Mixed H2/H∞ control for a class of nonlinear discrete-time networked control systems with random delays and stochastic packet dropouts.

It has been very popular to design a controller to attain multiple objectives in many engineering applications in the past few years. The so-called mixed H₂/H_∞ control is a typical this kind of case. Generally speaking, the problem of mixed H₂/H_∞ control is to find a controller not only to minimize the H2 performance (cost function) but also to satisfy the H_∞ performance in spite of the worst disturbance, see references [1-6]. To mention one of them, Yang et al. [2] has studied the robust mixed H₂/H_∞ control problem for a class of uncertain discrete-time nonlinear stochastic systems. The nonlinearities, which are represented by stochastic variables, have been tackled with by a new approach; the uncertainties, which are described as deterministic norm-bounded parameter perturbations, have been dealt with by the celebrated S-procedure. The resulting closed-loop system is exponentially mean square quadratically stable and attains the H₂ control performance with a prescribed H1 attenuation level. Hence, from the practical engineering application point of view, the mixed H₂/H_∞ controller design problem has an obvious physical meaning. In some industrial applications, such as automobiles, manufacturing plants, and aircrafts, system components (the physical plant, the sensor, and the controller) are located at different places, [ABSTRACT FROM AUTHOR]