Probability-Guaranteed H_∞ Filtering For Nonlinear Time-Varying Systems Based On Communication Protocols

In networked control systems,the signals generated by each system component are sampled and transmitted through the communication network.In the process of mutual transmission between nodes,the system will occur information conflicts and congestion.Therefore,communication protocols are usually used to allocate nodes.In practical engineering applications,considering that there are various unpredictable disturbances in the actual system,it is difficult for the system to accurately achieve the desired performance indicators.Therefore,it is very important to use probability to restrict the H_∞performance indicators to make the system more suitable for practical application.At present,the research on the probability-guaranteed problem mainly focuses on the control problem of linear system.The filtering problem of nonlinear time-varying system with network induced phenomenon under the constraint of probability-guaranteed has not been studied.Based on the above,this paper mainly studies the probability-guaranteed H_∞filtering for nonlinear time-varying systems under communication protocols.The communication protocols considered include Round-Robin protocol,Weighted Try-Once-Discard protocol and Stochastic Communication protocol.The main work is as follows:Firstly,the probability-guaranteed H_∞filtering problem for a class of nonlinear time-varying systems based on the Round-Robin protocol is studied.Considering network congestion and resource occupation during data transfer,the Round-Robin protocol is used to schedule data transfer between network nodes.Aiming at the problem that it is difficult for the actual system to meet the expected performance indicators with probability 1,the probability constrained performance index is used to design the probability-guaranteed H_∞filter.At the same time,due to the nonlinear disturbance between the system sensor and the filter to be designed,a probability-guaranteed non-fragile H_∞filter is constructed.The uncertain parameters of the system are controlled by random variables,which are uniformly distributed and independent of each other.By solving the recursive linear matrix inequality,the sufficient condition for the existence of the filter satisfying the performance index with probability is obtained,and the design of a probability-guaranteed non-fragile H_∞filter for nonlinear time-varying system under the RR protocol is realized.Secondly,the problem of probability-guaranteed H_∞filtering for nonlinear time-varying systems affected by the WTOD protocol and sensor saturation is studied.Aiming at the problem of communication authority distribution between multi-sensor nodes in complex network systems,using WTOD protocol to schedule data transmission between network nodes can solve this problem well.Aiming at the sensor saturation phenomenon of the system,the mathematical model of the sensor saturation phenomenon is described by using the sector bounded condition,and a probability-guaranteed filter is constructed at the same time.By solving the recursive linear matrix inequality,the sufficient condition for the existence of the filter whose probability meets the performance index is obtained,and the research on the problem of guaranteed probability filtering under WTOD protocol is realized..Finally,the probability-guaranteed H_∞filtering problem of nonlinear time-varying system under stochastic communication protocol is studied,and it is applied to the actual continuous stirred tank reactor system.Aiming at the randomness of the signal in the transmission process,the SCP protocol with better scalability is used to schedule each node.Aiming at the problem that unprotected data is vulnerable to malicious attacks,the influence of deception attack on the system is studied.The deception attack model is established on the basis of retaining the original signal,and the malicious signal is restrained by nonlinear conditions.The model of continuous stirred tank reactor is established,and the SCP protocol is used to transmit the information of the controller and the sensor to ensure the orderly operation of the reactor.For the established reactor system,the probability-guaranteed H_∞filter based on the SCP protocol is designed.