Periodically time-varying controller synthesis for multiobjective H2/H∞ control of discrete-time systems and analysis of achievable performance☆

Publication year: 2011
Source: Systems & Control Letters, In Press, Corrected Proof, Available online 14 June 2011

Yoshio, Ebihara , Jun, Yamaguchi , Tomomichi, Hagiwara

In this paper, we propose a linear periodically time-varying (LPTV) controller synthesis approach for the multiobjective H2/H∞ control problem of discrete-time linear time-invariant (LTI) systems. By artificially regarding the LTI plant as N-periodic and applying the discrete-time system lifting, we first derive a sequence of semidefinite programmings (SDPs) indexed by N for the synthesis of suboptimal multiobjective LPTV controllers. Furthermore, we show that we can reduce the conservatism and improve the control performance gradually by simply increasing the controller period N. On the other hand, in the latter part of the paper, we propose another sequence of SDPs for the…