Mixed H2/H∞ Control for a Class of Nonlinear Networked Control Systems

In this paper, the mixed H-2/H-infinity control problem is investigated for a class of nonlinear discrete-time networked control systems with random network-induced delays, stochastic packet dropouts and probabilistic sensor faults. The packet dropouts process is modeled as a homogeneous Markov chains taking values in a finite state space. Network-induced delays occur in a random way with known upper bound. A set of stochastic variables are exploited to describe sensor faults with different probabilistic density functions. By using a delay-dependent Lyapunov functional, a mode-dependent mixed H-2/H-infinity controller is designed to guarantee both stochastic stability of the closed-loop system and the prescribed H-2, H-infinity control performances. Sufficient conditions for the existence of the mixed H-2/H-infinity controller are presented in terms of a series of LMIs. If these LMIs are feasible, then the mode dependent mixed H-2/H-infinity controller can be obtained. A numerical example is given to demonstrate the effectiveness of the developed method.