Analysis And Application Of The Subway Door System Reliability

Door system is one of the most important subsystems in the metro vechile, and its reliability has significant meaning in protecting passengers, so it is an urgent need to carry out the reliability analysis on metro door system to identify the weak links. Based on the reliability index of the door system in this paper, the traditional FMECA and two improved criticality analysis methods are applied to make reliability analysis on the door system.Firstly, the goodness of fit test is carried out on the door system failure time data by the software Minitab, and then the maximum likelihood estimation method and K-S method are respectively used for parameter estimation and hypothesis testing, so the failure distribution models of door system, EDCU, S1and nut component are obtained and their reliability evaluation index are also obtained on the basis of their failure distribution model.Secondly, the traditional FMECA is introduced and used to make reliability analysis on five subsystems of metro door system. Failure causes, failure level and compensation measures of every failure mode are analyzed, and the criticality matrix diagram is also used for criticality analysis, so the key failure modes which have a great criticality are all found, and the result can provide theoretical guidance for subsequent improvement and maintenance decision.Thirdly, given the shortcomings of traditional criticality analysis, the method which is based on fuzzy evidential reasoning and grey relation theory and another method which applies fuzzy TOPSIS are proposed. The two methods are respectively used to make criticality analysis on subsystems, so the grey relation degree and relative closeness degree are calculated for obtaining the key failure modes and the results are more scientific and reasonable.Finally, on the basis of above study, the FMECA analysis software of door system is made by using VB, Matlab and Access. After making clear the functional demands and analysis process, the FMEA analysis, FMEA review and approval, CA analysis, FMECA form query and export and other functions are finally realized. The software system can reduce the reliability analysis workload to a great degree, so the FMECA analysis efficiency of metro door system could be improved.