Exploring The Predictability Of Fault Events In Stochastic Discrete Event Systems

Stochastic discrete event systems are derived from discrete event systems,while discrete event systems are mainly composed of system states and trigger by events.Research hotspots in discrete event systems include fault diagnosis and fault prediction.The main difference between fault diagnosis and fault prediction is that the fault diagnosis is to determine whether the system has failed,and the fault prediction is to judge whether the fault will occur before the fault occurs.This paper mainly studies the predictability of fault events under stochastic discrete event systems under the framework of predictability of event occurrences in discrete event systems.According to the fault prediction model under the classical discrete event system,the fault prediction theory is extended to a stochastic discrete event systems.In this paper,a stochastic discrete-event systems fault prediction method is proposed.First,the fault predictability of stochastic discrete event systems is formalized.Then a fault predictor automaton is constructed by introducing probability transfer matrix to obtain a sufficient and necessary condition for the fault predictability of stochastic discrete event systems.Therefore,based on the fault predictor,by calculating its extended Markov matrix,it can determine whether the random discrete event systems has fault predictability,so as to achieve accurate prediction of the fault event before it occurs.Finally,based on the fault prediction method of the stochastic discrete event systems,a distributed prediction method is proposed,which can further decompose the complex stochastic discrete event systems into relatively simple subsystems,through the predictable analysis of the subsystems.Determine whether the stochastic discrete event systems has the predictability of a fault event.This article made the following major contributions:First,the problem of fault prediction for stochastic discrete event systems is discussed in detail.A method for judging whether a fault event is predictable in a stochastic discrete event system is proposed.Firstly,the definition of the predictability of the fault event in the stochastic discrete event system is given,and the predictability of the fault event of the stochastic discrete event systems is formalized.Then,a predictor is constructed for the stochastic discrete event systems,and the constructed predictor determines whether the stochastic discrete event systems corresponding to the predictor has fault-to-failure events by determining whether the predictor contains certain“specified” states.Second,we are on the issue of predictability of failure events in a stochastic discrete event systems.In order to further reduce the complexity of the algorithm,a distributed computing method is proposed.Decomposition of stochastic discrete event systems into distributed stochastic discrete event systems.Judging whether the subsystem of the distributed system is predictable for failure events is the main criterion for judging whether a stochastic discrete event system has predictability for failure events.If we find that a subsystem is not predictable for a fault event in a distributed stochastic discrete event systems,then it can be concluded that the distributed stochastic discrete event systems is also not predictable for a fault event.The fault event predictability algorithm for constructing a stochastic discrete event systems is optimized to some extent.