Study On Green Heterogeneous Vehicle Routing Optimization For Hazardous Materials In Uncertain Environment

With the rapid development of our national economy,the demand for all kinds of hazardous materials increases continuously in the production manufacturing industry,which also causes the quantity of road transport to rise year by year.Due to the inherent risk characteristics of hazardous materials,their transport process is different from that of ordinary goods.Once a transport accident occurs,it may cause serious harm to the natural environment and social public safety.Therefore,how to control the transport risk of hazardous materials has become an urgent problem to be solved by government management departments,and is also a research hotspot in the field of transport decision-making and operation research optimization.In the transportation of hazardous materials,the transportation environment of the distribution of dangerous goods is complex,so it is necessary to comprehensively consider the decision of route selection and vehicle arrangement,so as to avoid the occurrence of catastrophic accidents and reduce the distribution cost,reduce the carbon emissions in transportation,and promote the realization of the "two-carbon" goal.Therefore,it is of great theoretical significance and practical application value to formulate a safe,economical and low-carbon distribution scheme by optimizing the distribution route of hazardous materials and arranging heterogeneous vehicles.In this paper,the domestic and foreign researches on the hazardous materials vehicle routing problem,green vehicle routing problem,heterogeneous vehicle routing problem and the risk measurement of hazardous materials transportation were reviewed,and the achievements and shortcomings were analyzed.In addition,the research content of this paper was put forward: the research on the optimization of the hazardous materials green heterogeneous vehicle routing under uncertain environment.In the route optimization of hazardous materials green homogeneous vehicles under uncertain environment,the uncertainty theory is used to establish a dynamic transport risk assessment model caused by the uncertain distribution of traffic flow of transport lines and the changes of real-time vehicle load.In the path planning stage,certain no-driving strategies are adopted to study the calculation method of carbon emissions of dangerous goods vehicles under the changes of driving speed and load.Considering soft time window and load limit,a multi-objective nonlinear optimization model is established.An improved model of fast non-dominated sorting genetic algorithm was designed,which improved the population initialization process and population renewal rules,introduced negative selection strategy,and improved the cross mutation process to variable neighborhood search.Finally,the model algorithm is verified and solved with a practical example.In the process of route optimization of green heterogeneous vehicles for hazardous materials under uncertain environment,the calculation method of carbon emissions of heterogeneous vehicles under the influence of speed and load is analyzed,the uncertain transport risk assessment model is established by combining uncertainty theory and traditional risk model,and the carbon emissions of heterogeneous vehicles are measured by comprehensive mode emission model.On the basis of considering time window constraints and capacity constraints,A multi-objective optimization model of green heterogeneous vehicle routing problem for hazardous materials was established with the minimum total transportation risk,transportation cost and carbon emission as the objective function.According to the attributes of the problem and the characteristics of the model,the chromosomes were divided into two parts: vehicle combination mode and node order.The coding method based on node priority was adopted,and the elite preservation method under the soft restart strategy was applied.The selection and variation processes of vehicle combination scheduling and node distribution order were adjusted to improve the second generation of fast non-dominated sorting genetic algorithm.A large number of numerical experiments are carried out to verify the correctness of the model and the effectiveness of the algorithm.Finally,the research content of this paper is summarized,and the next research direction is analyzed.The research results of this paper can provide theoretical support for government management departments to strictly control transportation risks and carbon emissions in the route planning stage of hazardous materials transport,and provide reference for hazardous materials transport enterprises to choose economical and reasonable distribution routes.