Research On Fault-tolerant Control Of Networked Control Systems

Networked Control Systems (NCSs) can be considered as a kind of feedbacksystems which the effective nodes transmit the data through network, and realizeresource sharing. With the rapid development of control technology in militaryand aerospace fields, networked control systems are also widely used. This kindof systems will gradually replace the tranditional control system. But inengineering practice, Networked Control System (NCS) is more vulnerable tofaults. The consequence could bring enormous harm. Fault-tolerant control is akind of effective strategy specially to solve some problems which make thesystem unstable. Therefore, the research on fault-tolerant control of networkedcontrol system has both theoretical and practical significance.In this paper we take the networked control system as the researchbackground, and mainly research the fault-tolerant control problem when one ofthe actuators fails to work.Firstly, we construct appropriate mathematical model for two cases withtime-delay uncertainty and packet loss respectively, and get the fault model of thesystem based on the quality of the switch matrix.Secondly, based on the above mathematical model we analyze the fault-tolerant control problem of the system with time-delay, use Lyapunov stabilitytheory and the technique of Linear Matrix inequalities(LMIs), a condition isgiven that can make the fault system asymptotically stable when the actuator failsto work. The results of simulations show the effectiveness and feasibility of thismethod.Finally, the NCS with network-induced delay and packet loss are modeled asa kind of systems with switching properties according to the theory ofasynchronous dynamical systems. The design approach of the controller is given. The research shows that this controller makes sure the system with packet loss isalso asymptotic stable when it has failures of the actuators. The results ofsimulations show the effectiveness of this method.