The Design and Control of Fine Tracking Loop of ATP System for Free Space Laser Communication

High accuracy of laser-beam pointing is crucial for reliable operation of Free Space Laser Communication. The tracking accuracy and bandwidth of rejection frequency response are directly determined by the performance of the fine tracking loop of Acquisition, Tracking and Pointing (ATP) system. In this paper, the architecture of the fine tracking system for the designing optical communication terminal is described. And each component´s unique function, hardware choice and operating principle will be discussed. Furthermore, in order to track with the beacon real time and high precisely, a novel control algorithm is presented in this paper-dynamic matrix control (DMC), which performs well in tracking system and compared with traditional PID control it has many advantages such as better Robust, less demanding on the system model and better control effect.