根据导弹舵机系统的特点，设计一种自抗扰控制器进行位置环控制，运用遗传算法优化参数，对负载力矩外部扰动和模型参数摄动进行补偿，通过与误差分段式PD控制比较，证明采用自抗扰控制的舵机达到指标要求，自抗扰控制动态响应相移、幅值衰减指标都优于分段式PD，大动态负载扰动输出脉动频率小，在电枢电阻、转动惯量变化时，具有很好的快速性和鲁棒性。

Based on the characteristics of servo system, a novel Active-Disturbance-Rejection Controller(ARDC) was designed to control positional loop.By making use of genetic algorithm to optimize the parameters, the disturbances such as load torque and model parameters’ variation were compensated.Simulation results showed that the ARDC servo system can meet the need of design.Compated with the error subsection PD controller,it has smaller phase difference and magnitude attenuation in dynamic response,and the ripple frequency over large dynamic load is decreased.The servo system is rapid and robust when the parameters such as stator resistor and rotor inertia are varied.