Research On Tracking And Synchronization Control Of Multi-motor Driven Servo Syste

Multi-motor driving servo system has the advantages of high power,high precision and strong overload ability,which is widely used in many industrial fields.Multi-motor servo system exists some nonlinear factors,including backlash nonlinearity,model uncertainty,external disturbance and so on,which will affect the load tracking and motor synchronization effect of the system.How to overcome these factors and improve the performance of the multi-motor servo system has important research significance.In this thesis,load tracking controllers and motor synchronization controllers are designed based on adaptive control,mean deviation coupling strategy,nonlinear disturbance observer,optimal control,finite time extended state observer,and command filter control for a multi-motor driving servo system with backlash nonlinearity,model uncertainty and external interference.The main research contents are as follows:(1)The working process and mathematical model of multi-motor servo system are analyzed.An adaptive tracking and synchronization control scheme is proposed for multimotor driving servo system with dead-zone nonlinearity.Firstly,a neural network is used to approximate the dead-time nonlinear term when the width of the system backlash is uncertain,and the approximate value is incorporated into the controller design to compensate the backlash nonlinearity.Then,an adaptive dynamic surface controller is designed to improve the tracking performance.Finally,a robust controller based on average deviation coupling strategy is proposed to ensure the synchronous operation of multiple motors.Lyapunov theorem and Matlab simulation results show the effectiveness of the proposed control strategy.(2)For the dual-motor servo system with model uncertainty,an optimal control strategy based on disturbance observer is proposed.Firstly,a nonlinear disturbance observer is introduced to estimate the uncertain parts of the model at the load end and the motor end.Then,the optimal tracking controller is designed by combining the backstepping control technique with the second-order filter.Based on the position difference and speed difference between the two motors,an optimal synchronization controller is designed.Combined with these two controllers,the control inputs of the two motors are obtained respectively.The stability of the system is proved by using Lyapunov theorem.Finally,through Matlab simulation,it is proved that the proposed control method has a better control effect on the dual motor servo system.(3)Aiming at the two-mass servo system with uncertain items and unknown disturbance,a command filtering tracking control method based on extended state observer is proposed.Firstly,the load information,motor information and total disturbance are estimated by the finite time extended state observer.Then,the derivative of the virtual control law is obtained by introducing a first-order command filter,which restrains the differential explosion problem in the backstepping method,and a load trajectory tracking controller is designed.Finally,the simulation results show that the algorithm has strong anti-interference ability and robustness.