Research On Fault Detection For Interconnected Systems

With the development of science and technology,the system is becoming more and more complex.In fact,the scale of the system is bigger,and it will also bring about the problem that the structure is easy to change.The main structural changes include interconnected disconnection between subsystems,and the new subsystems are added to the original system.The change of structure brings difficulty to the control and fault detection of the system.Therefore,it is necessary to take into account the disconnection of the interconnected system for the fault detection of the interconnected system.However,there are still few results that have been considered disconnected interconnection.The main contents of this paper are as follows:At first,fault detection for linear continuous interconnected systems is studied.The fault detection is carried out for a linear continuous interconnected system composed of two subsystems.The performance of the system is improved by introducing a weighted fault matrix.By using the real-bounded lemma,sufficient conditions for the asymptotical stability and H_?performance of the fault detection system are obtained.By using the Elimination lemma,the nonconvex conditions are converted into convex ones,and the fault detection filter gains can be obtained from these linear matrix inequalities.Secondly,fault detection for interconnected systems with packet dropouts via switched scheme.Concerning that there disconnected interconnection and packet dropouts in the measurement channel,the interconnection system is remodeled as an arbitrary switching system.The switched Lyapunov functional approach based on stochastic functional is adopted for the first time to deal with the fault detection problem of the interconnected system with packet dropout.Thirdly,robust fault detection filter design for discrete-time interconnected systems considering with disconnected interconnections.Concerning that the interconnections disconnect based on the mode-dependent average dwell time,by using the method of mode-dependent average dwell time,sufficient conditions are derived such that the fault detection systems is asymptotically stable and achieves weighted H_?performance.Fourthly,finite-time robust fault detection filter design for interconnected systems concerning with packet dropouts and changing structures.There are some packet dropouts occurring in the network before transmitting to the robust fault detection filter.Taking cases of randomly disconnected interconnections among these subsystems into account,a switched scheme is introduced,which is convenient to design the filter.An arbitrary switching signal is introduced to denote these subsystems at the switching instant.The filter is designed to guarantee the finite-time stable and achievement of the H_?performance to the fault detection system.Sufficient conditions on the existence of desired filter are presented in term of feasible linear matrix inequalities by using the switched Lyapunov functional approach based on stochastic functional.Fifthly,finite-time robust fault detection filter design for discrete-time interconnected systems with average dwell time.Taking these complex cases into account,a switched scheme is utilized to analysis these complex cases.By remodeling the interconnected systems into a switched systems based on average dwell time(ADT),and modeling these cases of disconnections into independent subsystems,a switching signal is introduced to specify which subsystem is activated.In the aid of the average dwell time method,sufficient conditions on existence of the desired filter are derived in term of linear matrices inequalities,which guarantee the augmented system is finite-time boundedness and achieve the H_?performance.A numerical example is used to illustrate the effectiveness of the proposed approach.Finally,robust fault detection filter design for interconnected systems subject to packet dropouts and structure changes.Concerning with the disconnections and packet dropouts in the measurement channel,by modeling instances of disconnected interconnections among subsystems into switched systems based on mode-dependent average dwell time(MDADT)and packet dropouts are established into event-driven switching according to the packet dropout or not,this paper proposes a switched scheme that combines MDADT with event-driven switching.A filter in which the fault detection system is exponentially stable and achieves a weighted L2performance can be derived from the optimal method of convex linear matrix inequalities.An entity model is given to demonstrate our scheme is feasible.