The vehicle routing problem(VRP) is a well-known combinatorial optimization issue in transportation and logistics network systems. There exist several limitations associated with the traditional VRP. Releasing the res...The vehicle routing problem(VRP) is a well-known combinatorial optimization issue in transportation and logistics network systems. There exist several limitations associated with the traditional VRP. Releasing the restricted conditions of traditional VRP has become a research focus in the past few decades. The vehicle routing problem with split deliveries and pickups(VRPSPDP) is particularly proposed to release the constraints on the visiting times per customer and vehicle capacity, that is, to allow the deliveries and pickups for each customer to be simultaneously split more than once. Few studies have focused on the VRPSPDP problem. In this paper we propose a two-stage heuristic method integrating the initial heuristic algorithm and hybrid heuristic algorithm to study the VRPSPDP problem. To validate the proposed algorithm, Solomon benchmark datasets and extended Solomon benchmark datasets were modified to compare with three other popular algorithms. A total of 18 datasets were used to evaluate the effectiveness of the proposed method. The computational results indicated that the proposed algorithm is superior to these three algorithms for VRPSPDP in terms of total travel cost and average loading rate.展开更多
The advancement of autonomous technology makes electric-powered drones an excellent choice for flexible logistics services at the last mile delivery stage.To reach a balance between green transportation and competitiv...The advancement of autonomous technology makes electric-powered drones an excellent choice for flexible logistics services at the last mile delivery stage.To reach a balance between green transportation and competitive edge,the collaborative routing of drones in the air and trucks on the ground is increasingly invested in the next generation of delivery,where it is particularly reasonable to consider customer time windows and time-dependent travel times as two typical time-related factors in daily services.In this paper,we propose the Vehicle Routing Problem with Drones under Time constraints(VRPD-T)and focus on the time constraints involved in realistic scenarios during the delivery.A mixed-integer linear programming model has been developed to minimize the total delivery completion time.Furthermore,to overcome the limitations of standard solvers in handling large-scale complex issues,a space-time hybrid heuristic-based algorithm has been developed to effectively identify a high-quality solution.The numerical results produced from randomly generated instances demonstrate the effectiveness of the proposed algorithm.展开更多
针对需求可拆分的多品种库存路径问题(multi-product inventory routing problem with split deliveries,MIRPSD),提出一种基于最小化库存持有成本、运输成本和车辆使用总成本的车辆路径优化模型。同时考虑每个客户的交货计划及每种货...针对需求可拆分的多品种库存路径问题(multi-product inventory routing problem with split deliveries,MIRPSD),提出一种基于最小化库存持有成本、运输成本和车辆使用总成本的车辆路径优化模型。同时考虑每个客户的交货计划及每种货物的运输数量。设计混合遗传算法进行求解,引入扰动策略以提高搜索效率,并通过实验选取合适的参数。探讨了平均日需求量与车辆载重量的比值、单位库存持有成本对需求拆分策略及总配送成本的影响。多组算例试验表明,本文提出的模型和算法可有效解决该问题。当需求量服从正态分布且平均日需求量为车辆载重量的55%时,采用需求拆分策略的效果最佳。本研究拓展了库存路径问题的相关理论,既可为解决MIRPSD问题提供一种新思路,也可为物流企业的相关决策提供理论依据。展开更多
基金Project supported by the National Natural Science Foundation of China(No.51138003)the National Social Science Foundation of Chongqing of China(No.2013YBJJ035)
文摘The vehicle routing problem(VRP) is a well-known combinatorial optimization issue in transportation and logistics network systems. There exist several limitations associated with the traditional VRP. Releasing the restricted conditions of traditional VRP has become a research focus in the past few decades. The vehicle routing problem with split deliveries and pickups(VRPSPDP) is particularly proposed to release the constraints on the visiting times per customer and vehicle capacity, that is, to allow the deliveries and pickups for each customer to be simultaneously split more than once. Few studies have focused on the VRPSPDP problem. In this paper we propose a two-stage heuristic method integrating the initial heuristic algorithm and hybrid heuristic algorithm to study the VRPSPDP problem. To validate the proposed algorithm, Solomon benchmark datasets and extended Solomon benchmark datasets were modified to compare with three other popular algorithms. A total of 18 datasets were used to evaluate the effectiveness of the proposed method. The computational results indicated that the proposed algorithm is superior to these three algorithms for VRPSPDP in terms of total travel cost and average loading rate.
基金supported by the National Natural Science Foundation of China(No.61961146005)。
文摘The advancement of autonomous technology makes electric-powered drones an excellent choice for flexible logistics services at the last mile delivery stage.To reach a balance between green transportation and competitive edge,the collaborative routing of drones in the air and trucks on the ground is increasingly invested in the next generation of delivery,where it is particularly reasonable to consider customer time windows and time-dependent travel times as two typical time-related factors in daily services.In this paper,we propose the Vehicle Routing Problem with Drones under Time constraints(VRPD-T)and focus on the time constraints involved in realistic scenarios during the delivery.A mixed-integer linear programming model has been developed to minimize the total delivery completion time.Furthermore,to overcome the limitations of standard solvers in handling large-scale complex issues,a space-time hybrid heuristic-based algorithm has been developed to effectively identify a high-quality solution.The numerical results produced from randomly generated instances demonstrate the effectiveness of the proposed algorithm.
文摘针对需求可拆分的多品种库存路径问题(multi-product inventory routing problem with split deliveries,MIRPSD),提出一种基于最小化库存持有成本、运输成本和车辆使用总成本的车辆路径优化模型。同时考虑每个客户的交货计划及每种货物的运输数量。设计混合遗传算法进行求解,引入扰动策略以提高搜索效率,并通过实验选取合适的参数。探讨了平均日需求量与车辆载重量的比值、单位库存持有成本对需求拆分策略及总配送成本的影响。多组算例试验表明,本文提出的模型和算法可有效解决该问题。当需求量服从正态分布且平均日需求量为车辆载重量的55%时,采用需求拆分策略的效果最佳。本研究拓展了库存路径问题的相关理论,既可为解决MIRPSD问题提供一种新思路,也可为物流企业的相关决策提供理论依据。
