Joint motor control method and device, robot and storage medium
By filtering and processing the actual torque of the joint motor and controlling the current with the expected torque, the problem of low control accuracy of the robot joint motor is solved, and the complexity of the robot's movement is improved.
Patent Information
- Application Number
- CN202310639914.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-05-31
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2043-05-31
AI Technical Summary
In the prior art, the joint motor control accuracy of the robot is low, resulting in the inability to complete complex actions.
By determining the expected joint torque according to the expected joint state and actual joint state in the motion control command, and filtering the actual joint torque, the filtering result is obtained, and then determining the intersection control current based on the expected joint torque and filtering result, combined with the preset The straight axis controls the current and controls the movement of the joint motor.
It improves the control accuracy and progress of joint motors and enhances the complexity of robot movements.
Smart Images
Figure CN119115919A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of robot technology, and in particular to a joint motor control method, device, robot and storage medium. Background Art
[0002] In recent years, the technology of robotics has been developing continuously, becoming more and more intelligent and automated, and the richness, stability and flexibility of actions have been improved to varying degrees. Bionic robots have multiple joints, each of which has a joint motor. The joint motor can drive the parts on both sides of the joint to move relative to each other. The robot relies on the movement of these joint motors to enable the robot to complete various actions. However, in the related technology, the control accuracy of the robot's joint motor is low, which makes the robot unable to complete more complex actions. Summary of the invention
[0003] In order to overcome the problems existing in the related art, the embodiments of the present disclosure provide a joint motor control method, device, robot and storage medium to solve the defects in the related art.
[0004] According to a first aspect of an embodiment of the present disclosure, a joint motor control method is provided, the method comprising:
[0005] Determine the expected joint torque according to the expected joint state and the actual joint state in the motion control command;
[0006] Filtering the actual joint torque fed back by the joint motor to obtain a filtering result of the actual joint torque;
[0007] According to the filtering results of the expected joint torque and the actual joint torque, the quadrature-axis control current is determined, and according to the quadrature-axis control current and the preset direct-axis control current, the joint motor is controlled to move.
[0008] In a possible embodiment of the present disclosure, filtering the actual joint torque fed back by the joint motor to obtain the filtering result of the actual joint torque includes:
[0009] The actual joint torque fed back by the joint motor is input into a pre-configured low-pass filter to obtain a filtering result output by the low-pass filter.
[0010] In a possible embodiment of the present disclosure, determining the expected joint torque according to the expected joint state and the actual joint state in the motion control instruction includes:
[0011] The desired joint state and the actual joint state are input into an impedance controller to obtain a desired joint torque output by the impedance controller.
[0012] In a possible embodiment of the present disclosure, the desired joint state includes a desired joint position and a desired joint velocity; and / or,
[0013] The actual joint state includes an actual joint position and an actual joint velocity.
[0014] In a possible embodiment of the present disclosure, determining the quadrature-axis control current according to the filtering result of the expected joint torque and the actual joint torque includes:
[0015] The filtering results of the desired joint torque and the actual joint torque are input into a torque loop controller to obtain the quadrature-axis control current output by the current loop controller.
[0016] In a possible embodiment of the present disclosure, controlling the joint motor to move according to the quadrature-axis control current and the preset direct-axis control current includes:
[0017] Inputting the quadrature-axis control current and the quadrature-axis actual current into a current loop quadrature-axis controller to obtain a quadrature-axis control voltage output by the current loop quadrature-axis controller;
[0018] Inputting the direct-axis control current and the direct-axis actual current into a current loop direct-axis controller to obtain a direct-axis control voltage output by the current loop direct-axis controller;
[0019] The joint motor is driven to move according to the quadrature-axis control voltage and the direct-axis control voltage.
[0020] In a possible embodiment of the present disclosure, the method further includes:
[0021] The actual joint state, actual joint torque, actual quadrature-axis current and actual direct-axis current fed back by the joint motor are obtained.
[0022] According to a second aspect of an embodiment of the present disclosure, a joint motor control device is provided, the device comprising:
[0023] A torque module is used to determine the expected joint torque according to the expected joint state and the actual joint state in the motion control instruction;
[0024] A filtering module, used for filtering the actual joint torque fed back by the joint motor to obtain a filtering result of the actual joint torque;
[0025] The motion module is used to determine the quadrature-axis control current according to the filtering results of the expected joint torque and the actual joint torque, and control the joint motor to move according to the quadrature-axis control current and a preset direct-axis control current.
[0026] In a possible embodiment of the present disclosure, the filtering module is used to:
[0027] The actual joint torque fed back by the joint motor is input into a pre-configured low-pass filter to obtain a filtering result output by the low-pass filter.
[0028] In a possible embodiment of the present disclosure, the torque module is used to:
[0029] The desired joint state and the actual joint state are input into an impedance controller to obtain a desired joint torque output by the impedance controller.
[0030] In a possible embodiment of the present disclosure, the desired joint state includes a desired joint position and a desired joint velocity; and / or,
[0031] The actual joint state includes an actual joint position and an actual joint velocity.
[0032] In a possible embodiment of the present disclosure, the motion module is used to:
[0033] The filtering results of the desired joint torque and the actual joint torque are input into a torque loop controller to obtain the quadrature-axis control current output by the current loop controller.
[0034] In a possible embodiment of the present disclosure, the motion module is used to:
[0035] Inputting the quadrature-axis control current and the quadrature-axis actual current into a current loop quadrature-axis controller to obtain a quadrature-axis control voltage output by the current loop quadrature-axis controller;
[0036] Inputting the direct-axis control current and the direct-axis actual current into a current loop direct-axis controller to obtain a direct-axis control voltage output by the current loop direct-axis controller;
[0037] The joint motor is driven to move according to the quadrature-axis control voltage and the direct-axis control voltage.
[0038] In a possible embodiment of the present disclosure, the device further includes an acquisition module, and the acquisition module is used to:
[0039] The actual joint state, actual joint torque, actual quadrature-axis current and actual direct-axis current fed back by the joint motor are obtained.
[0040] According to a third aspect of an embodiment of the present disclosure, a robot is provided, comprising a memory and a processor, wherein the memory is used to store computer instructions executable on the processor, and the processor is used to implement the joint motor control method described in the first aspect when executing the computer instructions.
[0041] According to a fourth aspect of an embodiment of the present disclosure, a computer-readable storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the method described in the first aspect is implemented.
[0042] The technical solution provided by the embodiments of the present disclosure may have the following beneficial effects:
[0043] The joint motor control method provided by the embodiment of the present disclosure first determines the expected joint torque according to the expected joint state and the actual joint state in the motion control instruction, then filters the actual joint torque fed back by the joint motor to obtain the filtering result of the actual joint torque, and finally determines the cross-axis control current according to the filtering results of the expected joint torque and the actual joint torque, and controls the joint motor to move according to the cross-axis control current and the preset direct-axis control current. Since the actual joint torque fed back by the joint motor is filtered, the accuracy of the cross-axis control current obtained by combining the filtering results of the expected joint torque and the actual joint torque is improved, thereby improving the control progress of the joint motor and ultimately improving the complexity of the robot's movements. BRIEF DESCRIPTION OF THE DRAWINGS
[0044] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.
[0045] Figure 1 is a flow chart of a joint motor control method shown in an exemplary embodiment of the present disclosure;
[0046] Figure 2 is a flow chart of a joint motor control method shown in an exemplary embodiment of the present disclosure;
[0047] Figure 3 is a structural schematic diagram of a joint motor control device shown in an exemplary embodiment of the present disclosure;
[0048] Figure 4 It is a structural block diagram of a robot shown in an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION
[0049] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.
[0050] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.
[0051] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".
[0052] In recent years, the technology of robotics has been developing continuously, becoming more and more intelligent and automated, and the richness, stability and flexibility of actions have been improved to varying degrees. Bionic robots have multiple joints, each of which has a joint motor. The joint motor can drive the parts on both sides of the joint to move relative to each other. The robot relies on the movement of these joint motors to enable the robot to complete various actions. However, in the related technology, the control accuracy of the robot's joint motor is low, which makes the robot unable to complete more complex actions.
[0053] Based on this, in the first aspect, at least one embodiment of the present disclosure provides a joint motor control method, please refer to the attached Figure 1 , which shows the process of the method, including steps S101 to S103.
[0054] Among them, the method can be applied to robots, for example, to legged robots such as bipedal robots or quadrupedal robots; the robot has multiple joints, each joint is provided with a joint motor, the method can be applied to each joint motor of the robot, and can also be applied to at least one joint motor, that is, the method is used to drive the joint motor to move, so as to complete the desired joint state obtained by the upper-level operation and control according to the desired action.
[0055] In step S101, the expected joint torque is determined according to the expected joint state and the actual joint state in the motion control instruction.
[0056] The expected joint state can be the expected state of the joint controlled by the method determined by the upper-level operation control according to the expected action of the robot. The joint motor can feedback the joint state at a certain frequency during movement, and the state is recorded as the actual joint state. Therefore, the actual joint state fed back by the joint motor can be obtained before executing this step. The joint torque is the torque of the joint motor, and the expected joint torque refers to the torque expected to be achieved by the joint motor.
[0057] Exemplarily, an impedance controller can be used to determine the expected joint torque, that is, in this step, the expected joint state and the actual joint state are input into the impedance controller to obtain the expected joint torque output by the impedance controller. For example, the expected joint state includes the expected joint position and the expected joint speed, and the actual joint state includes the actual joint position and the actual joint speed. The position error can be determined according to the expected joint position and the actual joint position, and the speed error can be determined according to the expected joint speed and the actual joint speed, and then the position error and the speed error are input into the impedance controller; the impedance controller can determine the expected joint torque based on the position error and the speed error, combined with its internal parameters and feedforward torque, etc.
[0058] In step S102, the actual joint torque fed back by the joint motor is filtered to obtain a filtering result of the actual joint torque.
[0059] Optionally, the joint motor is equipped with a torque sensor, which feeds back the actual joint torque at a certain frequency, so the actual joint torque fed back by the joint motor can be obtained before executing this step. The joint torque is the torque of the joint motor, and the actual joint torque refers to the actual torque fed back by the joint motor.
[0060] Exemplarily, the actual joint torque fed back by the joint motor is input into a preconfigured low-pass filter to obtain a filtering result output by the low-pass filter.
[0061] The low-pass filter may be an infinite impulse response (IIR) digital filter. The original transfer function of the IIR filter is as follows:
[0062]
[0063] Among them, z is the discrete time domain, and a, b, M, and N are adjustable parameters.
[0064] The difference equation of the above formula 1 is the following formula 2:
[0065]
[0066] Where x is the system state (i.e., the actual joint torque), y is the system output (i.e., the filtering result), and a, b, M, and N are adjustable parameters.
[0067] In this embodiment, the transfer function of the above formula 1 can be expressed as a general form shown in the following formula 3:
[0068]
[0069] Where z is, and a, b, and M are adjustable parameters.
[0070] The difference equation of the above equation 3 is the following equation 4:
[0071] y(n)=b 0 x(n)+b 1 x(n-1)+b 2 x(n-2)-a 1 y(n-1)-a 2 y(n-2)
[0072] In the formula, x is the system state (i.e., the actual joint torque), y is the system output (i.e., the filtering result), and a 1 、a 2 、b 0 、b 1 、b 2 It is an adjustable parameter.
[0073] A low-pass filter can be designed based on the above formula 4 to filter the actual joint torque fed back by the torque sensor.
[0074] In step S103, a quadrature-axis control current is determined according to the desired joint torque and the filtering result of the actual joint torque, and the joint motor is controlled to move according to the quadrature-axis control current and a preset direct-axis control current.
[0075] The quadrature-axis control current is the current value expected to be achieved on the quadrature axis of the armature winding; and the direct-axis control current is the current value expected to be achieved on the direct axis of the armature winding.
[0076] Exemplarily, determining the cross-axis control current based on the expected joint torque and the filtering result of the actual joint torque may include: inputting the expected joint torque and the filtering result of the actual joint torque into a torque loop controller to obtain the cross-axis control current output by the current loop controller.
[0077] Exemplarily, controlling the joint motor to move according to the quadrature-axis control current and the preset direct-axis control current may include:
[0078] First, the quadrature axis control current and the quadrature axis actual current are input into the current loop quadrature axis controller to obtain the quadrature axis control voltage output by the current loop quadrature axis controller, wherein the quadrature axis actual current fed back by the joint motor can be obtained before this step. The quadrature axis actual current is the actual current value on the quadrature axis of the armature winding. The quadrature axis control voltage is the voltage value expected to be reached on the quadrature axis of the armature winding.
[0079] Next, the direct-axis control current and the direct-axis actual current are input into the current loop direct-axis controller to obtain the direct-axis control voltage output by the current loop direct-axis controller, wherein the direct-axis actual current fed back by the joint motor can be obtained before this step. The direct-axis actual current is the actual current value on the direct axis of the armature winding. The direct-axis control voltage is the voltage value expected to be reached on the direct axis of the armature winding.
[0080] Finally, the joint motor is driven to move according to the quadrature-axis control voltage and the direct-axis control voltage.
[0081] Please refer to the attached Figure 2 , which exemplarily shows a flow chart of a joint motor control method obtained by combining the above multiple embodiments. d , expected joint velocity v d , impedance controller parameter K p , K d and feedback torque τ ff , combined with the actual joint position θ and actual joint velocity v fed back by the joint motor, the desired joint torque is obtained through the impedance controller and the actual joint torque T fed back by the torque sensor e After low-pass filtering, the T ed The error e t The quadrature axis control current is obtained through the torque loop controller and Combined with the actual current i of the quadrature axis fed back by the joint motor q And the actual direct axis current i d , the AC and DC axis control voltage U is obtained through the AC and DC axis current loop controller q and U d .U q and U d The three-phase voltage obtained through pulse width modulation drives the motor to run through the inverter.
[0082] This method takes the desired joint torque as input, combines the torque sensor and low-pass filtering algorithm, and introduces a torque loop controller in the joint electronic control layer to dynamically adjust the desired joint torque, solving the shortcomings of existing joint torque processing that is not timely and accurate and has low torque control bandwidth.
[0083] The joint motor control method provided by the embodiment of the present disclosure first determines the expected joint torque according to the expected joint state and the actual joint state in the motion control instruction, then filters the actual joint torque fed back by the joint motor to obtain the filtering result of the actual joint torque, and finally determines the cross-axis control current according to the expected joint torque and the filtering result of the actual joint torque, and controls the joint motor to move according to the cross-axis control current and the preset direct-axis control current. Since the actual joint torque fed back by the joint motor is filtered, the accuracy of the cross-axis control current obtained by combining the filtering results of the expected joint torque and the actual joint torque is improved, thereby improving the control progress of the joint motor and ultimately improving the complexity of the robot's movements.
[0084] According to a second aspect of the embodiment of the present disclosure, a joint motor control device is provided. Figure 3 , the device comprises:
[0085] The torque module 301 is used to determine the expected joint torque according to the expected joint state and the actual joint state in the motion control instruction;
[0086] A filtering module 302 is used to filter the actual joint torque fed back by the joint motor to obtain a filtering result of the actual joint torque;
[0087] The motion module 303 is used to determine the quadrature-axis control current according to the expected joint torque and the filtering result of the actual joint torque, and control the joint motor to move according to the quadrature-axis control current and a preset direct-axis control current.
[0088] In a possible embodiment of the present disclosure, the filtering module is used to:
[0089] The actual joint torque fed back by the joint motor is input into a pre-configured low-pass filter to obtain a filtering result output by the low-pass filter.
[0090] In a possible embodiment of the present disclosure, the torque module is used to:
[0091] The desired joint state and the actual joint state are input into an impedance controller to obtain a desired joint torque output by the impedance controller.
[0092] In a possible embodiment of the present disclosure, the desired joint state includes a desired joint position and a desired joint velocity; and / or,
[0093] The actual joint state includes an actual joint position and an actual joint velocity.
[0094] In a possible embodiment of the present disclosure, the motion module is used to:
[0095] The desired joint torque and the filtered result of the actual joint torque are input into the torque loop controller to obtain the quadrature-axis control current output by the current loop controller.
[0096] In a possible embodiment of the present disclosure, the motion module is used to:
[0097] Inputting the quadrature-axis control current and the quadrature-axis actual current into a current loop quadrature-axis controller to obtain a quadrature-axis control voltage output by the current loop quadrature-axis controller;
[0098] Inputting the direct-axis control current and the direct-axis actual current into a current loop direct-axis controller to obtain a direct-axis control voltage output by the current loop direct-axis controller;
[0099] The joint motor is driven to move according to the quadrature-axis control voltage and the direct-axis control voltage.
[0100] In a possible embodiment of the present disclosure, the device further includes an acquisition module, and the acquisition module is used to:
[0101] The actual joint state, actual joint torque, actual quadrature-axis current and actual direct-axis current fed back by the joint motor are obtained.
[0102] In a third aspect, at least one embodiment of the present disclosure provides a robot, please refer to the attached Figure 4 , which shows the structure of the robot, the robot includes a memory and a processor, the memory is used to store computer instructions that can be executed on the processor, and the processor is used to control the joint motor based on the method described in any one of the first aspects when executing the computer instructions.
[0103] In a fourth aspect, at least one embodiment of the present disclosure provides a computer-readable storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements any of the methods described in the first aspect.
[0104] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.
[0105] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.
Claims
1. A joint motor control method, It is characterized in that The method comprises: Determine the expected joint torque according to the expected joint state and the actual joint state in the motion control command; Filtering the actual joint torque fed back by the joint motor to obtain a filtering result of the actual joint torque; According to the filtering results of the expected joint torque and the actual joint torque, the quadrature-axis control current is determined, and according to the quadrature-axis control current and the preset direct-axis control current, the joint motor is controlled to move.
2. The joint motor control method according to claim 1, It is characterized in that The filtering process of the actual joint torque fed back by the joint motor to obtain the filtering result of the actual joint torque includes: The actual joint torque fed back by the joint motor is input into a pre-configured low-pass filter to obtain a filtering result output by the low-pass filter.
3. The joint motor control method according to claim 1, It is characterized in that Determining the expected joint torque according to the expected joint state and the actual joint state in the motion control instruction includes: The desired joint state and the actual joint state are input into an impedance controller to obtain a desired joint torque output by the impedance controller.
4. The joint motor control method according to claim 1 or 3, It is characterized in that The desired joint state includes a desired joint position and a desired joint velocity; and / or, The actual joint state includes an actual joint position and an actual joint velocity.
5. The joint motor control method according to claim 1, It is characterized in that The determining of the quadrature-axis control current according to the filtering result of the expected joint torque and the actual joint torque comprises: The filtering results of the desired joint torque and the actual joint torque are input into a torque loop controller to obtain the quadrature-axis control current output by the current loop controller.
6. The joint motor control method according to claim 1, It is characterized in that The controlling the joint motor to move according to the quadrature-axis control current and the preset direct-axis control current comprises: Inputting the quadrature-axis control current and the quadrature-axis actual current into a current loop quadrature-axis controller to obtain a quadrature-axis control voltage output by the current loop quadrature-axis controller; Inputting the direct-axis control current and the direct-axis actual current into a current loop direct-axis controller to obtain a direct-axis control voltage output by the current loop direct-axis controller; The joint motor is driven to move according to the quadrature-axis control voltage and the direct-axis control voltage.
7. The joint motor control method according to claim 6, It is characterized in that The method further comprises: The actual joint state, actual joint torque, actual quadrature-axis current and actual direct-axis current fed back by the joint motor are obtained.
8. A joint motor control device, It is characterized in that The device comprises: A torque module is used to determine the expected joint torque according to the expected joint state and the actual joint state in the motion control instruction; A filtering module, used for filtering the actual joint torque fed back by the joint motor to obtain a filtering result of the actual joint torque; The motion module is used to determine the quadrature-axis control current according to the filtering results of the expected joint torque and the actual joint torque, and control the joint motor to move according to the quadrature-axis control current and a preset direct-axis control current.
9. The joint motor control device according to claim 8, It is characterized in that The filtering module is used for: The actual joint torque fed back by the joint motor is input into a pre-configured low-pass filter to obtain a filtering result output by the low-pass filter.
10. The joint motor control device according to claim 8, It is characterized in that The torque module is used to: The desired joint state and the actual joint state are input into an impedance controller to obtain a desired joint torque output by the impedance controller.
11. The joint motor control device according to claim 8 or 10, It is characterized in that The desired joint state includes a desired joint position and a desired joint velocity; and / or, The actual joint state includes an actual joint position and an actual joint velocity.
12. The joint motor control device according to claim 8, It is characterized in that The motion module is used to: The filtering results of the desired joint torque and the actual joint torque are input into a torque loop controller to obtain the quadrature-axis control current output by the current loop controller.
13. The joint motor control device according to claim 8, It is characterized in that The motion module is used to: Inputting the quadrature-axis control current and the quadrature-axis actual current into a current loop quadrature-axis controller to obtain a quadrature-axis control voltage output by the current loop quadrature-axis controller; Inputting the direct-axis control current and the direct-axis actual current into a current loop direct-axis controller to obtain a direct-axis control voltage output by the current loop direct-axis controller; The joint motor is driven to move according to the quadrature-axis control voltage and the direct-axis control voltage.
14. The joint motor control device according to claim 13, It is characterized in that The device further includes an acquisition module, wherein the acquisition module is configured to: The actual joint state, actual joint torque, actual quadrature-axis current and actual direct-axis current fed back by the joint motor are obtained.
15. A robot, It is characterized in that The robot comprises a memory and a processor, wherein the memory is used to store computer instructions executable on the processor, and the processor is used to implement the joint motor control method according to any one of claims 1 to 7 when executing the computer instructions.
16. A computer-readable storage medium having a computer program stored thereon, It is characterized in that When the program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.
Citation Information
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