Fault Analysis And Maintenance Strategy Optimization Of Key System Of Metro Vehicle

Metro are the most popular means of transportation in large and medium-sized cities,which have the characteristics of large volume and convenient transportation.Maintenance of metro vehicles is the most important thing to ensure the reliability of Metro vehicles.However,existing preventive maintenance strategies based on design experience inevitably lead to over-maintenance or under-maintenance.In order to improve the utilization ratio of metro vehicles and reduce the maintenance cost,it is necessary to optimize the existing maintenance strategies.After investigating the vehicle failure and maintenance rules of depot,this paper makes a series of analysis on the failure of metro vehicle equipment,and optimizes the existing maintenance rules and maintenance strategies.The main research contents are as follows:Firstly,this paper collected and sorted out the maintenance strategies of metro vehicles in France,Japan,Hong Kong and other countries and regions.By comparing the contents,advantages and disadvantages of metro vehicle maintenance strategies,this paper analyzed the metro vehicle maintenance strategies in big cities of China.Secondly,the fault theory and methods are elaborated comprehensively,including fault quantitative and qualitative indicators,fault(life)distribution law and fault analysis methods.Then,the fault data given by Metro depots are filtered,classified and counted,and the key subsystems of vehicles affecting the safety of metro operation are selected as the research object.For the key subsystems,FMECA method is used to analyze the failure modes,causes,failure rates,number of faults and the impact of fault hazards on the subsystems,equipment and components,and to determine the distribution of fault models for the key subsystems of vehicles.After that,Elman neural network with time series prediction ability is established to predict the time interval of gating device fault taking the known time interval of gating device fault as training sample.Finally,the problems of existing maintenance strategies are studied in depth.According to the reliability and economic requirements of enterprises,the analytic hierarchy process(AHP)is combined with the fuzzy theory(decision-making),and the advantages of the two methods are synthesized to apply to the decision-making of vehicle equipment maintenance strategies.An evaluation index system including three indexes of economy,feasibility and validity is established,and then each index is divided in detail.Combining with practical maintenance application,a decision-making model for maintenance strategy of bogie gearbox is established and solved.Next,aiming at effectiveness,reliability and economy,a theoretical decision-making model of gater maintenance cycle in gate system is established and solved by applying multi-objective fuzzy theory.21 pictures,37 tables,54 references.