关键词: 燃气舵;高阶非线性扩张状态观测器;位置控制;变结构控制器;无刷直流电机

Abstract: In order to realize high precision position control of gas rudder， a high-order nonlinear extended state observer was designed for precise closed-loop control of the steering gear position system. By combining the parameter perturbation coupling term with the external perturbation term into a new state variable， the original third-order position system was extended to a fourth-order control system. The sliding mode variable structure controller was used to control the observational results of the state observer， so that the steering angle reached the predetermined value. The traditional PID control and the designed high-order nonlinear extended state observer were used to simulate the actuator control system respectively to verify the response and stability performance of the designed controller. The results show that compared with the traditional PID controller， the designed high-order nonlinear extended state controller has higher tracking accuracy and faster response performance. Its response time is less than 0.1s， which improves about 0.7s， and the control system has no overshoot. The controller has better robustness and anti-interference. Thus it can better realize position control of the whole servo system.

Key words: Gas rudder;High-order nonlinear extended state observer;Position control;Variable structure controller;Brushless DC motor