IQC-based L2-control of linear periodic systems

Stability analysis of linear periodically time-varying systems via integral quadratic constraints is extended to the problem of control design. A full-state feedback controller that satis5es exponential stability and L2-gain disturbance attenuation from an external disturbance to a controlled output is designed for linear systems with periodically time-dependent system matrices. The main result relies on dual forms of certain integral quadratic constraints. The solvability conditions for the problem are cast as a set of 5nite-dimensional linear matrix inequalities and thus, they are easily solvable. Moreover, the best possible disturbance attenuation level can be obtained as a convex problem. c © 2002 Elsevier Science B.V. All rights reserved.