A robot vibration suppression method based on a state observer and related apparatus

Abstract

The application relates to the technical field of robot vibration suppression, in particular to a robot vibration suppression method based on a state observer and related devices. The method comprises the following steps: receiving a motion control instruction, determining a command position and a command speed of a motor side and a command position and a command speed of a connecting rod side according to the motion control instruction; acquiring a state parameter of the motor side and acquiring a state parameter of the connecting rod side collected by the state observer; determining full-state feedback parameters of a PID control system according to the state parameter of the motor side and the state parameter of the connecting rod side; and determining a feedforward current and a feedback current of the PID control system. The application can effectively suppress the vibration of the motion of the robot.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of robot vibration suppression, and in particular to a robot vibration suppression method based on a state observer and related devices. BACKGROUND

[0002] Currently, industrial robots are rapidly developing in China and are widely used in the fields of automobiles, electronics, light industry, aerospace, etc. With the progress of manufacturing technology, robots are facing higher precision and speed requirements, such as high-speed and high-precision electronic assembly, smooth and no vibration polishing processing, and trajectory precision and efficiency emphasized in laser cutting and welding. In the future, with the deepening of intelligent manufacturing, enterprises' requirements for efficiency and quality are continuously improving, and high speed and high precision will become the inevitable direction of robot development.

[0003] In high-speed and high-precision operation, vibration has become an important factor limiting the performance improvement of industrial robots. In the structure of the robot, the connecting rod usually has high stiffness, and to achieve lightweight and compact design, the joint usually adopts flexible transmission methods such as RV reducer, harmonic reducer or synchronous belt, which results in limited joint stiffness and becomes the main source of vibration. The joint flexibility makes the robot prone to vibration during high-speed start and stop, which in turn affects the operation precision, positioning time and processing quality, and in severe cases, it also reduces the work efficiency and equipment life. Therefore, suppressing the vibration caused by joint flexibility is one of the key problems in high-speed and high-precision control.

[0004] Among the many vibration suppression techniques, active damping is a high-efficiency and practical method for industrial robot vibration control. This strategy feeds back the relative speed difference between the motor side and the connecting rod side in real time and applies it to the motor input torque, effectively improving the damping ratio of the system dominant pole, thereby significantly enhancing the vibration suppression capability. Compared with traditional passive damping methods, active damping does not need to rely on additional mechanical structures or energy-consuming devices, and is suitable for high-speed and high-precision dynamic task environments.

[0005] However, active damping has the following disadvantages:

[0006] 1) Insufficient accuracy of active damping feedback data: Industrial robots usually only have encoders on the motor side, and the information on the connecting rod side is unknown, so the accurate relative speed difference between the motor side and the connecting rod side cannot be obtained. The speed difference information fed back by active damping is usually roughly estimated from the model connecting rod side torque data, and then calculated by differentiation, resulting in low data accuracy. This may cause a certain deviation between theoretical calculation and actual effect.

[0007] 2) Limitations of active damping parameter adjustment: Active damping improves vibration suppression effect by optimizing the damping ratio of the dominant poles of the system. However, if the parameters are not properly set, the dominant poles may move to the right half of the virtual axis, causing system instability; or the damping ratio is too low, exacerbating the vibration problem and weakening the suppression effect.

[0008] 3) Robustness of active damping parameter algorithm: Since the algorithm highly depends on the system model, when the model or model parameters are inaccurate, the algorithm performance will be greatly affected, and in practical applications, the theoretical prediction may not match the actual performance. SUMMARY

[0009] The embodiments of the present application provide a robot vibration suppression method based on a state observer and related devices, which can solve at least one of the above technical problems.

[0010] According to an aspect of the embodiments of the present application, a robot vibration suppression method based on a state observer is provided, which is applied to a full-state feedback control system, the full-state feedback control system including a robot, a state observer, and a PID control system, the robot including a motor side and a link side, the state observer being configured to collect state parameters of the link side, and the PID control system being configured to adjust the motor side and the link side, the method including:

[0011] receiving a motion control instruction for the robot, and determining an instruction position and an instruction speed of the motor side and an instruction position and an instruction speed of the link side according to the motion control instruction;

[0012] during the process that the robot responds to the motion control instruction and moves, if the robot vibrates, obtaining state parameters of the motor side and state parameters of the link side collected by the state observer;

[0013] determining full-state feedback parameters of the PID control system according to the state parameters of the motor side and the state parameters of the link side;

[0014] determining a feedforward current and a feedback current of the PID control system according to the instruction position and the instruction speed of the motor side, the instruction position and the instruction speed of the link side, and the full-state feedback parameters, so as to suppress vibration of the robot according to the feedforward current and the feedback current.

[0015] In the above scheme, the state observer is obtained by the following way:

[0016] determining joint stiffness of the robot;

[0017] determining the motor-side state parameters and the linkage-side state parameters, the motor-side state parameters including motor-side position, motor-side velocity, motor-side acceleration, motor-side rotational inertia, motor-side driving torque, and the linkage-side state parameters including linkage-side position, linkage-side velocity, linkage-side acceleration, linkage-side rotational inertia, and linkage-side driving torque;

[0018] establishing a standard state space equation based on the joint stiffness, the motor-side position, the motor-side velocity, the motor-side acceleration, the motor-side rotational inertia, the motor-side driving torque, the linkage-side position, the linkage-side velocity, the linkage-side acceleration, the linkage-side rotational inertia, and the linkage-side driving torque;

[0019] constructing the state observer according to the standard state space equation.

[0020] In the above scheme, the full-state feedback control system further comprises a dual-inertia system, and the method further comprises:

[0021] determining control loop parameters of the PID control system, the control loop parameters including a position loop, a velocity loop, and a current loop;

[0022] determining an input of the dual-inertia system based on the position loop, the velocity loop, and the current loop;

[0023] taking the command position and the command velocity of the motor side as first initial state variables of the dual-inertia system, and taking the command position and the command velocity of the linkage side as second initial state variables of the dual-inertia system;

[0024] constructing a state space equation of state variable tracking error based on the input of the dual-inertia system, the first initial state variables, and the second initial state variables.

[0025] In the above scheme, the determining the full-state feedback parameters of the PID control system according to the motor-side state parameters and the linkage-side state parameters comprises:

[0026] determining initial position difference feedback coefficients of the motor side and initial position difference feedback coefficients of the linkage side;

[0027] constructing a state feedback equation of the full-state feedback parameters based on the initial position difference feedback coefficients of the motor side, the initial position difference feedback coefficients of the linkage side, the motor-side state parameters, and the linkage-side state parameters;

[0028] designing an optimization equation for the full-state feedback parameters based on the state feedback equation;

[0029] determine the full state feedback parameter according to the optimization equation.

[0030] In the above scheme, the feedforward current and the feedback current of the PID control system are determined according to the command position and the command speed of the motor side, the command position and the command speed of the connecting rod side, and the full state feedback parameter, including:

[0031] The target position difference feedback coefficient of the motor side, the target position difference feedback coefficient of the connecting rod side, the proportional coefficient of the position loop, and the proportional coefficient of the speed loop are determined according to the full state feedback parameter.

[0032] The feedforward current and the feedback current are determined according to the command position and the command speed of the motor side, the command position and the command speed of the connecting rod side, the target position difference feedback coefficient of the motor side, the target position difference feedback coefficient of the connecting rod side, the proportional coefficient of the position loop, and the proportional coefficient of the speed loop.

[0033] According to an aspect of an embodiment of the present application, a robot vibration suppression device based on a state observer is provided, which is applied to a full state feedback control system, the full state feedback control system including a robot, a state observer, and a PID control system, the robot including a motor side and a connecting rod side, the state observer being used to collect state parameters of the connecting rod side, and the PID control system being used to adjust the motor side and the connecting rod side, and the device including:

[0034] A first determination unit is configured to receive a motion control instruction for the robot, and determine the command position and the command speed of the motor side and the command position and the command speed of the connecting rod side according to the motion control instruction.

[0035] A second determination unit is configured to, in a process in which the robot responds to the motion control instruction and moves, if the robot vibrates, acquire state parameters of the motor side and acquire state parameters of the connecting rod side collected by the state observer.

[0036] A third determination unit is configured to determine a full state feedback parameter of the PID control system according to the state parameters of the motor side and the state parameters of the connecting rod side.

[0037] A fourth determination unit is configured to determine a feedforward current and a feedback current of the PID control system according to the command position and the command speed of the motor side, the command position and the command speed of the connecting rod side, and the full state feedback parameter, so as to suppress vibration of the robot according to the feedforward current and the feedback current.

[0038] In an aspect of an embodiment of the present application, an electronic device is provided, comprising a memory and a processor, the memory storing a computer program, and the processor implementing the state observer-based robot vibration suppression method as described above when executing the computer program.

[0039] In an aspect of an embodiment of the present application, a computer program product is provided, comprising a computer program, which is read and executed by a processor of an electronic device, so that the electronic device executes the state observer-based robot vibration suppression method as described above.

[0040] The present application has the following beneficial effects: The present application can acquire the state parameters of the motor side and the state parameters of the link side collected by the state observer in the process that the robot responds to the motion control instruction and moves, and then determine the full-state feedback parameters of the PID control system according to the state parameters of the motor side and the state parameters of the link side.

[0041] Further, the feedforward current and the feedback current of the PID control system are determined according to the instruction position and the instruction speed of the motor side, the instruction position and the instruction speed of the link side, and the full-state feedback parameters, so as to suppress the vibration of the robot according to the feedforward current and the feedback current.

[0042] Therefore, the present application comprehensively considers the state parameters of the motor side and the state parameters of the link side to calculate the feedforward current and the feedback current of the PID control system, so that the full-state feedback control system suppresses the vibration of the robot. Compared with the traditional active damping method which depends on the rough estimation of the link side torque and calculates the speed difference through differentiation, the present method significantly improves the calculation accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 is a system architecture diagram to which the state observer-based robot vibration suppression method provided by an embodiment of the present application is applied;

[0044] Figure 2 is a structure diagram of a dual-inertia system provided by an embodiment of the present application;

[0045] Figure 3 is a structure diagram of a PID control system provided by an embodiment of the present application;

[0046] Figure 4 is a structure diagram of a full-state feedback control system provided by an embodiment of the present application;

[0047] Figure 5 is a flowchart of the state observer-based robot vibration suppression method provided by an embodiment of the present application;

[0048] Figure 6 A block diagram of a robot vibration suppression device based on a state observer provided by an embodiment of the present application is shown in FIG. 1.

[0049] Figure 7 A logic flow chart of vibration suppression provided by an embodiment of the present application is shown in FIG. 2.

[0050] Figure 8 A structural schematic diagram of a terminal provided by an embodiment of the present application is shown in FIG. 3.

[0051] Figure 9 A structural schematic diagram of a server provided by an embodiment of the present application is shown in FIG. 4. DETAILED DESCRIPTION

[0052] In order to make the personnel in the technical field better understand the scheme of the present application, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the personnel in the technical field without creative labor fall within the scope of protection of the present application.

[0053] It should be noted that in some processes described in the specification, claims and the above drawings, a plurality of steps appear in a specific order, but it should be clearly understood that these steps can be executed or in parallel without the order appearing in the text, and the step number is only used to distinguish different steps, and the number itself does not represent any execution order. In addition, the description of "first", "second" or "target" in this paper is used to distinguish similar objects, not necessarily to describe a specific order or sequence. "Multiple" in this paper means at least two.

[0054] It should be noted that in the specific embodiments of the present application, the motion control instructions of the robot, the state parameters of the motor side, the state parameters of the connecting rod side and other related data are involved. When the above embodiments of the present application are applied to specific products or technologies, the permission or consent of the target object needs to be obtained, and the collection, use and processing of related data need to comply with relevant laws, regulations and standards. For example, when the embodiments of the present application need to obtain the motion control instructions of the robot, the state parameters of the motor side, the state parameters of the connecting rod side and other related data, the separate permission or separate consent of the target object can be obtained through a pop-up window or jumping to a confirmation page, and after obtaining the separate permission or separate consent of the target object, the necessary motion control instructions of the robot, the state parameters of the motor side, the state parameters of the connecting rod side and other related data for the normal operation of the embodiments of the present application are obtained.

[0055] Please refer toFigure 1 , Figure 1 is a system architecture diagram applied by the robot vibration suppression method based on a state observer provided in the embodiments of the present application. It comprises a terminal 140, an Internet 130, a gateway 120, a server 110, etc.

[0056] The terminal 140 comprises a desktop computer, a laptop computer, a PDA (personal digital assistant), a mobile phone, a vehicle-mounted terminal, a special-purpose terminal, etc. in various forms. In addition, it can be a single device or a combination of multiple devices. For example, multiple desktop computers are connected to each other through a local area network and work cooperatively by sharing a display, etc. to jointly constitute a terminal 140. The terminal 140 can communicate with the Internet 130 in a wired or wireless manner to exchange data.

[0057] The server 110 refers to a computer system capable of providing certain services to the terminal 140. Compared with the ordinary terminal 140, the server 110 has higher requirements in stability, security, performance, etc. The server 110 can be a high-performance computer in a network platform, a cluster of multiple high-performance computers, a part (for example, a virtual machine) of a high-performance computer, a combination of parts (for example, virtual machines) of multiple high-performance computers, etc. The server 110 can also communicate with the Internet 130 in a wired or wireless manner to exchange data.

[0058] The gateway 120 is also called an inter-network connector or a protocol converter. The gateway realizes network interconnection at the transport layer and is a computer system or device acting as a conversion function. In the case of two systems using different communication protocols, data formats or languages, or even having completely different architectures, the gateway is a translator. At the same time, the gateway can also provide filtering and security functions. The messages sent by the terminal 140 to the server 110 are sent to the corresponding server 110 through the gateway 120. The messages sent by the server 110 to the terminal 140 are also sent to the corresponding terminal 140 through the gateway 120.

[0059] The system model involved in the present application is introduced as follows, as shown in Figure 2 , Figure 2 is a schematic diagram of a dual-inertia system of the present application, Figure 3 is a schematic diagram of a combination of a PID control system and a dual-inertia system, Figure 4 is a schematic diagram of full-state feedback control.

[0060] The specific implementation of the embodiments of the present application is described in detail as follows:

[0061] Please refer to Figure 5 , Figure 5is a flowchart of a robot vibration suppression method based on a state observer provided by the embodiment of the present application. The robot vibration suppression method based on the state observer can be implemented by the server 110 and / or the terminal 140. Figure 5 The robot vibration suppression method based on the state observer shown includes:

[0062] In step 510, the motion control instruction for the robot is received, and the instruction position and speed of the motor side and the instruction position and speed of the link side are determined according to the motion control instruction.

[0063] In step 520, during the process in which the robot responds to the motion control instruction and moves, if the robot vibrates, the state parameters of the motor side are acquired, and the state parameters of the link side collected by the state observer are acquired.

[0064] In step 530, the full-state feedback parameters of the PID control system are determined according to the state parameters of the motor side and the state parameters of the link side.

[0065] In step 540, the feedforward current and the feedback current of the PID control system are determined according to the instruction position and speed of the motor side, the instruction position and speed of the link side, and the full-state feedback parameters, so as to suppress the vibration of the robot according to the feedforward current and the feedback current.

[0066] The complete embodiment scheme of the present application is explained in detail in combination with steps 510-540 as follows:

[0067] In step 510, the motion control instruction for the robot can be a control instruction sent by the terminal device to the robot, for example, a control instruction for controlling the robot to move forward or backward, so that the instruction position and speed of the motor side and the instruction position and speed of the link side can be determined.

[0068] In step 520, if the robot vibrates, the state parameters of the motor side can be directly acquired by the sensor arranged on the motor side, and the state parameters of the link side can be collected by the state observer proposed in the present application.

[0069] In step 530, after the state parameters of the motor side and the state parameters of the link side are obtained, the full-state feedback parameters of the PID control system can be determined according to the state parameters of the motor side and the state parameters of the link side.

[0070] In step 540, a feedforward current and a feedback current of the PID control system are determined according to the motor-side command position and command speed, the connecting rod-side command position and command speed, and the full-state feedback parameter, so that vibration suppression of the robot can be performed according to the feedforward current and the feedback current.

[0071] In some embodiments, the state observer is obtained by:

[0072] determining joint stiffness of the robot;

[0073] determining state parameters of the motor side and state parameters of the connecting rod side, the state parameters of the motor side including motor-side position, motor-side speed, motor-side acceleration, motor-side moment of inertia, motor-side driving torque, and the state parameters of the connecting rod side including connecting rod-side position, connecting rod-side speed, connecting rod-side acceleration, connecting rod-side moment of inertia, and connecting rod-side driving torque;

[0074] establishing a standard state space equation based on the joint stiffness, the motor-side position, the motor-side speed, the motor-side acceleration, the motor-side moment of inertia, the motor-side driving torque, the connecting rod-side position, the connecting rod-side speed, the connecting rod-side acceleration, the connecting rod-side moment of inertia, and the connecting rod-side driving torque;

[0075] constructing the state observer according to the standard state space equation.

[0076] Specifically, a single-joint structure of the robot is modeled and analyzed as a dual-inertia system, as shown in FIG. 1, in which joint flexibility is simplified as a set of torsional springs. According to this modeling manner, a dynamic model thereof can be expressed in the following mathematical form: Figure 2

[0077] (1)

[0078] wherein is joint stiffness, is motor-side position, is motor-side speed, is motor-side acceleration, is motor-side moment of inertia, is motor-side driving torque, and is connecting rod-side position, is connecting rod-side speed, is connecting rod-side acceleration, is connecting rod-side moment of inertia (which can be directly obtained through a sensor), is connecting rod-side driving torque, Figure 2 in the equation, represents the motor side, represents the connecting rod side.​

[0079] In combination with formula (1), positions and speeds of the motor side and the connecting rod side are selected The four parameters are taken as state variables of the dual-inertia system, and a motor driving torque The motor side position is taken as a system input , the motor side speed The motor side position is taken as a system output, and a standard state space equation is established:

[0080] (2)

[0081] Corresponding relationships of the matrices are shown as follows:

[0082] (3)

[0083] According to the state space equation in formula (2), a state observer is established as follows:

[0084] (4)

[0085] wherein, represents an estimated value of the state variable (i.e., the first initial state variable of the motor side and the second initial state variable of the connecting rod side) of the state observer, represents an estimated value of the system output, is a parameter matrix of the state observer.

[0086] In combination with formula (2) and formula (4), an error of the observer is analyzed as follows:

[0087] (5)

[0088] As shown in the above formula, by reasonably setting the parameter matrix of the state observer, real parts of eigenvalues of the matrix are all negative numbers, which can ensure that the error of the state observer gradually converges to 0, and thus more accurate estimation of the state of the connecting rod side is realized.

[0089] In some embodiments, the full-state feedback control system further includes a dual-inertia system, and the method further includes:

[0090] determining control loop parameters of the PID control system, the control loop parameters including a position loop, a speed loop and a current loop;

[0091] determining an input of the dual-inertia system based on the position loop, the speed loop and the current loop;

[0092] The command position and the command speed of the motor side are taken as the first initial state variables of the dual-inertia system, and the command position and the command speed of the connecting rod side are taken as the second initial state variables of the dual-inertia system.

[0093] The state space equation of the state variable tracking error is constructed based on the input of the dual-inertia system, the first initial state variable and the second initial state variable.

[0094] As shown in Figure 3 , Figure 3 is a schematic diagram of a PID control system, and the PID control system described in the present application can also be referred to as a cascade PID control system, is the command position of the system input, that is, the system input (obtained through a motion control command) of the full-state feedback control system, and are the disturbance amounts of the motor side and the connecting rod side of the system respectively, are the position loop, the speed loop and the current loop respectively, wherein:

[0095] (6)

[0096] In this control mode, the control input of the dual-inertia system is:

[0097] (7)

[0098] The tracking performance of the electromechanical coupling system is analyzed, and the tracking target of the motor side position and the connecting rod side position is , and the tracking target of the state variable of the dual-inertia system is:

[0099] (8)

[0100] The state variable tracking error of the dual-inertia system is analyzed:

[0101] (9)

[0102] Combined with equations (2)-(9), the state space equation of the state variable tracking error is constructed as:

[0103] (10)

[0104] Based on the control idea of full-state feedback, the control law is further set as:

[0105] (11)

[0106] wherein, represents the control parameter of full state feedback, while is the feedforward control term, i.e. the feedforward current described in the present application, used to compensate for the generated error.

[0107] According to the control law set by formula (11), the state variable tracking error in formula (10) can be expressed as a state space equation in the following form:

[0108] (12)

[0109] Next, the present application continues to design the feedforward control input, i.e. , which lays the foundation for the implementation of the subsequent control law:

[0110] (13)

[0111] According to formula (13), the tracking error of the motor side speed can be eliminated by designing , so that:

[0112] (14)

[0113] By observing that there is a tracking error in the connecting rod side speed during the acceleration stage . This error is due to the inherent characteristics of the dual-inertia system, and therefore cannot be eliminated by adjusting the feedforward control input.

[0114] Further comparison of formula (7) and formula (11) shows that the original cascade PID control law only considers the motor side position and speed tracking error, and does not include the connecting rod side position information and its speed error, so it is difficult to achieve true full state feedback control. Therefore, based on the original control structure, the present application adds a position difference and speed difference feedback link between the motor side and the connecting rod side, thereby constructing a complete full state feedback control structure, as shown in Figure 4 .

[0115] is the feedback current of full state feedback control, are the feedback coefficients of the motor side and the connecting rod side position difference and speed difference, respectively, where:

[0116] (15)

[0117] In the formula, is the position estimation value of the connecting rod side, is the speed estimation value of the connecting rod side.

[0118] At this time, the input of the dual-inertia system is:

[0119] (16)

[0120] is the proportional coefficient of the position loop, is the proportional coefficient of the velocity loop,

[0121] The present application can be designed to make the eigenvalues of the closed-loop state matrix quickly converge, so as to effectively suppress the vibration of the system while ensuring the tracking performance of the system.

[0122] The following proposes an optimization design idea of feedback parameters . In the theoretical derivation process, the influence of model uncertainty, parameter error and external disturbance has not been considered. Therefore, the present application unifies these influences into motor side disturbance and connecting rod side disturbance , wherein the motor side disturbance includes input error caused by inaccurate motor side model and parameter uncertainty, and external disturbance received by the motor side; and the connecting rod side disturbance includes the influence of inaccurate connecting rod side model and external disturbance.

[0123] The influence of the motor side disturbance and the connecting rod side disturbance on the position of the connecting rod side can be described by the following transfer functions (17)

[0124] The maximum amplitude of the transfer function can be represented by its infinity norm . Based on this, the optimization objective is designed as follows:

[0125] (18)

[0126] wherein is the optimization weight of the two transfer functions, and by minimizing the optimization objective , the disturbance rejection ability of the system to the motor side and the connecting rod side disturbance can be effectively improved, thereby enhancing the robustness of the control algorithm.

[0127] It should be noted that although the optimization algorithm is used to improve the robustness of the system, the tracking performance of the system may be affected. The tracking performance of the system is mainly affected by the maximum real part of the eigenvalues of the closed-loop state matrix, the smaller the real part, the faster the convergence speed of the system. The imaginary part of the eigenvalues of the closed-loop state matrix reflects the vibration characteristics of the system, in order to improve the stability of the system, the imaginary part of the eigenvalues can be appropriately reduced, so that the system response tends to be more stable. Let the maximum real part (each eigenvalue has a real part and an imaginary part) of the eigenvalues of the original cascade PID control closed-loop state matrix be ​​, the optimization process needs to satisfy the following constraint conditions:

[0128] (19)

[0129] wherein, represents the real part, and represents the imaginary part, and the overall optimization equation is:

[0130] (20)

[0131] In order to further understand the vibration suppression method of the present application, as shown in the flow chart, first, the servo controller sends control instructions (the angle of the robot joint (the angle to be rotated to reach), the rotation speed of the robot joint) to the robot body; at the same time, according to the foregoing optimization design scheme, the maximum real part of the closed-loop state matrix eigenvalue under the cascade PID control is calculated first, and then the full state feedback parameter (i.e. Figure 7 , , , ) is calculated according to the optimization equation of formula (20).

[0132] Specifically, the content of the full state feedback parameter calculated according to the optimization equation of formula (20) is as follows:

[0133] The calculation process has no specific mathematical formula, but through MATLAB mathematical software, taking the minimum as the optimization objective, combined with the constraint conditions mentioned above, the numerical values of the four parameters at the minimum are solved.

[0134] During the movement of the robot according to the control instructions, the system synchronously collects the torque, position and speed data on the motor side, and estimates the position and speed information on the connecting rod side through the state observer. If obvious vibration phenomenon is detected during the operation of the robot, the full state feedback mechanism is activated, the PID controller is adjusted according to the calculated parameters, and the feedforward current and feedback current are output at the same time, so as to realize effective suppression of the vibration.

[0135] The present application establishes the state space expression on the basis of the dual-inertia system model, and designs the state observer accordingly, uses the torque, position and speed measurement data on the motor side to realize high-precision estimation of the position and speed on the connecting rod side, and successfully applies the observed data to the full state feedback control algorithm.

[0136] ​​​A full state feedback control law is designed, and an optimization design method of full state feedback parameters is proposed. First, the factors not considered are summarized as motor side disturbance and connecting rod side disturbance, and then the minimization of the infinity norm of the transfer function of the two types of disturbance to the connecting rod side position is taken as the optimization objective; At the same time, the eigenvalues of the closed-loop state matrix are taken as the constraint condition to carry out the optimization design of the control parameters. This method effectively improves the robustness of the optimization algorithm under the premise of ensuring the tracking performance of the system.

[0137] On the basis of traditional cascade PID control, the application introduces feedforward control to eliminate the tracking error of the motor side in the acceleration stage, and fuses the position difference feedback coefficient and speed difference feedback coefficient of the motor side (the target position difference feedback coefficient of the motor side) and the position difference feedback coefficient and speed difference feedback coefficient of the connecting rod side (the target position difference feedback coefficient of the connecting rod side), to construct an improved full state feedback control structure. At the same time, an optimization scheme of full state feedback parameters is proposed, which effectively improves the robustness of the optimization algorithm under the premise of ensuring the tracking performance of the system, and overcomes the shortcomings of difficult parameter adjustment, high dependence on model and insufficient robustness in the traditional active damping method.

[0138] Please refer to Figure 6 , Figure 6 The structure schematic diagram of the robot vibration suppression device based on the state observer provided by the embodiment of the application is applied to a computer device, wherein the robot vibration suppression device based on the state observer 600 can include:

[0139] A first determination unit 601 is configured to receive a motion control instruction for the robot, and determine an instruction position and an instruction speed of the motor side and an instruction position and an instruction speed of the connecting rod side according to the motion control instruction;

[0140] A second determination unit 602 is configured to, in a process in which the robot responds to the motion control instruction and moves, if the robot vibrates, acquire a state parameter of the motor side and acquire a state parameter of the connecting rod side collected by the state observer;

[0141] A third determination unit 603 is configured to determine full state feedback parameters of the PID control system according to the state parameter of the motor side and the state parameter of the connecting rod side;

[0142] A fourth determination unit 604 is configured to determine a feedforward current and a feedback current of the PID control system according to the instruction position and the instruction speed of the motor side, the instruction position and the instruction speed of the connecting rod side, and the full state feedback parameters, so as to suppress vibration of the robot according to the feedforward current and the feedback current.

[0143] ReferenceFigure 8 , Figure 8 A structure block diagram of a part of the terminal 140 according to an embodiment of the present application is shown in FIG. 7. The terminal 140 includes a radio frequency (RF) circuit 710, a memory 715, an input unit 730, a display unit 740, a sensor 750, an audio circuit 760, a wireless fidelity (WiFi) module 770, a processor 780, and a power supply 790, etc. Those skilled in the art can understand that the terminal 140 can include more or less components than those shown in the figure, or combine some components, or arrange the components differently. Figure 8 The structure of the terminal 140 shown in the figure is not intended to limit the mobile phone or computer, and can include more or less components than those shown in the figure, or combine some components, or arrange the components differently.

[0144] The RF circuit 710 can be used for receiving and sending signals in the process of receiving or calling, and in particular, receiving the downlink information of the base station and processing it by the processor 780, and sending the uplink data to the base station.

[0145] The memory 715 can be used to store software programs and modules, and the processor 780 can execute various functions of the terminal and the robot vibration suppression method based on the state observer by running the software programs and modules stored in the memory 715.

[0146] The input unit 730 can be used to receive input digital or character information, and generate key signal input related to the setting and function control of the terminal. Specifically, the input unit 730 can include a touch panel 731 and other input devices 732.

[0147] The display unit 740 can be used to display input information or provided information and various menus of the terminal. The display unit 740 can include a display panel 741.

[0148] The audio circuit 760, the speaker 761, and the microphone 762 can provide an audio interface.

[0149] In the embodiment of the present application, the processor 780 included in the terminal 140 can execute the robot vibration suppression method based on the state observer of the previous embodiment.

[0150] The terminal 140 according to the embodiment of the present application includes but is not limited to a mobile phone, a computer, a smart voice interaction device, a smart home appliance, a vehicle-mounted terminal, an aircraft, etc. The embodiment of the present application can be applied to various scenes, including but not limited to cloud technology, artificial intelligence, intelligent transportation, and assisted driving, etc.

[0151] Figure 9A structural block diagram of a portion of the server 110 implementing embodiments of the present application. The server 110 can vary greatly in configuration and performance, and can include one or more central processing units (CPUs) 822 (e.g., one or more processors) and memory 832, one or more storage media 830 (e.g., one or more mass storage devices) storing applications 842 or data 844. The memory 832 and storage media 830 can be volatile or non-volatile storage. The programs stored in the storage media 830 can include one or more modules (not shown), each of which can include a series of instructions for operating on the server 110. Further, the central processing unit 822 can be configured to communicate with the storage media 830 to execute the series of instructions stored in the storage media 830 on the server 110.

[0152] The server 110 can also include one or more power supplies 826, one or more wired or wireless network interfaces 850, one or more input / output interfaces 858, and / or one or more operating systems 841, such as Windows Server™, Mac OS X™, Unix™, Linux™, FreeBSD™, etc.

[0153] The central processing unit 822 in the server 110 can be configured to execute the state observer based robot vibration suppression method of embodiments of the present application.

[0154] Embodiments of the present application also provide a computer readable storage medium for storing program code for executing the state observer based robot vibration suppression method of the various embodiments described above.

[0155] Embodiments of the present application also provide a computer program product including a computer program. A processor of a computer device reads the computer program and executes it, causing the computer device to perform the state observer based robot vibration suppression method described above.

[0156] In addition, the terms "comprises", "comprising", "includes", "including" and "contains", "containing" together with their conjugates mean "including but not limited to" and encompass the items listed after these terms as well as any other items.

[0157] It should be understood that, in the present application, "at least one" refers to one or more, and "multiple" refers to two or more. "And / or" is used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, "A and / or B" can mean that there are three cases of A only, B only, and A and B at the same time, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after it. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b or c can mean a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0158] It should be understood that in the description of the embodiments of the present application, the meaning of multiple (or multiple items) is two or more, greater than, less than, more than, etc. is not included in the number, and above, below, etc. is included in the number.

[0159] In several embodiments provided by the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of units is only a logical function division, and actual implementation can have another division manner. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0160] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0161] In addition, each functional unit in each embodiment of the present application can be integrated into one processing unit, or each unit can exist physically, or two or more units can be integrated into one unit. The above integrated unit can be realized in the form of hardware or in the form of software functional unit.

[0162] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or say the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0163] It should also be understood that the various embodiments provided by the embodiments of the present application can be combined in any manner to achieve different technical effects.

[0164] In the embodiments of the present application, the term "module" or "unit" refers to a computer program or a part of a computer program with a predetermined function, and works together with other related parts to achieve a predetermined target, and can be implemented entirely or partially by using software, hardware (such as a processing circuit or a memory) or a combination thereof. Similarly, one processor (or multiple processors or memories) can be used to implement one or more modules or units. In addition, each module or unit can be a part of an overall module or unit that includes the functions of the module or unit.

[0165] The above is a specific description of the embodiments of the present application, but the present application is not limited to the above-mentioned embodiments. Those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the present application, and these equivalent modifications or replacements are all included in the scope defined by the claims of the present application.

Claims

1. A state observer-based robot vibration suppression method characterized by, The method is applied to a full state feedback control system, the full state feedback control system comprises a robot, a state observer and a PID control system, the robot comprises a motor side and a linkage side, the state observer is used for collecting state parameters of the linkage side, and the PID control system is used for adjusting the motor side and the linkage side, and the method comprises the following steps: receiving a motion control instruction for the robot, determining an instruction position and an instruction speed of the motor side and an instruction position and an instruction speed of the linkage side according to the motion control instruction; in the process that the robot moves in response to the motion control instruction, if the robot vibrates, acquiring state parameters of the motor side and acquiring state parameters of the linkage side collected by the state observer; determining full state feedback parameters of the PID control system according to the state parameters of the motor side and the state parameters of the linkage side; determining a feedforward current and a feedback current of the PID control system according to the instruction position and the instruction speed of the motor side, the instruction position and the instruction speed of the linkage side and the full state feedback parameters, so as to suppress vibration of the robot according to the feedforward current and the feedback current; wherein the state observer is obtained by the following steps: determining joint stiffness of the robot; determining state parameters of the motor side and state parameters of the linkage side, the state parameters of the motor side comprising a motor side position, a motor side speed, a motor side acceleration, a motor side moment of inertia and a motor side driving torque, and the state parameters of the linkage side comprising a linkage side position, a linkage side speed, a linkage side acceleration, a linkage side moment of inertia and a linkage side driving torque; establishing a standard state space equation based on the joint stiffness, the motor side position, the motor side speed, the motor side acceleration, the motor side moment of inertia, the motor side driving torque, the linkage side position, the linkage side speed, the linkage side acceleration, the linkage side moment of inertia and the linkage side driving torque; constructing the state observer according to the standard state space equation; the full state feedback control system further comprises a dual-inertia system, and the method further comprises the following steps: determining control loop parameters of the PID control system, the control loop parameters comprising a position loop, a speed loop and a current loop; determining an input of the dual-inertia system based on the position loop, the speed loop and the current loop; taking the instruction position and the instruction speed of the motor side as first initial state variables of the dual-inertia system, and taking the instruction position and the instruction speed of the linkage side as second initial state variables of the dual-inertia system; constructing a state space equation of a state variable tracking error based on the input of the dual-inertia system, the first initial state variables and the second initial state variables; the step of determining the full state feedback parameters of the PID control system according to the state parameters of the motor side and the state parameters of the linkage side comprises the following steps: determining an initial position difference feedback coefficient of the motor side and an initial position difference feedback coefficient of the linkage side; constructing a state feedback equation of the full state feedback parameter based on the initial position difference feedback coefficient of the motor side, the initial position difference feedback coefficient of the connecting rod side, the state parameter of the motor side and the state parameter of the connecting rod side; designing an optimization equation for the full state feedback parameter based on the state feedback equation; determining the full state feedback parameter according to the optimization equation.

2. The method of claim 1, wherein, determining the feedforward current and the feedback current of the PID control system according to the command position and the command speed of the motor side, the command position and the command speed of the connecting rod side and the full state feedback parameter, including: determining the target position difference feedback coefficient of the motor side, the target position difference feedback coefficient of the connecting rod side, the proportional coefficient of the position loop and the proportional coefficient of the speed loop according to the full state feedback parameter; determining the feedforward current and the feedback current according to the command position and the command speed of the motor side, the command position and the command speed of the connecting rod side, the target position difference feedback coefficient of the motor side, the target position difference feedback coefficient of the connecting rod side, the proportional coefficient of the position loop and the proportional coefficient of the speed loop.

3. A state observer-based robot vibration suppression apparatus characterized by comprising: The application is applied to a full state feedback control system, the full state feedback control system includes a robot, a state observer and a PID control system, the robot includes a motor side and a connecting rod side, the state observer is used for collecting state parameters of the connecting rod side, and the PID control system is used for adjusting the motor side and the connecting rod side; the robot vibration suppression device based on the state observer is used for realizing the robot vibration suppression method based on the state observer in any one of claims 1-2, and the device includes: a first determination unit, used for receiving a motion control instruction for the robot, and determining the command position and the command speed of the motor side and the command position and the command speed of the connecting rod side according to the motion control instruction; a second determination unit, used for acquiring the state parameter of the motor side and the state parameter of the connecting rod side collected by the state observer if the robot vibrates in the process that the robot responds to the motion control instruction and moves; a third determination unit, used for determining the full state feedback parameter of the PID control system according to the state parameter of the motor side and the state parameter of the connecting rod side; a fourth determination unit, used for determining the feedforward current and the feedback current of the PID control system according to the command position and the command speed of the motor side, the command position and the command speed of the connecting rod side and the full state feedback parameter, so as to suppress the vibration of the robot according to the feedforward current and the feedback current.

4. An electronic device comprising a memory and a processor, the memory storing a computer program, characterized in that, The processor executes the computer program to realize the robot vibration suppression method based on the state observer in any one of claims 1-2.

5. A computer program product comprising a computer program, characterized in that, The computer program is read and executed by the processor of the electronic device, so that the electronic device executes the robot vibration suppression method based on the state observer in any one of claims 1-2.

Images