Decentralized adaptive control of interconnected systems with reduced-order models

Abstract

The adaptive control of interconnected systems whose subsystems possess slow and fast modes is investigated in the presence of external disturbances. A simple example is first used to show that a decentralized adaptive controller can become unstable due to the unmodeled interconnections and/or neglected parasitics. An approach is then developed for stabilization and tracking using decentralized adaptive controllers with modified adaptive laws. Sufficient conditions are obtained under which a region of attraction exists for boundedness and exponential convergence of the state/parameter errors to a small residual set. The size of the region of attraction depends on the frequency range of the local parasitics in such a way that if all the local parasitics become infinitely fast, the region of attraction becomes the whole space. © 1985.