Research On The Fault Isolation Of Rail Vehicle Suspension System Based On Information Fusion And Vehicle Safety Evaluation

Urban rail vehicle as one of the main mode of transportation for urban traffic, its safety and stable travelling directly influence the urban rail vehicle system’s reliability, security and operating efficiency. In addition, the system’s faults directly caring about passengers’safety of life, is the key factor that led to the travel suspending accidents. According to the data of statistics, among multiple faults of urban rail vehicles, the rail transit system has the highest failure frequency. Therefore, when the rail transit system occur failure, it directly affects the vehicle running. So you need to regularly assess the safety status of rail transit system. To discover the specific problems, still need to monitor condition of the subsystem, and timely detect and separate failures.As one of the key system of rail transit for suspension system, it is necessary to monitor safety condition, timely diagnosis and isolate faults. This paper is based on the Chinese863program "On-line condition monitoring and detecting techniques for urban rail vehicles key components based on sensor network". Both information fusion-based method and fuzzy comprehensive evaluation-based method are studied separately for the fault isolation of suspension system and the safety evaluation of rail vehicle’s main systems. Therefore, this paper has carried out the following research contents, mainly includes:(1) Rail vehicle suspension system dynamic analysis and fault simulation modelingThe composition and function of the rail vehicle suspension system are introduced at first. On this basis, through the vehicle dynamics analysis, respectively, establish urban rail vehicle and light rail vehicle vertical suspension system dynamics model, and analyze the established urban rail vehicle frequency response characteristics of the mathematical model, to validate the reliability of the model. Finally by using SIMPACK software, the fault simulation platform of urban rail vehicle suspension system is built for fault isolation algorithm validation work.(2) Rail vehicle vertical suspension system fault isolation algorithm research based on D-S evidence theoryThe related concepts of D-S evidence theory and its combination rules and decision rules are introduced at first, and then the steps of feature extraction and distance similarity are given. On the basis of the built suspension system model, by using the above theory, respectively realize suspension system fault isolation of the urban rail vehicle and light rail vehicle.(3) Rail vehicle lateral suspension system fault isolation algorithm research based on DSmTConsider the D-S evidence theory method requiring that all elements in the framework are exclusive, and the possibility of simultaneous faults can’t exist, the information fusion method by using DSmT is studied for the suspension system’s simultaneous faults isolation. The established urban rail vehicle lateral suspension system is used for simulation experiment. In the simulation application, this method can successfully separate the simultaneous faults of the suspension system.(4) Urban rail vehicle safety evaluation research based on fuzzy comprehensive evaluation and analytic hierarchyBy applying the analytic hierarchy process, the safety evaluation based on fuzzy comprehensive assessment method is used to study the running gears’safety, so as to get its safety condition. This method is more simple and intuitive, has strong practicality.