Research On The Vehicle Routing Problem With Pick-up And Delivery Of Logistics Distribution Enterprise

The vehicles routing optimization is a key link in the logistics distribution optimization, as well as is the hard problem of logistics distribution enterprises. But the solution of the vehicle routing problem in former research often focuses on unidirectional logistics distribution. And the research of bi-directional logistics is still immature. According to the reality, this article considers the situation that a customer point exits bi-directional logistics and is allowed to delivery and pick up goods at the same time. In other words, the vehicle meets the customers'needs of pick-up and delivery by only once service which called the vehicle routing problem with pick-up and delivery (VRPPD). This paper researches on the VRPPD and analyses an example of it.Firstly, the paper introduces the research background and reviews the current research status of vehicle routing problem. According to the lack of previous researches, the author describes the significance of this research and puts forward the main content of this paper.Secondly, the paper sets the assumptions and parameters of VRPPD by researching practical problems and considering the vehicle fixed cost and the full load of vehicle when it start from distribution center. Through the abstraction and mathematization of various constraints and setting up the parameter and premise of the reaseach, finally, the paper builds a more reality mathematical model of VRPPD.Then, the paper chooses simulated annealing algorithm to solve VRPPD, and introduces the basic principles of simulated annealing algorithm and its application of combinatorial optimization and analysis of its advantages and disadvantages as well. According to its disadvantages the author try to improve the algorithm strategy to enlarge the ability of searching solution space and designs a new simulated annealing algorithm with memory function for VRPPD.Finally, the paper selects authoritative date to test the algorithm. Compared to the experimental results, the algorithm designed by this paper is feasibility and superiority. At last, the algorithm is proved working when the paper takes the example of a logistics enterprise in Changsha for Dingwangtai books distribution.