A mechanical arm joint vibration suppression method and device, electronic equipment and readable storage medium

Abstract

The application discloses a mechanical arm joint vibration suppression method and device, electronic equipment and a readable storage medium, comprising: acquiring state characteristic data set of mechanical arm joint in a preset running state, and establishing a double inertia system model of the mechanical arm joint according to the state characteristic data set; predicting the output torque of the mechanical arm joint through the double inertia system model, and obtaining a first transfer function for representing the vibration degree of the mechanical arm joint; combining the output torque to optimize the first transfer function, obtaining a second transfer function with an added damping term; adjusting the damping term in the second transfer function, thereby realizing the vibration suppression of the mechanical arm joint. The application not only effectively realizes the mechanical arm joint vibration suppression, but also widens the use scene of the vibration suppression technology, and reduces the influence on the dynamic performance and stability of the mechanical arm joint.

Description

Technical Field

[0001] This invention belongs to the field of motion control technology and relates to a method, device, electronic device and readable storage medium for suppressing joint vibration of a robotic arm. Background Technology

[0002] Lightweight robotic arms are specifically designed for flexible movement and interaction with previously unknown environments and people. These applications often require a high load-to-weight ratio, and may even necessitate electromechanical integration, modular design methods, and sensing and control capabilities conducive to compliant interaction. Lightweight robotic arms exhibit deformation of joints and links; compared to link deformation, the flexible deformation of joints plays a dominant role, leading to problems such as hysteresis, nonlinearity, and resonance.

[0003] To suppress mechanical resonance, current solutions include using notch filters in the joint controller and adjusting the parameters of the joint position loop and velocity loop to suppress vibration. However, the notch filter method only works at specific resonant frequencies. As the robotic arm is used over time and the joints wear down, the resonant frequency changes, causing the notch filter to become ineffective. Furthermore, the notch filter introduces phase lag near the center frequency, which can lead to system instability. Adjusting the bandwidth of the joint position loop and velocity loop reduces the robotic arm's bandwidth, limiting its operation to low speeds.

[0004] Therefore, it is necessary to provide improved technical solutions to overcome the above-mentioned technical problems existing in the prior art. Summary of the Invention

[0005] The purpose of this application is to provide a method, device, electronic device, and readable storage medium for suppressing vibration of a robotic arm joint. By establishing a dual-inertia system model, the output torque of the robotic arm joint is predicted, the transfer function used to characterize the degree of vibration of the robotic arm joint is calculated and optimized, and the damping term is adjusted to achieve vibration suppression of the robotic arm joint, thereby broadening the application scenarios of vibration suppression technology and reducing the impact on the dynamic performance and stability of the robotic arm joint.

[0006] To achieve the above objectives: In a first aspect, the present invention provides a method for suppressing joint vibration of a robotic arm, comprising: Obtain a dataset of state features of the robotic arm joints under a preset operating state, and establish a dual inertia system model of the robotic arm joints based on the dataset of state features. The output torque of the robotic arm joint is predicted using the dual inertia system model, and a first transfer function is obtained to characterize the degree of vibration of the robotic arm joint. The first transfer function is optimized by combining the output torque to obtain a second transfer function with an added damping term; By adjusting the damping term in the second transfer function, vibration suppression of the robotic arm joints can be achieved.

[0007] In one embodiment, the state feature dataset includes the joint stiffness of the robotic arm joint, the motor rotational inertia, the load rotational inertia, the electromagnetic torque, and the motor side angle.

[0008] In one embodiment, the first transfer function used to characterize the degree of vibration of the robotic arm joint is defined as follows:

[0009] in, The angle on the motor side, The electromagnetic torque, Let the moment of inertia of the motor be... Let be the moment of inertia of the load, and s be a complex state variable. The joint stiffness is denoted as .

[0010] In one embodiment, the second transfer function with added damping term is defined as follows:

[0011] Where a is the damping gain coefficient.

[0012] In one embodiment, adjusting the damping term in the second transfer function includes: Adjust the damping gain coefficient until the second function meets the preset vibration suppression condition.

[0013] In one embodiment, after obtaining the first transfer function characterizing the degree of vibration of the robotic arm joints, the method further includes: By adding an acceleration feedback term to the first transfer function, the motor inertia is increased, thereby achieving vibration suppression of the robotic arm joints.

[0014] In one embodiment, increasing the motor inertia includes: Based on the acceleration feedback term, the inertia gain coefficient is obtained, and the inertia of the motor is assigned a value in combination with the inertia gain coefficient.

[0015] In a second aspect, the present invention provides a vibration suppression device for a robotic arm joint, comprising: The model building module is used to acquire the state feature dataset of the robotic arm joint in a preset operating state, and to build a dual inertia system model of the robotic arm joint based on the state feature dataset. The first transfer function calculation module is used to predict the output torque of the robotic arm joint through the dual inertia system model, and to obtain a first transfer function to characterize the degree of vibration of the robotic arm joint. The second transfer function calculation module is used to optimize the first transfer function in combination with the output torque to obtain a second transfer function with added damping term; The damping adjustment module is used to adjust the damping term in the second transfer function, thereby suppressing the vibration of the robotic arm joint.

[0016] Thirdly, this application provides an electronic device, characterized in that it includes: a processor, and a memory communicatively connected to the processor; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the method as described in the first aspect.

[0017] Fourthly, this application provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method described in the first aspect.

[0018] This application provides a method, apparatus, electronic device, and readable storage medium for suppressing vibration of a robotic arm joint. The method includes: acquiring a state feature dataset of the robotic arm joint in a preset operating state; establishing a dual-inertia system model of the robotic arm joint based on the state feature dataset; predicting the output torque of the robotic arm joint using the dual-inertia system model; obtaining a first transfer function characterizing the vibration level of the robotic arm joint; optimizing the first transfer function based on the output torque to obtain a second transfer function with an added damping term; and adjusting the damping term in the second transfer function to suppress vibration of the robotic arm joint. This invention not only effectively suppresses vibration of the robotic arm joint but also broadens the application scenarios of vibration suppression technology and reduces the impact on the dynamic performance and stability of the robotic arm joint. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic flowchart of a robotic arm joint vibration suppression method provided in an embodiment of the present invention; Figure 2This is a system structure diagram of damping and joint vibration suppression provided in an embodiment of the present invention; Figure 3 This is a system structure diagram of acceleration feedback for suppressing joint vibration provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the robotic arm joint vibration suppression device provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0021] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of systems and methods consistent with some aspects of this application as detailed in the appended claims.

[0022] It should be noted that step designations such as S1 and S2 are used in this document for the purpose of more clearly and concisely describing the corresponding content, and do not constitute a substantial limitation on the order. In specific implementation, those skilled in the art may execute S2 first and then S1, etc., but these should all be within the protection scope of this application.

[0023] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0024] like Figure 1 As shown, this application provides a method for suppressing joint vibration in a robotic arm, comprising: Step S101: Obtain the state feature dataset of the robotic arm joint in the preset operating state, and establish a dual inertia system model of the robotic arm joint based on the state feature dataset.

[0025] It is understandable that a lightweight robotic arm joint is generally composed of devices such as a driver, motor, brake, harmonic reducer, encoder, and torque sensor. Since the harmonic reducer transmits mechanical motion through the deformation of the flex wheel, the motor and the load are not rigidly connected. Therefore, a dual inertia system model of the robotic arm joint can be established by obtaining the data required by the dual inertia system.

[0026] In one embodiment, the state feature dataset includes the joint stiffness of the robotic arm joints, the moment of inertia of the motor, the moment of inertia of the load, the electromagnetic torque, and the motor side angle.

[0027] Specifically, the state feature dataset of the robotic arm joints in a preset operating state includes the joint parameters of the robotic arm, used to characterize the dynamic characteristics of the robotic arm joints. Preferably, the state feature dataset also includes joint state data, specifically including load torque, motor current, load-side angle, and external disturbance torque.

[0028] In step S102, the output torque of the robotic arm joint is predicted using a dual-inertia system model, and a first transfer function is obtained to characterize the degree of vibration of the robotic arm joint.

[0029] It is understandable that by subtracting the low-pass filtered value of the electromagnetic torque of the robotic arm joint from the low-pass filtered value of the motor's inertial force, the output torque of the robotic arm joint, i.e., the torque generated by the deformation of the harmonic reducer, can be predicted. Simultaneously, the predicted output torque is fed back to the electromagnetic torque after differentiation and low-pass filtering via an observer.

[0030] In one embodiment, the first transfer function used to characterize the degree of vibration of the robotic arm joints is defined as follows:

[0031] in, The angle is on the motor side. For electromagnetic torque, For the moment of inertia of the motor, Let be the load's moment of inertia, and s be a complex state variable. This refers to joint stiffness.

[0032] It can be understood that the left side of the equation of the first transfer function is the ratio of the motor side angle to the electromagnetic torque, which is also a value used to characterize the degree of vibration.

[0033] Further, see Figure 2 This is a structural diagram of a damping system for suppressing joint vibration provided in an embodiment of this application. Joint motor electromagnetic torque. The low-pass filtered value and the joint motor inertial force The difference between the low-pass filtered values ​​yields the joint output torque (i.e., the torque generated by the deformation of the harmonic reducer). The joint output torque estimated by the observer is then differentiated and low-pass filtered before being fed back to the electromagnetic torque. The time constant of the low-pass filter. The gain is adjustable.

[0034] Optionally, after obtaining the first transfer function characterizing the degree of vibration of the robotic arm joints, the method further includes: By adding an acceleration feedback term to the first transfer function, the motor inertia is increased, thereby suppressing the vibration of the robotic arm joints.

[0035] Furthermore, increasing the motor's inertia includes: Based on the acceleration feedback term, the inertia gain coefficient is obtained, and the motor inertia is assigned a value in combination with the inertia gain coefficient.

[0036] It can be understood that by transforming the first transfer function, we can obtain the following expression:

[0037] Among them, when the motor's moment of inertia When the value is extremely large, the vibration term The value of approaches zero, therefore increasing the motor's moment of inertia can suppress the vibration of the robotic arm joints.

[0038] Preferably, this application increases the motor's moment of inertia through acceleration feedback, that is, acceleration feedback is added to the original control system of the robotic arm motor to increase the motor's moment of inertia. Furthermore, to maintain the dynamic performance of the joint motor, the proportional and integral parameters of the speed controller are also increased by the same multiple as the motor's moment of inertia.

[0039] Further, see Figure 3 This is a system structure diagram of acceleration feedback for suppressing joint vibration provided in an embodiment of this application. The inertia of the motor itself is... After adding acceleration feedback, the inertia of the motor can be calculated to become At the same time, due to the increase in motor inertia To maintain the dynamic performance of the joint motor, the parameters of the speed controller also need to be increased. times.

[0040] Step S103: Optimize the first transfer function by combining the output torque to obtain a second transfer function with added damping term.

[0041] It is understandable that by adding a damping term to the first transfer function, the magnitude of damping can be adjusted by regulating the damping gain coefficient, thereby suppressing the vibration of the robotic arm joint.

[0042] In one implementation, a second transfer function for the damping term is added, defined as follows:

[0043] Where a is the damping gain coefficient.

[0044] It is understandable that the second transfer function, compared to the first transfer function, adds a damping term. When the value of the damping gain coefficient is adjusted, the damping term increases, and the values ​​on both sides of the second transfer function equation decrease, thereby suppressing the vibration of the robotic arm joint.

[0045] Step S104: Adjust the damping term in the second transfer function to suppress vibration of the robotic arm joint.

[0046] It is understandable that this application suppresses vibration by increasing the joint damping of the robotic arm and the rotational inertia of the motor. In order to prevent the position encoder noise from affecting the steady-state control effect of the joint, the feedback term that increases the joint damping and motor inertia can be removed when the joint motor reaches a steady state.

[0047] The above method can be used to predict the output torque of the robotic arm joint by establishing a dual-inertia system model, calculate and optimize the transfer function used to characterize the vibration degree of the robotic arm joint, increase the damping of the robotic arm joint and the rotational inertia of the motor to achieve vibration suppression of the robotic arm joint, suppress the vibration of the robotic arm joint for all robotic arm joint vibration frequency conditions, and does not affect the bandwidth of the robotic arm joint, thus broadening the application scenarios of vibration suppression technology and reducing the impact on the dynamic performance and stability of the robotic arm joint.

[0048] Based on the same inventive concept as the foregoing embodiments, this application provides a vibration suppression device for robotic arm joints. (See also...) Figure 2 This application provides a robotic arm joint vibration suppression device, which can be implemented using software and / or hardware. The device includes: The model building module 21 is used to acquire the state feature dataset of the robotic arm joint in a preset operating state, and to build a dual inertia system model of the robotic arm joint based on the state feature dataset. The first transfer function calculation module 22 is used to predict the output torque of the robotic arm joint through the dual inertia system model and obtain a first transfer function to characterize the vibration degree of the robotic arm joint. The second transfer function calculation module 23 is used to optimize the first transfer function in combination with the output torque to obtain a second transfer function with added damping term; The damping adjustment module 24 is used to adjust the damping term in the second transfer function, thereby suppressing the vibration of the robotic arm joint.

[0049] Based on the same inventive concept as the foregoing embodiments, this application provides an electronic device, such as... Figure 3 As shown, the device includes: a processor 301 and a memory 302 storing a computer program; wherein, Figure 3 The processor 301 shown in the diagram does not indicate that there is only one processor 301, but only indicates the positional relationship of processor 301 relative to other devices. In practical applications, there can be one or more processors 301; similarly, Figure 3The memory 302 shown in the diagram has the same meaning, that is, it is only used to indicate the positional relationship of the memory 302 relative to other devices. In practical applications, there can be one or more memories 302. When the processor 301 runs the computer program, it implements the above-mentioned method for suppressing joint vibration of the robotic arm.

[0050] The device may also include at least one network interface 303. The various components of the device are coupled together via a bus system 304. It is understood that the bus system 304 is used to implement communication between these components. In addition to a data bus, the bus system 304 also includes a power bus, a control bus, and a status signal bus. However, for clarity, in... Figure 3 The general designated all buses as Bus System 304.

[0051] The memory 302 can be volatile memory or non-volatile memory, or both. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), ferromagnetic random access memory (FRAM), flash memory, magnetic surface memory, optical disc, or compact disc read-only memory (CD-ROM); magnetic surface memory can be disk storage or magnetic tape storage. Volatile memory can be random access memory (RAM), used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Synchronous Static Random Access Memory (SSRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), Double Data Rate Synchronous Dynamic Random Access Memory (DDRSDRAM), Enhanced Synchronous Dynamic Random Access Memory (ESDRAM), SyncLink Dynamic Random Access Memory (SLDRAM), and Direct Rambus Random Access Memory (DRRAM).The memory 302 described in the embodiments of this application is intended to include, but is not limited to, these and any other suitable types of memory.

[0052] Based on the same inventive concept as the foregoing embodiments, this embodiment also provides a computer-readable storage medium storing a computer program. The computer-readable storage medium can be a magnetic random access memory (FRAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, a magnetic surface memory, an optical disc, or a compact disc read-only memory (CD-ROM), etc.; it can also be various devices including one or any combination of the above-mentioned memories, such as mobile phones, computers, tablet devices, personal digital assistants, etc. When the computer program stored in the computer-readable storage medium is executed by a processor, it implements the above method. For the specific steps of the computer program being executed by the processor, please refer to [link to relevant documentation]. Figure 1 The description of the illustrated embodiments will not be repeated here.

[0053] In this application, the same or similar terms, concepts, technical solutions and / or application scenario descriptions are generally described in detail only when they appear for the first time. When they appear again, they are generally not repeated for the sake of brevity. When understanding the technical solutions and other contents of this application, the same or similar terms, concepts, technical solutions and / or application scenario descriptions that are not described in detail later can be referred to their previous relevant detailed descriptions.

[0054] In this application, the descriptions of the various embodiments have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0055] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0056] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for suppressing joint vibration in a robotic arm, characterized in that, The method includes: Obtain a dataset of state features of the robotic arm joints under a preset operating state, and establish a dual inertia system model of the robotic arm joints based on the dataset of state features. The output torque of the robotic arm joint is predicted using the dual inertia system model, and a first transfer function is obtained to characterize the degree of vibration of the robotic arm joint. The first transfer function is optimized by combining the output torque to obtain a second transfer function with an added damping term; Adjusting the damping term in the second transfer function thereby suppressing vibrations at the joints of the robotic arm; The state feature dataset includes the joint stiffness of the robotic arm joints, the moment of inertia of the motor, the moment of inertia of the load, the electromagnetic torque, and the motor side angle. The first transfer function used to characterize the degree of vibration of the robotic arm joint is defined as follows: in, The angle on the motor side, The electromagnetic torque, Let the moment of inertia of the motor be . Let be the moment of inertia of the load, and s be a complex state variable. The joint stiffness; The second transfer function with added damping term is defined as follows: Where a is the damping gain coefficient.

2. The method according to claim 1, characterized in that, The adjustment of the damping term in the second transfer function includes: Adjust the damping gain coefficient until the second transfer function meets the preset vibration suppression condition.

3. The method according to claim 1, characterized in that, After obtaining the first transfer function characterizing the degree of vibration of the robotic arm joints, the method further includes: By adding an acceleration feedback term to the first transfer function, the motor inertia is increased, thereby achieving vibration suppression of the robotic arm joints.

4. The method according to claim 3, characterized in that, The increase in motor inertia includes: Based on the acceleration feedback term, the inertia gain coefficient is obtained, and the inertia of the motor is assigned a value in combination with the inertia gain coefficient.

5. A vibration suppression device for a robotic arm joint, characterized in that, The device is used to perform the robotic arm joint vibration suppression method as described in any one of claims 1-4.

6. An electronic device, characterized in that, include: A processor and a memory for storing executable instructions; wherein the processor is configured to execute the instructions to implement the robotic arm joint vibration suppression method as described in any one of claims 1-4.

7. A computer-readable storage medium, characterized in that, When the instructions in the computer-readable storage medium are executed by a processor, the method for suppressing joint vibration of a robotic arm as described in any one of claims 1-4 is implemented.

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