Research On Multi-objective Optimization Of Vehicle Routing Problem In Municipal Solid Waste Collection And Transportation

With the rapid development of economy and the continuous increase of urban population,the quantity of municipal solid waste increases sharply.Simultaneously,under the trend of the continuous expansion of urban space,the sources of municipal solid waste(MSW)are becoming more and more scattered.These factors result in the complicated management of MSW,and put tremendous pressure on the urban sanitation department and garbage removal company.Therefore,MSW management has received high attention from the government and urban residents.Among many steps of MSW management,MSW collection and transportation process is a bridge connecting the source of garbage production and the terminal treatment facilities,which seriously affects the economic,environmental and social benefits of MSW management.Thus,it is very important to optimize the collection and transportation parts of MSW.Considering the current status and development direction of MSW collection and transportation management in China,this paper selects the problem of MSW collection and transportation routing with multiple transfer stations as the research object.Adopting theoretical research,model construction,algorithm design,experimental demonstration and other research methods to establish a multi-objective optimization model from multiple collection points to multiple waste transfer stations.Designing an improved twostage multi-objective optimization algorithm to solve the model,so as to obtain the collection and transportation scheme of “economy and high efficiency”,“low carbon emissions” and “balanced workload of sanitation workers”,providing a scientific decision-making basis for decision-makers in charge of MSW collection and transportation management.The main research work of the thesis includes the following contents:First of all,in the theoretical research,the paper analyzes the theory of MSW collection and transportation,vehicle routing problem and multi-objective optimization,and clearly defines the research object.Secondly,in the aspect of model construction,according to the vehicle load and other constraints,this paper carries out the vehicle routing optimization for MSW collection and transportation with multi-transfer stations,and the multi-objective optimization model is established by taking the minimum transportation cost,the minimum carbon emissions and the minimum standard deviation of vehicle distances as the objective functions of economy,environment and society.Then,in the aspect of algorithm design,multi-objective particle swarm optimization and multiobjective tabu search are combined to establish an improved two-stage multi-objective optimization algorithm.And the value of maximum particle swarm velocity in the algorithm parameters is determined by carrying out numerical experiments with international standard examples.Finally,in the aspect of experimental demonstration,six standard examples are used to conduct comparative experiments between different algorithms to verify the effectiveness of the two-stage multi-objective optimization algorithm.Then,through a case experiment,this paper compares and analyzes the advantages and disadvantages of different solutions when each single objective function takes the minimum value,verifying the practical significance of multi-objective optimization.Besides,by using fuzzy mathematics method,the compromise optimal solution with a relatively balanced value of each objective function is obtained,so as to assist the decision-maker to choose the optimization scheme.To deal with the vehicle routing problem of MSW collection and transportation with multi-transfer stations,this paper builds a multi-objective optimization model including three objective dimensions of economy,environment and society,and designs a two-stage multi-objective optimization algorithm to solve the model.In the theoretical application aspect,this study will enrich the optimization method of MSW collection and transportation routes.In the aspect of MSW collection and transportation industrial development,the transformation can be promoted from the pursuit of a single economic benefit to the management mode of the economic,environmental protection,and emphasis on the sanitation employees’ task balance,so as to improve the sustainable development ability of MSW collection and transportation management.