. The tool carrier actuator 235 is illustrated as a hydraulic cylinder and is commonly referred to as a tilting cylinder.

[0081] By enabling the tool carrier to attach to multiple different tools, the transfer from one tool to another can be accomplished relatively easily. For example, machinery with a tool carrier can provide an actuator between the tool carrier and the lifting arm assembly, such that removing or attaching the tool does not involve removing or attaching the actuator from the tool or removing or attaching the tool from the lifting arm assembly. Tool carrier 272 provides a mounting structure for easily attaching the tool to the lifting arm (or other part of the power machinery), a mounting structure not present in lifting arm assemblies without a tool carrier.

[0082] Some power machinery may have implements or implement-like devices attached to a lifting arm, for example, by pinning to it, wherein the tilting actuator is also directly connected to the implement or implement-like structure. A common example of such implements rotatably pinned to the lifting arm is a bucket, with one or more tilting cylinders attached to a bracket, which is directly fixed to the bucket, for example, by welding or fasteners. Such power machinery does not have an implement carrier, but rather has a direct connection between the lifting arm and the implement.

[0083] The implement interface 270 also includes an implement power source 274 for use with implements connected to the boom assembly 230. The implement power source 274 includes a pressurized hydraulic fluid port to which the implement can be removably coupled. The pressurized hydraulic fluid port selectively provides pressurized hydraulic fluid for powering one or more functions or actuators on the implement. The implement power source may also include a power source for powering electric actuators and / or electronic controllers on the implement. The implement power source 274 also exemplarily includes an electrical conduit that communicates with a data bus on the excavator 200 to allow communication between controllers on the implement and electronics on the loader 200.

[0084] The frame 210 supports and generally surrounds the power system 220, allowing the various components of the power system 220 to... Figures 2 to 3 Not visible in the image. The arrangement of the drive pump, motor, and axle in power machinery 200 is merely one example of the arrangement of these components. As discussed above, power machinery 200 is a skid-steer loader, and therefore, the traction element on each side of the power machinery is controlled via the output of a single hydraulic pump or by a single drive motor as in power machinery 200, or by means of several individual drive motors. Various other configurations and combinations of hydraulic drive pumps and motors can be employed, which may be advantageous.

[0085] The description of the power machinery 100 and the loader 200 above is provided for illustrative purposes to provide an illustrative environment in which the examples discussed below can be practiced. While the examples discussed can be, for example, by... Figure 1The block diagram of the power machinery 100 generally describes the practice on power machinery (and more specifically, on the loader of, for example, tracked loader 200), but unless otherwise indicated or stated, the concepts discussed below are not intended to limit their application to the specific context described above.

[0086] Figure 4 A schematic diagram of a block diagram of power machinery 400 is shown. Power machinery 400 can be any of a variety of different types of power machinery (e.g., wheeled or tracked skid steer loaders), including any of the types broadly discussed above. To perform various tasks and drive operations, power machinery 400 may include a power source 402, a control unit 404, and electric actuators 406, 408. Any one or two of the electric actuators 406, 408 may be configured differently as one or more drive actuators or one or more workgroup actuators, and may provide [equipment / features / etc.]. Figure 4 The diagram generally illustrates different numbers of individual actuators. For example, as discussed further below, some power machinery may include left-side and right-side drive actuators, each comprising a corresponding electronically driven motor configured to power an associated traction element (e.g., annular track assembly), as well as various extendable (or other) working actuators (e.g., one or more extendable boom actuators, one or more extendable tilting actuators, etc.). In some cases, and also as... Figure 4 As shown, one or more brakes 410, 412 may be configured to stop the movement of one or more associated actuators 406, 408 based on a control signal from the control device 404.

[0087] In the illustrated example, power machinery 400 may be electrically powered, and therefore, power source 402 may include an electrical source, such as, for example, a battery pack comprising one or more battery cells (e.g., lithium-ion batteries). In some examples, power source 402 may include other electrical storage devices (e.g., capacitors) and other power sources. Additionally, power machinery 400 may, but does not need to, include an internal combustion engine that provides electric power to power source 402 via a generator (e.g., to charge one or more batteries of the electrical source).

[0088] Typically, control device 404 can be implemented in a variety of different ways and may include one or more known electronic controllers of one or more types or examples. For example, control device 404 may be implemented as a processor device of a known type (e.g., microcontroller, field-programmable gate array, programmable logic controller, logic gate, etc.), including as part of one or more general-purpose or special-purpose computers. Additionally, control device 404 may include or be operatively communicating with other computing components, including memory, input devices, output devices, etc. (not shown). In this respect, control device 404 may be configured to perform some or all of the operations of the processes described herein, which may be retrieved from memory or otherwise interact with memory, as appropriate. In some examples, control device 404 may include multiple control devices (or modules) that may be integrated into a single component or arranged as multiple separate components. In some examples, control device 404 may be a larger control system (e.g., Figure 1 It is part of the control system 160 and therefore may include or be in electronic communication with various control modules, including hub controllers, engine controllers, drive controllers, etc.

[0089] In different examples, different types of actuators can be configured to operate under power from power source 402, including electric actuators configured as rotary actuators, linear actuators, and combinations thereof. Figure 4 In the example shown, actuator 406 is a drive actuator and includes an electric motor 416, which is configured to drive one or more traction elements. Figure 4 (Not shown) provides rotational power. As noted above, some power machinery may include multiple drive actuators, including drive actuators that can be arranged for skid steering operations.

[0090] Also Figure 4As shown in the example, actuator 408 is a workpiece actuator and therefore includes an electric motor 420 configured to provide rotational power for operating one or more non-driven working elements (e.g., lifting arms, tools, etc.). In some cases, motor 420 may be configured to provide power for the movement of extender 422 (e.g., a lead screw, ball screw, another similar threaded assembly, or other known component for providing rotationally powered non-rotational movement), which can convert the rotational power of motor 420 into translational movement of extender 422 to provide translational force to the working elements of power machinery 400. For example, motor 420 may rotate in a first direction to drive the extension of extender 422, and when the motor rotates in a second rotational direction opposite to the first rotational direction, it may rotate in the second direction to drive the retraction of extender 422. In this way, and depending on how the electric actuator 406 is connected to the components of the power machinery 400, the extension (and retraction) of the electric actuator 406 can, for example, raise (or lower) the lifting arm of the power machinery 400, change the posture of the implements (e.g., bucket) of the power machinery 400, etc.

[0091] Therefore, each motor 416, 420 can typically be controlled to implement a specific function of the power machinery 400. As noted in general above, in some cases, different configurations of multiple drive actuators or workgroup actuators (e.g., multiple examples of actuators 406, 408 as shown) may be included to provide different functions for a particular power machinery. For example, in some configurations, the power machinery 400 may include: an electric actuator for a first lifting actuator on a first lateral side of the power machinery 400; an electric actuator for a second lifting actuator on a second lateral side of the power machinery 400; an electric actuator for a first tilting actuator on a first lateral side of the tool interface of the power machinery 400; an electric actuator for a second tilting actuator on a second lateral side of the tool interface of the power machinery 400; an electric actuator for a first drive actuator of a first drive system for powering one or more traction elements on a first lateral side of the power machinery 400 (or otherwise powering one or more traction elements); and an electric actuator for a second drive actuator of a second drive system for powering one or more traction elements on a second lateral side of the power machinery 400 (or otherwise powering one or more traction elements).

[0092] As noted above, in some examples, brakes 410, 412 may be coupled to (e.g., included therein) corresponding electric actuators 406, 408. In this regard, a wide variety of known braking systems can be used. For example, one or more brakes may be mechanical brakes including mechanical stops that can be moved to engage to block movement of the associated extender or associated motor in one or more directions, and can be moved to disengage to allow movement of the associated extender or motor. In some cases, a mechanical brake may include an arm that contacts the linear screw of the extender to prevent further movement of the linear screw. In some examples, one or more electrically operated brakes may be provided (i.e., brake assemblies including one or more electric actuators for applying braking force).

[0093] like Figure 4 As shown, power source 402 can be electrically connected to control unit 404, electric actuators 406, 408, and brakes 410, 412 (as applicable), as well as one or more auxiliary loads 414. Therefore, power source 402 can provide power to each motor 416, 420 to drive the movement (e.g., extension and retraction) of the corresponding extenders 418, 422, to control unit 404, to each brake 410, 412 (as applicable), to each of the auxiliary loads 414, etc. Furthermore, the power source can provide power to auxiliary loads 414 used for various auxiliary functions (i.e., loads not associated with providing traction or workgroup power). For example, auxiliary loads may include climate control systems (e.g., heaters, air conditioning systems, fans, etc.), sound systems (e.g., speakers, radios, etc.). In some cases, auxiliary loads 414 may be handled with lower priority according to certain power management modes.

[0094] like Figure 4As shown, control device 404 can be electrically communicated with power source 402, actuators 406, 408, brakes 410, 412 (as applicable), and (multiple) auxiliary loads 414, and can adjust (e.g., limit) the power supplied from power source 402 to each of these electrical loads (or others) or the power consumed by each of these electrical loads (or others). For example, control device 404 can adjust (e.g., reduce) the power supplied to each of these electrical loads by adjusting (e.g., reducing) the current that can be consumed by at least some of these electrical loads. In some cases, control device 404 can adjust the current supplied to the electrical load by adjusting the drive signal supplied to a current source (e.g., a voltage-controlled current source), which may be electrically connected to the electrical load (e.g., integrated within a power electronics driver board (e.g., a motor driver)) to supply current to the electrical load. For example, the current source may include one or more field-effect transistors, and the drive signal may be a voltage applied to one or more field-effect transistors to adjust the delivered current and thus the power delivered to the electrical load (e.g., a motor).

[0095] In some examples, similar to each of the electrical loads in power machinery 400, the power source of power source 402 may include (or may otherwise be electrically connected to) a current source (e.g., a power electronics board) that adjusts (e.g., and may limit) the amount of power to be delivered to the electrical loads of power machinery 400. In this case, control device 404 may adjust the drive signal to the power source to adjust the total current, and thus adjust the amount of power delivered to the electrical loads of power machinery 400. For example, control device 404 may adjust the output from power source 402 to regulate the torque, position, direction, and speed of one or more motors powered by power source 402.

[0096] In some examples, control device 404 may be configured to determine the current (i.e., temporally current) power usage of one or more actuators or other electrical loads, or the current power delivery from a power source. In some cases, the current power usage or delivery may be measured instantaneously. In some cases, the current power usage or delivery may be measured as the average power delivery over the most recent time interval (e.g., the previous 2 seconds). Thus, for example, control device 404 may determine the current power usage of each electrical load of power machinery 400, or it may determine the current power delivery from the power source 402.

[0097] In some cases, each electrical load and power source 402 of the power machinery may include, or may otherwise be electrically connected to, a current sensor to determine the current supplied to (or provided by) a particular electrical component, and may also (e.g., based on a voltage sensor or a fixed voltage supplied by the power source 402) determine the voltage supplied to (or provided by) a particular electrical component. In this way, for example, control device 404 may receive information about the current voltage and current supplied to each individual electrical load, or about the total current voltage and current supplied by the power source of the power machinery 400, and thereby determine the current power usage of the relevant (e.g., all) electrical loads and the power source of the power machinery 400.

[0098] In some examples, control device 404 may determine the current power usage of the power source of power machinery 400 by adding the current power usage of each associated electrical load of power machinery 400 (e.g., by multiplying the current and voltage of the loads). Alternatively, for example, the power may be determined by multiplying the torque and speed of one or more associated motors. In some cases, it may be advantageous to use any of these known methods. In other cases, control device 404 may determine the current power usage of the power source of power machinery 400 simply by determining the power delivered by the power source. For example, control device 404 may receive the current value of the current delivered by power source 402, and then determine the total current power usage of the power source based on the voltage of power source 402. In some cases, control device 404 may assume a substantially constant voltage for the power source, and then determine the current power usage of the power source by using a constant voltage and the current current value.

[0099] In some examples, power source 402 may include or may be electrically connected to a sensor to sense the current remaining energy of the power source. In some cases, for example, a voltage sensor may sense the voltage of the power source, which may indicate the current remaining energy remaining within the power source (e.g., because the voltage of the power source may be correlated with the current remaining energy within the power source). Any suitable means for sensing the remaining energy of the power source may be used, including taking into account how much current is supplied by the energy storage device over time.

[0100] In some examples, the power mechanism 400 may include one or more sensors capable of sensing various aspects of the power mechanism 400. For example, the power mechanism 400 may include torque sensors for one or more electric actuators to sense the current torque of one or more electric actuators. In some cases, the torque sensor may be the same as a current sensor electrically connected to the electric actuator (e.g., because current is related to torque). As another example, the power mechanism 400 may include position sensors (as applicable) for one or more extenders or other components of one or more electric actuators, including sensors capable of sensing the current extension amount of the extender of the electric actuator (e.g., relative to the housing of the electric actuator). In some cases, this may be a Hall effect sensor, a rotary encoder for a motor (e.g., which may be used to determine the extension amount of an actuator with an extender), an optical sensor, etc. In some cases, the power mechanism 400 may include a rotary transformer (not shown) configured to track the relative movement of one or more actuators (e.g., in a manner similar to...). Figure 5 The rotary transformer 548 is positioned to track the movement of the actuator 518. As yet another example, the power machinery 400 may include angle sensors for (e.g., of a lifting arm) one or more pivotable joints to determine the current orientation of the lifting arm (and any implements coupled thereto). As yet another example, the power machinery 400 may include velocity sensors or acceleration sensors (e.g., accelerometers) to determine the current velocity or current acceleration of the entire power machinery 400 or its components, respectively. As yet another example, the power machinery 400 may include inclinometers (e.g., accelerometers) that can sense the current attitude of the main frame of the power machinery 400 relative to gravity.

[0101] Figure 5 The diagram shows a side isometric view of an electrically powered mechanism 500 in which the lifting arm is in the fully lowered position. The mechanism 500 can be a specific embodiment of mechanisms such as mechanism 200, mechanism 400, etc. Figure 5As shown, the power machinery 500 may include a main frame 502, a lifting arm 504 connected to the main frame via a driven link 506, a drive link 508 pivotally connected to the lifting arm 504 and the main frame 502, an operator enclosure 510 (e.g., a cab, as shown), an implement interface 514 connected to the end of the lifting arm 504, an implement 516 (e.g., a bucket, as shown) connected to the implement interface 514, an electric lifting actuator 518, an electric tilting actuator 522, a power source 526, a drive system 528 (e.g., including an electric drive motor), a traction device 532 (e.g., a ring track as shown), and a climate control system 536 (e.g., as generally represents the entire auxiliary electrical load). In some examples, a suspension system 540 (e.g., a torsion suspension system) may be included to provide improved ride control and overall ride smoothness. As generally noted above, in some cases, similar (e.g., substantially identical) other components may be symmetrically (or otherwise) arranged on opposite lateral sides of the power machinery 500, including another electric lifting actuator, another electric tilting actuator, etc. Additionally, various examples may employ various lifting arm geometries, including lifting arm structures that do not include drive or driven links.

[0102] In some cases, power source 526 may be implemented in a manner similar to the previously described power source (e.g., power source 402). Therefore, power source 526 may include a battery pack comprising one or more batteries. Typically, power source 526 may supply power to some or all of the electrical loads of power machinery 500. For example, power source 526 may supply power to lifting actuator 518, tilt actuator 522, drive system 528, climate control system 536, etc.

[0103] The power machinery 500 may also include a control device 546, which may, as appropriate, communicate with some (or all) of the power source 526 and the electrical loads of the power machinery 500. For example, the control device 546 may communicate with a lift actuator 518, an electric tilt actuator 522, a drive system 528, a climate control system 536, etc. In this way, the control device 546 can control the operation of these components or other related systems to adjust how power is routed to each of these electrical loads (e.g., depending on criteria defined by a specific power management mode), and correspondingly, how power from the power source 526 is consumed within a given operating function or time interval.

[0104] As noted above, some examples may include a control system or method for calibrating the position of the lifting arm during the start-up operation of the powered machinery. For example, when the powered machinery 500 is started from a power-off state, the control device 546 may certainly not know the current position of the lifting arm 504 (e.g., as indicated by the current extension distance of the lifting actuator 518). Correspondingly, to ensure reliable operation of the lifting arm 504, it may be useful to identify a reference (or “original”) position of the lifting arm 504, which corresponds to the reference position (e.g., extension length) of the lifting actuator 518.

[0105] In some examples, the execution of the return operation can be advantageously delayed until appropriate operator input is received. Correspondingly, for example, if the lifting arm 504 is to be lowered to the lower mechanical stop corresponding to the return position of the lifting arm 504 and the lifting actuator 518, the control device 546 can delay the actual command to lower the lifting arm 504 until the operator has actively commanded the lowering movement.

[0106] In some examples, control device 546 may sometimes control the speed of the return movement of the working element, regardless of the movement speed commanded by the corresponding operator input. For example, during the start-up mode and before the lifting arm 504 has returned to its position, control device 547 may command a reduction in movement to return the lifting arm 504 to its position based on received operator input for reducing movement; however, even if the operator commands a faster movement, it may control the lifting arm 504 to move at or below the return speed.

[0107] In some examples, the return position can be in the fully lowered position (i.e., where the lifting arm engages with a stop on the frame of the machine), such that the lifting arm cannot move further in the lowering direction physically. In other examples, the return position can correspond to a position where the lifting arm passes at least one position sensor (e.g., a switch) that can sense when the lifting arm is in a particular position. In various examples, the power machinery can have more than one such limit switch (or other limit sensor), each individually identifiable and each capable of operating as a return position.

[0108] For the purposes of this discussion, the start-up mode can be the initial period of time when an operator has begun using the machinery by, for example, turning on a key or other similar action. Alternatively, or additionally, the start-up mode can be the period in which the operator takes specific actions to start or unlock working elements on the machinery (including drive systems and boom controls) to cause the machinery to move to a fully activated state in which, for example, the boom and drive system functions can be operated. Correspondingly, during the start-up mode, operator-controlled or other powered operation can be prevented for specific actuators, specific functions, or for traction elements or other specific power mechanical subsystems.

[0109] In some examples, once the return position of the lifting arm has been established for a specific start-up mode, subsequent operation of the lifting arm can be controlled to a commanded position based on the known (e.g., fixed or otherwise pre-determined) return position and sensed movement away from the return position. For example, once a return (e.g., fully lowered) position has been established for the lifting arm 504, subsequent control of the lifting arm 504 may include tracking the actual position (e.g., extension length) of the lifting actuator 518 based on the determined return position and the relative movement of the lifting actuator 518 sensed by the resolver 548.

[0110] In some examples, it may be possible to bypass one or more of the homing operations described above, or to use historical information to approximate the current actuator orientation (multiple) before the homing operation has been completed (e.g., before the relevant actuator has reached its homing position). For example, the last position of the lifting arm 504, as sensed by the resolver 548, can be stored when the power machinery 500 stops, and then compared with the current position sensed by the resolver 548 during a subsequent start-up mode. If the stored position and the current position coincide, the operational control of the lifting arm 504 can sometimes continue without re-establishing the homing position (e.g., via control based on the previously stored homing position). Correspondingly, in some cases, the shutdown sequence of the power machinery may include a delay imposed between the operator-requested power outage and the actual power cut-off of the relevant control device (e.g., device 546 or dedicated motor controller) to allow for the proper reception and storage of the current resolver position.

[0111] In some examples, other conditions may be applied, including allowing the return operation to be delayed in certain situations until certain physical states of the power machinery are achieved. For example, a return operation requiring movement (e.g., lowering) of the boom relative to the main frame of the power machinery may be prevented until the doors of the power machinery are fully closed or other physical state conditions of the power machinery are met (e.g., the cab door is closed, seatbelts or other safety or restraint systems are engaged, a valid access code has been entered, or other authorization conditions have been met). In some examples, the return operation may be interrupted, including when operator input to initiate the return operation is stopped. This allows the operator to abort the return operation for any reason if they wish to do so.

[0112] In some examples, for actuators that are not used for lifting actuators of the lifting arm, a reference position can be determined during the start-up mode. For example, a similar homing operation as discussed above with respect to lifting actuator 518 can be performed relative to tilt actuator 522 (e.g., where the fully retracted position of tool interface 514 corresponds to the homing position of tilt actuator 522). Therefore, the discussion above should be understood to also apply to homing operations relative to tilt actuator 522 or other actuators, where appropriate variations correspond to different positions and functional roles of the associated actuator(s).

[0113] Also refer to Figure 6 Some implementations may include a method 600 for starting up the powered machinery, which in some cases may implement some or all of the return functionality discussed above. In the illustrated example, at block 610, method 600 may include operating the powered machinery in a start-up mode, such as corresponding to a predetermined sequence of operations for transitioning the powered machinery from a power-off state to a fully operational energized state or a fully enabled state.

[0114] When in startup mode, method 600 may include receiving operator input at block 615, the operator input corresponding to movement of at least one electric actuator (e.g., one of actuators 518, 522) requested by an operator to move a corresponding working element of the power machinery. Once the operator input is received, method 600 may include determining at block 620 whether the operator input includes a non-zero component corresponding to the return direction. For example, method 600 may include determining whether the operator input for lifting actuator 518 corresponds to a non-zero lowering command (e.g., toward a fully lowered return position), or whether the operator input for tilting actuator 522 corresponds to a non-zero command in the retraction direction (e.g., toward a fully retracted return position).

[0115] In some implementations, the operator command may not correspond to a non-zero command in the reference direction. In such cases, method 600 may sometimes include moving the relevant actuator in the requested direction (e.g., raising the lifting arm 504) based on any associated constraints of the activation mode (e.g., having a limited maximum speed or reduced functionality relative to certain actuators). In some cases (e.g., alternatively), method 600 may include not moving the relevant actuator at all based on the corresponding zero movement constraint of the activation mode. For example, method 600 may include preventing movement of the relevant actuator unless required by a homing operation, until the homing position has been reached (e.g., reached due to a subsequent operator movement received at block 615, determined at block 620 as a command to move in the homing direction).

[0116] In some cases, under method 600, moving the actuator in a direction other than the return direction may include tracking the actuator's movement based on relative movement from a predicted position. For example, even if the return position has not yet been reached, the estimated starting position of the lifting actuator 518 (e.g., represented by a stored value from a previous stop sequence) may be used in conjunction with a relative movement, such as that determined by the resolver 548, to track (e.g., estimate) the movement of the lifting arm 504. Similar tracking based on sensed (or commanded) movement and stored starting (or other) positions may also be implemented using different types of sensors or actuators.

[0117] While the power machinery continues to operate in the start-up mode and the operator input continues to correspond to non-zero movement of the relevant actuator in the relevant return direction, method 600 may include: commanding the relevant actuator to move toward the return position at block 630. In some cases, the operation at block 630 may include: commanding the actuator to move at or below a threshold return speed, which may be less than the actuator's maximum possible operating speed or maximum rated operating speed. For example, regardless of the commanded speed used to reduce the lifting boom 504 or the retraction implement interface 514, method 600 may include: limiting the reduction speed or retraction speed, respectively, to at or below the relevant threshold speed during the return movement (or generally, for movement prior to reaching the return position). In some cases, such a threshold for the return (or pre-return) movement may be a deceleration threshold, which is slower than the rated operating speed of the relevant actuator (e.g., the maximum permissible speed for the actuator during normal traction or work operations). In some cases, the method 600 may be implemented with different speed thresholds for different actuators or for movement in different directions (e.g., a lower speed threshold for movement away from the homing direction compared to movement towards the homing direction, or vice versa).

[0118] Once the homing position has been reached, method 600 may include tracking subsequent movement of the actuator at block 640 based on the homing position. For example, once the homing position of the lifting arm 504 has been reached, subsequent operation of the lifting arm 504 can be controlled based on the homing position (e.g., a reference extension length indicating the lifting actuator 518) and the tracked movement relative to the homing position, as indicated by a signal from the resolver 548. If the homing position is not reached due to the removal of a non-zero signal before reaching the homing position, a subsequent non-zero signal from operator input can re-establish the homing process. In some examples, the operator may be allowed to abandon or bypass the homing process.

[0119] In some cases, the functionality discussed above (e.g., implemented in method 600 instead of at block 610) can advantageously be implemented outside of the startup mode scenario, or within the startup mode but outside of the scenario where the machine starts from a normal power-off state. For example, in some cases, the repositioning operation, as generally discussed above, can be implemented after the operator has engaged "release," "lift down," or other similar interfaces (e.g., the corresponding mechanical or virtual button) to automatically reposition the lifting arm or other working element (e.g., not under power), or can be implemented after the operator has engaged an emergency stop of the powered machine.

[0120] As noted above, some examples may include control systems or methods used to compensate for oscillations caused by travel in a suspension system or to compensate for fluctuations in the power demand of a power source caused by travel (e.g., oscillations that may involve the suspension or may be due to unsustainable vehicles), which could otherwise lead to substantial component wear (e.g., capacitor burnout) and other problems. Specifically, it has been found that selective operation under a control loop with a reduced (e.g., zero or effectively zero) integral control term for drive speed can provide a substantial improvement in overall power management. In other words, in some examples, instead of using proportional-integral-derivative (PID) control to precisely control the drive speed of the drive actuator of the power machinery, the control system can selectively control the drive speed with proportional rather than integral control (i.e., with a control loop that does not have an integral term (e.g., no integral block or operation), also referred to herein as hydraulic simulation mode. Therefore, for example, as implemented for power machinery 500, some examples of the disclosed technology can substantially reduce the oscillations of the suspension system 540 and the corresponding oscillations in the power flow of the power source 526 (e.g., ranging from full power delivery to maximum recharge) compared to conventional control methods. In some examples, for operation in hydraulic simulation mode, the integral gain of the control loop used in normal operating mode can be substantially reduced (i.e., reduced by more than 85%). In some examples, the integral gain used for speed control in hydraulic simulation mode can be effectively zero (i.e., with zero integral gain or no integral gain, or with an integral gain less than 0.005). In some cases, also as noted below, the effective zero integral gain in hydraulic simulation mode may lead to some steady-state error, which in turn may cause the electric actuator (like the hydraulic actuator) to tend to drift slightly relative to the load.

[0121] In some examples, the control system can be configured to selectively operate in different control modes based on the needs of a specific operation. For example, in some implementations, operator input may indicate whether to operate in a precise drive mode with PID control (and non-zero integral gain) or in a hydraulic simulation (or other similar) mode that allows for more stable or efficient operation, despite some loss of accuracy due to the absence of integral control. It has been found that in many operations of power machinery such as the power machinery 100 and 200 described above, precise control of the speed of travel of the power machinery may not be necessary or even desired. For example, overly precise control may lead to fluctuating power demands, as mentioned above. To offset the potential losses or other inefficiencies of such fluctuations, the so-called hydraulic simulation mode provides a drive response similar to that of a hydrostatic drive motor, with the added benefit of reduced power consumption and potential damage to the electronic components supplying power to the drive motor. On the other hand, in certain cases where precise operation is required, PID control can provide a more accurate speed of travel. Therefore, depending on the needs of the current (or currently commanded) operation, control can be selectively implemented in a hydraulic simulation mode with correspondingly reduced power fluctuations or in a default (or other) power mode with non-zero integral control and correspondingly improved accuracy.

[0122] Specifically, for reference Figure 7 Some embodiments may include a method 700 for operating a power machine, which in some cases may implement some or all of the functionalities discussed above. In the illustrated example, at block 710, method 700 may include determining whether the power machine is operating in a specific drive mode (e.g., a precise drive mode, as shown). In some cases, as generally noted above, method 700 may correspondingly include receiving operator input at block 712 indicating a selection of a mode (e.g., an explicit selection of a mode, or a lack of a change from a default mode), and at block 710 determining whether a specific mode is active based at least in part on that selection. In other cases, other parameters may additionally or alternatively influence the determination of a specific drive mode at block 710, including by monitoring the power consumption or other activities of various actuators. For example, some implementations can automatically identify specific patterns of current or future operations based on recognizing patterns in the commanded or actual movement of non-traction or other actuators (e.g., movement of a lifting or tilting actuator corresponding to a specific job operation, or no movement of a lifting or tilting actuator combined with non-zero traction power consumption).

[0123] continue Figure 7For example, if the precision drive mode is active, method 700 may include, at block 720, controlling the drive speed with a PID control loop having a non-zero integral gain, which can provide relatively precise control over the travel speed and is therefore particularly suitable for operations requiring relatively fine speed control. In contrast, if the precision drive mode is not active (e.g., if the hydraulic simulation mode is active), method 700 may include, at block 730, controlling the drive speed without an integral control term (e.g., with proportional rather than integral control, or otherwise having zero integral gain). As noted above, operation at block 730 can therefore result in improved power management of the power source and other components of the power machinery, as well as improved operator comfort and other benefits associated with smoother travel over terrain. Correspondingly, depending on which drive mode is active (e.g., as selected by user input at block 712), the control system may selectively provide drive control with greater overall precision for improved performance of specific traction operations, or drive control with reduced power fluctuations, including those that can reduce overall battery wear from high-amplitude power cycles. Therefore, method 700 can provide selective control for the drive operation of power machinery to match the needs of a specific operation (e.g., to effectively balance control accuracy, power management, and operator comfort).

[0124] In some examples, selective implementations of non-integral control may correspond to the operation of power machinery in a hydraulic simulation mode, where certain actuators of the power machinery are controlled to respond in a manner similar to conventional hydraulic actuators. For example, in some hydraulic simulation modes, eliminating integral control of the drive speed may cause the power machinery to drift slightly with sloping terrain, as may the hydraulic machinery, due to unavoidable hydraulic leakage. In some examples, selective implementations of non-integral control may include an implementation that continues the current control loop but with a modified (e.g., zeroed) gain for the integral term.

[0125] As also noted above, some examples may include control systems or methods for improving the overall functionality of the lifting arm and other working elements by allowing selective operation of specific working elements in floating mode. For example, when floating mode is active for power machinery 500, the lifting actuator 518 can be controlled to allow the lifting arm 504 to move by external forces (e.g., gravity or contact with the ground), wherein the lifting actuator 518 is powered as needed to slow down but not stop such movement. Thus, for example, efficient floating movement of the lifting arm 504 can be achieved with minimal power loss due to unnecessary operation of the actuator 518.

[0126] Specifically, reference Figure 8 Some implementations may include a method 800 for floating operation of a working element (e.g., a boom). In the illustrated example, at block 810, method 800 may include determining whether the power machinery is operating in a floating mode (e.g., the floating mode for the boom as shown). In some cases, as generally noted above, method 800 may correspondingly include receiving operator input at block 812 indicating a selection of a mode (e.g., an explicit selection of a floating mode, or a lack of a change from the default floating mode), and at block 810 determining whether a particular floating mode is active based at least in part on that selection.

[0127] continue Figure 8 For example, if the floating mode is active, method 800 may include: controlling the lifting (or other) actuator at block 820 according to the active floating mode. Typically, as noted above, operating the lifting arm in floating mode may include: controlling the lifting actuator such that an external force can move the lifting arm within a set of applicable constraints. For example, such as... Figure 8 As illustrated in the diagram (see the bending bracket), controlling the lifting actuator at block 820 according to the floating mode may include controlling the lifting actuator at block 822 such that the movement speed of the lifting arm remains below a threshold speed (e.g., as corresponding to the threshold extension or retraction speed of the lifting actuator). For example, based on the sensed movement speed of the lifting arm in floating mode exceeding or approaching an relevant threshold, method 800 may include providing current to the electric lifting actuator, the current partially counteracting but not stopping the movement. As another example, the method may provide a small amount of current to partially counteract gravity, regardless of the presence of any sensors to sense the movement speed of the lifting arm (e.g., such that the weight of the lifting arm does not alone cause the lifting arm to move toward the ground). In such cases, for example, although the actuator may be powered to resist gravity and maintain position, the actuator may generally not be powered to resist additional external forces (in the direction of gravity) exceeding gravity to maintain position. Similarly, in response to further external forces resisting gravity (e.g., an upward contact force on the lifting arm), the force provided to the actuator to maintain resistance to gravity may be reduced.

[0128] In some cases, controlling the lifting actuator according to the floating mode at block 820 may include controlling the lifting actuator at block 824 to not maintain the position of the lifting arm. For example, if zero movement of the lifting arm (e.g., lifting arm 504) is detected, zero current may be supplied to the associated lifting arm actuator (e.g., actuator 518) so that the actuator does not provide any active force to hold the lifting arm in place. In this case, the lifting arm may move freely under the influence of gravity or contact with an external (e.g., ground) surface, and in some cases, there is no control provided by the actuator.

[0129] In some cases, controlling the lifting actuator at block 820 according to the floating mode may include controlling the lifting actuator at block 826 to provide non-actively powered movement of the lifting arm, but the controller may provide some non-zero level of current to provide some upward force to partially counteract gravity. For example, while the lifting actuator may be controlled to prevent high-speed movement of the lifting arm due to external loads (e.g., gravity or ground contact) applied in floating mode (e.g., as discussed above), it may also be controlled to actively actuate the lifting actuator to resist external loads. In some cases, such active actuation may resist but not stop movement under external loads, but not actively move the lifting arm (i.e., not cause movement or supplement movement caused by net external loads). This may, for example, reduce the pressure exerted by the lifting arm on the ground or other external surfaces in floating mode.

[0130] Therefore, the disclosed examples of power machinery and components can provide improvements over conventional designs. For example, some examples can provide improved calibration of the boom or other working elements during start-up operation, help reduce power surges and associated negative effects, improve operator comfort during drive operation, and provide improved functionality for electrically powered working elements in floating mode. Other benefits will also be apparent to those skilled in the art in light of the full scope of this disclosure.

[0131] Unless otherwise specified or limited, the terms “about” and “approximately” as used herein with respect to reference values ​​mean a variation of ±15% or less relative to the reference value, including the endpoints of the range. Similarly, the term “substantially” as used herein with respect to reference values ​​means a variation of ±5% or less relative to the reference value, including the endpoints of the range.

[0132] As used herein, unless otherwise limited or defined, "or" indicates a non-exclusive list of components or operations that may exist in any kind of combination, rather than an exclusive list of components that may exist only as alternatives to each other. For example, a list of "A, B, or C" indicates options for: A; B; C; A and B; A and C; B and C; and A, B, and C. Correspondingly, the term "or" as used herein is intended to indicate an exclusive alternative only when preceded by an exclusive term such as "any," "one of," "only one of," or "exactly one of." For example, a list of "one of A, B, or C" indicates options for: A, but not B and C; B, but not A and C; and C, but not A and B. A list preceded by "one or more" (and its related variations) and including "or" to separate the listed elements indicates an option for any or all of the listed elements. For example, the phrases “one or more of A, B, or C” and “at least one of A, B, or C” indicate options for: one or more A's; one or more B's; one or more C's; one or more A's and one or more B's; one or more B's and one or more C's; one or more A's and one or more C's; and one or more A's, one or more B's, and one or more C's. Similarly, a list preceded by “multiple” (and its variations) and including “or” to separate the listed elements indicates options for multiple examples of any or all of the listed elements. For example, the phrases “multiple A's, B, or C” and “two or more of A's, B, or C” indicate options for: A and B; B and C; A and C; and A, B, and C.

[0133] In some examples, aspects of the disclosed technology, including computerized implementations of methods according to the disclosed techniques, can be implemented as systems, methods, apparatus, or articles of manufacture using standard programming or engineering techniques to produce software, firmware, hardware, or any combination thereof to control processor devices (e.g., serial or parallel general-purpose or special-purpose processor chips; single-core or multi-core chips; microprocessors; field-programmable gate arrays; any kind of combination of control units, arithmetic logic units, and processor registers, etc.), computers (e.g., processor devices operatively coupled to memory), or other electronically operated controllers to implement the aspects detailed herein. Thus, by way of example, the configuration of the disclosed technology can be implemented as a set of instructions tangibly embodied on a non-transitory computer-readable medium, such that the processor device can execute the instructions based on reading them from the computer-readable medium. Some examples of the disclosed technology may include (or utilize) control devices consistent with the discussion below, such as automation devices, special-purpose or general-purpose computers including various computer hardware, software, firmware, etc. As specific examples, the control device may include a processor, microcontroller, field-programmable gate array, programmable logic controller, logic gate, and other typical components known in the art for implementing appropriate functionality (e.g., memory, communication system, power source, user interface, and other inputs). In some examples, the control device may include a centralized hub controller that receives, processes control signals and other data, and (re)transmits control signals and other data to and from other distributed control devices, including those part of a hub-and-spoke architecture or other forms (e.g., engine controllers, implement controllers, drive controllers, etc.).

[0134] As used herein, the term "article of manufacture" is intended to encompass any computer program accessible from any computer-readable device, carrier (e.g., a non-transitory signal), or medium (e.g., a non-transitory medium). For example, computer-readable media may include, but is not limited to, magnetic storage devices (e.g., hard disks, floppy disks, magnetic stripes, etc.), optical discs (e.g., compact discs (CDs), digital universal discs (DVDs), etc.), smart cards, and flash memory devices (e.g., cards, sticks, etc.). Furthermore, it should be understood that carrier waves can be used to carry computer-readable electronic data, for example, in transmitting and receiving emails or in accessing networks such as the Internet or a local area network (LAN). Those skilled in the art will recognize that many modifications can be made to these configurations without departing from the scope or spirit of the claimed subject matter.

[0135] Certain operations of methods or systems performing those methods according to the disclosed techniques may be schematically illustrated in the accompanying drawings or otherwise discussed herein. Unless otherwise specified or limited, specific operations shown in a particular spatial order in the drawings may not necessarily need to be performed in a specific sequence corresponding to that spatial order. Correspondingly, certain operations shown in the accompanying drawings or otherwise disclosed herein may be performed in an order different from the explicitly illustrated or described order, as appropriate for specific examples of the disclosed techniques. Furthermore, in some examples, certain operations may be performed in parallel, including via dedicated parallel processing devices or separate computing devices configured to interact as part of a larger system.

[0136] As used herein in the context of computer implementations, unless otherwise specified or limited, the terms “component,” “system,” “module,” “block,” and the like are intended to encompass part or all of a computer-related system, including hardware, software, combinations of hardware and software, or software in execution. For example, a component can be, but is not limited to, a processor device, a process executed (or executable) by a processor device, an object, an executable file, a thread of execution, a computer program, or a computer. Illustrated, both an application running on a computer and the computer itself can be components. One or more components (or systems, modules, etc.) may reside within an executing process or thread, may be located on a single computer, may be distributed across two or more computers or other processor devices, or may be included within another component (or system, module, etc.).

[0137] Although the currently disclosed techniques have been described with reference to preferred examples, those skilled in the art will recognize that changes in form and detail may be made to the disclosed examples without departing from the spirit and scope of the concepts discussed herein.

Claims

1. A power machine, comprising: Main framework; A power source, which is supported by the main frame; A drive system configured to be powered by the power source to provide traction power for moving the main frame over the terrain; and A lifting arm structure supported by the main frame, the lifting arm structure including a lifting arm, a tool carrier supported by the lifting arm, and one or more electric actuators, the one or more electric actuators being configured to be powered by the power source to perform one or more of the following operations: moving the lifting arm relative to the main frame, or moving the tool carrier relative to the lifting arm; and A control system, comprising one or more control devices configured to, during the start-up mode of the power machinery: Receive operator input for moving at least one of the one or more electric actuators in a first predetermined direction; Based on the received operator input, the at least one electric actuator is commanded to move in the first predetermined direction until at least one of the following is achieved: the at least one electric actuator reaches a predetermined reference position, or the control system no longer receives the operator input; and In response to the at least one electric actuator reaching the predetermined reference position, the actual position of the at least one electric actuator is determined based on the predetermined reference position.

2. The power machinery according to claim 1, wherein, Receiving additional operator input prompts the control system to command the at least one electric actuator to perform additional movement; and The one or more control devices are configured to determine the actual position of the at least one electric actuator corresponding to the additional movement based on the sensed movement relative to the predetermined reference position.

3. The power machinery according to claim 1, wherein, Commanding the at least one electric actuator to move in the first predetermined direction includes: commanding the movement to be performed at a speed less than or equal to a predetermined speed, the predetermined speed being slower than the rated operating speed of the at least one electric actuator.

4. The power machinery according to claim 3, wherein, Commanding the at least one electric actuator to move in the first predetermined direction includes commanding the movement to be at a speed less than or equal to the predetermined speed, regardless of a requested speed exceeding the predetermined speed as indicated by the operator input.

5. The power machinery according to claim 1, wherein, The control system includes a rotary transformer that communicates with the at least one electric actuator to track the relative movement of the at least one electric actuator; and One or more control devices are configured to further determine the actual position based on the tracking of the relative movement of the at least one electric actuator by the rotary transformer.

6. The power machinery according to claim 1, wherein, One or more of the following conditions must be met: The received operator input corresponds to a lifting arm command, and the first predetermined direction corresponds to the lowering of the lifting arm; or The received operator input corresponds to a machine carrier command, and the first predetermined direction corresponds to the retraction of the machine carrier.

7. The power machinery according to claim 1, wherein, The one or more control devices are configured to, after determining that the physical state conditions of the power machinery are satisfied and further based on determining that the physical state conditions of the power machinery are satisfied, command the at least one electric actuator to make the movement in the first predetermined direction.

8. A method for operating power machinery, the method comprising: Receive operator input for moving at least one electric actuator of the power machinery; Determine the component of the operator input corresponding to the homing direction; and Based on the fact that the power machinery is in the start-up mode, and when it is determined that the component is a non-zero component: While the component remains non-zero, the at least one electric actuator is commanded to move in the homing direction at a homing speed until the at least one electric actuator reaches a predetermined reference position. as well as The subsequent command-controlled movement of the at least one electric actuator is tracked based on the relative movement with respect to the predetermined reference position.

9. The method according to claim 8, further comprising: Based on the fact that the power machinery is in the start-up mode, and when the component is determined to be zero, the at least one electric actuator is commanded to move in a direction corresponding to the operator input, and the movement of the at least one electric actuator is tracked based on the relative movement with respect to the predicted reference position.

10. The method according to claim 9, wherein the method further comprises: During the shutdown period of the power machinery before it is in the start-up mode, the shutdown position of the at least one electric actuator is determined. and During the startup mode, the predicted reference position is determined based on the determined shutdown position.

11. The method according to claim 8, further comprising: In response to the at least one electric actuator reaching the predetermined reference position, the actual position of the at least one electric actuator is determined based on the predetermined reference position.

12. The method according to claim 11, wherein, Determining the actual position of the at least one electric actuator includes using a rotary transformer that communicates with the at least one electric actuator to determine the actual position of the at least one electric actuator, the rotary transformer being configured to track the relative movement of the at least one electric actuator, wherein the actual position is determined based on the tracking of the relative movement of the at least one electric actuator by the rotary transformer.

13. The method according to claim 8, wherein, Commanding the at least one electric actuator to move in the homing direction at the homing speed includes commanding the at least one electric actuator to move in the homing direction at a speed less than or equal to a predetermined speed, the predetermined speed being slower than the rated operating speed of the at least one electric actuator.

14. The method according to claim 13, wherein, Commanding the at least one electric actuator to move in the homing direction at the homing speed includes commanding the movement to be performed at a speed less than or equal to the predetermined speed, regardless of a requested speed exceeding the predetermined speed as indicated by the operator input.

15. The method according to claim 8, wherein, Receiving operator input for moving at least one electric actuator of the power machinery includes receiving a lifting arm command, wherein the return direction corresponds to the lowering of the lifting arm.

16. The method according to claim 8, wherein, Receiving operator input for moving at least one electric actuator of the power machinery includes receiving a tool carrier command, wherein the return direction corresponds to the retraction of the tool carrier.

17. The method according to claim 8, wherein, Commanding the at least one electric actuator to move in the return direction includes: commanding the at least one electric actuator to move in the return direction based on determining that the physical state conditions of the power machinery are satisfied.

18. The method according to claim 17, wherein, Commanding the at least one electric actuator to move in the return direction based on determining that the physical state conditions of the power machinery are satisfied includes: after determining that the physical state conditions of the power machinery are satisfied, commanding the at least one electric actuator to move in the return direction.

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