In order to effectively reduce the risks and costs of road transportation of hazardous materials,aiming at vehicle routing problem(VRP)for hazardous materials with time windows(HMVRPTW),a two-stage optimization was studied.First of all,according to its characteristics,it was divided into bi-objective shortest path problem and bi-objective VRP with time window.Secondly,the mathematical models were established and two-stage methods were designed to solve them.In the first stage,the pulse algorithm was used to filter the path to obtain the Pareto-optimal path between the distribution center and each demand node.In the second stage,an ant colony algorithm was designed for the bi-objective VRP with time window.Then,taking the test of 9 nodes and 17 edges as an example,the solution process was explained.Finally,taking the oil delivery of 16 gas stations in the main urban area of Lanzhou city as an example,this method calculated an average time of 24.38 seconds to obtain the Pareto-optimal solution for the vehicle scheduling,while using multi-objective genetic algorithm,the average time was 41.05 seconds.The results show that the proposed method simplifies the problem scale through the filtering paths,fully consider the changes in risk and the constraint of time window of hazardous materials transportation,and guides the ants to search for optimization in the specified search space.The proposed method has obvious advantages in efficiency compared to the multi-objective genetic algorithm.
关键词
时间窗/危险货物/车辆路径问题(VRP)/2阶段优化/蚁群算法/Pareto最优
Key words
time window/hazardous material vehicle routing problem(VRP)two-stage optimization/ant colony/Pareto-optimal
维普
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