Research On DSP Drive Control Technique For PAT In Satellite Optical Communication Systems

In the space laser communication, the PAT(pointing, acquisition and tracking)system plays a critical role for establishing the communication access between the moving terminals. The antenna servo control system of the satellite is the key part of the entire PAT system, and directly relating to the successful accomplishment of the whole satellite communication task. Focusing on the high precision requirement of the antenna servo control system, a full-digital solution of the antenna servo system based on DSP is presented and the architecture, control method, hardware resource of DSP and the servo program design are analyzed.This paper briefly introduces the drive principle of the step motor, and gives the control program based on the DSP function. The mixing programming of C and assembly language is adopted in order to take advantage of both languages. This program can control the start-up & stop, the direction and speed of the step motor' s rotation. In order to restrain the interference to the servo system caused by the vibration of the antenna platform, this paper presents a self-adjusting algorithm to modify the PID parameters based on the fuzzy theory, so the controller may be adapted to the variation of the object parameters.The results acquired from the experiments and simulations reveal that the servo system is well-designed and feasible with a reliable performance, and it has achieved the scheduled dynamic and static requirement.