Research On Vehicle Scheduling Planning For Mixed Bus Fleet Considering Reliability

With the rapid development of China's economy and the improvement of urbanization,urban traffic congestion has increasingly become the focus of all walks of life.The development of public transport is the main way to solve traffic congestion in large and medium sized cities in China.The actual operation process of public transport vehicles is interfered by many external factors.According to different directions and different periods,different bus schedules are formulated.The impact of bus operation reliability is considered in the timetable optimization,which can improve the transport efficiency of urban public transport to a certain extent.In recent years,due to the advantages of energy conservation,environmental protection,low noise,and cleaning,the proportion of pure electric buses in the bus fleet had been increasing year by year.The battery performance of pure electric buses does not match the operation demand,so it is necessary to consider the characteristics of pure electric buses to prepare the vehicle scheduling planning.However,the promotion of pure electric buses still needs a certain transition period.In a certain period in the future,there will be a more common scheduling planning situation of mixed traditional fuel buses and pure electric buses.Therefore,how to effectively carry out joint scheduling planning of traditional fuel buses and pure electric buses is an urgent problem in the field of urban bus scheduling planning.The major of this paper is the mixed bus fleet scheduling planning considering reliability,mainly including the optimization of bus timetable considering reliability and the preparation of the mixed bus fleet scheduling planning.First,the evaluation indexes of bus operation reliability are determined as the reliability of arrival time rate,operation time,and arrival interval.Second,the objective function is to minimize the cost of passengers waiting for the bus,the cost of time inside the bus,and the total cost of the bus enterprise operation.The three evaluation indexes of the bus operation reliability are the main constraints of the bus timetable optimization model considering reliability.The model is solved by the objective programming approach through Lingo software.Then,a mixed bus fleet scheduling planning model is constructed.The objective function of this model is the minimum total operating cost of traditional fuel buses and pure electric buses.The main constraints include the driving mileage,charging time,parking capacity of pure electric buses.The model is solved by the genetic algorithm(GA)and the particle swarm optimization(PSO)through Matlab software.Finally,taking a bus line in Beijing as an example.The basic data of bus operation is input into the bus timetable optimization model to obtain the departure interval for each period of the whole day.The mixed bus fleet scheduling planning is obtained based on this bus timetable.Comparative analysis and conclusions are made from two perspectives: traditional fuel buses and pure electric buses have different task commitment rates,and pure electric buses under mixed bus fleet conditions different discharge depths and charging powers.In the process of solving,the solution effects of GA and PSO are compared.The results show that the PSO performs better within a certain iteration.Furthermore,when the task commitment rate of pure electric buses is 80%,the discharge depth is 80%,and the charging power is 360 k W,the total operation cost of the bus enterprise is the smallest.30 figures,21 tables,80 references.