Study On Multi-depot Open Vehicle Routing Problem With Time Windows From The Perspective Of Green

Natural disasters caused by global warming are leading people to pay attention to low-carbon environmental protection.But the logistics and transportation industry generate a large amount of carbon-containing pollution gases,and the path optimization method is usually used to achieve carbon emission reduction.For restricting the increase of carbon emissions effectively,low-carbon emission reduction policies have been introduced into the formulation of path optimization programs.On the basis of the literature analysis of open vehicle routing problem and the green vehicle routing problem,this thesis studies the more complex green multi-depot open vehicle routing problem considering customer time windows from the time and space dimensions.So as to obtain a win-win situation of economy and environmental protection,this thesis builds a mathematical model that considers the total cost of carbon trading to minimize,including driver salary,time penalty cost,fuel consumption cost and carbon emission cost,which is handled by a designed two-stage algorithm.The two-phase algorithm first adopts the particle swarm algorithm to quickly gain the preliminary optimal solution,then further optimizing the preliminary optimal solution to the global optimal solution is acquired by tabu search.Subsequently,this thesis uses standard databases to determine the value of the learning factor in the two-phase algorithm,and verifies the effectiveness of the two-phase algorithm for dealing with multi-depot open vehicle routing problems with time windows and its applicability to small-scale calculations.Then,combined with the government carbon trading policy,the two-stage algorithm proposed in this thesis is used to solve it according to a small-scale example.Through the comparison experiment of the multidepot open vehicle routing problem with time windows without considering green and considering green,it is showed that the carbon emissions and total cost are smaller when the built model is acquired when the green is under consideration.The variable carbon trading price and carbon quota were used to solve the multi-depot open vehicle routing problem with time windows,and when the carbon price is the initial value,the vehicle route length,carbon emissions,and total operating costs were the lowest.It shows the rationality of the carbon trading price setting,and only the carbon quota changes while the carbon trading price doesn’t change,the vehicle route length and carbon emissions obtained are not Through the detailed map of route planning,it is verified that only carbon quota varies within a certain range will not affect the planning of vehicle routes.Finally,according to the conclusions obtained from the carbon trading example,for promoting the development of low-carbon emission reduction,relevant suggestions were made on the operation management of logistics enterprises and the policy formulation of relevant government departments.