H2 state estimation for network-based systems subject to probabilistic delays

In this paper, the estimation problem for network-based systems is investigated. The networked system is with limited communication capacity and the network-induced delay from the sampler to the estimator is considered. By studying the network characteristic, we assume that the probability of occurrence for each delay within a known set is known. The network-induced delay is detectable at the estimator node. We propose to design a class of delay-scheduling estimators. With the state augmentation technique, we obtain a stochastic estimation error system. The stochastic stability of the estimation error system is firstly studied. In order to evaluate and suppress the effect of the external input, the H-2 performance is employed. Based on the derived sufficient conditions, we propose an iterative algorithm to compute the estimator parameters. A numerical example is given to illustrate the effectiveness of the proposed algorithm. (c) 2012 Elsevier B.V. All rights reserved.