Multi-objective Optimization Model of Track Utilization for Depot-returning Urban Rail Transit Trains with Shunting Operation Con-straints
[Objective]To improve the impact of shunting operations on the track utilization for the depot-returning urban rail transit trains and enhance the train maintenance efficiency,it is necessary to optimize the track utilization of the depot-re-turning train with shunting operation constraints.[Method]Regarded as a depot-returning train,the transition train is in-corporated into the early and late depot-returning plans respec-tively according to the shunting time.With the minimum num-ber of shunting operations and the shortest running distance for maintenance as the objective function,and taking the con-straints of shunting operations into account,a multi-objective optimization model for train track utilization is developed based on an improved grey wolf algorithm,featuring first for individ-ual independent depot-returning plan(early and late depot-re-turning)and then for all depot-returning plans as a whole.In a case study of the track utilization plan for the depot-returning train on a metro line in Tianjin,the effectiveness and feasibility of the established optimization model are verified.[Result &Conclusion]The train running distance of the track utilization plan obtained from the proposed model is reduced by 65.7%compared with the manual plan(with a 25%reduction in the early depot-returning stage and a 77.7%reduction in the late depot-returning stage),and the number of train shunting opera-tions is zero.The model can achieve the optimal arrangement of track utilization for the depot-returning train on the basis of satisfying the constraints of shunting operations such as train washing,maintenance,and departure on the next day.
urban rail transitdepot-returning trainmulti-objective optimization model for train track utilizationshun-ting operation constraint