Anti-windup design using auxiliary input for constrained linear systems

Stability and performance degradation in feedback control systems under saturation can be overcome by anti-windup techniques. In this paper, a new anti-windup approach called ldquoauxiliary input anti-winduprdquo is proposed, which incorporates an auxiliary input into the controller of the system. Finding the maximal output admissible set of the augmented closed-loop system, the control effort is then obtained from a quadratic optimization problem subjected to linear inequality constraints. Performance and effectiveness of the proposed anti-windup approach, as compared with other methods, is illustrated with simulation examples. Experimental results show that the introduced auxiliary input (AI) anti-windup scheme improves the performance of the system.