Multiple Model Adaptive Control with Safe Switching 1 Brian

The purpose of this paper is to marry the two concepts of Multiple Model Adaptive Control and Safe Adaptive Control. In its simplest form, Multiple Model Adaptive Control involves a supervisor switching among one of a nite number of controllers as more is learnt about the plant, until one of the controllers is nally selected and remains unchanged. Safe Adaptive Control is concerned with ensuring that when the controller is changed in an adaptive control algorithm, the frozen plant-controller combination is never (closed-loop) unstable. This is a nontrivial task since by deenition of an adaptive control problem, the plant is not fully known. The proposed solution method involves a frequency-dependent performance measure and employs the Vinnicombe metric and is able to guarantee safe switching only insofar as reasonably accurate, but not perfect, identiication of particular closed-loop transfer functions is possible. If, in the presence of noise, probabilistic guarantees of identiication accuracy are available, the safe switching guarantee will also be probabilistic. Absolute safe switching guarantees require absolute bounds on transfer function identiication error.