A simple redesign of model reference adaptive control system and its robustness

A simplified design method of model reference adaptive control systems is proposed. In the scheme, the structure of the overall control system does not become so complex as relative degrees of controlled processes grow larger, and the stability conditions of error systems are explicitly reduced to the proper choice of two design parameters (one parameter should be sufficiently large, and the other should be sufficiently small). In the ideal case where no unstructured uncertainty exists, it is shown that overall systems are globally bounded and that magnitude of output errors can be made arbitrary small by adjusting one of those two parameters. When there exist some unstructured uncertainties (such as unmodelled dynamics or disturbances), semiglobal or global boundedness of systems is assured just like the traditional robust adaptive control schemes