Research On The Half-open Vehicle Routing Optimization Of Rural Logistics Based On The Strategy Of Cooperative Transshipment Of Tasks By Vehicle

The online retail of rural developed rapidly in recent years.As one of the very important parts,rural logistics links urban,rural areas,production and consumption closely.Which can promote the employment of rural population,and increase the income of rural residents and promote the development of rural economy.However,there are some of the causes of higher rural logistics costs,including the particular geographical environment of rural,the dispersed population of rural,the small coverage of logistics,the lack of cooperation between logistics enterprises,and the single logistics distribution strategy and other reasons.The cost of rural logistics is higher 2-5 times than the cost of urban logistics,which has become a bottleneck problem restricting the development of rural logistics.Therefore,according to the issues and features of rural logistics,this thesis studies on the optimization of rural logistics vehicle rout.(1)In the planning stage of vehicle route.Firstly,according to the issues of the partitioned,closed and independent strategy in rural logistics.A strategy of multi-center and semi-open cooperative distribution based on the integration of pickup and delivery is proposed.Then,a mathematical model of multi-center and semi-open cooperative distribution of rural logistics is established according to the optimal distribution cost.Finally,a coding method of threelayer,an improved crossover operator and adaptive transfer strategy are proposed to improve the ACO-GA based on the characteristics of the model,ACO and GA.(2)In the optimization stage of vehicle route.Firstly,aiming at the dynamic optimization problem of vehicle route of dynamic demand,a hybrid strategy of event trigger and rolling cycle is proposed to process the dynamic demand information,and develop the dynamic optimization strategy of vehicle route.Then,the strategy of cooperative transshipment of tasks by vehicle was proposed to solve the problem of repeated and cross routes of the vehicles onroad.The vehicle route was re-optimized through the cooperation and transfer of tasks among vehicles on-board.Finally,the mathematical model of rural logistics is constructed.According to the characteristics of the model,the algorithm of dynamic optimization and the reoptimization of rural logistics distribution route are designed.(3)Using MATLAB software to validate these methods.The simulation including the semiopen collaborative distribution vehicle route planning of rural logistics based on the integration of pickup and delivery,and the vehicle route optimization of rural logistics based on the strategy of cooperative transshipment of tasks by vehicle.The experimental results show that compared with the traditional single-center closed distribution method in rural logistics,the strategy of semi-open integrated cooperative distribution can reduce the average distribution cost by 33.14%,and increase the average vehicle load rate by 21.25%.The hybrid strategy of event triggering and rolling cycle can respond to the dynamic demand in time and optimize the route dynamically.The strategy of cooperative transshipment of tasks by vehicle reduces the delivery cost of vehicles on-board by 11.32% and 11.15%.The optimal solution and convergence speed found by the improved ACO-GA are better than that of the ACO and GA.This thesis contains 33 pictures,14 tables and 61 references.