Research On Robust Scheduling Of Hazardous Materials Transport Vehicles Based On Bi-level Programming

Road transportation has the advantages of direct transportation and easy connection to other modes of transportation.It has now become the main mode of transportation of hazardous materials.However,due to the dense density of roads and dense vehicles around the road,road transport is prone to accidents.Moreover,once an accident occurs due to the transport of hazardous materials,it will result in heavy casualties,serious environmental pollution and huge economic losses.Therefore,in order to ensure social stability and the safety of people's lives and property,protect the ecological environment,balance the requirements of the governments and enterprises for the safety and economical transportation of hazardous materials,enable the hazardous materials to be transported safely,economically,and efficiently to the transportation destinations.It is particularly important to make reasonable plans for the dispatch of hazardous materials vehicles.In this paper,the optimization of the transport of hazardous materials vehicles is taken as the research object.First,after analyzing the characteristics of the hazardous materials transport vehicle risk model,bi-level programming model and robust optimization theory,a multi objective scheduling bilevel programming model for hazardous materials transportation vehicles with time windows is built under the established environment.Among them,the upper level model takes the minimum risk and the minimum cost as the optimization objective,and the lower level model adopts the user equilibrium model to minimize the vehicle transportation time.Aiming at the model,a bilevel programming model algorithm is designed based on multi-objective genetic algorithm SPEA2 and traffic assignment algorithm,then case study and result analysis are carried out.Thirdly,a multi-objective robust scheduling bi-level programming model of hazardous materials transport vehicles with uncertain risk is established.The upper level model takes the minimum risk and the minimum cost as the optimization goal,and the lower level model uses the user equilibrium model in order to optimize the vehicle transportation time.In view of the model,a corresponding double layer programming model is designed to study the case and analyze the results.Finally,a robust scheduling bi-level programming model for hazardous materials transportation considering time windows is established under uncertain OD demand.The upper model takes the risk and the cost as the optimization objectives,and the lower model adopts the user equilibrium model.The algorithm for solving the double bilevel programming model is designed,and then the result analysis of case are carried out.The research results show that after solving the multi-objective scheduling bi-level programming model for hazardous materials transport vehicles with time windows,the uncertain risk multi-objective robust scheduling bi-level programming model for hazardousmaterials transport vehicles with time windows,and the OD demand uncertainty of transport vehicles robust scheduling bilevel programming model with time windows,it is possible to obtain a hazardous materials vehicle scheduling scheme with different robustness,which can reduce the risk of hazardous materials transportation and improve the economic and timeliness of hazardous materials transportation.