The application of active disturbance rejection control method to tactical missile electro-hydraulic actuator

Nowadays, electro-hydraulic actuator plays an important role in some modern tactical missiles. High power, great robustness and high tracking precision are the most significant targets for the actuator. However, the dynamics of the electro-hydraulic position servo system are highly nonlinear and have a large extent of model uncertainties, such as tremendous changes in the rudder load and external disturbance torque. So an advanced method of active disturbance rejection control (ADRC) is presented in this paper. Firstly, the general principle and structure of the ADRC strategy are introduced in order to improve the robust performance of the system. Then, a novel ADRC controller is designed for estimating and compensating total disturbance based on the mathematical model of the system. Compared with proportional integral derivative (PID) control, various simulation results show that the ADRC control approach can give faster and accurate response, and enhance the robustness of the system. Therefore, the ADRC control strategy is much superior in dealing with dynamic uncertainties and external disturbance for the electro-hydraulic actuator position servo system.