Friction Feedforward Compensation Composite Control of Continuous Rotary Motor with Sliding Mode Variable Structure Based on an Improved Power Reaching Law

Abstract

In order to meet the accuracy requirements and tracking performance of continuous rotary electro-hydraulic servo motor system under nonlinear uncertainty and strong disturbance factors, the sliding mode variable structure composite control strategy based on an improved power reaching law is proposed. Based on the principle of valve-controlled hydraulic motor, the state space model of the motor system is established, and a continuous friction model is adopted. Then, the genetic algorithm is used for parameter identification to determine the friction feedforward compensation scheme. In addition, an improved power reaching law is designed, which can adaptively adjust the system chattering according to the system state. The simulation results show that the sliding mode variable structure composite controller with the friction feedforward compensation can achieve a system frequency of 15 Hz, and tracking accuracy and response speed meet the double-decade index requirements, which improve the performance of continuous rotary electro-hydraulic servo motor.