Design And Analysis Of Networked Control Systems For Linear Uncertain Plants

Feedback control systems, in which control loop is closed through a real-time network, are called networked control systems(NCSs). Due to less wires, high reliability, increased system agility, good flexibility and share of information resources, NCSs are widely used in every area of life. However, NCSs also introduce many new problems, such as network-induced delay, packet dropouts, bandwidth constraints and so on. Therefore, after summarizing the researches about above problems, this paper focuses on the Bandwidth constraints. It is known that much attention about NCSs is paid to linear time invariant plants, which are not in accord with reality because of the influence of many factors, so NCSs for linear uncertain plants are studies in this paper.Communication logic is used to solve the problem of bandwidth constraints in NCSs. Firstly, NCS structures with periodic and stochastic communication logic for linear constant uncertain plants are designed and modeled, then the stability of the systems is analyzed with modern control theory, matrix theory and stochastic theory. Secondly, NCS structures for linear time varying uncertain plants are designed. In order to overcome the effect of time varying uncertainty on the system performance, the synchronous estimated model state feedback control combined with impulse control is used to NCSs for linear time varying uncertain plants. Then the stability of the system is analyzed with impulse theory. Finally, the simulations of NCSs for linear uncertain plants are validated in Matlab/Simulink, in which simulation structures of NCSs for linear uncertain plants with periodic and stochastic communication logic are designed and Stochastic communication logic is compared with periodic communication logic.