Stable direct adaptive periodic control of nonminimum-phase systems

This paper shows that stable direct adaptive control of an LTI plant is possible using knowledge of only the plant order. The approach is based on periodic control, which relocates system zeros. No prior knowledge of the plant high-frequency gain or relative degree is used, and persistent excitation is not required. More importantly, no assumption or knowledge is required as to whether the plant is minimum or nonminimum phase