Optimization On Rolling Stock Departure Plan Of Urban Rail Transit ATC Depot During Morning Peak

With the continuous growth of urban rail transit passenger flow and the increasing demand for the number of online operating trains during morning peak,improving the departure capacity of urban rail transit depot is particularly critical.In order to match the departure capacity of the depot with the requirements of the main line operation,some cities have begun to build ATC depot with fully automatic trains,high operation efficiency and stable operation time.In this paper,the optimization of departure sequence and departure plan is studied for ATC depot.Firstly,the operation process of the train out section of the depot is analyzed.Then,the departure sequence is optimized with the shortest total departure time.Finally,the morning rush hour departure schedule is optimized taking into account the impact of the main line and the outbound train at the connecting station.The main contents and conclusions of the paper are as follows:The rolling stock departure operation of the depot is divided into the area within the section from the parking column inspection depot to the clearance of the conversion rail and the area outside the section from the conversion rail to the main line connection station.The starting operation process under different signal modes was studied by the method of operation schedule and time distance diagram,and the rolling stock departure operation mode of train approach mode and train adjustment combination mode under the traditional depot were compared with the ATC lighting mode and ATC light off mode under the ATC depot.In ATC off mode,the departure sequence will affect the travel interval of adjacent trains,which in turn will affect the departure capacity.The loading operation of the docking station was analyzed,and the process of the train entering the main line from the entry and exit section line was studied by taking three typical connecting stations as an example.For the terminal station connection and the form of the folding line,during morning peak,it can only adopt the single-line out section,and the output capacity is less than the intermediate station and the single-station single-sided connection of the intermediate station.In ATC off mode,the problem of optimizing the departure sequence of the depot is studied.Under the conditions of known depot layout and rolling stock departure operation process,the starting sequence optimization model is constructed,and the cutting plane method is used to solve the minimum time of the given number of departures in ATC lights off mode.Compared to the experience-based departure sequence,the optimized departure sequence shortens the departure time by 2.2%.Finally,comparing the average departure interval of the four signal modes,the ATC light extinguishing mode can compress the departure interval to 112 s,which can shorten the average departure interval by 61.9% compared with the traditional train approach mode,which can greatly improve the departure efficiency.Considering the influence of the main line train at the connecting station,the optimization goal is the minimum total departure time of the specified number of trains and the maximum number of departures for a given time length,and the departure sequence and departure time of the depot are the decision variables,and the optimization model of the departure plan is constructed.A genetic algorithm for optimizing the departure sequence without considering the influence of the positive train is designed,and then the departure time is adjusted to avoid the time window constraint based on the adjustment rules,and the genetic algorithm is used to optimize the departure sequence and the departure time considering the time window constraint.Compared with the genetic algorithm based on the adjustment rules,the genetic algorithm that optimizes the departure sequence and departure time based on the time window constraint can shorten the total departure time of 24 trains by 3.6%,which proves the necessity of considering the influence of the positive train when determining the departure sequence and departure time.For ATC bases,the total departure time of 24 trains in lights out mode was reduced by 11.97% compared to the lighting mode,and the number of departures in the ATC light off mode is greater than the number of departures in the ATC lighting mode when the number of main trains and the time when the main line trains arrive at the connecting station are the same.