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

Abstract

The invention discloses a mechanical arm joint vibration suppression method and device, electronic equipment and a readable storage medium, and the method comprises the steps: obtaining a state feature data set of a mechanical arm joint in a preset operation state, and building a double-inertia system model of the mechanical arm joint according to the state feature data set; the output torque of the mechanical arm joint is predicted through the double-inertia system model, and a first transfer function used for representing the vibration degree of the mechanical arm joint is obtained; optimizing the first transfer function in combination with the output torque to obtain a second transfer function added with a damping item; and a damping item in the second transfer function is adjusted, so that vibration suppression of the mechanical arm joint is achieved. Vibration suppression of the mechanical arm joint is effectively achieved, the use scene of the vibration suppression technology is widened, and the influence on the dynamic performance and stability of the mechanical arm joint is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of motion control, and relates to a method, a device, an electronic device and a readable storage medium for suppressing joint vibration of a robot arm. Background Art

[0002] Lightweight robotic arms are designed to facilitate flexible movement and interaction with unknown environments and people. Such applications often require a high load or weight ratio, and even require electromechanical integration, modular design methods, and perception and control capabilities that are conducive to flexible interaction. Lightweight robotic arms have deformations of joints and connecting rods. Compared with the deformation of the connecting rod, the flexible deformation of the joints plays a dominant role, which brings problems such as hysteresis, nonlinearity and resonance.

[0003] In order to suppress mechanical resonance, the current solutions include using notch filters in joint controllers, and suppressing vibration by adjusting the parameters of the joint position loop and speed loop. Among them, the method of suppressing vibration by using notch filters can only work for specific resonant frequencies, but as the robot arm is used for a long time and the joints wear out, the resonance point frequency of the robot arm will change, which will cause the notch filter to lose its effect, and the notch filter will cause phase lag near the center frequency point, which may cause system instability; and the method of adjusting the bandwidth of the joint position loop and speed loop will reduce the bandwidth of the robot arm, so that the robot arm can only be used at low speeds.

[0004] Therefore, it is necessary to provide an improved technical solution to overcome the above technical problems existing in the prior art. Summary of the invention

[0005] The purpose of the present 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 vibration of a robot arm joint, comprising: Acquire a state feature data set of a mechanical arm joint under a preset operating state, and establish a dual-inertia system model of the mechanical arm joint according to the state feature data set; Predicting the output torque of the mechanical arm joint by the dual-inertia system model, and obtaining a first transfer function for characterizing the vibration degree of the mechanical arm joint; Optimizing the first transfer function in combination with the output torque to obtain a second transfer function with a damping term added; The damping term in the second transfer function is adjusted to achieve vibration suppression of the joint of the robotic arm.

[0007] In one embodiment, the state feature data set includes the joint stiffness, motor moment of inertia, load moment of inertia, electromagnetic torque and motor side angle of the robot arm joint.

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

[0009] in, is the motor side angle, is the electromagnetic torque, is the motor moment of inertia, is the load moment of inertia, s is the state complex variable, is the joint stiffness.

[0010] In one embodiment, the second transfer function with the damping term added 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 comprises: The damping gain coefficient is adjusted until the second function meets a preset vibration suppression condition.

[0013] In one embodiment, after obtaining the first transfer function for characterizing the vibration degree of the mechanical arm joint, 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 robot arm joint.

[0014] In one embodiment, increasing the motor inertia comprises: An inertia gain coefficient is obtained according to the acceleration feedback item, and the motor inertia is assigned a value in combination with the inertia gain coefficient.

[0015] In a second aspect, the present invention provides a mechanical arm joint vibration suppression device, comprising: A model building module, used to obtain a state feature data set of a mechanical arm joint under a preset operating state, and to build a dual-inertia system model of the mechanical arm joint according to the state feature data set; a first transfer function calculation module, used for predicting the output torque of the mechanical arm joint through the dual-inertia system model, and obtaining a first transfer function for characterizing the vibration degree of the mechanical arm joint; A second transfer function calculation module, configured to optimize the first transfer function in combination with the output torque to obtain a second transfer function with a damping term added; The damping adjustment module is used to adjust the damping term in the second transfer function, so as to achieve vibration suppression of the joint of the mechanical arm.

[0016] In a third aspect, the present 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 described in the first aspect.

[0017] In a fourth aspect, the present application provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores computer execution instructions, and when the computer execution instructions are executed by a processor, they are used to implement the method described in the first aspect.

[0018] The present application provides a method, device, electronic device and readable storage medium for suppressing vibration of a mechanical arm joint, comprising: obtaining a state characteristic data set of a mechanical arm joint under a preset operating state, and establishing a dual-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 dual-inertia system model, and obtaining a first transfer function for characterizing the degree of vibration of the mechanical arm joint; optimizing the first transfer function in combination with the output torque to obtain a second transfer function with a damping term added; adjusting the damping term in the second transfer function, thereby achieving vibration suppression of the mechanical arm joint. The present invention not only effectively achieves vibration suppression of the mechanical arm joint, but also broadens the application scenarios of vibration suppression technology, and reduces the impact on the dynamic performance and stability of the mechanical arm joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 A schematic diagram of a flow chart of a method for suppressing joint vibration of a mechanical arm provided by an embodiment of the present invention; Figure 2A structural diagram of a system for damping and suppressing joint vibration provided by an embodiment of the present invention; Figure 3 A structural diagram of a system for suppressing joint vibration by using acceleration feedback provided by an embodiment of the present invention; Figure 4 A schematic diagram of the structure of a mechanical arm joint vibration suppression device provided by an embodiment of the present invention; Figure 5 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0021] 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, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of systems and methods consistent with some aspects of the present application as detailed in the appended claims.

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

[0023] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0024] like Figure 1 As shown, the embodiment of the present application provides a method for suppressing vibration of a mechanical arm joint, comprising: Step S101, obtaining a state characteristic data set of a robot arm joint in a preset operating state, and establishing a dual-inertia system model of the robot arm joint according to the state characteristic data set.

[0025] It can be understood that the joints of light robotic arms are generally composed of devices such as drivers, motors, brakes, harmonic reducers, encoders, torque sensors, etc. Since the harmonic reducer realizes mechanical motion transmission through the deformation of the flexible wheel, the motor and the load are not rigidly connected. Therefore, the 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 data set includes joint stiffness, motor moment of inertia, load moment of inertia, electromagnetic torque, and motor side angle of the robot arm joint.

[0027] Specifically, the state characteristic data set of the robot arm joint under the preset operating state includes the joint parameters of the robot arm, which are used to characterize the dynamic characteristics of the robot arm joint. Preferably, the state characteristic data set also includes joint state data, specifically including load torque, motor current, load side angle and external interference torque.

[0028] Step S102 , predicting the output torque of the robot arm joint by using the dual inertia system model, and obtaining a first transfer function for characterizing the vibration degree of the robot arm joint.

[0029] It can be understood that the output torque of the mechanical arm joint, that is, the torque generated by the deformation of the harmonic reducer, can be predicted by subtracting the value of the electromagnetic torque of the mechanical arm joint after low-pass filtering from the value of the motor inertia force after low-pass filtering. At the same time, the predicted output torque is fed back to the electromagnetic torque through the observer after differentiation and low-pass filtering.

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

[0031] in, is the motor side angle, is the electromagnetic torque, is the motor moment of inertia, is the load moment of inertia, s is the state complex variable, is the 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, and is also a value used to characterize the vibration degree.

[0033] Further, see Figure 2 , is a diagram of the system structure for damping and suppressing joint vibration provided by an embodiment of the present application. Electromagnetic torque of the joint motor The value after low-pass filtering and the inertia force of the joint motor The values ​​after low-pass filtering are subtracted to obtain 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 fed back to the electromagnetic torque after differentiation and low-pass filtering. is the time constant of the low-pass filter, For adjustable gain.

[0034] Optionally, after obtaining the first transfer function for characterizing the vibration degree of the robot arm joint, 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 robot arm joint.

[0035] Further, increasing the motor inertia includes: According to the acceleration feedback item, the inertia gain coefficient is obtained, and the motor inertia is assigned in combination with the inertia gain coefficient.

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

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

[0038] Preferably, the present application increases the motor moment of inertia by means of acceleration feedback, that is, acceleration feedback is added to the original control system of the manipulator motor to increase the motor moment of inertia. In addition, in order to keep the dynamic performance of the joint motor unchanged, the proportional and integral parameters of the speed controller should also be increased by the same multiple as the motor inertia.

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

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

[0041] It can be understood that by adding a damping term to the first transfer function, the magnitude of the damping can be adjusted by adjusting the damping gain coefficient, thereby achieving the suppression of the vibration of the robot arm joint.

[0042] In one embodiment, a second transfer function with a damping term is added, which is defined as follows:

[0043] Where a is the damping gain coefficient.

[0044] It can be understood that the second transfer function adds a damping term compared to the first transfer function. ; 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 achieving the suppression of the vibration of the robot arm joint.

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

[0046] It can be understood that the present 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 item of increasing the joint damping and motor inertia can be removed when the joint motor reaches a steady state.

[0047] Through the above method, a dual-inertia system model can be established to predict the output torque of the robotic arm joint, calculate and optimize the transfer function used to characterize the vibration degree of the robotic arm joint, increase the robotic arm joint damping and motor rotational inertia to achieve robotic arm joint vibration suppression, and have a suppressive effect on all robotic arm joint vibration frequency conditions without affecting the bandwidth of the robotic arm joint, thereby broadening the use 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 above embodiments, the present application provides a mechanical arm joint vibration suppression device. Figure 2 , is a mechanical arm joint vibration suppression device provided in an embodiment of the present application, and the mechanical arm joint vibration suppression device can be implemented in software and / or hardware. The device includes: A model building module 21 is used to obtain a state feature data set of a mechanical arm joint under a preset operating state, and to build a dual-inertia system model of the mechanical arm joint according to the state feature data set; A first transfer function calculation module 22, used for predicting the output torque of the mechanical arm joint through the dual inertia system model, and obtaining a first transfer function for characterizing the vibration degree of the mechanical arm joint; A second transfer function calculation module 23, configured to optimize the first transfer function in combination with the output torque to obtain a second transfer function with a damping term added; The damping adjustment module 24 is used to adjust the damping term in the second transfer function, so as to achieve vibration suppression of the joint of the robotic arm.

[0049] Based on the same inventive concept as the above embodiments, the present application embodiment 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 figure is not used to indicate that the number of processors 301 is one, but is only used to indicate the position relationship of the processor 301 relative to other devices. In actual applications, the number of processors 301 may be one or more; similarly, Figure 3The memory 302 shown in the figure has the same meaning, that is, it is only used to refer to the position relationship of the memory 302 relative to other devices. In practical applications, the number of memories 302 can be one or more. When the processor 301 runs the computer program, the above-mentioned mechanical arm joint vibration suppression method is implemented.

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

[0051] The memory 302 may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. The non-volatile memory may be 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 magnetic random access memory (FRAM), a flash memory, a magnetic surface memory, an optical disc, or a compact disc read-only memory (CD-ROM); the magnetic surface memory may be a disk memory or a tape memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and 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), synchronous link dynamic random access memory (SLDRAM, SyncLink Dynamic Random Access Memory), and direct RAMbus random access memory (DRRAM, Direct Rambus Random Access Memory).The memory 302 described in the embodiments of the present application is intended to include but is not limited to these and any other suitable types of memories.

[0052] Based on the same inventive concept as the above-mentioned embodiment, this embodiment further provides a computer-readable storage medium, in which a computer program is stored. The computer-readable storage medium may be a ferromagnetic 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); it may also be various devices including one or any combination of the above memories, such as a mobile phone, a computer, a tablet device, a personal digital assistant, etc. When the computer program stored in the computer-readable storage medium is executed by the processor, the above method is implemented. For the specific steps implemented when the computer program is executed by the processor, please refer to Figure 1 The description of the illustrated embodiment will not be repeated here.

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

[0054] In the present application, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0055] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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 is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for suppressing vibration of a robot arm joint, characterized in that: The method comprises: Acquire a state feature data set of a robotic arm joint under a preset operating state, and establish a dual-inertia system model of the robotic arm joint according to the state feature data set; Predicting the output torque of the mechanical arm joint by the dual-inertia system model, and obtaining a first transfer function for characterizing the vibration degree of the mechanical arm joint; Optimizing the first transfer function in combination with the output torque to obtain a second transfer function with a damping term added; The damping term in the second transfer function is adjusted to achieve vibration suppression of the joint of the robotic arm.

2. The method according to claim 1, characterized in that The state feature data set includes the joint stiffness of the robot arm joint, the motor moment of inertia, the load moment of inertia, the electromagnetic torque and the motor side angle.

3. The method according to claim 2, characterized in that The first transfer function used to characterize the vibration degree of the mechanical arm joint is defined as follows: in, is the motor side angle, is the electromagnetic torque, is the motor moment of inertia, is the load moment of inertia, s is the state complex variable, is the joint stiffness.

4. The method according to claim 3, characterized in that The second transfer function with added damping term is defined as follows: Where a is the damping gain coefficient.

5. The method according to claim 4, characterized in that The adjusting the damping term in the second transfer function comprises: The damping gain coefficient is adjusted until the second function meets a preset vibration suppression condition.

6. The method according to claim 1, characterized in that After obtaining the first transfer function for characterizing the vibration degree of the mechanical arm joint, 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 robot arm joint.

7. The method according to claim 6, characterized in that The increasing the motor inertia comprises: An inertia gain coefficient is obtained according to the acceleration feedback item, and the motor inertia is assigned a value in combination with the inertia gain coefficient.

8. A mechanical arm joint vibration suppression device, characterized in that: The device comprises: A model building module, used to obtain a state feature data set of a mechanical arm joint under a preset operating state, and to build a dual-inertia system model of the mechanical arm joint according to the state feature data set; a first transfer function calculation module, used for predicting the output torque of the mechanical arm joint through the dual-inertia system model, and obtaining a first transfer function for characterizing the vibration degree of the mechanical arm joint; A second transfer function calculation module, configured to optimize the first transfer function in combination with the output torque to obtain a second transfer function with a damping term added; The damping adjustment module is used to adjust the damping term in the second transfer function, so as to achieve vibration suppression of the joint of the mechanical arm.

9. 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 method for suppressing vibration of a mechanical arm joint as described in any one of claims 1-7.

10. 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 vibration of a robot arm joint as described in any one of claims 1 to 7 is implemented.

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