Discrete-time prototype repetitive controllers considering pole-assignment and its application

In this paper, a new repetitive control system is proposed from the viewpoint of pole-placement. The contributions are as follows. Firstly, the proposed repetitive controller can assign all poles of the closed loop system on a disk with a given radius whose center is the origin. As a result, faster convergence of the controlled error to zero than the previous ones is obtained. Secondly, the proposed controller is obtained explicitly with no equation to solve. The design effort is independent of the period of the repetitive signals to be tracked or rejected, in other words, the design effort is very small even if the period is greatly large. Thirdly, the robustness of the control system is improved by introducing a low pass FIR filter in the controller. Finally, the proposed scheme is applied to DC servo motor system and the effectiveness is demonstrated by both simulations and experiments.