Research On Algorithm Of Twin-load Vehicle Dispatching And Storage Allocation Problem Of Container Terminal Considering Traffic Factors

With the rapid development of China’s economy and the popularization of economic globalization,container terminals,as a transportation hub for land and water transportation in world trade,are playing an increasingly important role in China’s economic development.The problem of vehicle dispatching and storage allocation in container terminals is an important optimization problem to improve the efficiency of unloading process at the terminal.In the current research on this problem,multi-load vehicles and traffic factors,as the key conditions in many real-world container terminals,have not been considered by many researchers.Therefore,we added the twin-loaded vehicles and the traffic factors to the problem of vehicle scheduling and storage allocation,established a new mathematical model and designed an algorithm to solve this model,applied this algorithm to the simulation system of container terminal finally.This paper first introduces the twin-load vehicle into the traditional vehicle dispatching and storage allocation model,and establishes a new twin-load vehicle dispatching and storage allocation model.In addition,the differences between these two models and the properties of the twin-load model are analyzed and discussed.For the consideration of traffic factors and vehicle congestion factors,this paper builds a graph model based on th3 e physical layout of the terminal.We abstract traffic rules into the attributes of edges in the graph,and vehicle congestion into the weight of edges in the graph.The goal is to find the shortest path between two points in the graph,corresponding to the simulation of the shortest travel time of the vehicle in reality.In terms of algorithm design,we analyzed the relationship between the vehicle dispatching problem and the storage allocation problem in detail.After weighing the time consumption of the three main calculation modules of vehicle dispatching,storage allocation and vehicle routing,we designed a two-stage solution algorithm based on variable neighborhood search.For the storage allocation problem in the first stage,we have used optimization strategies such as scattered vehicles in congested blocks and concentrated vehicles in vacant blocks to design three neighborhoods for searching.For the vehicle scheduling problem,we use heuristic strategy to allocate vehicles.For the vehicle routing problem,the graph search algorithm is used to solve the problem.Finally,we design numerical experiments of different scales to verify the effectiveness and performance of the algorithm,determine the important parameters of the algorithm,compare the calculation time of different algorithms at the same data scale,and analyze the influence of traffic factors on the calculation time of the algorithm.At last,this paper applies the algorithm to the container terminal simulation system to verify that considering traffic factors can effectively avoid the occurrence of vehicle collisions and crossovers.Compared with algorithms that do not consider traffic factors,the algorithm in this paper is more suitable for the real-world container terminal scheduling.