Study On Combinatorial Optimization For Combined Transport Based On Tabu Search Algorithm

Combined transport is a cooperative transportation mode that uses two or more than two modes of transport to complete a cargo transportation task. Since combined transport has the incomparable advantages, it becomes one of the most important transport means in modern logistics. Selection of transport mode and transport route is a key factor influencing time and cost of combined transport and relates directly to the interests of carriers and clients. Although there are many studies on this issue, it still has the significance and value of continuing to explore.The paper studies the combinatorial optimization of transport route and transport mode in the combined transportation, aiming to arrange transport plans within a limited time and reduce transportation costs. We linked combined transport issues with conventional traveling salesman problem and improved them based on practical conditions. With transport sequence unfixed, we have established a mathematical model with minimal total cost as the objective function; set up 0-1 decision variables including multiple elements, e.g, transport node, transport sequence and transport mode; restrained the overall transport time and transport capacity in different cities. Then, we have designed a heuristic algorithm based on tabu search(TS) to solve this problem, proposing a coding method of the direct permutation of the target function value, the tabu object, the order of the city access and the corresponding transportation mode. Computed by programming with C# language based on a practical example and acquired an overall transport plan. Compared the influence of different conditions, such as the different iterations, different total time limit and whether the cities have capacity constraints, on the choice of transport modes and transport routes.The results in this paper show that the setting of the initial parameters of the tabu search algorithm will have some effect on the efficiency of the solution. TS algorithm designed in the paper has the advantages of convenient for express and easy to comprehend. It can solve problems of such kind quickly and effectively. Meanwhile, it is hoped that we can provide reference for the decision-making of the relevant enterprise in similar problems through the concrete numerical results.