Abstract
Recently, simple adaptive control (SAC) has become of general interest in regard to its simple but robust adaptive control structure. However, the application of SAC was confined to the plant which satisfies the almost strictly positive real (ASPR) condition. This paper deals with this problem and it is proved that the use of parallel feedforward compensation makes it possible to apply SAC to non-ASPR plants under usual assumptions in the design of robust adaptive control system. Since the SAC algorithm does not depend on the degree of the plant, it becomes robust even if the plant contains unmodeled dynamics. This fact is confirmed by applying SAC with parallel feedforward compensation to the well-known Rohrs' example.
