ON SELF-TUNING CONTROL OF NONMINIMUM-PHASE DISCRETE-TIME STOCHASTIC-SYSTEMS

This paper presents a new method for the self-tuning control of nonmin imum phase discrete-time stochastic systems using approximate inverse systems obtained from the least-squares approximation. Using this appr oximate inverse system the gain response of the system can be made app roximately unit and phase response exactly zero. We show how unstable pole-zero cancellations can be avoided. This approximate inverse syste m can be used in the same manner for both minimum and nonminimum phase systems. Moreover, the degrees of the controller polynomials do not d epend on the approximate inverse system. We just need an extra FIR fil ter in the feedforward path.