CRH3型动车组辅助变流器半实物仿真系统

基于对CRH3型动车组辅助变流器电路结构、控制器K1及其接口的分析,采用的模拟方案有:使用电磁继电器模拟接触器的闭合和关断;使用常闭按钮开关模拟熔断器、主风扇M30和变压器超温保护的反馈触点;采用反相器将IGBT的控制信号取反,以模拟IGBT的反馈信号;设置2个可调电阻用以模拟功率模块进风口和出风口的PT100温度传感器,并通过调节电流实现对主风扇M30的控制。采用Matlab软件的Simulink工具箱建立辅助变流器半实物仿真系统主电路的仿真模型,在Matlab软件的实时开发环境(Real-Time Win-dows Target,RTW)模块中经过模型分析、代码转换、程序生成并运行联编文件等步骤,获取该模型的可执行文件。运行该可执行文件,通过选择外部模式、构造、连接目标机、运行等步骤,再打开控制器K1,实现半实物仿真系统和控制器的协同工作。使用Visual Basic软件开发该仿真模型的人机界面。实践证明,这一方式完全能满足设计需求,同时又具有较高的性价比。该辅助变流器半实物仿真系统已经成为辅助变流器国产化设计的重要工具。     

有时间窗车辆路径问题的混合算法

提出了一种基于模拟退火算法（SA）和大规模邻域搜索（LNS）的混合算法,并采用PFIH算法构造较高质量的初始解,同时给出了一种调整客户时间窗的回归迭代策略,从而计算出每辆车的最佳出发时间,并证明这种策略可使每辆车的等待时间均为零。从试验结果可以看出,该算法用于求解VRPTW问题效果显著,计算速度较快;与其他算法相比,显示了其较强的实用性和可操作性,为解决VRPTW提供了一种有效的算法。     

一种能防霜的侧窗玻璃结构

介绍一种能防霜的低成本侧窗结构,供北方寒冷地区客运车使用,增加乘客视野,减少乘客晕车。     

带回程取货的逆向物流车辆路径建模及其蚁群算法

对逆向物流车辆路径问题进行了概述和分类,构建了以VRPPDTW为基础的带回程取货的逆向物流车辆路径数学模型,设计了求解该模型的最大-最小蚁群算法,对设计要素进行了详细介绍,包括初始蚁群分布,状态转移策略,以及信息素更新策略等,并给出了具体的算法步骤. 最后,以Solomon中的R101、R102、R103、R104和R105等5项示例为背景,分别取前25节点和50节点,以取货点的取货量比例分别占全部客户节点需求量的10％、30％、50％取货,得到30个算例的计算结果,并将其与Tangian和模拟退火等计算结果进行了比较,结果表明最大-最小蚁群算法在某种程度上优于其他算法     

一种基于FBD的改进谐波检测算法分析与研究

为了快速、准确地检测出钻井船供电系统中的基波和谐波电流,本文提出一种基于FBD的改进谐波检测算法.该算法利用移动窗算法取代传统FBD的低通滤波器(LPF),通过对正序电流畸变率和直流分量响应时间2个指标进行分析,验证改进FBD在谐波电流检测的速度和精度.为了验证改进的算法在钻井船电网工作状态下的效果,本文加入了动态负载验证改进FBD算法.利用Matlab在稳态和动态负载下对正序电流畸变率和直流分量响应时间分别进行仿真,根据实验结果分析,表明算法具有良好的动态响应、检测精度高、易实现等特点.最后用改进的FBD电流检测配合PR控制方式对钻井船复杂电力系统进行补偿,通过观察谐波电流畸变率可知谐波电流补偿的效果,验证了改进FBD的可行性.     

Techniques for inserting additional trains into existing timetables

In this paper techniques for scheduling additional train services (SATS) are considered as is train scheduling involving general time window constraints, fixed operations, maintenance activities and periods of section unavailability. The SATS problem is important because additional services must often be given access to the railway and subsequently integrated into current timetables. The SATS problem therefore considers the competition for railway infrastructure between new services and existing services belonging to the same or different operators. The SATS problem is characterised as a hybrid job shop scheduling problem with time window constraints. To solve this problem constructive algorithm and meta-heuristic scheduling techniques that operate upon a disjunctive graph model of train operations are utilised. From numerical investigations the proposed framework and associated techniques are tested and shown to be effective.     

The time-dependent vehicle routing problem with soft time windows and stochastic travel times

This paper studies a vehicle routing problem with time-dependent and stochastic travel times. In our problem setting, customers have soft time windows. A mathematical model is used in which both efficiency for service as well as reliability for customers are taken into account. Depending on whether service times are included or not, we consider two versions of this problem. Two metaheuristics are built: a Tabu Search and an Adaptive Large Neighborhood Search. We carry out our experiments for well-known problem instances and perform comprehensive analyses on the numerical results in terms of the computational time and the solution quality. Experiments confirm that the proposed procedure is effective to obtain very good solutions to be performed in real-life environment.     

A unified-adaptive large neighborhood search metaheuristic for periodic location-routing problems

This paper introduces three variants of the Periodic Location-Routing Problem (PLRP): the Heterogeneous PLRP with Time Windows (HPTW), the Heterogeneous PLRP (HP) and the homogeneous PLRP with Time Windows (PTW). These problems extend the well-known location-routing problem by considering a homogeneous or heterogeneous fleet, multiple periods and time windows. The paper develops a powerful Unified-Adaptive Large Neighborhood Search (U-ALNS) metaheuristic for these problems. The U-ALNS successfully uses existing algorithmic procedures and also offers a number of new advanced efficient procedures capable of handling a multi-period horizon, fleet composition and location decisions. Computational experiments on benchmark instances show that the U-ALNS is highly effective on PLRPs. The U-ALNS outperforms previous methods on a set of standard benchmark instances for the PLRP. We also present new benchmark results for the PLRP, HPTW, HP and PTW.     

Partial recharge strategies for the electric vehicle routing problem with time windows

The Electric Vehicle Routing Problem with Time Windows (EVRPTW) is an extension to the well-known Vehicle Routing Problem with Time Windows (VRPTW) where the fleet consists of electric vehicles (EVs). Since EVs have limited driving range due to their battery capacities they may need to visit recharging stations while servicing the customers along their route. The recharging may take place at any battery level and after the recharging the battery is assumed to be full. In this paper, we relax the full recharge restriction and allow partial recharging (EVRPTW-PR), which is more practical in the real world due to shorter recharging duration. We formulate this problem as a 0–1 mixed integer linear program and develop an Adaptive Large Neighborhood Search (ALNS) algorithm to solve it efficiently. We apply several removal and insertion mechanisms by selecting them dynamically and adaptively based on their past performances, including new mechanisms specifically designed for EVRPTW and EVRPTW-PR. These new mechanisms include the removal of the stations independently or along with the preceding or succeeding customers and the insertion of the stations with determining the charge amount based on the recharging decisions. We test the performance of ALNS by using benchmark instances from the recent literature. The computational results show that the proposed method is effective in finding high quality solutions and the partial recharging option may significantly improve the routing decisions.     

公交车安全气压窗及火灾隐患监测预警器设计

针对紧急情况下公交乘客的逃生需求,设计了一种气压式安全公交车窗,当事故发生时,使车窗在3s内打开,为乘客提供及时有效的逃生通道。通过制作模型和力学分析计算,此设计既能在常规状态下保证车窗的强度和密封性,又能在紧急情况下使其迅速开启。此外,为预防事故,以AT89S52单片机为核心,采用2M007型可燃气体传感器和MQ-2型烟雾传感器建立公交车火灾监测报警系统,实时检测发动机舱及车体内可燃气体浓度和烟雾情况,具有声光报警功能。结合GSM通信模块,向公交车指挥中心传输报警信息,以便进行救援指挥。