Robust Control for Networked Control Systems With Admissible Parameter Uncertainties

Abstract

In this paper, robust H∞ control problems for networked control systems (NCSs) with network-induced time delays and subject to norm-bounded parameter uncertainties are presented and solved. Based on a new discrete-time model, two approaches of robust controller design are proposed—design of a memoryless state-feedback controller and design of a dynamic state-feedback controller. The proposed memoryless state-feedback controller design method is given in terms of linear matrix inequalities (LMIs), and the delay bound can be computed by using the standard LMI techniques. A numerical example is given to illustrate the feasibility and effectiveness of this methodology. The proposed dynamic state-feedback controller design method is based on a discrete-time Artstein transform. With the sufficient conditions for robust stability and H∞ control developed in this paper, we also derive the upper bound of network-induced time delays and the lower bound of the network date-transmission rate that can be used as a guideline in choosing proper networks as communication media for NCSs. We constructed an NCS test bed to experimentally verify the feasibility and effectiveness of proposed design methodologies.