A robust fault-tolerant control strategy for networked control systems

Networked control systems (NCS) are one type of distributed control systems where serial communication networks is used to exchange system information and control signals between various physical components of the systems that may be physically distributed. The existence of real-time network in the feedback control loop makes analysis and design of an NCS complex, and conventional control theories such as synchronized control and non-delayed sensing and actuation must be reevaluated prior to application to networked control systems. NCS is a kind of feedback control systems where the control loops are closed through real-time control network. The performance of the closed-loop system is not only determined by the characteristics of the control system, but also determined by the scheduling manner imposed by network. In this paper, adjustable deadbands are explored as a solution to reduce network traffic in networked control systems and we presented a new modeling method for networked control systems with random time delays and communication constraints based on quasi-T-S fuzzy models. The integrity design for the kind of networked control systems is analyzed based on robust fault-tolerant control theory and information scheduling. Parametric expression of controller is given based on feasible solution of linear matrix inequality (LMI). After detailed theoretical analysis, this paper also provides the simulation results, which further validate the proposed scheme. (C) 2010 Elsevier Ltd. All rights reserved.