Signal And Energy Coordinated Control Of Robot Joint Position Servo Syste

Joint robots are used more and more in daily life and work,mainly to complete some repetitive work and some high-risk work.Therefore,it is particularly important to realize the fast and accurate tracking position change of the joint robot.It is difficult for a single control method to meet the fast and accurate tracking requirements of joint robots at the same time.The signal control method can make the robot system have a fast dynamic response speed,but the steady-state performance is relatively poor;the energy control method can make the robot system have a good steady-state performance,but the dynamic response speed is relatively slow.In this paper,a method of signal and energy cooperative control is proposed,so that the joint robot system has both the rapidity of signal control and the accuracy of energy control.The cooperative control method satisfies the fast and accurate tracking of the desired position of the joint robot.The main research contents of the paper are as follows:1.The sliding mode control(SMC)and port-controlled Hamiltonian(PCH)are used for cooperative control.Select fraction,Gaussian function,a relatively smooth nonlinear function and arctangent function as cooperative functions,the cooperative function can be error-based or time-based,and error-based and time-based cooperative control strategies are designed respectively.The control effects of various cooperative control strategies are analyzed and compared,and the cooperative function with the best cooperative control effect is obtained.MATLAB/Simulink simulation results show that the cooperative control effect is the best when using Gaussian function to design error based cooperative control strategy.2.For the case of unload or adding a known load at the end of the joint robot,a fuzzy sliding mode control(FSMC)signal controller and an error port-controlled Hamiltonian(EPCH)energy controller are designed,and an error-based Gaussian function is used to design a cooperative control strategy.The MATLAB/Simulink simulation platform and the robot joint position servo system research experimental platform are used for experimental verification.The results show that when the robot end is unloaded and a known load is added,the cooperative control can quickly track the change of the desired position and has high control accuracy.3.For the case of an unknown load is added to the end of the joint robot,a nonlinear disturbance observer is designed to observe the unknown load,a neural network sliding mode control(NNSMC)signal controller and an EPCH energy controller are designed,and an error-based Gaussian function is used to design a cooperative control strategy,and the stability of the whole controlled system is proved.The MATLAB/Simulink simulation platform and the robot joint position servo system research experimental platform are used for experimental verification.The results show that when the cooperative control is used,the joint robot has a faster dynamic response speed and better steady-state performance,and when an unknown load is added,the disturbance caused by the load is small and the control can quickly recover to a high control accuracy.In this paper,the signal controller is designed from the perspective of signal transformation,and the energy controller is designed from the perspective of energy transformation.The cooperative control strategy is adopted to realize the cooperative control of signal and energy of robot joint position servo system.By analyzing and comparing different cooperative control strategy,the most suitable cooperative functions is obtained;in different situations of no-load,known load and unknown load,the cooperative control method can make the robot system quickly and accurately track the desired position.Compared with the single-signal control method,the proposed cooperative control method has better steady-state performance;compared with the single-energy control method,it has a faster dynamic response speed.