Optimization Of Headway And Vehicle Allocation For Multi Vehicle Bus System

In the public transport system,there is a variety of types of vehicles available for selection.There is an interactive relationship between the departure interval and the types of vehicles,so we should consider the coordination and optimization of these two in the bus scheduling process.At the same time,the number of vehicle population and the type of vehicles are limited in the depot.In the case of sharing one or more depots,the vehicle scheduling of each line has mutual influence,so the relationship between the lines should to be considered in the bus scheduling process.In this paper,the multiple-vehicle bus system is taken as the research object.In this system,we study on coordination and optimization of bus and departure interval,departure interval and vehicle scheduling.First of all,the current research status about the optimization of departure interval and vehicle scheduling at home and abroad is described in this paper,and the bus schedule function,type,mode and other related concepts about departure interva are illustrated.At the same time,the features of bus service,the main influencing factors of bus scheduling,the vehicle departure mode and the vehicle scheduling optimization methods are expounded in this paper.Secondly,the single-depot multiple-vehicle system is taken as the research object.In this system,considering the change of public transit passenger flow,the method of division of bus operation period which based on the Fischer ordered clustering method is present.On this basis,the coordination and optimization model of bus and departure interval is established.The objective of this model is the smallest deviation departure,and the constraints include the interval and the types of vehicle.The heuristic algorithm to solve the coordination and optimization model is proposed.Thirdly,in the case of sharing a depot for multiple bus lines,the number of vehicles held by the depot and its type are limited.At the same time,the vehicle scheduling between the lines has a mutual influence.Therefore,it is necessary to study the coordination optimization problem for multiple-vehicle and multiple bus lines.In this paper,we aim at the optimization of the single line with the minimum deviation of the passenger capacity,and add the capacity constraints of the depot.Based on the optimal headway determined by the objective function with the minimum deviation of the passenger capacity,an initial solution for scheduling is obtained after a random change in minutes.The vehicle scheduling program is simulated to select the feasible initial solution.The multiple groups of feasible solutions are used as the initial population of the genetic algorithm for interval optimization program.Through optimization,the optimal solution of multiple lines under the condition of depot capacity is obtained,and the coordination and optimization of multiple lines,multiple vehicles and limited vehicle capacity is completed.Finally,the example is used to verify the optimization model for multiple-vehicle bus line interval and the coordination and optimization model for multiple-vehicle departure interval with multiple-bus lines in this paper.The conclusions are as follows.(1)When the time division is divided,the maximum total passenger volume deviation of the multiple-vehicle model is less than that of the single vehicle.Moreover,after the time division,the maximum total passenger volume deviation,the frequency and the maximum congestion degree are less than the non-time division.Therefore,the time division can reduce the frequency and maximum congestion degree,which is able to effectively reduce operating costs and increase the comfort of public transport.The use of multi-vehicle is also the case.The combined effect of the two is more obvious.(2)Compared with the single vehicle type and the multi-vehicle type scheduling results,although the total number of vehicles of the latter is larger than the former,but the total cost of vehicle scheduling of the latter is less than the former.From the perspective of the public transport enterprises of the total cost,the scheduling cost advantage is obvious under the condition of multi vehicle scheduling.Therefore,the use of multi-vehicle with multi-bus line scheduling is better than single-type scheduling.it is an effective method to solve the bus scheduling problem in real life and has high accuracy and operability.