CAJ | 학술논문

为提高车辆的可装载性,对考虑三维装载约束带时间窗的循环取货路径问题进行研究.在给定假设与约束条件的前提下,建立该问题的多目标数学模型,并设计用于问题求解的基于改进策略的启发式算法.数值实例的计算结果表明,该算法可有效求解考虑零件三维装载约束带时间窗的循环取货路径问题;且与时间窗优先法的求解结果相比,可大幅提高车辆的可装载性,并能有效减少不同车型车辆的投入数量.
위제고차량적가장재성,대고필삼유장재약속대시간창적순배취화로경문제진행연구.재급정가설여약속조건적전제하,건립해문제적다목표수학모형,병설계용우문제구해적기우개진책략적계발식산법.수치실례적계산결과표명,해산법가유효구해고필령건삼유장재약속대시간창적순배취화로경문제;차여시간창우선법적구해결과상비,가대폭제고차량적가장재성,병능유효감소불동차형차량적투입수량.
The extensively applied milk run system is a type of logistic system that can be used to take delivery of commodities on time.The logistics networks of this system could be abstracted as the classic vehicle routing model.The vehicle routing problem is an important branch and hotspot research field of logistics and supply chain management all the time.To effectively solve this problem plays an important role in the aspects of reducing logistics cost and improving customer satisfaction.One of the most common constraints of the vehicle routing problem is delivery or pickup time.The vehicle routing problem with time windows is therefore an important category of the vehicle muting problems.The existing research achievements for the vehicle routing problem with time windows generally only consider some simplex constraint conditions,such as nominal on-load capacity,maximum mileage,or total onload volume of one certain pickup vehicle.The optimization milk-run routes obtained by the existing research methods often lead to the usual results that the pickup vehicle cannot be loaded successfully in practice.Therefore,it is very urgent and necessary for the study of the vehicle routing problem with time windows under three-dimensional loading constrain to solve the former problem.First of all,we review the existing relevant literatures associated with this research topic and indicate the deficiency of the existing research results to lead to the research topic concerned by us in our paper.Secondly,in view of the characteristic the vehicle routing problem with hard time windows under three-dimensional loading constrain and with the premise of giving hypotheses and constraints,we put forward a multi-objective model,taking the rate of time windows satisfied,the total waiting time,the on-load rate,the total mileage,and the total number of pickup vehicles respectively into consideration,for the milk-run problem.Thirdly,given the challenge for users to solve the model,we design a heuristic algorithm based on improved strategy to solve the multi-objective model of the milk-run problem with hard time windows under three-dimensional loading constrain.Improved strategies include the small volume of pickup vehicle instead of big one,the adjustment of the pickup sequences for one certain milk-run route,the adjustment of the departure time of one certain pickup vehicle from the logistics center,and the completion of the subsequent pickup tasks in milk-run routes by pickup vehicles returned to the logistics center.And lastly,we analyze the model and algorithm using a numerical example from an enterprise.The computational results of numerical example show that the heuristic algorithm can solve the vehicle routing problem with hard time windows under three-dimensional loading constraint effectively.The study in this thesis can improve the loading feasibility of pickup vehicles greatly and reduce the number of different pickup vehicles effectively compared with the time window priority model （TWPM）.There are some problems that need to be further studied about the research topic.For example,some strategies of supplier partitions can be researched.The suppliers could be divided into different service regions of picking up at first.According to different pickup areas,you can establish a new mathematical model of the milk-run problem with hard time windows under three-dimensional loading constrain and then design a new heuristic algorithm for solving the problem.