Adaptive controller modularization using dwell time for a set of stabilizing controllers

This paper deals with a problem of controller adaptation for a system known to be in a certain set of linear time-invariant systems. It is assumed that there exists a set of linear stabilizing controllers. A method for calculating a minimum switching time between controllers commonly known as dwell time such that stability of the closed loop linear time-varying system is guaranteed is given in this paper. This method was adapted and simplified from known results in supervisory controls, switched systems, and slowly varying systems. Modularity is achieved because any on-line adaptation law that updates the controller using an interval longer than this minimum can be used. Examples are given to compare between the proposed method and the results from a theory of slowly varying system and to illustrate the applications of the proposed method to improve performance of a control system.