Research On Vehicle Routing Problem With Hard Time Window Based On FCM-PSO

According to forecast from the National Post Office,the annual volume of mail will reach 121.9 billion pieces in 2021.It is obviously that the mail/express distribution has been integrated into our life.With the continuous improvement of people’s living standards,more and more consumers pay attention to the delivery time besides the quality of products.Many enterprises promise to deliver service within agreed time to seize the market.However it is a problem that how to balance the relationship between the total cost of distribution and hard time window(limit the earliest and latest time of delivery).The Vehicle Routing Problem with Hard Time Window(VRPHTW)is a combinatorial optimization problem derived from increasing time window constraints based on Vehicle Routing Problem(VRP).According to the current research situation,how to improve its solution accuracy and efficiency is still the main problem.Taking the minimum number of distribution vehicles and total distance as the main objective,this paper proposes an algorithm FCM-PSO for vehicle path planning based on the combination of fuzzy clustering and particle swarm optimization.The algorithm dynamically adjusts the clustering results of customer points and outputs the optimal distribution path.From the perspective of distribution accuracy and convergence speed,this paper discusses the solution of distribution vehicle path optimization scheme with hard time window constraints.The main work is as follows:(1)Sort out the current situation,analyze the main problems existing in the optimization of vehicle distribution path with hard time window constraints,and improve the shortcomings of VRPHTW.(2)Build FCM-PSO algorithm,combines the advantages of fuzzy clustering algorithm and particle group algorithm,and constructs a vehicle path optimization algorithm(FCM-PSO)with hard time window constraint.On the basis of constructing all customer point membership matrix,this algorithm introduces single customer distribution time,roulette,distribution security detection and processing mechanism,dynamically adjusts customer class ownership through initial classification,customer class update,group optimization,and finally output the optimal path and number of vehicles of customer distribution.(3)Through simulation experiments and example applications,the FCM-PSO algorithm is simulated to solve the vehicle routing problem under the constraint of hard time window,and the constructed FCM-PSO algorithm is applied to Shimen Citrus Distribution Center to verify the effectiveness of the algorithm.The simulation and example application results show that when solving the customer distribution problem with hard time window constraints,the fcm-pso vehicle planning strategy designed in this paper has a good effect on the total distribution path,the number of vehicles and the convergence speed,which proves the effectiveness of fcm-pso distribution strategy and can provide a reference for the research of such problems in the future.There are 9 figures,21 tables and 66 references...