Switching LPV controller design under uncertain scheduling parameters

This paper addresses the problem of designing output-feedback switching linear parameter-varying (LPV) controllers under inexact measurement of scheduling parameters. The switching LPV controllers are robustly designed so that the stability and L2-gain performance of the switched closed-loop system can be guaranteed even under controller switching determined by measured (not actual) scheduling parameters. As for the switching rules, both hysteresis switching and average-dwell-time (ADT) switching are considered. Solvability conditions for the controller design problem are expressed in terms of parameter-dependent linear matrix inequalities and nonconvex switching surface conditions, with a line search parameter. The nonconvex conditions can be convexified for hysteresis switching controller design by imposing practical validity constraints, and for ADT switching controller design by adding equality constraints on some of Lyapunov variables on the switching surfaces. The effectiveness of the proposed method is demonstrated with a numerical example.