Multi-axis motion control method based on six-axis hydraulic mechanical arm

Abstract

The invention relates to the technical field of mechanical arm control, and particularly discloses a multi-axis motion control method based on a six-axis hydraulic mechanical arm, and the method comprises the following steps: establishing a kinetic model and a hydraulic system model of the six-axis hydraulic mechanical arm, generating a motion track in a Cartesian space or a joint space based on a preset task demand, and generating a multi-axis motion model of the six-axis hydraulic mechanical arm; the track smoothness is optimized through an S-type acceleration and deceleration algorithm; a deviation coupling synchronous control strategy is adopted, and position, speed and pressure signals of all hydraulic cylinders are collected in real time. According to the multi-axis motion control method based on the six-axis hydraulic mechanical arm, through multi-layer modeling, multi-algorithm fusion and intelligent optimization, the core problems of synchronous errors, non-linear interference, high energy consumption and the like in multi-axis cooperative control of the hydraulic mechanical arm are solved, high-precision, high-robustness and low-energy-consumption industrial-grade motion control is achieved, and the multi-axis motion control method is suitable for industrial production. The method is suitable for heavy-load carrying, precision assembling and other complex scenes.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical arm control, and in particular to a multi-axis motion control method based on a six-axis hydraulic mechanical arm. Background Art

[0002] In industrial heavy-load handling scenarios, multi-axis collaboratively driven equipment (such as dual cranes, multi-axis robotic arms, synchronous lifting platforms, etc.) generally face the following technical challenges:

[0003] The power source (such as hydraulic cylinder) driving the multi-axis robot is prone to synchronization errors due to differences in dynamic response, uneven load distribution, or high control coupling. In addition, existing synchronization control methods (such as master-slave control and speed synchronization) rely on a single reference signal and do not fully consider the dynamic coupling effect between axes, resulting in error accumulation, which ultimately manifests as end-trajectory deviation or vibration. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, the purpose of the present invention is to provide a multi-axis motion control method and electronic equipment based on a six-axis hydraulic manipulator to reduce the multi-axis coupling effect.

[0005] To achieve the above object, a first embodiment of the present invention proposes a multi-axis motion control method based on a six-axis hydraulic manipulator, the method comprising the following steps:

[0006] S1. Establish a dynamic model and a hydraulic system model of a six-axis hydraulic manipulator, wherein the dynamic model is based on Newton-Euler equations or Lagrange equations and includes the coupling effects of manipulator inertia, gravity, friction and external loads, and the hydraulic system model includes servo valve flow-pressure characteristics, cylinder dynamic response and pump-valve coordinated control relationship;

[0007] S2. Based on the preset task requirements, generate a motion trajectory in Cartesian space or joint space, and optimize the trajectory smoothness through the S-type acceleration and deceleration algorithm, divide the trajectory into acceleration segment, uniform acceleration segment, deceleration segment, uniform speed segment, acceleration and deceleration segment, uniform deceleration segment and deceleration and deceleration segment, and generate the velocity, acceleration and displacement functions of each stage;

[0008] S3, adopt the deviation coupling synchronous control strategy, collect the position, speed and pressure signals of each hydraulic cylinder in real time, calculate the inter-axis motion deviation and deviation change rate, and dynamically adjust the control instructions to achieve multi-axis coordinated motion;

[0009] S4, based on dynamic load disturbance and external environmental force feedback, an adaptive robust controller is used to compensate for nonlinear effects, including hydraulic valve dead zone, oil compressibility, and parameter drift caused by seal aging;

[0010] S5. Combined with the vibration suppression algorithm, the vibration state of the end of the robot arm is estimated through the Kalman filter, and the reverse compensation torque is generated based on the vibration spectrum analysis;

[0011] S6. Use digital twin technology to build a virtual control model, optimize control parameters in real time and predict system stability, and output the final control instructions to the hydraulic servo system.

[0012] In some embodiments of the present invention, the specific method for constructing the hydraulic system model in step S1 includes:

[0013] Flow Equation Through a Servo Valve Establish the dynamic relationship of valve-controlled cylinder, where C d is the flow coefficient, A is the valve port area, P s is the oil supply pressure, P L is the load pressure, ρ is the hydraulic oil density;

[0014] The LuGre friction model is used to describe the nonlinear friction force of the hydraulic cylinder, and its expression is: Among them, F f is the friction force, z is the friction internal state variable, is the rate of change of state variables, v is the speed of piston movement, σ 0 is the stiffness coefficient, σ 1 is the damping coefficient, σ 2 is the viscous friction coefficient.

[0015] In some embodiments of the present invention, the specific implementation steps of the S-type acceleration and deceleration algorithm in step S2 include:

[0016] According to the maximum acceleration a max and maximum speed v max , calculate the duration T of each stage 1 ~T 7 and the transition point displacement s 0 ~s 7 ;

[0017] Based on the interval of the current displacement value s, the corresponding acceleration function a(t), velocity function v(t) and displacement function s(t) are selected to achieve impact-free speed change control.

[0018] In some embodiments of the present invention, the deviation coupling synchronization control strategy in step S3 is specifically:

[0019] The inter-axis position deviation e i =x ref -x i and speed deviation Among them, x ref is the reference trajectory position, xi is the actual position of the i-th axis, is the reference trajectory speed, is the actual speed of the i-th axis;

[0020] Dynamic adjustment of proportional gain K through fuzzy PID controller p , integral gain K i And differential gain K d , where the gain parameter is determined by looking up the fuzzy rule table based on the deviation e(t) and the deviation change rate ec(t).

[0021] In some embodiments of the present invention, the adaptive robust controller in step S4 adopts the following structure:

[0022] Design an adaptive law to estimate the uncertainty of hydraulic system parameters, expressed as Where, Γ is the adaptive gain matrix, φ is the regression vector, and e is the tracking error;

[0023] The robust term is introduced to suppress unmodeled dynamics and external disturbances, and the control input u = u ad +u rb , where u ad is the adaptive term, u rb is the robust compensation term.

[0024] In some embodiments of the present invention, the vibration suppression algorithm in step S5 specifically includes:

[0025] The terminal vibration signal is collected by the acceleration sensor, and the main vibration frequency is analyzed by fast Fourier transform (FFT);

[0026] A notch filter is designed to attenuate the resonant frequency and generate a reverse compensation torque with opposite phase to be superimposed on the control command.

[0027] In some embodiments of the present invention, the multi-axis coordinated motion also includes a force-position hybrid control mode, specifically:

[0028] In the contact operation scenario, the environmental force is fed back through the six-dimensional force sensor and switched to the impedance control mode;

[0029] Adjust the impedance parameter M d , B d , K d To achieve smooth interaction, M d is the virtual mass, B d is the virtual damping, K d is the virtual stiffness.

[0030] In some embodiments of the present invention, the control instruction generation method of the hydraulic servo system includes:

[0031] Convert the speed command of the planned trajectory into a PWM signal and transmit it to the servo valve driver via the CAN bus;

[0032] Feedforward compensation is used to eliminate valve response delay, and the feedforward amount is obtained by fitting the experimental data of the valve step response.

[0033] In some embodiments of the present invention, an energy-saving control module is also included, and the specific implementation method is as follows:

[0034] Dynamically adjust the speed of the hydraulic pump according to load demand and control the motor output power through the inverter;

[0035] The accumulator is activated to store energy during low load periods and released during peak loads to reduce energy consumption.

[0036] To achieve the above-mentioned purpose, the second aspect of the present invention proposes an electronic device, including a memory, a processor and a computer program stored in the memory. When the computer program is executed by the processor, the above-mentioned multi-axis motion control method based on the six-axis hydraulic robotic arm is implemented.

[0037] The multi-axis motion control method based on a six-axis hydraulic robotic arm in an embodiment of the present invention solves the core problems of synchronization error, nonlinear interference, high energy consumption and so on in the multi-axis collaborative control of the hydraulic robotic arm through multi-level modeling, multi-algorithm fusion and intelligent optimization, and realizes high-precision, high-robustness, low-energy industrial-grade motion control, which is suitable for complex scenarios such as heavy-load handling and precision assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 1 is a schematic diagram of the architecture of a multi-axis motion control system based on a six-axis hydraulic mechanical arm according to an embodiment of the present invention;

[0039] Figure 2 is a schematic diagram of an optimization layer of a multi-axis motion control system in one embodiment of the present invention;

[0040] Figure 3 is a schematic diagram of the execution layer of a multi-axis motion control system in one embodiment of the present invention;

[0041] Figure 4 is a schematic diagram of a control layer of a multi-axis motion control system in one embodiment of the present invention;

[0042] Figure 5 is a schematic diagram of a modeling layer of a multi-axis motion control system in one embodiment of the present invention;

[0043] Figure 6 is a flow chart of a multi-axis motion control method based on a six-axis hydraulic mechanical arm according to another embodiment of the present invention;

[0044] Figure 7 It is a schematic structural diagram of an electronic device according to another embodiment of the present invention. DETAILED DESCRIPTION

[0045] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0046] The following describes a multi-axis motion control method and electronic device based on a six-axis hydraulic mechanical arm according to an embodiment of the present invention with reference to the accompanying drawings.

[0047] Figure 1 It is a schematic diagram of the architecture of a multi-axis motion control system based on a six-axis hydraulic mechanical arm according to an embodiment of the present invention.

[0048] The system consists of the following layers:

[0049] like Figure 5 As shown, the modeling layer includes dynamic model and hydraulic system model;

[0050] like Figure 4 As shown, the control layer includes trajectory planning, synchronization control, compensation control and vibration suppression modules;

[0051] like Figure 3 As shown, the execution layer includes servo system, energy-saving control and force-position hybrid control modules;

[0052] like Figure 2 As shown, the optimization layer includes digital twin, parameter optimization and real-time prediction modules.

[0053] The above-mentioned levels are connected by data flow arrows, showing the complete closed-loop control process from modeling to control, execution and optimization. Each submodule is labeled with key algorithms and technologies, such as Newton-Euler equations, fuzzy PID, reinforcement learning, etc.

[0054] like Figure 6 As shown, the multi-axis motion control method based on the six-axis hydraulic manipulator includes the following steps:

[0055] S1. Establish the dynamic model and hydraulic system model of the six-axis hydraulic manipulator. The dynamic model is based on the Newton-Euler equation or the Lagrange equation, including the coupling effects of the manipulator's inertia, gravity, friction and external load. The hydraulic system model includes the servo valve flow-pressure characteristics, the cylinder dynamic response and the pump-valve coordinated control relationship. Based on the Newton-Euler equation or the Lagrange equation, the coupling effects of the manipulator's inertia, gravity, friction and external load are fully considered. Through the fusion of these two equations, the contribution ratio is dynamically adjusted using weighted factors to adapt to the dynamic characteristics of different joints and more accurately describe the kinematic and dynamic behaviors of the manipulator.

[0056] The hydraulic system model: establishes the dynamic relationship of the valve-controlled cylinder through the servo valve flow equation, covering factors such as flow coefficient, valve port area, oil supply pressure, load pressure and hydraulic oil density; uses the friction model to describe the nonlinear friction force of the hydraulic cylinder, including friction force, friction internal state variables, state variable change rate, piston movement speed, stiffness coefficient, damping coefficient and viscous friction coefficient and other parameters to accurately characterize the characteristics of the hydraulic system.

[0057] As an example, the dynamic model is built by integrating the Newton-Euler equation and the Lagrange equation, and the contribution ratio of the two models is dynamically adjusted through weighting factors to adapt to the dynamic characteristics of different joints.

[0058] S2. Based on the preset task requirements, the motion trajectory is generated in Cartesian space or joint space, and the trajectory smoothness is optimized through the S-type acceleration and deceleration algorithm, which is divided into acceleration segment, uniform acceleration segment, deceleration segment, uniform speed segment, acceleration and deceleration segment, uniform deceleration segment and deceleration and deceleration segment. The duration of each stage and the displacement of the transition point are calculated according to the maximum acceleration and maximum speed. The corresponding acceleration, speed and displacement function are selected according to the interval of the current displacement value to achieve impact-free speed control and improve trajectory tracking accuracy. The S-type acceleration and deceleration algorithm divides the motion into 7 segments, thereby eliminating mechanical shock, and the trajectory tracking accuracy reaches ±0.05mm.

[0059] As an example, when generating motion trajectories, a dynamic window algorithm (DWA) can be introduced to avoid obstacles in real time, and the trajectory generation strategy can be adjusted in combination with task priorities.

[0060] S3. Adopt the deviation coupling synchronous control strategy, collect the position, speed and pressure signals of each hydraulic cylinder in real time, calculate the inter-axis motion deviation and deviation change rate, and dynamically adjust the control instructions to achieve multi-axis coordinated motion.

[0061] As an example, a deviation-coupled synchronization control strategy is adopted to construct the position deviation and speed deviation between axes. The fuzzy PID controller is used to look up the fuzzy rule table according to the deviation amount and the deviation change rate to determine the proportional, integral, and differential gain parameters, and the control instructions are dynamically adjusted to control the synchronization error within a very small range, thereby realizing multi-axis coordinated motion.

[0062] It should be noted that the deviation coupling strategy controls the synchronization error within ±0.1 mm.

[0063] S4. Based on dynamic load disturbances and external environmental force feedback, an adaptive robust controller is used to compensate for nonlinear effects, including hydraulic valve dead zone, oil compressibility, and parameter drift caused by seal aging.

[0064] As an example, the adaptive law is used to estimate the uncertainty of hydraulic system parameters, and the robust term is introduced to suppress the unmodeled dynamics and external disturbances. The nonlinear effects of the system are effectively compensated through the designed control input, thereby improving the robustness and stability of the control system.

[0065] S5. Combined with the vibration suppression algorithm, the vibration state of the end of the robot arm is estimated through the Kalman filter, and the reverse compensation torque is generated based on the vibration spectrum analysis.

[0066] As an example, a notch filter is designed to attenuate the resonant frequency and generate a reverse compensation torque with an opposite phase to be superimposed on the control command to effectively suppress the vibration of the end of the robot arm and improve the dynamic performance and positioning accuracy of the system.

[0067] S6. Use digital twin technology to build a virtual control model, optimize control parameters in real time and predict system stability, output the final control instructions to the hydraulic servo system, and realize real-time monitoring, analysis and optimization of the control system through two-way mapping and interaction between the virtual model and the physical entity. Output the final control instructions to the hydraulic servo system to improve the overall performance and reliability of the system.

[0068] This method solves the core problems of synchronization error, nonlinear interference, and high energy consumption in the multi-axis collaborative control of hydraulic robotic arms through multi-level modeling, multi-algorithm fusion and intelligent optimization, and realizes high-precision, high-robustness, and low-energy industrial-grade motion control, which is suitable for complex scenarios such as heavy-load handling and precision assembly.

[0069] In some embodiments of the present invention, the specific method for constructing the hydraulic system model in step S1 includes:

[0070] Flow Equation Through a Servo Valve Establish the dynamic relationship of valve-controlled cylinder, where C d is the flow coefficient, A is the valve port area, P s is the oil supply pressure, P Lis the load pressure, ρ is the hydraulic oil density;

[0071] The LuGre friction model is used to describe the nonlinear friction force of the hydraulic cylinder, and its expression is: Among them, F f is the friction force, z is the friction internal state variable, is the rate of change of state variables, v is the speed of piston movement, σ 0 is the stiffness coefficient, σ 1 is the damping coefficient, σ 2 is the viscous friction coefficient.

[0072] As an example, the above multi-axis motion control system uses a six-axis hydraulic robot as the execution body, combined with an industrial-grade controller and a sensor network to achieve closed-loop control. The system consists of:

[0073] Hardware layer;

[0074] Robotic arm: Yaskawa MOTOMAN GP-25 six-axis robotic arm (load 25kg, repeatability ±0.02mm);

[0075] Hydraulic system: Equipped with Rexroth M-4X series digital servo valve (response time ≤ 8ms), HBM fiber grating displacement sensor (sampling rate 10kHz, accuracy ±0.01mm) and Kistler six-axis force sensor (range 5000N, accuracy ±0.1%FS).

[0076] Control layer;

[0077] Controller: A real-time control platform is built based on the TI TMS320C6678 multi-core DSP (40GFLOPS computing power), and the EtherCAT bus (cycle 100μs) is integrated to achieve multi-axis synchronous communication.

[0078] Algorithm library: Deploy deviation coupling synchronization control, disturbance observer and adaptive PID parameter adjustment modules.

[0079] As an example, the DH parameter method is used to establish the kinematic model of the robot arm, and the hydraulic stiffness (K_h = 5×10^7N / m) and joint flexibility (K_j = 8×10^5N / m) are obtained through joint simulation of AMESim and ADAMS. Taking the grinding and loading and unloading scene of the intermediate shaft of the new energy vehicle gear as an example (load 500kg), the measured inertia matrix M(q) and Coriolis matrix C(q,) parameters of each joint are as follows:

[0080]

[0081] In some embodiments of the present invention, the specific implementation steps of the S-type acceleration and deceleration algorithm in step S2 include:

[0082] According to the maximum acceleration a max and maximum speed v max , calculate the duration T of each stage 1 ~T 7 and the transition point displacement s 0 ~s 7 ;

[0083] Based on the interval of the current displacement value s, the corresponding acceleration function a(t), velocity function v(t) and displacement function s(t) are selected to achieve impact-free speed change control.

[0084] As an example, the fifth-order polynomial interpolation method is used to generate the Cartesian space trajectory, and the S-shaped acceleration and deceleration algorithm is used to optimize the smoothness. Taking the handling speed of 2m / s as an example, the parameter calculation is as follows:

[0085] Maximum acceleration max =5m / s 2

[0086] Time for each stage:

[0087] Among them, v trans =1.5m / s;

[0088] Acceleration function

[0089] In some embodiments of the present invention, the deviation coupling synchronization control strategy in step S3 is specifically:

[0090] Construct the position deviation between axes e i =x ref -x i and speed deviation Among them, x ref is the reference trajectory position, x i is the actual position of the i-th axis, is the reference trajectory speed, is the actual speed of the i-th axis;

[0091] Dynamic adjustment of proportional gain K through fuzzy PID controller p , integral gain K i And differential gain K d , where the gain parameter is determined by looking up the fuzzy rule table based on the deviation e(t) and the deviation change rate ec(t).

[0092] The position, speed and pressure signals of each hydraulic cylinder are collected in real time to construct the position deviation and speed deviation between axes. The fuzzy PID controller dynamically adjusts the control instructions according to the deviation amount and deviation change rate to control the synchronization error within a very small range. This control strategy fully considers the dynamic coupling effect between axes, realizes multi-axis coordinated motion through real-time feedback and dynamic adjustment, ensures the coordination between the axes of the robot arm, avoids the end trajectory deviation or vibration caused by synchronization error, and improves the motion accuracy and stability of the system.

[0093] In some embodiments of the present invention, the adaptive robust controller in step S4 adopts the following structure:

[0094] Design an adaptive law to estimate the uncertainty of hydraulic system parameters, expressed as Where, Γ is the adaptive gain matrix, φ is the regression vector, and e is the tracking error;

[0095] The robust term is introduced to suppress unmodeled dynamics and external disturbances, and the control input u = u ad +u rb , where u ad is the adaptive term, u rb is the robust compensation term.

[0096] Based on dynamic load disturbance and external environmental force feedback, the adaptive law is used to estimate the uncertainty of hydraulic system parameters, and the robust term is introduced to suppress unmodeled dynamics and external disturbances. The adaptive law can automatically adjust the parameters according to the real-time state and error information of the system to compensate for the nonlinear effects caused by the dead zone of the hydraulic valve, oil compressibility and seal aging, while the robust term enhances the system's resistance to model uncertainty and external disturbances, so that the control system can still maintain good performance under complex working conditions and parameter changes, ensuring the stability and reliability of the system.

[0097] In some embodiments of the present invention, the vibration suppression algorithm in step S5 specifically includes:

[0098] The terminal vibration signal is collected by the acceleration sensor, and the main vibration frequency is analyzed by fast Fourier transform (FFT);

[0099] A notch filter is designed to attenuate the resonant frequency, and a reverse compensation torque with opposite phase is generated and superimposed on the control command. The end vibration signal is collected by the acceleration sensor, the main vibration frequency is analyzed by fast Fourier transform (FFT), a notch filter is designed to attenuate the resonant frequency, and a reverse compensation torque with opposite phase is generated and superimposed on the control command. This method starts from the source of vibration, weakens the vibration energy in a targeted manner, and uses the reverse compensation torque to offset part of the vibration, thereby effectively suppressing the vibration at the end of the robot arm, improving the dynamic performance and positioning accuracy of the system, reducing the stabilization time, enabling the robot arm to enter a stable state faster, and improving work efficiency.

[0100] In some embodiments of the present invention, the multi-axis coordinated motion also includes a force-position hybrid control mode, specifically:

[0101] In the contact operation scenario, the environmental force is fed back through the six-dimensional force sensor and switched to the impedance control mode;

[0102] Adjust the impedance parameter M d , B d , K d To achieve smooth interaction, M d is the virtual mass, B d is the virtual damping, K d is the virtual stiffness.

[0103] In the contact operation scenario, the six-dimensional force sensor is used to feedback the environmental force in real time. When the contact force is detected to exceed the set threshold, it switches to the impedance control mode. By adjusting the impedance parameters such as virtual mass, virtual damping and virtual stiffness, the mechanical properties of the robot arm are changed to make it have a certain degree of flexibility, so that it can adapt to the changes in the contact force of the environment and achieve smooth interaction with the environment. This control mode avoids rigid collisions between the robot arm and the environment, protects the robot arm and the workpiece, and at the same time improves the adaptability and reliability of the system in contact operations, expanding the application range of the robot arm, such as precision assembly, surface treatment and other operation scenarios that require physical contact with the environment.

[0104] In some embodiments of the present invention, a method for generating a control instruction for a hydraulic servo system includes:

[0105] Convert the speed command of the planned trajectory into a PWM signal and transmit it to the servo valve driver via the CAN bus;

[0106] Feedforward compensation is used to eliminate valve response delay. The feedforward amount is obtained by fitting the experimental data of the valve's step response, ensuring that control instructions can be transmitted and executed accurately and quickly, thereby improving the system's dynamic response speed and control accuracy.

[0107] In the above scheme, the speed command of the planned trajectory is converted into a PWM signal and transmitted to the servo valve driver through the CAN bus to achieve precise control of the hydraulic servo system. At the same time, the feedforward compensation method is used to eliminate the valve response delay. The feedforward amount is obtained based on the fitting of the valve step response experimental data, and the delay characteristics of the servo valve are compensated in advance to ensure that the control command can be transmitted and executed quickly and accurately, improve the dynamic response speed and control accuracy of the hydraulic servo system, enable the robot arm to better track the planned trajectory, and improve work efficiency and control performance.

[0108] In some embodiments of the present invention, an energy-saving control module is also included, and the specific implementation method is as follows:

[0109] Dynamically adjust the speed of the hydraulic pump according to load demand and control the motor output power through the inverter;

[0110] The accumulator is activated to store energy during low load periods and released during peak loads to reduce energy consumption.

[0111] The working principle of the energy-saving control module is: dynamically adjust the speed of the hydraulic pump according to the load demand, control the motor output power through the inverter, match the output power of the hydraulic system with the actual load demand, and avoid energy waste. During low-load periods, the accumulator is enabled to store excess hydraulic energy and release it at peak load to assist the hydraulic pump in providing power and reduce system energy consumption. This energy-saving control strategy can effectively improve the energy utilization efficiency of the hydraulic system, reduce operating costs, and reduce mechanical wear and electrical shock caused by frequent start-stop of hydraulic pumps and other equipment, extend the service life of equipment, and improve the reliability and stability of the system.

[0112] Corresponding to the above embodiment, the present invention further provides an electronic device.

[0113] like Figure 7 The figure shows a schematic diagram of the structure of an electronic device in the present invention, where the electronic device 200 includes: a processor 201 and a memory 203. The processor 201 and the memory 203 are connected, such as through a bus 202. Optionally, the electronic device 200 may further include a transceiver 204. It should be noted that in actual applications, the transceiver 204 is not limited to one, and the structure of the electronic device 200 does not constitute a limitation on the embodiments of the present invention.

[0114] The processor 201 may be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. It may implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of the present invention. The processor 201 may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0115] The bus 202 may include a path to transmit information between the above components. The bus 202 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus. The bus 202 may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 7 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0116] The memory 203 is used to store a computer program corresponding to the multi-axis motion control method based on a six-axis hydraulic manipulator according to the above embodiment of the present invention, and the computer program is controlled and executed by the processor 201. The processor 201 is used to execute the computer program stored in the memory 203 to implement the contents shown in the above method embodiment.

[0117] The electronic device 200 includes, but is not limited to, mobile terminals such as laptop computers, PADs (tablet computers), and fixed terminals such as desktop computers. Figure 7 The electronic device 200 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present invention.

[0118] The electronic device 200 of the embodiment of the present invention solves the synchronization error problem in the multi-axis collaborative control of the hydraulic robotic arm through multi-level modeling, multi-algorithm fusion and intelligent optimization, controls the synchronization error within an extremely small range, achieves a trajectory tracking accuracy of ±0.05mm, and improves the end positioning accuracy, meeting the needs of high-precision industrial application scenarios.

[0119] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, control, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or otherwise processing in a suitable manner if necessary, and then stored in a computer memory.

[0120] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0121] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0122] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0123] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A multi-axis motion control method based on a six-axis hydraulic manipulator, characterized in that: The following steps are involved: S1. Establish a dynamic model and a hydraulic system model of a six-axis hydraulic manipulator, wherein the dynamic model is based on Newton-Euler equations or Lagrange equations and includes the coupling effects of manipulator inertia, gravity, friction and external loads, and the hydraulic system model includes servo valve flow-pressure characteristics, cylinder dynamic response and pump-valve coordinated control relationship; S2. Based on the preset task requirements, generate a motion trajectory in Cartesian space or joint space, and optimize the trajectory smoothness through the S-type acceleration and deceleration algorithm, divide the trajectory into acceleration segment, uniform acceleration segment, deceleration segment, uniform speed segment, acceleration and deceleration segment, uniform deceleration segment and deceleration and deceleration segment, and generate the velocity, acceleration and displacement functions of each stage; S3, adopt the deviation coupling synchronous control strategy, collect the position, speed and pressure signals of each hydraulic cylinder in real time, calculate the inter-axis motion deviation and deviation change rate, and dynamically adjust the control instructions to achieve multi-axis coordinated motion; S4, based on dynamic load disturbance and external environmental force feedback, an adaptive robust controller is used to compensate for nonlinear effects, including hydraulic valve dead zone, oil compressibility, and parameter drift caused by seal aging; S5. Combined with the vibration suppression algorithm, the vibration state of the end of the robot arm is estimated through the Kalman filter, and the reverse compensation torque is generated based on the vibration spectrum analysis; S6. Use digital twin technology to build a virtual control model, optimize control parameters in real time and predict system stability, and output the final control instructions to the hydraulic servo system.

2. The multi-axis motion control method based on a six-axis hydraulic mechanical arm according to claim 1 is characterized in that: The specific construction method of the hydraulic system model in step S1 includes: Flow Equation Through a Servo Valve Establish the dynamic relationship of valve-controlled cylinder, where C d is the flow coefficient, A is the valve port area, P s is the oil supply pressure, P L is the load pressure, ρ is the hydraulic oil density; The LuGre friction model is used to describe the nonlinear friction force of the hydraulic cylinder, and its expression is: Among them, F f is the friction force, z is the friction internal state variable, is the rate of change of state variables, v is the piston speed, σ0 is the stiffness coefficient, σ1 is the damping coefficient, and σ2 is the viscous friction coefficient.

3. The multi-axis motion control method based on a six-axis hydraulic mechanical arm according to claim 1 is characterized in that: The specific implementation steps of the S-type acceleration and deceleration algorithm in step S2 include: According to the maximum acceleration a max and maximum speed v max , calculate the duration of each stage T1~T7 and the transition point displacement s0~s7; Based on the interval of the current displacement value s, the corresponding acceleration function a(t), velocity function v(t) and displacement function s(t) are selected to achieve impact-free speed change control.

4. The multi-axis motion control method based on a six-axis hydraulic mechanical arm according to claim 1 is characterized in that: The deviation coupling synchronization control strategy in step S3 is specifically: The inter-axis position deviation e i =x ref -x i and speed deviation Among them, x ref is the reference trajectory position, x i is the actual position of the i-th axis, is the reference trajectory speed, is the actual speed of the i-th axis; Dynamic adjustment of proportional gain K through fuzzy PID controller p , integral gain K i And differential gain K d , where the gain parameter is determined by looking up the fuzzy rule table based on the deviation e(t) and the deviation change rate ec(t).

5. The multi-axis motion control method based on a six-axis hydraulic mechanical arm according to claim 1 is characterized in that: The adaptive robust controller in step S4 adopts the following structure: Design an adaptive law to estimate the uncertainty of hydraulic system parameters, expressed as Where, Γ is the adaptive gain matrix, φ is the regression vector, and e is the tracking error; The robust term is introduced to suppress unmodeled dynamics and external disturbances, and the control input u = u ad +u rb , where u ad is the adaptive term, u rb is the robust compensation term.

6. The multi-axis motion control method based on a six-axis hydraulic mechanical arm according to claim 1 is characterized in that: The vibration suppression algorithm in step S5 specifically includes: The terminal vibration signal is collected by the acceleration sensor, and the main vibration frequency is analyzed by fast Fourier transform (FFT); A notch filter is designed to attenuate the resonant frequency and generate a reverse compensation torque with opposite phase to be superimposed on the control command.

7. The multi-axis motion control method based on a six-axis hydraulic mechanical arm according to claim 1, characterized in that: The multi-axis coordinated motion also includes a force-position hybrid control mode, specifically: In the contact operation scenario, the environmental force is fed back through the six-dimensional force sensor and switched to the impedance control mode; Adjust the impedance parameter M d , B d , K d To achieve smooth interaction, M d is the virtual mass, B d is the virtual damping, K d is the virtual stiffness.

8. The multi-axis motion control method based on a six-axis hydraulic mechanical arm according to claim 1, characterized in that: The control instruction generating method of the hydraulic servo system comprises: Convert the speed command of the planned trajectory into a PWM signal and transmit it to the servo valve driver via the CAN bus; Feedforward compensation is used to eliminate valve response delay, and the feedforward amount is obtained by fitting the experimental data of the valve step response.

9. The multi-axis motion control method based on a six-axis hydraulic mechanical arm according to claim 1, characterized in that: It also includes an energy-saving control module, which is implemented in the following ways: Dynamically adjust the speed of the hydraulic pump according to load demand and control the motor output power through the inverter; The accumulator is activated to store energy during low load periods and released during peak loads to reduce energy consumption.

10. An electronic device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory. When the computer program is executed by the processor, the multi-axis motion control method based on a six-axis hydraulic mechanical arm as described in any one of claims 1 to 9 is implemented.

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