基于PWS-1409的便携式测控系统

本文介绍了基于PWS-1409的便携式测控系统的原理、特点、硬件构成和软件设计。该系统采用研华公司的PCI-1710、PCLD-885板和ActiveDAQ软件构成。试验证明该系统具有较高的通用性、灵活性和稳定性。     

Optimization of headways with stop‐skipping control: a case study of bus rapid transit system

Bus rapid transit system is designed to provide high‐quality and cost‐efficient passenger transportation services. In order to achieve this design objective, effective scheduling strategies are required. This research aims at improving the operation efficiency and service quality of a BRT system through integrated optimization of its service headways and stop‐skipping strategy. Based on cost analysis for both passengers and operation agencies, an optimization model is established. A genetic algorithms based algorithm and an application‐oriented solution method are developed. Beijing BRT Line 2 has been chosen as a case study, and the effectiveness of the optimal headways with stop‐skipping services under different demand levels has been analyzed. The results has shown that, at a certain demand level, the proposed operating strategy can be most advantageous for passengers with an accepted increase of operating costs, under which the optimum headway is between 3.5 and 5.5 min for stop‐skipping services during the morning peak hour depending on the demand with the provision of stop‐skipping services. The effectiveness of the optimal headways with stop‐skipping services is compared with those of existing headways and optimal headways without stop‐skipping services. The results show that operating strategies under the optimal headways with stop‐skipping services outperforms the other two operating strategies with respect to total costs and in‐vehicle time for passengers. Copyright © 2014 John Wiley & Sons, Ltd.     

An improved headway-based holding strategy for bus transit

Abstract

This paper presents an improved headway-based holding strategy integrating bus transit travel and dwelling time prediction. A support vector machine-based (SVM) model is developed to predict the baseline travel and dwell times of buses based on recent data. In order to reduce prediction errors, an adaptive algorithm is used together with real-time bus operational information and estimated baseline times from SVM models. The objective of the improved holding strategy is to minimize the total waiting times of passengers at the current stop and at successive stops. Considering the time-varying features of bus running, a ‘forgetting factor’ is introduced to weight the most recent data and reduce the disturbance from unexpected incidents. Finally, the improved holding strategy proposed in this study is illustrated using the microscopic simulation model Paramics and some conclusions are drawn.     

Integrating GIS concepts into transportation network data structures

Transportation network data structures must be designed to meet the requirements of the analyses being conducted and must be compatible with the selected graphical user interface. Increasing interest in geographic information systems (GIS) and intelligent transportation systems (ITS) have further burdened the network data structure. It is possible to implement object oriented programming (OOP) technology to satisfy these needs, without making the data structure excessively complicated.

This paper shows how a well‐developed network data structure can incorporate major capabilities normally associated with stand‐alone GIS's. The design of a network data structure derives from both theoretical and practical considerations. A design of a network data structure, composed entirely of objects, is presented. Examples of its implementation, limitations, advantages, and possible extensions are drawn from experience with the General Network Editor (GNE).     

QKW5型速动开关可靠性试验的数据分析

通过对机车接触器、继电器用QKW5型速动开关在加工工艺改进后可靠性试验数据的统计分析,绘制出产品的失效浴盆曲线,为QKW5型速动开关产品改进的合理性提供试验依据,通过累积检测数据的概率分析,为该产品质量提升方案提供理论依据.     

CATIA V5在客车底盘设计中的应用

随着三维设计软件的普及,客车底盘的设计正在逐渐采用三维设计。本文简要介绍CATIA V5在客车底盘设计中的应用。     

客车前后顶三维造型设计及模型模具制作

简述利用UG软件进行客车前后顶的三维造型设计模型制作和模具翻制。     

某客车底架结构局部优化设计研究

以底架局部为研究对象,抽取有代表性的局部结构建立有限元模型,提出多个改进方案;通过对比各改进方案,得到综合效果较好的优化结构。该方法在结构优化设计中简单、高效。     

一种客车自动喷洒灭火装置的方案设计

介绍一种客车自动喷洒灭火装置的技术方案及实验验证。     

客车骨架构件吸能特性的对比分书

针对汽车耐撞性的要求,以客车骨架常用的矩形管件为研究对象,利用参数化建模的方法,分析了截面形状,壁厚,材料对吸能特性的影响。通过仿真分析表,明在相同情况下方形薄壁构件吸收能量较多且变形量小,但是在碰撞开始产生的峰值加速度较大,在碰撞事故中对人体造成的伤害很大,有必要在此基础上对方形构件进行优化设计。壁厚因素对构件碰撞吸能特性的影响较大,构件的抗变形能力和缓冲吸能能力存在相互矛盾。