An anti-windup scheme for multivariable nonlinear systems

In this paper, an approach to control synthesis for constrained multivariable nonlinear systems using feedback linearization is described. The synthesis of a multivariable saturation element which preserves the directionality of the input vector and produces control action which upholds constraints within the original coordinate system is discussed. Nominal stability analysis is performed using nonlinear mu-analysis for a restricted region of the state-space. A set of conditions is obtained which defines the region of the state space over which the stability analysis is applicable. The results are applied to both a numerical example and to a multivariable polymerization reactor model. (C) 1997 Elsevier Science Ltd.