Robot joint vibration control method and system

Abstract

The application provides a robot joint vibration control method and system, the vibration control method comprises the following steps: obtaining a reference speed of a robot joint; calculating a motor end speed, an output end speed and an output end acceleration; taking the motor end speed as an initial feedback signal, obtaining a deviation speed by subtracting the initial feedback signal from the reference speed and inputting the deviation speed into a speed controller, and obtaining initial control parameters of the speed controller according to a first open-loop transfer function from the reference speed to the motor end speed; adding an output end acceleration term to the initial feedback signal to obtain a feedback signal, wherein the output end acceleration term is a product of an output end acceleration feedback coefficient and the output end acceleration; obtaining control parameters of the speed controller according to the initial control parameters and the feedback signal to realize vibration suppression of the robot joint, wherein the control parameters of the speed controller comprise the initial control parameters and the output end acceleration feedback coefficient. The application can effectively realize vibration suppression of the robot joint.

Description

Technical Field

[0001] This invention relates to the field of robot joint vibration control technology, specifically to a robot joint vibration control method and a robot joint vibration control system. Background Technology

[0002] Robots typically employ a drive transmission scheme combining a torque motor and a lightweight harmonic reducer to improve the load-to-weight ratio. A dual-encoder scheme, with one encoder installed at the motor end and another at the output end after transmission through the reducer, is used to enhance positioning accuracy. However, due to the inherent flexibility of the harmonic reducer, robot joint vibration is a significant problem, making vibration suppression a pressing challenge.

[0003] Currently, most robots employ trajectory planning, input shaping, or limiting filter techniques for vibration suppression. These methods achieve vibration suppression by filtering out frequency components in the reference trajectory that can induce vibration. However, the vibration frequencies of robot joints often fall within the joint servo bandwidth, thus these methods, while suppressing vibration, negatively impact servo tracking control performance. Furthermore, because the stiffness and efficiency of harmonic reducers vary with factors such as load torque, speed, and temperature, the estimation accuracy of vibration frequencies is low. Therefore, in practical applications, the vibration suppression effects of these methods are limited. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method and system for controlling robot joint vibration, which can effectively suppress robot joint vibration.

[0005] The technical solution adopted in this invention is as follows:

[0006] A method for controlling robot joint vibration, the robot joint including a motor end, an output end, a joint transmission element, and a speed controller, the vibration control method comprising the following steps: acquiring a reference speed of the robot joint; calculating the motor end speed, the output end speed, and the output end acceleration; using the motor end speed as an initial feedback signal, subtracting the reference speed from the initial feedback signal to obtain a deviation speed and inputting it into the speed controller; obtaining initial control parameters of the speed controller based on a first open-loop transfer function from the reference speed to the motor end speed; adding an output end acceleration term to the initial feedback signal to obtain a feedback signal, wherein the output end acceleration term is the product of the output end acceleration feedback coefficient and the output end acceleration; obtaining control parameters of the speed controller based on the initial control parameters and the feedback signal to achieve vibration suppression of the robot joint, wherein the control parameters of the speed controller include the initial control parameters and the output end acceleration feedback coefficient.

[0007] Furthermore, the robot joint vibration control method proposed above according to the present invention may also have the following additional technical features:

[0008] According to one embodiment of the present invention, the speed controller is a speed proportional-integral controller, and the control parameters of the speed proportional-integral controller include speed proportional control parameters and speed integral control parameters.

[0009] According to an embodiment of the present invention, the step of adding an output acceleration term to the initial feedback signal to obtain a feedback signal specifically includes: adding an output acceleration term to the initial feedback signal to obtain a calculation formula for the feedback signal; obtaining a third open-loop transfer function from the reference speed to the feedback signal based on the calculation formula of the feedback signal, the first open-loop transfer function, and the second open-loop transfer function from the reference speed to the output speed; obtaining the specific value of the output acceleration feedback coefficient according to the initial control parameters of the speed controller and the third open-loop transfer function to obtain the feedback signal.

[0010] Specifically, the first open-loop transfer function G m,open (s) is:

[0011]

[0012] Among them, K v Here, Ki is the proportional speed control parameter, s represents the integral control parameter, B represents the moment of inertia at the motor end connected to the rotor, J represents the moment of inertia at the reducer output end connected to the load, and ω represents the speed proportional control parameter. n ω z Let ξ represent the resonant frequency and the anti-resonant frequency, respectively. n ξ z These represent the damping ratios corresponding to the resonant frequency and the anti-resonant frequency, respectively.

[0013] The second open-loop transfer function G l,open (s) is:

[0014]

[0015] The third open-loop transfer function G′ m,open for:

[0016]

[0017] Among them, K a The output acceleration feedback coefficient is...

[0018] Preferably, after obtaining the control parameters of the speed controller based on the initial control parameters and the feedback signal, the method further includes: performing gravity feedforward compensation and friction feedforward compensation on the robot joint.

[0019] In addition, to achieve the above objectives, the present invention also proposes a robot joint vibration control system.

[0020] A robot joint vibration control system, the robot joint including a motor end, an output end, a joint transmission element, and a speed controller, the system comprising: a speed acquisition unit for acquiring a reference speed of the robot joint; a motor end speed observer for calculating the motor end speed; an output end speed and acceleration observer for calculating the output end speed and output end acceleration; a vibration controller for providing an output end acceleration term; and a first calculation module for using the motor end speed as an initial feedback signal and comparing the reference speed with the initial feedback signal. The deviation speed is obtained by subtracting the reference speed and input to the speed controller. Based on the first open-loop transfer function from the reference speed to the motor end speed, the initial control parameters of the speed controller are obtained. A second calculation module is used to add the output acceleration term to the initial feedback signal to obtain a feedback signal, wherein the output acceleration term is the product of the output acceleration feedback coefficient and the output acceleration. The system obtains the control parameters of the speed controller based on the initial control parameters and the feedback signal to achieve vibration suppression of the robot joints. The speed controller parameters include the initial control parameters and the output acceleration feedback coefficient.

[0021] Furthermore, the robot joint vibration control system proposed above according to the present invention may also have the following additional technical features:

[0022] According to one embodiment of the present invention, the speed controller is a speed proportional-integral controller, and the control parameters of the speed proportional-integral controller include speed proportional control parameters and speed integral control parameters.

[0023] According to one embodiment of the present invention, the second calculation module is specifically used to: add an output acceleration term to the initial feedback signal to obtain a calculation formula for the feedback signal; based on the calculation formula of the feedback signal, the first open-loop transfer function, and the second open-loop transfer function from the reference speed to the output speed, obtain a third open-loop transfer function from the reference speed to the feedback signal; and obtain the specific value of the output acceleration feedback coefficient according to the initial control parameters of the speed controller and the third open-loop transfer function to obtain the feedback signal.

[0024] Specifically, the first open-loop transfer function G m,open (s) is:

[0025]

[0026] Where Kv is the speed proportional control parameter, K i The integral control parameters are: s represents the Laplace operator, B represents the moment of inertia at the motor end connected to the rotor, J represents the moment of inertia at the reducer output end connected to the load, and ω... n ω z Let ξ represent the resonant frequency and the anti-resonant frequency, respectively. n ξ z These represent the damping ratios corresponding to the resonant frequency and the anti-resonant frequency, respectively.

[0027] The second open-loop transfer function G l,open (s) is:

[0028]

[0029] The third open-loop transfer function G′ m,open for:

[0030]

[0031] Among them, K a The output acceleration feedback coefficient is...

[0032] Preferably, the system further includes a compensation module, which is used to perform gravity feedforward compensation and friction feedforward compensation on the robot joints.

[0033] The beneficial effects of this invention are:

[0034] The robot joint vibration control method of the present invention obtains the initial control parameters of the speed controller by using the motor end speed as the initial feedback signal, adding the output end acceleration term to the initial feedback signal to obtain the feedback signal, and obtaining the control parameters of the speed controller based on the initial control parameters and the feedback signal, thereby effectively suppressing robot joint vibration. Attached Figure Description

[0035] Figure 1 This is a flowchart of a robot joint vibration control method according to an embodiment of the present invention;

[0036] Figure 2 This is a block diagram of a robot joint vibration control system according to an embodiment of the present invention;

[0037] Figure 3This is a block diagram of a robot joint vibration control system according to an embodiment of the present invention. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] The robot joint in this embodiment of the invention includes a motor end, an output end, a joint transmission element, and a speed controller.

[0040] like Figure 1 As shown, the robot joint vibration control method of this embodiment includes the following steps:

[0041] S1, obtain the reference velocity of the robot joint.

[0042] When controlling the speed of robot joints, the command speed of the robot joint given by the host computer can be used as the reference speed of the robot.

[0043] When controlling the position of a robot joint, the output of the robot joint's position controller can be used as the robot's reference speed.

[0044] S2 calculates the motor end speed, output end speed, and output end acceleration.

[0045] In one embodiment of the present invention, the robot may be a robot employing a dual encoder scheme, that is, a motor-end encoder and an output-end encoder are installed at the motor end and the output end after transmission through the harmonic reducer, respectively.

[0046] The motor end position and output end position can be measured by the encoder at the motor end and the encoder at the output end. Then, the speed at the motor end and the speed and acceleration at the output end can be calculated by using a Kalman filter.

[0047] S3: The motor end speed is used as the initial feedback signal. The difference between the reference speed and the initial feedback signal is used to obtain the deviation speed, which is then input into the speed controller. The initial control parameters of the speed controller are obtained based on the first open-loop transfer function from the reference speed to the motor end speed.

[0048] In one embodiment of the present invention, the speed controller is a proportional-integral (PI) controller, and the initial control parameters of the PI controller include proportional control parameters and integral control parameters. At this time, the speed controller transfer function C... v (s) is shown in equation (1):

[0049]

[0050] Among them, K v K i represents the proportional control parameter and the integral control parameter, respectively, and s represents the Laplace operator.

[0051] The joint dynamics equation of the robot joint in this embodiment is shown in equation (2):

[0052]

[0053] Where B represents the moment of inertia of the motor end connected to the rotor, J represents the moment of inertia of the output end connected to the load, and τ m τ represents the joint driving torque. ext τ represents the vector of external torques at the joint; j Represents joint torque, θ, and These represent the motor end position, motor end velocity, and motor end acceleration, respectively. q , and These represent the output end position, output end velocity, and output end acceleration, respectively, while K and D represent the stiffness and damping of the joint transmission part, respectively.

[0054] By analyzing the open-loop frequency response characteristics of the joint, the transfer function P from the joint driving torque to the motor end velocity can be obtained. m The transfer function P from the joint driving torque to the output velocity l As shown in equation (3):

[0055]

[0056] Where s represents the Laplace operator, ω n ω z Let ξ represent the resonant frequency and the anti-resonant frequency, respectively. n ξ z Let represent the damping ratios corresponding to the resonant frequency and anti-resonant frequency, respectively. The calculation formula is as follows:

[0057]

[0058] When the speed controller uses the motor end speed as the initial feedback signal for control, by analyzing the response characteristics of the robot joint vibration control system and combining formulas (1) and (3), the first open-loop transfer function G from the reference speed to the motor end speed can be obtained. m,open (s) and the second open-loop transfer function G from the reference velocity to the output velocity. l,open (s), as shown in equations (5) and (6) respectively:

[0059]

[0060]

[0061] Using motor-end speed feedback to form a closed loop, the initial control parameters and the speed proportional control parameter K of the speed controller can be obtained from the closed-loop poles. v and integral control parameter K i .

[0062] From equation (5), it is known that if only the motor end speed feedback is used to form a closed loop, since ξ z Much less than 1, G m,open If the graph of the (s) function has zeros close to the imaginary axis, the closed-loop frequency response of the velocity will have poles close to the imaginary axis, affecting the closed-loop response of the system, increasing overshoot, causing system vibration, and leading to vibration control failure.

[0063] When a robot uses a dual encoder scheme, due to the flexible transmission characteristics of the harmonic reducer, if the control relies solely on the speed feedback from the motor end to form a closed loop, even if the control performance at the motor end is good, the vibration phenomenon at the output end will still be severe after the harmonic reducer transmission.

[0064] S4. Add the output acceleration term to the initial feedback signal to obtain the feedback signal, where the output acceleration term is the product of the output acceleration feedback coefficient and the output acceleration.

[0065] In one embodiment of the present invention, step S4 specifically includes:

[0066] S41, by adding the output acceleration term to the initial feedback signal, the calculation formula for the feedback signal is obtained, as follows:

[0067]

[0068] Where y is the feedback signal. For the output acceleration term, Ka is the output acceleration feedback coefficient.

[0069] S42, based on the calculation formula of the feedback signal, the first open-loop transfer function, and the second open-loop transfer function from the reference speed to the output speed, the third open-loop transfer function from the reference speed to the feedback signal is obtained.

[0070] According to formulas (5)-(7), the third open-loop transfer function from the reference velocity to the feedback signal after the initial feedback signal is added to the output acceleration term can be obtained, as shown in formula (8):

[0071]

[0072] in,

[0073] S43, based on the initial control parameters of the speed controller and the third open-loop transfer function, obtains the specific value of the output acceleration feedback coefficient, and thus obtains the feedback signal.

[0074] It should be noted that by adjusting the output acceleration feedback coefficient K... a This allows adjustment of the open-loop zero of the third open-loop transfer function. The specific value of the output acceleration feedback coefficient in the feedback signal is the specific value of the output acceleration feedback coefficient when the third open-loop transfer function is at its open-loop zero.

[0075] S5: Based on the initial control parameters and feedback signals, the control parameters of the speed controller are obtained to achieve vibration suppression of the robot joints. The control parameters of the speed controller include the initial control parameters and the output acceleration feedback coefficient.

[0076] Specifically, the control parameters of the speed controller can be obtained based on the initial control parameters obtained in step S3 and the output acceleration feedback coefficient in the feedback signal obtained in step S4. By introducing the output acceleration term into the feedback signal and modulating the open-loop zero of the speed, the closed-loop speed response is optimized, thereby achieving vibration suppression.

[0077] In one embodiment of the present invention, after the step of obtaining the control parameters of the speed controller based on the initial control parameters and the feedback signal, the method may further include: performing gravity feedforward compensation and friction feedforward compensation on the robot joints.

[0078] Specifically, the gravitational torque of the robotic arm can be calculated through the robotic arm dynamics model and gravity feedforward compensation can be applied to each joint of the robotic arm. The joint friction force can be calculated through the joint friction model and friction feedforward compensation can be applied to reduce the influence of gravity and friction force in the joints, which is beneficial to improving the performance of the speed controller.

[0079] According to the robot joint vibration control method of the present invention, the initial control parameters of the speed controller are obtained by using the motor end speed as the initial feedback signal, the output end acceleration term is added to the initial feedback signal to obtain the feedback signal, and the control parameters of the speed controller are obtained according to the initial control parameters and the feedback signal, thereby effectively realizing the suppression of robot joint vibration.

[0080] Corresponding to the robot joint vibration control method in the above embodiments, the present invention also proposes a robot joint vibration control system.

[0081] like Figure 2As shown, the robot joint vibration control system of this embodiment includes: a velocity acquisition unit 10, a motor end velocity observer 20, an output end velocity and acceleration observer 30, a vibration controller 40, a first calculation module 50, and a second calculation module 60. The velocity acquisition unit 10 is used to acquire the reference velocity of the robot joint; the motor end velocity observer 20 is used to calculate the motor end velocity; the output end velocity and acceleration observer 30 is used to calculate the output end velocity and output end acceleration; the vibration controller 40 is used to provide the output end acceleration term; and the first calculation module 50 is used to use the motor end velocity as an initial feedback signal. The deviation speed is obtained by subtracting the reference speed from the initial feedback signal and inputting it into the speed controller. The initial control parameters of the speed controller are obtained according to the first open-loop transfer function from the reference speed to the motor end speed. The second calculation module 60 is used to add the output acceleration term to the initial feedback signal to obtain the feedback signal. The output acceleration term is the product of the output acceleration feedback coefficient and the output acceleration. The system obtains the control parameters of the speed controller according to the initial control parameters and the feedback signal to realize the vibration suppression of the robot joint. The speed controller parameters include the initial control parameters and the output acceleration feedback coefficient.

[0082] In one embodiment of the present invention, when controlling the speed of a robot joint, the speed acquisition unit 10 can use the command speed of the robot joint given by the host computer as the reference speed of the robot; when controlling the position of a robot joint, the speed acquisition unit 10 can use the position controller output of the robot joint as the reference speed of the robot.

[0083] In one embodiment of the present invention, the robot may be a robot employing a dual encoder scheme, that is, a motor-end encoder and an output-end encoder are installed at the motor end and the output end after transmission through the harmonic reducer, respectively.

[0084] The motor end position and the output end position can be measured by the motor end encoder and the output end encoder. The motor end speed observer 20 and the output end speed and acceleration observer 30 can calculate the motor end speed and the output end speed and acceleration respectively based on the motor end position and the output end position using a Kalman filter.

[0085] In one embodiment of the present invention, the speed controller is a proportional-integral (PI) controller, and the initial control parameters of the PI controller include proportional control parameters and integral control parameters. At this time, the speed controller transfer function C... v (s) is shown in equation (1).

[0086] By analyzing the open-loop frequency response characteristics of the joint, the transfer function P from the joint driving torque to the motor end velocity can be obtained. m The transfer function P from the joint driving torque to the output velocityl As shown in equation (3).

[0087] When the speed controller uses the motor end speed as the initial feedback signal for control, by analyzing the response characteristics of the robot joint vibration control system and combining formulas (1) and (3), the first open-loop transfer function G from the reference speed to the motor end speed, as shown in formula (5), can be obtained. m,open (s) and the second open-loop transfer function G from the reference velocity to the output velocity as shown in equation (6). l,open (s).

[0088] By employing motor-end speed feedback to form a closed loop, the first calculation module 50 can obtain the initial control parameters and speed proportional control parameters K of the speed controller based on the closed-loop poles. v and integral control parameter K i .

[0089] From equation (5), it is known that if only the motor end speed feedback is used to form a closed loop, since ξ z Much less than 1, G m,open If the graph of the (s) function has zeros close to the imaginary axis, the closed-loop frequency response of the velocity will have poles close to the imaginary axis, affecting the closed-loop response of the system, increasing overshoot, causing system vibration, and leading to vibration control failure.

[0090] When a robot uses a dual encoder scheme, due to the flexible transmission characteristics of the harmonic reducer, if the control relies solely on the speed feedback from the motor end to form a closed loop, even if the control performance at the motor end is good, the vibration phenomenon at the output end will still be severe after the harmonic reducer transmission.

[0091] In one embodiment of the present invention, the second calculation module 60 is specifically used to: add an output acceleration term to the initial feedback signal to obtain a calculation formula for the feedback signal; based on the calculation formula for the feedback signal, the first open-loop transfer function, and the second open-loop transfer function from the reference speed to the output speed, obtain a third open-loop transfer function from the reference speed to the feedback signal; and obtain the specific value of the output acceleration feedback coefficient according to the initial control parameters of the speed controller and the third open-loop transfer function to obtain the feedback signal.

[0092] Specifically, the formula for calculating the feedback signal is shown in equation (7). According to equations (5)-(7), the third open-loop transfer function from the reference velocity to the feedback signal after the acceleration term at the output end is added to the initial feedback signal can be obtained, as shown in equation (8).

[0093] It should be noted that by adjusting the output acceleration feedback coefficient K... aThis allows adjustment of the open-loop zero of the third open-loop transfer function. The specific value of the output acceleration feedback coefficient in the feedback signal is the specific value of the output acceleration feedback coefficient when the third open-loop transfer function is at its open-loop zero.

[0094] In one embodiment of the present invention, the system can obtain the control parameters of the speed controller based on the initial control parameters obtained in the first calculation module 50 and the output acceleration feedback coefficient in the feedback signal obtained by the second calculation module 60. By introducing the output acceleration term into the feedback signal and modulating the open-loop zero of the speed, the closed-loop speed response is optimized, thereby achieving vibration suppression.

[0095] like Figure 3 As shown, in one embodiment of the present invention, the robot joint vibration control system further includes a compensation module, which is used to perform gravity feedforward compensation and friction feedforward compensation on the robot joint. (See figure.) Indicates the reference speed.

[0096] Specifically, the compensation module can calculate the gravitational torque of the robotic arm through the robotic arm dynamics model and perform gravity feedforward compensation to each robot joint of the robotic arm. It can also calculate the joint friction force through the joint friction model and perform friction feedforward compensation to reduce the influence of gravity and friction force in the joints, which is beneficial to improving the performance of the speed controller.

[0097] According to the robot joint vibration control system of the present invention, the initial control parameters of the speed controller are obtained by using the motor end speed as the initial feedback signal, the output end acceleration term is added to the initial feedback signal to obtain the feedback signal, and the control parameters of the speed controller are obtained according to the initial control parameters and the feedback signal, thereby effectively realizing the suppression of robot joint vibration.

[0098] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. "A plurality of" means two or more, unless otherwise explicitly specified.

[0099] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0100] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0101] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0102] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0103] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which programs can be printed, because programs can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0104] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0105] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by a program instructing related hardware, and the program can be stored in a computer-readable storage medium. When executed, the program includes one or a combination of the steps of the method embodiments.

[0106] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0107] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for controlling robot joint vibration, wherein the robot joint includes a motor end, an output end, a joint transmission element, and a speed controller, characterized in that, The vibration control method includes the following steps: Obtain the reference velocity of the robot joint; Calculate the motor end speed, output end speed, and output end acceleration; The motor end speed is used as the initial feedback signal. The difference between the reference speed and the initial feedback signal is used to obtain the deviation speed, which is then input into the speed controller. The initial control parameters of the speed controller are obtained based on the first open-loop transfer function from the reference speed to the motor end speed. An output acceleration term is added to the initial feedback signal to obtain a feedback signal, wherein the output acceleration term is the product of the output acceleration feedback coefficient and the output acceleration. The control parameters of the speed controller are obtained based on the initial control parameters and the feedback signal to achieve vibration suppression of the robot joints. The control parameters of the speed controller include the initial control parameters and the output acceleration feedback coefficient. The speed controller is a proportional-integral (PI) controller, and its control parameters include proportional control parameters and integral control parameters. The step of adding an output acceleration term to the initial feedback signal to obtain a feedback signal specifically includes: adding an output acceleration term to the initial feedback signal to obtain a calculation formula for the feedback signal; based on the calculation formula for the feedback signal, the first open-loop transfer function, and the second open-loop transfer function from the reference speed to the output speed, obtaining a third open-loop transfer function from the reference speed to the feedback signal; and obtaining the specific value of the output acceleration feedback coefficient according to the initial control parameters of the speed controller and the third open-loop transfer function to obtain the feedback signal.

2. The robot joint vibration control method according to claim 1, characterized in that, First open-loop transfer function for: in, The speed proportional control parameter, The integral control parameter is... s To represent the Laplace operator, B This represents the moment of inertia at the connection point between the motor and the rotor. J This represents the moment of inertia at the output end of the reducer when connected to the load. , These represent the resonant frequency and the anti-resonant frequency, respectively. , These represent the damping ratios corresponding to the resonant frequency and the anti-resonant frequency, respectively. Second open-loop transfer function for: ； The third open-loop transfer function for: in, The output acceleration feedback coefficient is... .

3. The robot joint vibration control method according to claim 1, characterized in that, After obtaining the control parameters of the speed controller based on the initial control parameters and the feedback signal, the method further includes: performing gravity feedforward compensation and friction feedforward compensation on the robot joint.

4. A robot joint vibration control system, wherein the robot joint includes a motor end, an output end, a joint transmission element, and a speed controller, characterized in that, The system includes: A velocity acquisition device, which is used to acquire a reference velocity of the robot joint; A motor end speed observer, which is used to calculate the motor end speed; An output velocity and acceleration observer, which is used to calculate the output velocity and output acceleration; A vibration controller, wherein the vibration controller is used to provide an output acceleration term; The first calculation module is used to take the motor end speed as the initial feedback signal, calculate the difference between the reference speed and the initial feedback signal to obtain the deviation speed and input it into the speed controller, and obtain the initial control parameters of the speed controller according to the first open-loop transfer function from the reference speed to the motor end speed. The second calculation module is used to add the output acceleration term to the initial feedback signal to obtain a feedback signal, wherein the output acceleration term is the product of the output acceleration feedback coefficient and the output acceleration. The system obtains the control parameters of the speed controller based on the initial control parameters and the feedback signal, thereby achieving vibration suppression of the robot joints. The speed controller parameters include the initial control parameters and the output acceleration feedback coefficient. The speed controller is a proportional-integral (PI) controller, and its control parameters include proportional control parameters and integral control parameters. The second calculation module is specifically used for: adding an output acceleration term to the initial feedback signal to obtain a calculation formula for the feedback signal; obtaining a third open-loop transfer function from the reference speed to the feedback signal based on the calculation formula of the feedback signal, the first open-loop transfer function, and the second open-loop transfer function from the reference speed to the output speed; obtaining the specific value of the output acceleration feedback coefficient according to the initial control parameters of the speed controller and the third open-loop transfer function, and thus obtaining the feedback signal.

5. The robot joint vibration control system according to claim 4, characterized in that, First open-loop transfer function for: in, The speed proportional control parameter, The integral control parameter is... s To represent the Laplace operator, B This represents the moment of inertia at which the motor terminals are connected to the rotor. J This represents the moment of inertia at the output end of the reducer when connected to the load. , These represent the resonant frequency and the anti-resonant frequency, respectively. , These represent the damping ratios corresponding to the resonant frequency and the anti-resonant frequency, respectively. Second open-loop transfer function for: ； The third open-loop transfer function for: in, The output acceleration feedback coefficient is... .

6. The robot joint vibration control system according to claim 4, characterized in that, The system further includes a compensation module, which is used to perform gravity feedforward compensation and friction feedforward compensation on the robot joints.

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