Networded Control Systems Modeling Analysis And Comprehensive With Intelligent Scheduling Method

NCSs are the extension and application of computer network in the control field,whose study is an interdisciplinary research area, combining both network and controltheory. The insertion of network in NCSs raises new interesting and challengingproblems such as time delays and packet losses to be addressed, and conventionalcontrol theories must be re-evaluated before applying to NCSs. Recently, NCSs havebeen a hot research topic and a wealth of literature have appeared. However, there arestill some open problems to be addressed. To improve the universality of the networkedmethod, the problems of analysis and design of NCSs with short time delay and longtime delay are studied. The main contributions of the thesis are summarized as follows:Firstly, the stabilization and optimization methods are proposed for NCSs withshort time delay. By using state augmentation technique, the closed-loop NCS isrepresented as a discrete-time switched system. Under this framework, the stabilitycondition is derived via Lyapunov approach, and the stabilizing control parameters canbe obtained by the cone complementary linearization method (CCL). Moreover, theoptimal controller design problem is also addressed, where distribution estimationalgorithm method (EDA) is used to compute the optimal control parameters. Simulationresults demonstrate that the resulting NCSs under the proposed method showsatisfactory control performance.Secondly, to improve the control performance of the NCSs, the stabilization andoptimization problem based on control parameter scheduling strategy are addressed forNCSs with short time delay. The quality of service (QoS) of the network is estimated bythe packet loss ratio and the average network time delay in a period. Based on thevariation of QoS, the controller with both control parameters scheduling and samplingperiod scheduling is constructed. Simulation results demonstrate the effectiveness of theproposed methods.Thirdly, the stabilization and optimization problem of NCSs with parameterscheduling are addressed for NCSs with long time delay. According to the actualnetwork conditions, the network time delay is divided into the fixed time delay and therandom time delay. Then, the stabilization controller and the gain scheduling controller are constructed, where the stabilizing control parameters are obtained with CCLapproach and the optimizing control parameters are solved with EDA algorithm.Simulation results demonstrate the effectiveness of the proposed methods.