Zero phase error tracking controller with a desired gain error and application

摘要

In this paper, a tracking control problem for a discrete time non-minimal phase system is considered in the framework of frequency domain. The proposed control scheme can provide the overall system with attractive frequency characteristics such that the phase is exactly zero for all frequencies and the maximum gap over a given frequency range between the gain and unity is minimized for a given degree of controller. A simple algorithm is proposed to find the minimum degree of the controller so as to make the gap of the maximum gain less than any given positive number. Finally, the proposed scheme is applied to the servomotor used in a direct drive robot. Through computer simulations and online experiments, it was confirmed that the proposed scheme achieved a better tracking performance than the previous ones.