Research On Joint Servo Control Method Of Industrial Robot Based On New Sliding Mode Control

Industrial robot joint servo control is the most fundamental and core technology of industrial robots.High-performance industrial robots require the servo control system to have high instantaneous overload capability,trajectory tracking accuracy and fast dynamic response capabilities.The key to the good control performance of the joint servo system is the speed of the drive motor control.In the servo drive system of industrial robots,because the permanent magnet synchronous motor has the advantages of fast response speed,small mechanical size,high conversion efficiency and simple structure,the joint servo system of the robot often uses permanent magnet synchronization as the servo drive device.Based on the driving requirements of the individual joints of industrial robots,this paper takes the permanent magnet synchronous motor as the control object,and studies the method of servo control of the joints of industrial robots based on a new type of sliding mode control driver.The main contents of this paper are as follows:(1)A joint servo control scheme for industrial robots based on a new sliding mode variable structure control drive is proposed.The application requirements and development trends of the industrial robot joint servo system are investigated,and the advantages and disadvantages of several commonly used control strategies are compared.Based on the traditional coordinate transformation principle and the motor mathematical model of dq coordinates,the control system framework is constructed by the three closed loops of current,speed,position and space voltage pulse width modulation(Space Vector Pulse Width Modulation,referred to as SVPWM),and the drive system is modulated Algorithms for simulation and physical system verification.(2)The controller of the three-closed-loop servo control system is researched and designed,and the design principles of the three-closed-loop controller,the structure of the controller and the method of parameter selection are pointed out.This article demonstrates the model and control algorithm of the permanent magnet synchronous motor.In order to improve the responsiveness and robustness of the three-closed-loop servo control system,a new type of sliding mode controller is used to achieve position and speed closed-loop control,while the current inner loop still uses a PI controller..Among them,the new sliding mode controller improves the expression of the variable exponential approach rate in approach motion.(3)The simulation model and control performance of the new sliding mode control servo drive system are established and verified.In order to verify the advantages of the new sliding mode controller,on the basis of mastering the sliding mode control principle and the mathematical model of the motor,four groups of three closed-loop servo system simulation models with different controllers were built,namely the new sliding mode control servo system,the traditional variable The simulation model of the sliding mode control servo system with exponential approach rate,the PI controller servo system with the best parameter ratio,and the PI controller servo system with overshoot parameter ratio.The simulation results show that the new sliding mode controller servo system is faster The responsiveness and more stable robust performance.(4)The software and hardware experiment platform of the new sliding mode control servo drive system is built with the main control chip STM32F106RCT6 as the core.In terms of hardware,it mainly includes a power amplifier circuit that amplifies six complementary PWM pulse waves with dead zones,a three-phase inverter circuit that converts DC to AC,a permanent magnet synchronous motor with a quadrature encoder,and a three-resistance sampling circuit for current collection.And STM32F103 minimum system and other circuits.In terms of software design,with the C language of Keil u Vision5 software as the development background,edit the custom function body for the call of the main program and interrupt service routine.The software design mainly includes ADC information collection,encoder position and speed information update and control Algorithm and PWM pulse wave update and other parts,so as to realize the high-performance control of the joint drive device.The experimental results show that compared with the traditional PID control servo system,the new sliding mode control system with STM32F103 as the core has a faster response rate,higher robustness and more precise positioning.