Research On Control And Simulation Of Flexible Joint Servo System

Most operating assignments of the capturing and docking in space are mainly accomplished by the space manipulator,which depends on the high precision position control of the space manipulator.So it is very important to control the position of the space manipulator.Joints as an important part of the space manipulator,the performance of them is related to the high precision position control of the space manipulator directly.The joint is composed of a motor,a transmission device and a measuring element,and the output of the joint is affected the stable control of the output of the motor.Therefore,the high precision servo control system of the space manipulator joint was researched based on the above research.(1)The structure and working principle of permanent magnet synchronous motor(PMSM)is introduced in the thesis.The different mathematical models of PMSM were established in the three-phase static A-B-C and the two-phase rotating d-q coordinate system by the transformation of two coordinate systems.Based on the vector control theory of AC servo system of PMSM,a double loop control system of PMSM is established,which include current loop and speed loop.And Vector control scheme of id = 0 is applied in the double loop control system.(2)Under the establishment of the mathematical model of PMSM,the design of current loop and speed loop controller as the central research,the research on intelligent fractional order control of multi loop joint drive motor servo control system is carried out for the high precision position,fast dynamic response and strong anti disturbance ability of servo system.This paper provides a guarantee for the safe operation of the space manipulator by the control methods from above researches.(3)The composition and nonlinear factors of the manipulator joint were analyzed.A simplified joint dynamic model included motor model is built in the simulation software through the reasonable simplification.A PID and a fractional PI?D?position controller were designed for this simplified model.The parameters of each controller were tuned by optimization function and genetic algorithm respectively.The simulation results show that the two controllers can track the input well under different input signals,but the fractional order PI?D? controller had higher precision compared with the integer order PID controller.(4)The joint model with clearance is established and the influence of clearance on the position control of space manipulator is analyzed.A disturbance observer is proposed for eliminating the influence of clearance on the system.The simulation results showed that the disturbance observer can reduce the influence of the clearance on the joint output.