Model Reference Adaptive Control with Inexact Model Matching Part I

A new scheme for designing model reference adaptive control systems using only input and output measurements is presented. With the proposed scheme, the requirement on the commonly assumed a priori knowledge of (i) the relative degree n* of the plant and (ii) sign of the high frequency gain, can be eliminated. Besides the elimination of requirement of the two restrictive assumptions, the proposed algorithm has the advantage of using fewer adaptive gains and of improving the speed of convergence. The same method has also been employed to address the important problem of using a reduced order model.