Design of active disturbance rejection controller for the velocity loop of optical tracking servo system

For the optical tracking servo system with characteristics of large inertia and the non-linear friction, the improved ADRC (active disturbance rejection controller) method is designed to improve the velocity response of the servo system. This paper establishes a mathematical model of servo system and introduces the ADRC´s working principle, then based on the step of the ADRC method, the parameters are given by simulation analysis, finally, the compared experiments are finished on the actual optical tracking servo system between the traditional PID controller and ADRC method. The actual results show that the ADRC method can not only achieve high speed fast step response without overshoot, and improve low-speed stability, its performance is better than traditional PID controller. Besides, the ADRC method can also improve the optical servo system speed performance by inhibiting the saturation and other nonlinear factors.