Industrial robot distributed driving and control integrated system and method based on fusion dynamics

Abstract

The invention relates to the technical field of industrial robots, in particular to an industrial robot distributed driving and control integrated system and method based on fusion dynamics, and the system comprises the steps that a first central processing unit operates a Linux system, loads a dynamics model, and sends a position instruction and model parameters to a second central processing unit; the dynamic model has the functions of robot parameter identification, vibration suppression, friction compensation, speed feed-forward and acceleration feed-forward; the second central processing unit operates a bare computer program, performs data interaction with the first central processing unit, and performs interpolation operation on the position instruction, the speed feed-forward and the acceleration feed-forward to obtain optimized trajectory curve, position instruction, speed feed-forward and acceleration feed-forward data; and the controller is used for acquiring data of the central processing unit II, running a plurality of hardware motor position rings in parallel and driving each joint motor of the robot to move, so that each controller can work cooperatively, and the overall control of the robot is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial robots, and particularly to a distributed drive and control integrated system and method for industrial robots based on fused dynamics. Background Art

[0002] With the development of technology, industrial robots are increasingly widely used in modern manufacturing. They can improve production efficiency, reduce production costs, and improve product quality. Industrial robots usually consist of multiple joints, and complex motion operations can be achieved through precise control of each joint. However, due to the complexity of industrial robot systems, precise control of them is a challenge. Existing industrial robot control technologies mainly adopt a centralized control method, that is, all control tasks are completed by a central controller. Although this control method is simple, when the scale of the robot system increases, the computational burden on the central controller will increase, which may lead to a decrease in control accuracy.

[0003] To solve the problems existing in the centralized control method of industrial robots, some researchers have proposed a distributed control system, which distributes control tasks to multiple controllers. This method can reduce the computational burden on the central controller and improve the reliability and flexibility of the system.

[0004] However, using the above method, although the existing distributed control system can reduce the computational burden, it is difficult to achieve effective cooperation between controllers, resulting in difficulty in overall control of the robot. Summary of the Invention

[0005] The purpose of the present invention is to provide a distributed drive and control integrated system and method for industrial robots based on fused dynamics, enabling each controller to work collaboratively to achieve overall control of the robot.

[0006] To achieve the above purpose, in the first aspect, the present invention provides a distributed drive and control integrated method for industrial robots based on fused dynamics, including:

[0007] A first central processor runs a Linux system and loads a dynamics model, and sends a position instruction and model parameters to a second central processor. The dynamics model has functions of robot parameter identification, vibration suppression, friction compensation, velocity feedforward, and acceleration feedforward;

[0008] The second central processor runs a bare-metal program, conducts data interaction with the first central processor, and performs interpolation operations on the position instruction, velocity feedforward, and acceleration feedforward to obtain an optimized trajectory curve, position instruction, velocity feedforward, and acceleration feedforward data;

[0009] Obtain the data of the second central processor and run multiple hardware motor position loops in parallel to drive the motors of each joint of the robot.

[0010] Among them, the first central processing unit and the second central processing unit achieve data interaction by means of shared memory, and software-generated interrupts are used to avoid access conflicts.

[0011] Among them, the specific steps for the first central processing unit and the second central processing unit to achieve data interaction by means of shared memory and use software-generated interrupts to avoid access conflicts include:

[0012] The first central processing unit enables the timer interrupt.

[0013] In the interrupt service function of the first central processing unit, the first central processing unit performs a write operation on the shared memory, packs and writes the position instruction, compensation value, and feedforward value into the shared memory area. After the writing is completed, it triggers the second central processing unit to generate an interrupt.

[0014] After receiving the interrupt from the first central processing unit, the second central processing unit performs a read operation on the shared memory in the interrupt service program, performs interpolation processing on the read data to generate an optimized trajectory. At the same time, the second central processing unit enables the timer interrupt, sets the interrupt period to 125 μs, and sets the priority to the highest.

[0015] The timer interrupt of the second central processing unit generates a position loop synchronization signal for the communication between the second central processing unit and the FPGA. When each synchronization signal arrives, the second central processing unit sends the interpolated position instruction, velocity feedforward, and acceleration feedforward real-time data to the FPGA through the AXI bus.

[0016] In a second aspect, the present invention also provides an industrial robot distributed drive and control integrated system based on fusion dynamics, including a first central processing unit, a second central processing unit, and an FPGA chip;

[0017] The first central processing unit, the second central processing unit, and the FPGA chip are connected in sequence;

[0018] The first central processing unit is used to run the Linux system and load the dynamics model, and send the position instruction and model parameters to the second central processing unit. The dynamics model has functions of robot parameter identification, vibration suppression, friction compensation, velocity feedforward, and acceleration feedforward;

[0019] The second central processing unit is used to run the bare-metal program, perform data interaction with the first central processing unit, perform interpolation operations on the position instruction, velocity feedforward, and acceleration feedforward, obtain an optimized trajectory curve, position instruction, velocity feedforward, and acceleration feedforward, and send the optimized position instruction, velocity feedforward, and acceleration feedforward to the FPGA chip;

[0020] The FPGA chip is used to obtain the data of the second central processing unit, run multiple hardware motor position loops in parallel, and drive the motors of each joint of the robot.

[0021] A distributed drive and control integrated system and method for an industrial robot based on fused dynamics. By adopting a distributed drive and control integrated method and allocating control tasks to multiple controllers, the computing burden on the central controller can be effectively reduced, and the problem of affecting control accuracy due to excessive computing burden can be avoided. In addition, global dynamic speed feedforward and acceleration feedforward are carried in each joint control. This control method can improve the response speed and control accuracy of the system, enabling the industrial robot to achieve more precise motion operations. At the same time, by adopting the multi-axis linkage servo control technology based on fused dynamics, effective cooperation between controllers can be achieved, enabling the control of each joint to take into account the dynamic characteristics of the entire system, thereby improving the overall control performance of the system. Finally, the dynamic control strategy adopted in the present invention can not only handle linear problems but also handle non-linear problems, with stronger adaptability and robustness. Compared with the prior art, it not only improves the control accuracy and response speed of the industrial robot but also enhances the cooperation between controllers, and can better cope with the challenges brought by the increase in the scale of the industrial robot system. Brief Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art.

[0023] Figure 1 is a flowchart of a distributed drive and control integrated method for an industrial robot based on fused dynamics of the present invention.

[0024] Figure 2 is a flowchart of the first central processing unit and the second central processing unit of the present invention realizing data interaction in a shared memory manner and using software to generate interrupts to avoid access conflicts.

[0025] Figure 3 is a schematic structural diagram of a distributed drive and control integrated system for an industrial robot based on fused dynamics of the present invention.

[0026] Figure 4 is a schematic diagram of the principle of a distributed drive and control integrated system for an industrial robot based on fused dynamics of the present invention.

[0027] Figure 5 is an architecture diagram of drive and control integrated data interaction of a distributed drive and control integrated system for an industrial robot based on fused dynamics of the present invention.

[0028] Figure 6 is a schematic diagram of the FPGA distributed hardware position loop of the present invention.

[0029] Figure 7 It is a schematic structural diagram of a simplified single-axis position loop of the present invention.

[0030] Figure 8 It is a calculation flow chart of the single-axis position loop of the present invention.

[0031] Figure 9 It is a comparison schematic diagram of the single-sampling single-update strategy and the double-sampling double-update strategy of the present invention.

[0032] 101 - Central Processing Unit 1, 102 - Central Processing Unit 2, 103 - FPGA chip. Detailed implementation manners

[0033] Please refer to Figures 1 - 2 , in the first aspect, the present invention provides an industrial robot distributed drive and control integrated method based on fusion dynamics, including:

[0034] S101 Central Processing Unit 101 runs the Linux system and loads the dynamics model, and sends position instructions and model parameters to Central Processing Unit 2 102. The dynamics model has functions of robot parameter identification, vibration suppression, friction compensation, velocity feedforward, and acceleration feedforward;

[0035] Using the Xilinx zynq7020 SOC chip, which integrates Central Processing Unit 1 101, Central Processing Unit 2 102 and FPGA. The models of Central Processing Unit 1 101 and Central Processing Unit 2 102 adopt ARM Cortex-A9 CPUs. Central Processing Unit 1 101 runs the Linux system and loads the dynamics model, which has functions of robot parameter identification, vibration suppression, friction compensation, velocity feedforward, and acceleration feedforward, and sends position instructions and model parameters to Central Processing Unit 2 102. At the same time, it can be connected to a teach pendant or a personal computer through a network interface to facilitate monitoring the operating state and querying historical information.

[0036] S102 Central Processing Unit 2 102 runs a bare-metal program, conducts data interaction with Central Processing Unit 1 101, and performs interpolation operations on the position instructions, velocity feedforward, and acceleration feedforward to obtain optimized trajectory curves, position instructions, velocity feedforward, and acceleration feedforward data;

[0037] Central Processing Unit 2 102 runs a bare-metal program, receives data from Central Processing Unit 1 101, further performs interpolation operations on the position instructions, velocity feedforward, and acceleration feedforward to obtain an optimized trajectory curve to improve the positioning accuracy and response speed of the driver. Central Processing Unit 2 102 sends the optimized position instructions, velocity feedforward, and acceleration feedforward to the FPGA.

[0038] The central processor 1 (101) and the central processor 2 (102) achieve data interaction by sharing memory, and use software to generate interrupts to avoid access conflicts. The specific steps are as follows:

[0039] S201 The central processor 1 (101) enables the timer interrupt, and the timer interrupt period is set to 4 ms;

[0040] S202 In the interrupt service function of the central processor 1 (101), the central processor 1 (101) performs a write operation on the shared memory, packs the position instruction, compensation value, and feedforward value and writes them into the shared memory area. After the writing is completed, it triggers the central processor 2 (102) to generate an interrupt;

[0041] S203 After receiving the interrupt from the central processor 1 (101), the central processor 2 (102) performs a read operation on the shared memory in the interrupt service program, and performs interpolation processing on the read data to generate an optimized trajectory. At the same time, the central processor 2 (102) enables the timer interrupt, the interrupt period is set to 125 μs, and the priority is set to the highest;

[0042] S204 The timer interrupt of the central processor 2 (102) generates a position loop synchronization signal for the communication between the central processor 2 (102) and the FPGA. When each synchronization signal arrives, the central processor 2 (102) sends the interpolated position instruction, velocity feedforward, and acceleration feedforward real-time data to the FPGA through the AXI bus.

[0043] S103 Obtain the data of the central processor 2 (102), and run multiple hardware motor position loops in parallel to drive the motors of each joint of the robot.

[0044] The FPGA is used to receive data from the central processor 2 (102), sample the motor current and encoder, and run the multi-axis motor hardware position loop to output PWM waves. The PWM waves finally drive the motors of each joint of the robot through the inverter bridge. Specifically, the FPGA runs six hardware motor position loops (including the position loop, speed loop, and current loop) in parallel to achieve the position control of the motor. The traditional solution is to run all six-axis position loops, speed loops, and current loops in the ARM core or run the position loop and speed loop partially in the ARM core. For this solution, assuming the running time of one position loop is t, the running time of N position loops is N times the time t, that is, N*t. As the number of axes increases, it may lead to insufficient CPU computing power, resulting in problems such as multi-axis out-of-sync and decreased control accuracy. The present invention accelerates the execution process of the motor control program using the FPGA, and runs all six-axis position loops, speed loops, and current loops in the FPGA in a parallel manner, realizing the distributed control of the motor. The total running time of the multi-axis position loop is t, which is independent of the number of axes. Based on the distributed hardware position loop design of the FPGA, while greatly improving the synchronization performance of multi-axis operation, it also improves the expandability and can be easily expanded to more than six axes. To accelerate the response of the current loop, a double-sampling and double-update strategy is adopted, that is, the current is sampled twice in one PWM cycle, and the PWM output is also refreshed twice. The traditional single-sampling and single-update strategy is that the PWM can only be refreshed in the next sampling, and the sampling-refresh delay is 1.25 servo control cycles. However, adopting the double-sampling and double-update strategy can achieve this sampling and this refresh, and its sampling-refresh delay is shortened to 0.25 servo control cycles. Due to the shortening of the sampling-refresh delay, the bandwidth of the current loop is increased.

[0045] A distributed drive and control integrated method for an industrial robot based on fused dynamics according to the present invention adopts a distributed drive and control integrated method to allocate control tasks to multiple controllers, which can effectively reduce the computing burden of the central controller and avoid the problem of affecting control accuracy due to excessive computing burden. In addition, global dynamic speed feedforward and acceleration feedforward are carried in each joint control. This control method can improve the response speed and control accuracy of the system, enabling the industrial robot to achieve more precise motion operations. At the same time, the multi-axis linkage servo control technology based on fused dynamics is adopted, which can realize the effective cooperation between controllers, enabling the control of each joint to consider the dynamic characteristics of the entire system, thereby improving the overall control performance of the system. Finally, the dynamic control strategy adopted by the present invention can not only handle linear problems but also handle non-linear problems, with stronger adaptability and robustness. Compared with the prior art, the present invention not only improves the control accuracy and response speed of the industrial robot but also enhances the cooperation between controllers, and can better cope with the challenges brought by the increase in the scale of the industrial robot system.

[0046] For a second aspect, please refer to Figures 3 - 9 , the present invention further provides an industrial robot distributed drive and control integrated system based on fusion dynamics, including a central processor 101, a central processor 102 and an FPGA chip 103;

[0047] The central processor 101, the central processor 102 and the FPGA chip 103 are connected in sequence;

[0048] The central processor 101 is used to run the Linux system and load the dynamics model, and send position instructions and model parameters to the central processor 102. The dynamics model has functions of robot parameter identification, vibration suppression, friction compensation, velocity feedforward, and acceleration feedforward;

[0049] The central processor 102 is used to run the bare-metal program, perform data interaction with the central processor 101, and perform interpolation operations on the position instructions, velocity feedforward, and acceleration feedforward to obtain an optimized trajectory curve, position instructions, velocity feedforward, and acceleration feedforward, and send the optimized position instructions, velocity feedforward, and acceleration feedforward to the FPGA chip 103;

[0050] The FPGA chip 103 is used to obtain the data of the central processor 102 and run multiple hardware motor position loops in parallel to drive the motors of each joint of the robot.

[0051] A distributed drive and control integrated system of an industrial robot based on fusion dynamics uses a Xilinx zynq7020 SOC chip, which integrates a central processor 101, a central processor 102 and an FPGA chip 103. The models of the central processor 101 and the central processor 102 adopt ARM Cortex-A9 CPUs. The central processor 101 runs the Linux system and loads the dynamics model, and has functions such as robot parameter identification, vibration suppression, friction compensation, velocity feedforward, and acceleration feedforward. It sends position commands and model parameters to the central processor 102, and can also be connected to a teach pendant or a personal computer through a network interface to facilitate monitoring the operating state and querying historical information. The central processor 102 runs a bare-metal program, receives data from the central processor 101, and further performs interpolation operations on the position command, velocity feedforward, and acceleration feedforward to obtain an optimized trajectory curve to improve the positioning accuracy and response speed of the driver. The central processor 102 sends the optimized position command, velocity feedforward, and acceleration feedforward to the FPGA chip 103. The central processor 101 and the central processor 102 realize data interaction in a shared memory manner and use software to generate interrupts to avoid access conflicts. The specific implementation process is as follows: The central processor 101 enables a timer interrupt, and the timer interrupt period is set to 4 ms; in the interrupt service function of the central processor 101, the central processor 101 performs a write operation on the shared memory, packs the position command, compensation value, and feedforward value and writes them into the shared memory area. After the writing is completed, it triggers the central processor 102 to generate an interrupt; after receiving the interrupt from the central processor 101, the central processor 102 performs a read operation on the shared memory in the interrupt service program and performs interpolation processing on the read data to generate an optimized trajectory. At the same time, the central processor 102 enables a timer interrupt, the interrupt period is set to 125 us, and the priority is set to the highest; the timer interrupt of the central processor 102 generates a position loop synchronization signal for the communication between the central processor 102 and the FPGA chip 103. When each synchronization signal arrives, the central processor 102 sends the interpolated position command, velocity feedforward, and acceleration feedforward real-time data to the FPGA chip 103 through the AXI bus. The FPGA chip 103 receives data from the central processor 102, and the FPGA chip 103 runs six hardware motor position loops (including position loop, velocity loop, and current loop) in parallel to realize the position control of the motor. The FPGA chip 103 is used to accelerate the execution process of the motor control program, and the six-axis position loop, velocity loop, and current loop are all placed in the FPGA chip 103 to run in parallel, realizing the distributed control of the motor.

[0052] A distributed drive and control integrated system for industrial robots based on fusion dynamics of the present invention adopts a distributed drive and control integrated method to allocate control tasks to multiple controllers, which can effectively reduce the computing burden of the central controller and avoid the problem of affecting control accuracy due to excessive computing burden. In addition, each joint control is equipped with global dynamic speed feedforward and acceleration feedforward. This control method can improve the response speed and control accuracy of the system, enabling the industrial robot to achieve more precise motion operations. At the same time, the multi-axis linkage servo control technology based on fusion dynamics is adopted to achieve effective cooperation between controllers, enabling the control of each joint to consider the dynamic characteristics of the entire system, thereby improving the overall control performance of the system. Finally, the dynamic control strategy adopted by the present invention can not only handle linear problems but also handle non-linear problems, with stronger adaptability and robustness. Compared with the prior art, the present invention not only improves the control accuracy and response speed of industrial robots but also enhances the cooperation between controllers, and can better cope with the challenges brought by the increasing scale of industrial robot systems.

[0053] The above-disclosed are only one or more preferred embodiments of the present application, and the scope of rights of the present application cannot be limited thereby. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present application still fall within the scope covered by the present application.

Claims

1. A distributed drive and control integrated method for industrial robots based on fusion dynamics, characterized in that Including: The first central processing unit runs the Linux system and loads the dynamic model, and sends position instructions and model parameters to the second central processing unit. The dynamic model has functions of robot parameter identification, vibration suppression, friction compensation, velocity feedforward, and acceleration feedforward; The second central processing unit runs the bare-metal program, conducts data interaction with the first central processing unit, and performs interpolation operations on the position instructions, velocity feedforward, and acceleration feedforward to obtain optimized trajectory curves, position instructions, velocity feedforward, and acceleration feedforward data; Obtain the data of the second central processing unit and parallelly run multiple hardware motor position loops to drive the motors of each joint of the robot.

2. The distributed drive and control integrated method for an industrial robot based on fused dynamics according to claim 1, wherein: The first central processing unit and the second central processing unit achieve data interaction by using shared memory and use software to generate interrupts to avoid access conflicts.

3. The distributed drive and control integrated method for an industrial robot based on fused dynamics according to claim 2, wherein: The specific steps for the first central processing unit and the second central processing unit to achieve data interaction by using shared memory and use software to generate interrupts to avoid access conflicts include: The first central processing unit enables the timer interrupt; In the interrupt service function of the first central processing unit, the first central processing unit performs a write operation on the shared memory, packs and writes the position instructions, compensation values, and feedforward values into the shared memory area. After the writing is completed, it triggers the second central processing unit to generate an interrupt; After receiving the interrupt from the first central processing unit, the second central processing unit performs a read operation on the shared memory in the interrupt service program and performs interpolation processing on the read data to generate an optimized trajectory. At the same time, the second central processing unit enables the timer interrupt, sets the interrupt period to 125 μs, and sets the priority to the highest; The timer interrupt of the second central processing unit generates a position loop synchronization signal for the second central processing unit to communicate with the FPGA. When each synchronization signal arrives, the second central processing unit sends the interpolated position instructions, velocity feedforward, and acceleration feedforward real-time data to the FPGA through the AXI bus.

4. A distributed drive and control integrated system for an industrial robot based on fused dynamics, adopting the distributed drive and control integrated method for an industrial robot based on fused dynamics according to any one of claims 1-3, wherein: It includes a first central processing unit, a second central processing unit, and an FPGA chip; The first central processing unit, the second central processing unit, and the FPGA chip are connected in sequence; The first central processing unit is used to run the Linux system and load the dynamic model, and send position instructions and model parameters to the second central processing unit. The dynamic model has functions of robot parameter identification, vibration suppression, friction compensation, velocity feedforward, and acceleration feedforward; The central processor 2 is used to run the bare-metal program, perform data interaction with the central processor 1, and perform interpolation operations on the position command, velocity feedforward, and acceleration feedforward to obtain an optimized trajectory curve, position command, velocity feedforward, and acceleration feedforward, and send the optimized position command, velocity feedforward, and acceleration feedforward to the FPGA chip; The FPGA chip is used to obtain the data of the central processor 2, run multiple hardware motor position loops in parallel, and drive the motors of each joint of the robot to move.

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