Application of controller with complex zeros in the photoelectric tracking system

摘要

In the photoelectric imaging tracking system with the low frame-frequency CCD, low sampling frequency and delay in the system restrain the closed-loop bandwidth and the tracking precision of the system. In general, the zeros-poles cancellation method is employed in this system to cure for resonance and broaden the bandwidth of the system, but the method depends on the precise mathematical model and relatively higher sampling frequencies. In this paper, a PID controller with complex zeros is proposed and analyzed, which is applied to the FSM system based on the low frame-frequency CCD; next, good closed-loop performance obtained through the controller is presented. It is found from many experiments that zeros-poles cancellation cannot be applied to the tracking system with low sampling frequency without other assistant methods, which may not be required in the new method. Finally, the CCD with a frequency of 200Hz is used in the FSM tracking experiment to verify the method, and the experiment result shows that the performance of the system achieved by means of the novel controller can meet the design requirements.