Modeling And Stability Analysis Of Networked Control System With Long Time Delay And Data Packet Loss

Network control systems (NCS) are feed-back control systems formed bynetwork. In these systems, the control object and controller as well as the controllerand the actuator are connected through a common network platform. Networkcontrol systems break space physics position limit of traditional control system,reduce the complexity of the system, the operation cost and maintenance cost,integration easily management and control, improve the information integration. Asthe communication network is a non-reliable transmission channel, when externaldisturbance or network congestion occurs, there is data transmission delay or packetloss. Therefore the study of networked control system, compared with the traditionalcontrol system, is more complicated. This thesis studies stability of networkedcontrol systems with long time delay and packet dropout. From the control point ofview, the influence of long time delay is discussed on the stability of the system bydesigning deterministic control. By presenting a hypothesis of data packet lossbetween two sample time, the influence of packet loss on the stability of the systemis investigated. This thesis is organized as follows:For network control systems with data transmission delay, if the system sensors,controllers and actuators are event-driven and time-driven, time driven, respectively,a discrete system with multiple time delay for random long time delay uncertaincontinous systems model is established. By applying discrete Lyapunov method thestability of the model is analyzed. Stability conditions are presented based on thelinear matrix inequality. An iterative optimization algorithm of controllers isdesigned. The feasibility and effectiveness of the control algorithm is verified bysome numerical examples. For uncertain network control systems with data loss, under the assumption thatthe loss quantity is a bounded function, a corresponding continuous time-varyingdelay system model is established. By applying continuous Lyapunov-Razumikhinmethod the stability of the model is analyzed, sufficient conditions for asymptoticstability of the system model are obtained, and a state feedback controller isdesigned based on linear matrix inequalities. The feasibility and effectiveness of thecontrol algorithm is verified by some numerical examples.