Research On Traction Control Strategy Of Automatic Train Operation For Urban Rail Vehicle Based On Improved Genetic Algorithm

With the rapid development of China's urban rail transit construction,the speed of the train is increasing constantly,so that the traditional manual driving is unable to meet the needs of train running control.In this case,the automatic train operation system(ATO)comes into being,which can replace manual driving and overcome the problems of artificial driving,such as poor comfort and low operation efficiency,poor safety,etc,it also can operate the train autorunning under the speed limit of automatic train protection system(ATP).At present,the research on ATO system control strategy mainly aims at saving the energy consumption of the train.However,the train running process is a multi-objective optimization problem which assembles comfortability,energy saving,punctuality,accurate stopping and safe operation.Therefore,to solve the above problem,this thesis designs a multi-objective control strategy of ATO system,which achieves multiple performance evaluation indexes of the train operation process.The main research contents are as follows:First of all,the relationship ATO system,ATP system,automatic train supervision system(ATS)and automatic train control system(ATC),functions of ATO system and performance evaluation indexes of ATO system are introduced.At the same time,the operating mode transit conditions of the automatic train operation system and the control strategy are analyzed;Then,the ATO system multi-objective optimization model of urban rail transit train is established by using comfortability,energy saving,punctuality,accurate stopping and safe operation.According to the average speed of the train,the train running procession is divided into low running speed period and high running speed period.The weights values of performance evaluation indexes in different running periods are calculated by using cosine similarity and expert evaluation.On the basis of Urban rail transit line 6 track conditions,for getting the train running target curve,the ATO system multi-objective optimization model is solved by using improved genetic algorithm,which initial population is evaluated by using chaos optimization Tent map;Finally,fuzzy-PID controller based on fuzzy control and PID control is designed.According to track conditions,and combining the fuzzy-PID control algorithm of the ATO system,the automatic train operation procession is simulated and analyzed with MATLAB Simulink.Comparison with PID control algorithm shows that the fuzzy-PID control algorithm is adopted to design the speed controller,which has a better control effect,can improve the robustness of the ATO system and meet the performance requirements of train operation,thereby the feasibility of the application of fuzzy-PID control algorithm in ATO system is verified.