Study On Control Technology Of Course Tracking Servo-turntable For Free-space Optical Communication

With the development of the free-space optical communication and the optical communication requirements for the performance have been improved continuously, APT becomes especially important. Coarse tracking servo-turntable is the important turntable and hinge of APT, it can quickly capture and lock, automatically track and initiatively interfere with both flying objects in the air and moving objects on the ground. It has the characteristic of fast response, high track precision and high reliability etc.This paper firstly introduces the research significance, related technical status and main research contents, introduces the function and controlling precision of coarse tracking servo-turntable in details. Then on the basis of composing and working principle, design the hardware of servo control system, and deduce the math model, lastly do experimental process simulation. This paper analysis the stabilization servo, the open loop pointing servo and the dynamic tracking servo during the course of tracking, and provides method of design, analyze the problems which should be solved in each loop in the system. Lag lead correction, square lag and lead correction compensation are put forward. Gain of open loop is upgraded greatly, at the same time, overshoot is restrained effectively, system control effect is content terrifically.