车辆路径问题的可靠性研究

首先分析车辆路径问题中随机因素,以及现有考虑行程时间波动的车辆路径问题,从而确立以配送车辆为研究对象,建立对应的行程时间可靠性模型,以不超过规定值,用来适应处理交通状态的不确定性。通过粒子群算法求解,验证表明,考虑道路运行的不确定对车辆调度的影响,制定的车辆调度方案能够更加可靠,对于配送过程更加有效。     

The potential of optimization in communal routing problems: case studies from Finland

In many European countries, municipalities offer their inhabitants a wide variety of social services. In this paper we will focus on efficiently scheduling home care, transportation of the elderly, and home meal delivery. These so-called municipal or communal routing problems can be modeled as different variants of the vehicle routing problem, a well-known optimization problem from the literature. We present a focused literature review and report on case studies using Finnish data. The computational results show that there is a significant potential for cost savings for all applications considered.     

Profiling road transport activity: Emissions from 2000 to 2005 in Ireland using national car test data

This work describes a methodology for determining the average vehicle kilometres travelled by the private national car fleet in Ireland and estimating the disaggregated CO₂ and NO_x emissions from private vehicles in the Irish road transport sector for the period 2000–2005 using national car test records. The developed methodology facilitates the calculation of greatly improved estimates for vehicle kilometres under a range of constraint variables and thereby enables the disaggregated analysis of specific vehicle fleet groups and their associated activity patterns to support evidence-based policy development. The results indicate that while older vehicles are contributing significantly to car NO_x emissions; newer cars produce a higher share of CO₂ emissions than older cars in the vehicle fleet.     

基于前后轮侧偏角的汽车自动转向头灯转角计算及联合仿真研究

由于汽车前照灯转角和汽车的运动状态有关,而汽车的运动状态又受轮胎侧偏特性的影响,因此本文利用前后轮侧偏角的绝对值之差来修正前照灯理论转角;然后,我们在simulink中建立步进电机仿真模型,在ADAMS中建立前照灯减速机构虚拟样机模型,再通过两者组合成前照灯转角开环控制系统,并把前照灯理论转角输给该开环控制系统,得出了前照灯的实际输出转角对需求理论转角的跟随曲线。     

RSB-CWS算法解决CVRP问题

RSB-CWS算法结合了蒙特卡洛模拟和CWS节省算法,利用蒙特卡洛模拟对CWS算法节省列表中顾客对间的边进行模拟,模拟过程中采用基于类几何分布的直接抽样方法进行路径采样。对模拟得到的边序列应用CWS算法,所得解的质量能达到或者优于当前最优解.与其他CVRP问题算法相比具有高效、高质量的特点,且可以解决规模较大的CVRP问题。     

A Green Vehicle Routing Problem

A Green Vehicle Routing Problem (G-VRP) is formulated and solution techniques are developed to aid organizations with alternative fuel-powered vehicle fleets in overcoming difficulties that exist as a result of limited vehicle driving range in conjunction with limited refueling infrastructure. The G-VRP is formulated as a mixed integer linear program. Two construction heuristics, the Modified Clarke and Wright Savings heuristic and the Density-Based Clustering Algorithm, and a customized improvement technique, are developed. Results of numerical experiments show that the heuristics perform well. Moreover, problem feasibility depends on customer and station location configurations. Implications of technology adoption on operations are discussed.     

自主水下航行器导航与定位技术

精确导航与定位对AUV执行水下作业任务的安全性和有效性至关重要.与陆地导航定位相比,由于全球卫星导航系统(GNSS)在水下不可用以及海洋环境的独特物理特性,水下导航定位更具挑战性.近年来用于AUV导航定位的传感器在性能和精度方面有了显著的提升,除此之外,同步定位与地图构建、协同定位算法的日益成熟极大的提升了AUV导航定...     

后补贴时代中国新能源汽车产业发展研究

2019年3月,四部委公布新一轮新能源汽车补贴政策,相比2018年标准平均退坡超50%。自政策公布之后,国内新能源汽车市场环境发生巨变,新能源汽车销量增长明显放缓,部分新能源汽车及零部件企业经营困难甚至倒闭,加之以特斯拉为首的外资新能源汽车企业陆续在华设厂投产,使国内新能源汽车市场竞争加剧,下行压力增大,新能源汽车产业正式进入后补贴时代,在此背景下,需要政府部门、相关企业重新评估市场现状,制定新的新能源汽车产业发展战略和路径,推动产业持续健康地发展。     

高速铁路动车组检修资源布局优化研究

高速铁路网的日趋完善,高速列车开行数量的进一步增加,对高速铁路动车组检修资源布局提出新的要求。为合理优化动车组检修资源布局,提高动车组检修效率,在分析我国动车段和动车运用所管理模式及布局方案的基础上,将动车组检修资源布局优化问题转化为基于多基地车辆路径运用的基地选址问题,基于"备选运用所-运输需求-动车组运用"间的关联关系构建动车组运用检修接续网络,建立动车组检修资源布局优化模型。以某区域的铁路网为例,利用近远期规划优化动车组检修资源布局,验证模型有效性,为今后动车组检修资源布局优化提供参考。     

车辆路线安排的一种改进节约算法

首先介绍了求解路线安排的节约算法,指出了其存在的不足,然后提出了一种改进的节约算法,可以更好地解决车辆路线安排问题。