Stabilization And Filtering For Networked Control System With Delay And Packet Loss Issues

Networked control systems is one of the hot issues of the control field in recent years. The important feature of the networked control systems is that the communication network for information transmission is uncertainty. Limited network bandwidth makes information and data appear delay and packet loss in communications. These problems lead to networked control systems performance degradation and instability. How to design rationally networked control systems to ensure the stability and control performance of the entire networked control systems is one of the important research issues on the networked control systems.In this dissertation, based on the networked control systems existing network-induced delay and packet loss, we have established a new model of the linear and nonlinear networked control systems with network induced delay and packet loss issues. We have also proposed some lower conservative design methods for stabilization controller and robust H∞filter in networked control systems. Main results of this dissertation are as follows:(1) By introducing a logical zero-order hold (ZOH) with the latest signal selection function, we have established a new linear networked control systems model with account of network-induced delay and packet loss. Using Lyapunov-Krasovskii function combined with integral inequality, we have developed an improved stability analysis method for the linear networked control systems, and further based on an improved cone complementarity linearization iterative algorithm(ICCL), a lower conservative controller design method has been presented. Numerical simulations show that the proposed method has a lower conservative.(2) By taking into account non-linear Lurie networked control systems with network-induced delay and packet loss issues, we have put forward a new kind of time-varying delay model for Lurie networked control systems. We have also developed a new design method for nonlinear Lurie networked control systems with time-delay state feedback controller by constructing Lyapunov-Krasovskii function with upper and lower bounds of the network-induced delay, and through integral inequality approach. Numerical results show that the method is effective and advantageous.(3) For the nonlinear networked control systems with T-S fuzzy model, using the input-delay and parallel distributed compensation(PDC) techniques, a new model has firstly been established in which both network-induced delay and data loss are taken into consideration, and then using Lyapunov-Krasovskii function and combined the free-weighting matrix method, we have developed an improved networked control systems stability analysis method based on LMI T-S model without overlooking the useful items in the Lyapunov-Krasovskii functional derivative. By solving a set of LMI, fuzzy controller gain matrix is obtained. The simulation results show that the delay upper bound based on this method has lower conservative.(4) For the Lurie networked control systems with time-varying network-induced delay and packet loss, we have developed a new multi-delay Lurie nonlinear networked control systems model. Furthermore, through retaining useful items often overlooked in the Lyapunov functional derivative, we have developed a multi-delay Lurie nonlinear networked control systems stability analysis method. In the controller design, we have proposed a new dynamic output feedback controller design method through the transformation of the non-linear LMI into the linear LMI solvability problem. By theoretical analysis and simulation examples, the advantages of the proposed method are verified.(5) Study on robust H∞filter issues in the networked control systems. Considering the measured signals is transmitted to the filter through the system, being inevitably subjected to the effect of the network-induced delay and packet loss, we have established networked control systems based on continuous-time and discrete-time model. By using Lyapunov-Krasovskii functional and integral inequality method to deal with the uncertainty in the system, we have established a new kind of robust H∞performance analysis criteria for networked control systems. Based on H∞performance analysis results, we have achieved the sufficient conditions for the existence of the H∞filter and determined the filter coefficient matrix. Numerical examples demonstrate that the design method is less conservative.