| Distributed consensus filtering of nonlinear delayed systems is one of the hotspots problems in recent years.Nonlinear filtering algorithms have been widely used in bioengineering systems,neural networks and population models.Nonlinear consensus filtering has the advantages of simple,easy-to-implement and low communication cost,etc.However,in the information transmission of the sensor network,it is easy to appear time delay,saturation,deception attacks,which make the filter unable to receive complete measurement information.In order to reduce the occurrence of network induced phenomena in the process of network transmission,communication protocols are introduced into sensor networks.In this paper,the variance-based method is used to study the distributed consensus filtering problem of nonlinear delayed systems based on communication protocols.The research contents are as follows:Firstly,distributed consensus filtering is studied for stochastic nonlinear delayed systems under Round-robin protocol.Discrete systems with random nonlinear time delays are described.In order to save communication resources,Round-robin protocol is used in communication networks.Based on the node information and node neighborhood information,a distributed nonlinear consensus filter is designed.Next,the filtering error and its covariance matrix is calculated.The upper bound of the filtering error covariance is obtained by the variance-limited method.Subsequently,the filter gain matrix is given.Finally,Matlab is used to perform numerical simulation experiments to demonstrate the reliability of the filter.Secondly,the distributed consensus filtering is studied for nonlinear systems with random switching nonlinear time delay and uniform quantization under random access protocol.Systems with the random switching nonlinear time delay are constructed.In order to reduce the transmission burden of the communication network,the random access protocol is introduced between the filter and the sensor.Then,using the measurement information received at the filter,a consensus filter is constructed for the nonlinear system.Through the variance constraint method and mathematical technique,the upper bound of the filtering error covariance and appropriate filter gain matrix are given.Finally,through numerical simulation,the practicability of the proposed filtering scheme is demonstrated.Thirdly,the distributed consensus filtering problem is studied for nonlinear delayed systems with stochastic measurement saturation and deception attacks under Weighted Try-Once-Discard protocol.Systems with random saturation of sensors are modeled.In addition,in order to reduce the congestion during information transmission,Weighted Try-Once-Discard protocol is added into the communication networks.Then,based on the measurement information received at the filter,a distributed consensus filter is constructed.Then,the methods of variance constraint and matrix theory are used to obtain the upper bound of the covariance of the filtering error and give appropriate filter gain matrix.Finally,the estimation accuracy of the proposed filtering algorithm is demonstrated by a simulation example. |
