Research On The Robust Control For Networked Control Systems With Distributed Delay

With the constant development of the technology,the research on the field of Networked Control Systems?NCSs?has gradually become a research hotspot for scholars.However,due to the limitations of network bandwidth and communication mechanism,the delay and packet loss are common in NCSs communication channels.At the same time,with the introduction of the communication networks,time delay inevitably appears in the controlled plants,affecting the control effect of the system.Distributed delay is dissimilar from network-induced delay and stochastic time-delay.It is widely used in practical systems such as material thermal processing,aircraft power and rocket engines.Therefore,it is more practical to study systems with distributed delays.In this dissertation,different performance indexes are selected for different types of the external noise,and the design of NCSs robust controllers with distributed delays are studied step by step.The main research contents are as follows:Firstly,a class of robust H_?and L₁ controllers are designed respectively by using T-S fuzzy model for non-linear NCSs with distributed delays.On the one hand,the global fuzzy model of the closed-loop control system is obtained by applying the T-S fuzzy model and the Parallel Distributed Compensation?PDC?principle.When the external disturbance signal and the output signal of the system are both energy-bounded,delay-dependent and basis-dependent Lyapunov-Krasovskii function is constructed to reduce the conservative.This gives an effective controller design method.On the other hand,the new Lyapunov function is used to obtain the performance criterion for the closed-loop control system to satisfy the mean-square exponential stability.Then the controller parameter meeting the L₁ performance index is obtained by solving the convex optimization problem of LMI.Secondly,when there are the deviation changes in the controller parameters,a class of robust H_?and L₂-L_?non-fragile controller design methods for NCSs with distributed delays are proposed.Based on Lyapunov stability theory and related lemmas,the existence conditions of H_?and L₂-L_?controllers which make the closed-loop control system asymptotically stable and meet the given performance constraints are derived.The method of solving non-fragile robust controller parameters is obtained by decoupling the nonlinear terms.The numerical simulations show that the non-fragile controller has the same good convergence effect as the conventional controller.Finally,considering the influence of actuator failure and controller parameter perturbation on non-linear NCSs with distributed delays,a class of robust non-fragile L₂-L_?fault-tolerant controller is designed,which is used for non-ideal network condition with quantization errors.Two static logarithmic quantizers are introduced,and the sector bounded method is used to express the quantization error in the form of parameter uncertainty.The global fuzzy fault model matrix is established by using T-S fuzzy model and PDC principle.By selecting the appropriate Lyapunov-Krasovskii function,the L₂-L_?controller designed in this dissertation has lower conservation,and the effectiveness of the controller design method is further verified by numerical simulation.