A CONTROL VECTOR SIMPLEX APPROACH TO VARIABLE-STRUCTURE CONTROL OF NONLINEAR-SYSTEMS

An effective way to extend to the multi-input case the variable struct ure control philosophy is the method based on a set of m + 1 control v ectors forming a simplex in R-m, and on the corresponding switching of the controlled system from one to another of m + 1 different structur es. In this paper, the basic method is briefly recalled and conditions for the possible extension of its validity to the case of uncertain n onlinear systems affine in the control law are sought. The possibility of guaranteeing the convergence of the simplex method also in the cas e of nonlinear systems non-affine in the control law is investigated. (C) 1997 by John Wiley & Sons, Ltd.