DISCRETE-TIME ADAPTIVE CONTROL FOR CONTINUOUS-TIME SYSTEMS USING N-DELAY LIMITING-ZERO MODEL AND ITS APPLICATION TO A DD SERVO SYSTEM

A new method for designing a discrete-time adaptive control system for continuous-time system is presented. Using a new discrete-time model called the n-delay limiting-zero model, this method avoids the problem that the non-minimum phase zeros which arise in the case of rapid sampling of the continuous-time systems having the relative degree greater than one. In this paper, first, the motivation and principle of the n-delay limiting-zero model of the continuous-time system is discussed. Next, the procedure of constructing the adaptive control system based on the n-delay limiting-zero model is presented. Moreover, in order to illustrate the effectiveness of the proposed method, computer simulations and on-line experiments for DD servo system are carried out.