Design of FO [PI] Fractional Order Controller of ATP Rough Tracking System

ATP (acquisition, tracing and pointing) technology is one of key technology in laser space communication system. In order to improve the bandwidth ratio of rough tracking system and fine tracking system, the bandwidth of rough tracking system should be smaller than 10Hz. Integral-order PID controllers can improve dynamic performance of rough tracking system, but the system often has little robust performance. From the standpoint of improving robust performance, fractional order control technology was adopted to design the controller of ATP rough tracking system in this paper. A FO[PI] fractional order controller was designed to compensate rough tracing system. It was realized by Tustin method. The simulation result indicates that the tracking stable state error of sine input is 0.00003, and the system bandwidth is 41.6rad/s (6.6Hz). The FO[PI] controller is not sensitive to the change of controlled object gain and it can make the rough tracing system have more stronger robustness.