Research On Railway Train Sets Assignment Optimization

Rational use of railway train set is one of the key tasks in railway organization. Trail setis the carrier during passenger railway transport. And proportion of the cost of train set is bigamong the total fixed inverstment. Rational use of railway train set can reduce the operationtrain set number and reduce the staying time at station for train sets. Meantime, rational use oftrain sets can improve the efficiency of train sets’ operation. So, rational use of train setoperation mode is important for decreasing inverstment, saving operation cost and improvingthe total profits. At present, train sets belong to fixed railway department and they are used onfixed lines. During national day holiday, spring festival period, train sets are in multi-use toease shortage of train sets because of adding lines. However, there is little research on trainsets multiple-use. And there is no complete theory and complete train sets assignmentschedule. So, it is necessary for research on train sets assignment.By statistic on indicators that staying time at station, train sets amount belonging todifferent staying period, reasons for long staying time at stations have been studied. Thestatistic is from stations in Beijing area, shanghai area, Guangdong area, wuhan area andLanzhou area, And rational train sets assignment mode has been established for decreasingstaying time.According to analysis of current train sets assignment, on the basis of research onuncertain railroad region, main factors which impact on train sets assignment have beenstudied on. Optimal model under given train schedule has been established where timeconstraints have been considered. And the objective of the model is the minimum stayingtime at station. Based on current train sets assignments mode, optimal model have been set upconsidering train delay propagation effect. Matching degree between train number and trainsets are also taken into consideration and the objective of the model is the same as the above.According to difference between uncertain railroad operation mode and fixed railroadoperation mode, operimal model of train sets assignment under uncertain railroad operationmode has been established. At the same time, to study on reliability of railway operationorganization under multiple-use mode, factors impacting on trains delay are classified intothree parts that are, facility factor, human factor and environment factor. Bayesian networkmodel has been proposed regarding factors as nodes. And the examples are used in the modeland solutions have been reached. Main factor which impacts on train departure delay has beenfound. At last, the annealing simulating algorithm has been applied in the paper for solution inthe train sets assignment model. According to results, optimized staying time at station andtrain sets number all have been reduced. And the results can provide support for managers.