Research On ATO Operation Strategy Of High-speed Train Based On Dynamic Multi-objective Optimization Algorithm

Along with the rapid development of high speed railway in our country,the requirements of all standards including on schedule,energy-saving and comfort in operating process have also been improved.The high-speed train operator’s operating skill depends on experience,which compels operation service level to be improved further.The ATO(Automatic Train Operation)system of high-speed train can control the train operation based on the accurately calculated operation strategy,replacing the operator to operate the train and representing the development direction of the train control system.In addition,the automatic train operation system is of great practical significance for the research on ATO operation strategy of high-speed trains.At the same time,with the departure headway shortened,the ATO operation strategy of tracking train shall be adjusted according to the forward train position,so as to keep an appropriate distance between two trains.Therefore,based on optimizing the ATO operation strategy of a single train,there should also conduct a research on dynamic adjustment method of the ATO operation strategy of tracking train under the tracking operation situation.The main research contents of this thesis include:(1)a High-speed train operation process modeling.Through analyzing the force situation of train,multi-particle kinematic model has been established.Based on the actual traction/braking gear of CRH3 C,the working conditions of the train have been classified.In consideration of the characteristic that the gear of traction/braking needs to be switched step by step in operation process,the working conditions switch rules have been established,and a gear switch process of the train in operation process has been described through working conditions switch points.When modeling the operation process of the train,the impacts of the train forced coasting through neutral zone on speed have been considered.The operation process of the train in station has been divided into three stages.The operation strategy of each stage has been represented by a set of variables,and then the ATO operation strategy in complete operation process has been represented as an operation sequence.(2)a ATO operation strategy of a single train optimization.Aiming at the optimization problems of ATO operation strategy when a single train operating between the stations,the working principle of ATO system has been analyzed,and based on the actual operation requirements,the optimization targets including on schedule,energy-saving and comfort of ATO operation strategy have been determined and multi-objective optimization model of ATO operation strategy has been established.The solution shall be proposed by using MOPSO-CR(Multi-objective Particle Swarm Optimization-Comprehensive Ranking)algorithm and improved NSGA-II(Nondominated Sorting Genetic Algorithm II)algorithm,and optimization process has been analyzed in detail.Aiming at the selection of optimal solution in optimization results,the screen method of optimal operation strategies has been designed based on fuzzy membership function.According to the railway line data of Beijing-Shenyang high-speed railway from Heishanbei railway station to Fuxin railway station,the ATO operation strategies have been calculated by MOPSO-CR algorithm and NSGA-II algorithm respectively,and compare the operation strategies with the result of basic NSGA-II algorithm.The research results have shown that the optimization results of the algorithms selected in this thesis are better than the basic NSGA-II algorithm,and the MOPSO-CR algorithm has the best optimization effect,whether temporary speed restriction has happened in railway line.(3)a ATO operation strategy of tracking operation optimization.Aiming at the moving block condition,which the tracking distance between the forward and rear train is short and tracking running status of the train is affected by the forward train,dynamic optimization of ATO operation strategy of tracking train has been researched.In consideration of the characteristics of moving block,based on the real-time speed of tracking train,the minimum tracking distance and standards of tracking distance have been calculated.Based on the multi-objective optimization of ATO operation strategy of a single train,tracking operation security constraints have been designed according to minimum tracking distance,and the optimization targets of tracking distance have been designed according to tracking distance standards,and dynamic multi-objective optimization model of ATO operation strategy of tracking train has been established.The deviation rate of tracking distance and retention indicator of tracking distance have been designed,so as to evaluate the retention status of tracking distance.With the application of prediction-based dynamic MOPSO-CR algorithm,to conduct dynamic optimization and adjustment of ATO operation strategy of tracking train,and analyze optimization process in detail.Based on the railway line data of Beijing-Shenyang high-speed railway from Shenyangxi railway station to Heishanbei railway station,the simulation optimization shall be conducted.The research results have shown that after adjusting ATO operation strategy of tracking train through dynamic optimization methods,the tracking distance between the forward and rear train can be kept in a relatively ideal distance,and the characteristics including on schedule,energy-saving and comfort of tracking train operation process has not been susceptible to be severely affected by the forward train running status.