| At the beginning of the 21 st century,the logistics industry is a crucial service industry to promote economic globalization.In the rapid development of the national economy and the gradual improvement of macro-control,China's logistics market demand gradually increased,and the industry maintained a rapid development.But the cost of China's logistics industry is still so high.According to the "National Logistics Operation Bulletin" shows,that the total cost of social logistics was 10.6 trillion Yuan in 2014,in 2015 was 10.8 trillion Yuan and from January to November in 2016 was 9.6 trillion Yuan.Thus,logistics costs of the distribution industry are still too high.Therefore,to reduce the distribution cost of the logistics industry,the proposed algorithm is particularly important to solve this problem.VRP proposed by Ramser and Dantzig in 1959 has been a hot topic in the industry.The goal of VRP is to minimize the cost of path distribution and get the optimal path.VRP problems can be classified according to various constraints,such as VRP problems with vehicle volume constraints,VRP problems with time window constraints,VRP problems in single or multi-yard,and so on.In this paper,we are going to focus on the problem of with hard time window VRP and solve the optimal path.Nowadays,there are many algorithms to solve VRPTW.In this paper,based on the CW algorithm to further improve,under the conditions of time constraints,it adds the concept of segmentation distribution,not only improves the accuracy and feasibility of the algorithm,reduces the cost of transportation,but also increases the vehicle's load rate.It is more practically solving the VRPTW.This paper,is adding a time constraint to the original CW algorithm for VRPTW,so that delivery vehicles must be transported within a fixed time,or customers refuse to receive the goods.That is not only in the CW algorithm adding the vehicle load controlling,but also adding a time controlling,and it makes more comprehensively close to the real problem.In order to deeply explore the application of split distribution in CW algorithm,this article defines a new concept of split delivery response values.In order to solve this variable,this paper firstly introduces the Bee Colony Optimization(BCO)algorithm.In this algorithm,the stimulus value of the goods to the vehicle is mentioned.The stimulus value is proportional to the vehicle mileage and the transit time,and the transport mileage and transportation time have indirect effects on the result.Therefore,AHP is used to determine the weights of these two influencing factors.In the final paper,the formula H=?L/c~at~b(?L is the saving value in the CW algorithm)of the distributed reaction value is obtained,which determines which customer needs are divided firstly in the order of the response value H from large to the small.And finally the optimal solution of the VRPTW is obtained by combining the original CW algorithm.The improved CW algorithm is applied to concrete examples.After further analysis and comparison,a satisfactory solution is obtained,therefore,the feasibility and practicability of the proposed improved CW algorithm are verified.At the same time,compared with the classical CW algorithm,the accuracy,practicability and vehicle loading rate of the improved algorithm are obviously better than those of the original algorithm.Furthermore,compared with other scholars' improved CW algorithm,it is concluded that the algorithm is more suitable for VRPTW with multiple influencing factors. |
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