Abstract

The dynamic characteristics of a controller designed by the gain-scheduling approach can be strongly dependent on the realisation adopted; that is, the manner in which the local linear controller designs are combined to obtain a nonlocal controller. The purpose of the present paper is to investigate the choice of appropriate realisations for general MIMO gain-scheduled controllers. An extended local linear equivalence condition for MIMO gain-scheduled nonlinear controllers is proposed which minimises the controller nonlinearity. It is shown that, with few exceptions, it is possible to realise all gain-scheduled controllers as nonlinear controllers satisfying the extended local linear equivalence condition and requiring the controller to do so is not at all restrictive.