Research On Set-Membership State Estimation For Several Classes Of Nonlinear Discrete Complex Networks With Time-Delays

Complex networks contains a mass of interactional nodes which are coupled to each other according to a certain topology.Complex networks are characterized by large scale,many nodes and complex coupling relationships among them,it is difficult to directly obtain the state information of all nodes by measurement information.Generally,only partial nodes information can be measured,so it is realistic to build the complex network state estimatores to estimate the state of all nodes by using available information.In practical engineering,due to the influence of network bandwidth,finite speed,node competition and other factors,time-delays are inevitable in the transmission and processing of complex network information,so time-delay systems have become an important part of complex network systems.The main purpose of this paper is to study the set-membership state estimation problems and non-fragile set-membership state estimation problems of several kinds of nonlinear discrete complex networks with time-delays,and to discuss the effects of time-delays,nonlinearity,sensor saturation and incomplete measurements on state estimation performance.The main research contents are as follow:Firstly,set-membership state estimation problem is studied for nonlinear complex networks with mixed time-delays and incomplete measurements,the complex network model is considered with both discrete time-delays and distributed time-delays.For this kind of complex networks,a new set-membership state estimator is designed by using the available measurement information,and the interval matrix representational method of uncertainty is used to describe the incomplete measurement phenomena.By using the linear matrix inequality(LMI)method combined with the S-process lemma and the Schur complement lemma,sufficient conditions are obtained to ensure that all state estimators exist in the ellipsoid set,and the gain matrix of the estimator and the minimum sequence of ellipsoid set where the error of corresponding state estimator is obtained by solving the optimal problem.Finally,the MATLAB software is used to verify the feasibility of the designed set-membership state estimation scheme.Secondly,the non-fragile set-membership state estimation problem is discussed for complex networks with sensor saturation under the Maximum-Error-First(MEF)protocol,and the complex network model with coupled time-delays.For this kind of complex networks,a new non-fragile set-membership state estimator under the influence of MEF protocol is designed by using the available measurement information,and MEF protocol is used to determine the nodes that have access to network communication in each transmission moment.By using the LMI method combined with S-process,a recursive algorithm is proposed to limit all state estimators to a certain ellipsoid set,and the ellipsoid set is optimized by using the optimization algorithm.Finally,a simulation example is given to prove the effectiveness of the designed non-fragile set-membership state estimation scheme.Thirdly,the non-fragile set-membership state estimation problem is addressed for a class of nonlinear time-varying time-delay complex networks with sensor saturation and partial-nodes-known under dynamic event-triggered scheduling.For this kind of complex network,a new non-fragile set-membership state estimator is designed by using available measurement information and information fusion method,and dynamic event-triggered scheduling is used to reduce the frequency of information transmission.By using S-process and recursive LMI,a sufficient condition is obtained to insure the true state of all possible exists in its estimated ellipsoid set,and then the ellipsoid set is minimized by convex optimization.Finally,the gain matrix is obtained by MATLAB software,and a simulation example is given to verify the feasibility of the non-fragile set-membership state estimation method.