DYNAMIC TRANSFER AMONG ALTERNATIVE CONTROLLERS AND ITS RELATION TO ANTIWINDUP CONTROLLER-DESIGN

Advanced control strategies and modern consulting pro,ide new challeng es for the classical problem of bumpless transfer, It can, for example , be necessary to transfer between an only approximately known existin g analog controller and a new digital or adaptive controller without a ccessing any states. Transfer ought to be bidirectional and not presup pose steady state, so that an immediate backtransfer is possible if th e new controller should drive the plant unstable. We present a scheme that meets these requirements. By casting the problem of bidirectional transfer into an associated tracking control problem, systematic anal ysis and design procedures from control theory can be applied, The ass ociated control problem also has a correspondence to the design of ant iwindup controllers. The paper includes laboratory and industrial appl ications.