Online security assessment of rail vehicles in service status based on safety region estimation

For security service of rail vehicles,the online quantitative security assessment method of service status of key equipments of rail vehicles is urgently needed.So,the method based on safety region was proposed.At first,the formal description and definition of the safety region were given for railway engineering practice.And for research objects whose models were known,safety region estimation method of system stability analysis based on Lyapunov exponent was proposed;and for research objects whose models were unknown,the data-driven safety region estimation method was presented.Safety region boundary equations of different objects can be obtained by above two approaches.At last,by real-time analysis of location relationship and generalized distance between equipment service status points and safety region boundary,the online safety assessment model of key equipments can be established.This method can provide a theoretical basis for online safety evaluation of trains operation;furthermore,it can support for real-time monitoring,early warning and systematic maintenance of rail vehicles based on active security.