global practical stabilization of discrete-time switched affine systems via switched lyapunov functions and state-dependent switching functions

This paper addresses the problem of global practical stabilizationof discrete-time switched affine systems via switched lyapunovfunctions with the objectives of achieving less conservativestability conditions and less conservative size of the ultimateinvariant set of attraction. the main contribution is to propose astate-dependent switching controller synthesis that guaranteessimultaneously the invariance and global attractive properties of aconvergence set around a desired equilibrium point. this set isconstructed by the intersection of a family of ellipsoids associatedwith each of switched quadratic lyapunov functions. the globalpractical stability conditions are proposed as a set of bilinearmatrix inequalities (bmis) for which an optimization problem isestablished to minimize the size of the ultimate invariant set ofattraction. a dc-dc buck converter is considered to illustrate theeffectiveness of the proposed stabilization and controller synthesismethod.