Research On Optimization Of Green Vehicle Routing Problem With Heterogeneous Fixed Fleet

In order to reduce the waste gas pollution generated by vehicles in the process of logistics,on the basis of the traditional VRPTW model and the perspective of energy saving and emission reduction,an approximate calculation method for fuel consumption and carbon emissions is introduced firstly,then a green vehicle routing problem with time windows and heterogeneous fixed fleet under static network(G-HVRPTWSN)model with considering low-carbon and cost savings is established,which minimizes the total cost as an optimization objective to find environment-friendly green paths.Simultaneously,an improved tabu search algorithm is designed to solve this problem.When the initial solution and the neighborhood solution are generated,the algorithm sets the order of customer sequence is according to the ascending order of the service time and the time window size of each customer.At the same time,through the three indexes(the minimum subpath,the total cost of subpath and the overload),the evaluation function is improved,and the mechanism proposed by Gendreau to reduce the possibility of precocious maturing is adopted.Finally,the effectiveness and feasibility of the model and the algorithm are verified by a numerical example.The factors affecting energy saving and emission reduction are analyzed,Through the data obtained,the ton-kilometer index can better measure the fuel consumption and carbon emission costs,and the new energy vehicle input transportation market will be a new trend.this paper provides decision support and method guidance for low-carbon transportation and management.Starting from the conclusion of Chapter 3,the driver's salary accounts for about 60% of the total cost and is a function of speed,so the speed is also an objective based on carbon emission optimization.In order to be more relevant to the reality of city traffic congestion,traffic demand with short-term changes,traffic accidents and bad weather conditions will lead to uncertainty in the road network,so,the congestion delay index and travel speed are explained firstly.On the other hand,considering that a road section may contain one or several time zones(That is in different time zones,vehicles will travel at different speeds in a road section and the carbon emissions should be calculated according to different speeds.),so a method for calculating the travel time between a road section is studied.Then,the optimization model of green vehicle routing problem with time windows and heterogeneous fixed fleet under time-varying network(G-HVRPTWTVN)is established,finally,an ant colony algorithm is designed to solve this problem and some corresponding conclusions are drawn trough the examples.