Research On Robust Tracking Control Of Manipulator Driven By Permanent Magnet Synchronous Motor

With the wide application of manipulators,people put forward higher and higher requirements for its high-performance tracking control.Most of the previous research on the tracking control of manipulators did not consider the driving device,but the tracking control performance will be reduced or even unstable at high speed or with large load changes.Therefore,in order to improve the tracking performance of the manipulator,its actuator dynamics must be taken into account.Permanent magnet synchronous motors are widely used as actuators in robotic systems due to their high controllability and reliable operation.This thesis takes the permanent magnet synchronous motor driven manipulator system as the research object and aims at highperformance tracking control,and conducts research from two aspects:separate modeling and overall modeling.The main contents of this thesis are as follows:(1)Aiming at the speed robust control of permanent magnet synchronous motors,a speed controller based on cascaded extended state observers and a sliding mode current controller based on disturbance estimation of extended state observers are designed to reduce chattering.The simulation verifies that it has strong robustness to parameter changes and extermal disturbances.Aiming at the position robust control problem of permanent magnet synchronous motor,the position loop and current loop robust controllers are designed according to the active disturbance rejection control and passive theory.The structure of the extended state observer is improved to improve the position tracking accuracy.The combination of the nonlinear disturbance observer and passive control improves the steady-state accuracy and robustness of the current tracking,and the simulation verifies the effectiveness of the algorithm.(2)Aiming at the robust tracking control problem of a permanent magnet synchronous motor driven manipulator,it is firstly modeled as a mechanical subsystem and an electrical subsystem.For the port hamiltonian structure of the mechanical subsystem including matching and non-matching disturbances,a composite Hamiltonian position controller is designed based on the nonlinear disturbance observer.Then for the port hamiltonian structure of the perturbed electrical subsystem,the integral action of the current error is added on the basis of the hamiltonian current controller to enhance the robustness,and the closed-loop system after the integration still retains the port hamiltonian structure.Simulation verifies that position tracking has strong robustness and good steady-state accuracy to parameter changes and external disturbances.(3)In order to further improve the steady-state accuracy,and consider both mechanical and electrical dynamics to reduce the number of controllers,based on the independent joint control strategy,the mechanical and electrical equations of the ith motor driving the ith joint are modeled as a port hamiltonian structure.Based on the hamiltonian structure,the active disturbance rejection-hamiltonian-H∞ combined control structure is proposed,and the problem of large initial control input is improved.Simulation verifies that the algorithm has higher steady-state accuracy,faster response speed and stronger robustness.(4)Further reduce the complexity of the control structure and the number of controllers,and the permanent magnet synchronous motor-driven manipulator system is modeled as a whole under the framework of the voltage control strategy,and the dynamics of the manipulator,including parameter changes and external disturbances,as well as motor parameter changes are all considered disturbances.The adaptive law of the disturbance is compensated in the backstepping controller,and the designed voltage control strategy has nothing to do with the dynamics of the manipulator,and is simple in form and easy to implement.Simulation verifies that the algorithm has strong robustness and good steady-state accuracy.