Research On The Joint Motor Parameters' Identification And Tuning Technology Of Light Weight Arm

As the wide application of the robot,it is hoped that robots are qualified in more situations to complete diverse work for humans,which requires the robot to ensure the safety when working in unknown environment or with humans around.Scholars and robot manufacturers began the study of the light wight arm as a cause of this demand.The light mechanical arm joints are powered usually by permanent magnet synchronous machine(PMSM).In this paper,the parameter identification of PMSM and the tuning of its servo control parameters are studied.Firstly,the development of the light weight arm is briefly introduced,and then the position-speed-current cascade control structure used in PMSM servo control is introduced.In order to achieve high servo control performance,the control parameters need to be well-tuned.Therefore,it is necessary to identify the parameters of the PMSM to provide reference for t he tunig process.Vector control based on rotor field orientation enables PMSM servo control to be implemented in dq rotating coordinate system.In this paper,the principle of SVPWM technology,which is often used in vector control,is analyzed.The principle that the inverter causes the loss of control voltage is analyzed.A mathematical model of the inverter is established to improve the accuracy of parameter identification.This paper adopts TMS320F2808 as the control chip to complish PMSM servo control on an experimental platform.Before identified,PMSM parameters are measured using multimeter,oscilloscope,LCR measurement tools,to be used to determine the accuracy of parameter identification results.Through the separate identification of each parameter,reasonable excitation signal s are designed respectively to eliminate the influence of the inverter on the identification results.The successful completion of the accurate identification of PMSM parameters Rs?Lq?Ld??_f,verifies the validity of the proposed algorithm.After the parameter identification is completed,the open-loop transfer function of the current loop,speed loop and position loop are analyzed in turn according to classical control theory,and the theoretical design formulas of the closed-loop control parameters are obtained.Using the parameter identification results,calculated control parameters of the closed-loop,combined with anti windup algorithm and control parameter optimization method,the current loop PI parameters,PI parameters of the speed loop and the position loop PD parameters are tuned well,the effectiveness of the tuning algorithm is verified in the experimental platform.Finally,in order to further improve the servo performan ce of the PMSM,the speed loop fluctuation is analyzed,a full order state observer is designed to solve this problem,and the simulation verifies its effectiveness.