基于等效坡度的自动手动变速器换档规律研究

针对自动变速器在复杂路面情况下很难进行较好的路面识别,导致换挡规律很难适应路面状况的问题,文章从汽车动力学的角度,对其进行建模分析;提出了等效坡度概念,提取各种复杂路面共性因素,并进行换档规律研究;利用车辆动力学模型及发动机特性及整车传动系统特性,分析了车辆在特殊路面上行驶规律;分析得出了特殊路面的共性因素,即路面阻力...     

AMT车辆坡道行驶综合控制换档规律的研究

分析AMT车辆坡道行驶时容易出现的意外升档和换档循环的原因;提出坡道工况的模糊识别方法,制定坡道行驶综合控制换档规律,不仅解决了意外升档和换档循环的问题,而且实现了坡道换档性能的最优。通过仿真分析,验证了该方法的有效性。     

A new approach to cross-sector cooperation in road safety through a comparison of policies in selected countries

Statistics from the databases of various countries and international organizations show that road accident rates and fatalities have fallen since the 1970s. With demographic changes taking place in many developed countries, however, accident and accident-risk patterns have changed in the last two decades. This study aims to introduce a new approach to cross-sector cooperation with the hope of making road safety more holistic and sustainable. The authors compare the road safety policies of three selected countries based on various categories, using a simple quantitative method. The results show some fragmentation within the policies, illustrating the need for a new road safety approach. The effort to reduce road traffic accidents by 50% by the year 2020 has also increased the pressure on stakeholders to meet this goal. This paper's contribution toward the 2020 goal lies in its recommendation of a new approach to road safety that will enlighten stakeholders on probable missing links in road safety.     

不良天气环境下高速公路运营安全与管理

作为道路环境的组成部分,气候条件与行车安全性之间有着密切的联系。本文将首先对影响交通的天气气象因素进行分类,然后通过对沪宁高速公路事故资料及相应气象资料的综合分析,统计不同天气条件下的事故分布,从事故原因、形态、时间分布以及严重程度等方面对灾害性天气下的事故特征进行讨论,并初步探讨了不良天气环境下高速公路安全管理系统的建立。     

Observer-based clutch disengagement control during gear shift process of automated manual transmission

A clutch disengagement strategy is proposed for the shift control of automated manual transmissions. The control strategy is based on a drive shaft torque observer. With the estimated drive shaft torque, the clutch can be disengaged as fast as possible without large driveline oscillations, which contributes to the reduction of total shift time and shift shock. The proposed control strategy is tested on a complete powertrain simulation model. It is verified that the system is robust to the variations of driving conditions, such as vehicle mass and road grade. It is also demonstrated that the revised system with switched gain can provide satisfactory performance even under large estimation error of the engine torque.     

四轮车辆非平稳路面不平度时域模拟及小波分析

建立了非平稳的四轮相关滤波白噪声路面时域模型，并用计算机模拟得出四轮的路面不平度时间序列。理论验证的结果表明该模型与路面的实际情况非常接近，进而采用谱分析、小波分析等数据处理技术对路面信号的时频特征进行了深入的探讨，得出了一些有价值的结论。     

不同路面下汽车ABS仿真检测研究

进行不同路面下汽车ABS性能仿真检测,开发了汽车ABS性能仿真检测系统,对ABS的ECU进行了几种典型路面下的仿真检测,并对试验结果进行分析.结果表明开发的ABS性能检测系统具有良好的路面仿真功能与测试功能,可以用于ABS ECU生产的在线检测.     

基于模糊推理的驾驶员意图识别研究

对驾驶员换档操作进行了动力学分析,定义了平直道路匀速行驶的平衡节气门开度和相对节气门开度,研究了典型工况下驾驶员操作特征,将平直道路行驶时的驾驶员意图分为相互关联的五类,并在此基础上提出了将驾驶环境和驾驶员操作相统一的识别方法。根据相应的实车实验数据和经验收集,制定了模糊推理的规则库,建立了多输入单输出的模糊推理模型。对实车实验数据进行了离线识别验证,能够比较准确完整的识别驾驶员意图。     

合肥市道路汽车行驶工况的开发与研究

阐述了汽车行驶工况的开发程序和测试方法。通过对合肥市道路交通状况的调查,选择五条具有代表性的路段进行合肥市城区的汽车行驶工况的研究,采集了大量合肥城区道路汽车行驶数据资料,运用多元统计学方法进行了道路汽车行驶工况的解析,从而建立合肥市道路汽车行驶工况。     

城市交通出行方式对能源与环境的影响

社会经济的快速增长使得人们的出行日益频繁,从而导致城市机动车保有量迅速增加和能源需求及其大气污染排放不断上升。本文以上海为例,应用LEAP模型,研究了在确保交通需求增长的前提下,发展不同的交通出行方式对能源需求和大气污染物排放的影响。结果表明,调整上海市交通发展模式,即有序发展私人交通、大力发展公共交通对于减少全市道路交通能源需求,减缓供应压力,降低大气污染排放具有重要意义。     

Slope Shift Strategy for Automatic Transmission Vehicles Based on the Road Gradient

Motivated by the development of high-precision digital maps for advanced driver assistance system (ADAS) in recent years, this study provides a new approach to solve the problems of the conventional automatic transmission vehicle travelling on sloping roads. Based on vehicle dynamics, shift problems on hilly roads are analyzed. A novel intelligent shift strategy is proposed, which consists of a dynamic shift schedule for the uphill, a safety shift schedule for the downhill, and a comprehensive economical shift schedule for the gentle slopes. A set of driver-in-loop co-simulation tests was conducted in a driving simulator that is equipped with a MATLAB/Simulink dynamics simulation platform. The test results verified the effectiveness of the new intelligent shift strategy. With the road information provided by a high-precision digital map, busy shifting can be eliminated, and improved dynamic performance can be achieved for a vehicle travelling on the uphill roads; undesired upshift can be prevented, and engine traction resistance can be used to relieve the load of braking system when a vehicle travelling on the downhill roads; also, fuel consumption can be reduced for a vehicle travelling on a gently sloped road. Consequently, this novel intelligent shift strategy offers a reliable and effective solution for improving a vehicle’s driving performance on a hilly road.     

上海市花木-龙阳路副中心路网系统改善研究

上海市花木-龙阳路副中心依托既有的龙阳路交通枢纽进行高强度开发,以实现交通和土地利用的最大化效益。针对巨大的交通出行需求、用地条件受限等不利因素,提出应该在交通需求预测的基础上,解决路网系统方面存在的问题,优化对外和内部交通通道的改善方案,从而提高区域路网系统的承载能力和道路交通运行效率。     

运行速度和发动机油耗预测模拟技术研究

描述一种根据九五国家重点科技攻关"公路投资综合效益分析系统的研究"项目研究成果,开发的汽车运行速度和主要经济指标———发动机油耗的预测和模拟技术。本项技术主要是通过改变道路的几何条件、路面状况、交通量、交通组成、车辆特征、车辆载重和环境等因素,预测和模拟上述任一或组合因素的变化对车辆运行速度和油耗的影响。模拟结果将为进一步研究道路纵断面和平曲线的最佳组合、道路的改建条件和路面大、中修养护时机的确定提供决策和分析的数据基础。     

公路限速值设计方法研究

针对我国公路限速管理决策中缺乏相关的科学、合理的依据,对公路限速值设计方法进行了研究.通过总结欧美等发达国家公路所使用法定限速、最优限速法、工程研究法与专家系统法等限速值设计方法应用中存在的优缺点,结合我国公路状况,进一步分析影响我国公路限速的因素,应用系统分析方法,综合考虑运行速度、公路线形、设计速度和交通安全等因素提出了基于运行速度、线形、安全多因素的适合我国交通特性的公路限速值设计方法并给出具体实施流程.     

基于安全车速的北京冬奥会山地道路冰雪路面通行能力研究

复杂山地线形和道路冰雪路面结合条件下的安全车速设置及通行能力保障是交通管理面临的新挑战。针对北京冬奥会延庆赛区复杂山地道路冰雪路面场景，建立了安全车速与道路线形设计及路面附着系数之间的关系，以安全车速为依据得到了不同路面条件下山地道路的通行能力。依据道路平曲线、竖曲线和横断面数据建立了山地道路三维空间模型；分析了车辆在山地道路平纵组合路段的受力情况，构建了车辆安全行驶速度与圆曲线半径、道路超高、纵坡坡度和路面附着系数的关系模型，并分析了基于安全车速模型的道路通行能力。为了验证模型，选取2种常见的冰雪路面状况和2种常用的车辆类型，获得不同条件下山地道路冰雪路面的安全车速。采用VISSIM软件设计了20种仿真场景，结合道路实测数据验证了安全车速模型的对山地道路冰雪路面车辆安全行驶的提升作用。实测与结果表明:相比全程单一限速模型，所建立的安全车速模型在冰膜路面的行程时间缩短了约38%（小汽车）和32%（大客车），雪板路面的行程时间缩短了约26%（小汽车）和24%（大客车）。山地道路交通流量存在1个自由流到饱和流的相变过程，冰膜路面小汽车下行最大交通量为241辆/h（单向行驶）和231辆/h（双向行驶），大客车下行最大交通量为227辆/h（单向行驶）和222辆/h（双向行驶）；雪板路面小汽车下行最大交通量为319辆/h（单向行驶）和249辆/h（双向行驶），大客车下行最大交通量为301辆/h（单向行驶）和236辆/h（双向行驶）。      

驾驶员车道变换视点转移模型及其参数标定

为了获取驾驶员车道变换行程中的视点转移特性,构建视点转移模型,解决驾驶员行为监控设备布设缺乏依据的难题,采用眼动仪和人工记录的方式,分别以轿车和公交车驾驶员为研究样本,获取了车道变换行为过程中驾驶员视点停留时间和视点位置转移特性数据,给出驾驶员的眼动停留时间均值和分布规律,基于外界的交通运行环境,根据驾驶员对外界信息的获取程度,考虑驾驶员、车辆、道路、环境等影响因素,设定其符合泊松分布,将驾驶行为分为决策阶段和执行阶段,给出了基于6个模块的流程结构,构建基于信息满意度的视点位置转移模型并标定了模型参数。     

防抱死制动系统模糊自学习控制研究

由于车辆参数和运行工况的复杂多变，针对特定参数和路面条件所设计的防抱死制动系统往往难以适应。为解决这一问题，文中首先建立了带有盘式制动器的双轮车辆直线制动系统的数学模型；而后提出了模糊自学习控制策略，该方案通过引入模糊学习机制以调整模糊控制器的规则集，可使车辆对象输出跟踪理想参考模型的输出；接着对所设计控制算法在不同路面条件下进行了性能模拟；最后开发了模糊自学习微控制器，基于硬件在环仿真技术，对设计控制器的性能进行了实验验证。     

Vehicle-Generated Road Damage: A Review

The literature concerned with road damage caused by heavy commercial vehicles is reviewed. The main types of vehicle-generated road damage are described and the methods that can be used to analyse them are presented. Attention is given to the principal features of the response of road surfaces to vehicle loads and mathematical models that have been developed to predict road response. Also discussed are those vehicle features which, to a first approximation, can be studied without consideration of the dynamics of the vehicle, including axle and tyre configurations, tyre contact conditions and static load sharing in axle group suspensions. The main emphasis of the paper is on the dynamic tyre forces generated by heavy vehicles: their principal characteristics, their simulation and measurement, the effects of suspension design on the forces and the methods that can be used to estimate their influence on road damage. Some critical research needs are identified.     

深圳市城市道路机动车排放特征的研究

利用"GPS定位技术和废气分析仪"构建的机动车车载实时排放测试系统研究了深圳市城市道路机动车不同行驶工况排放特征以及速度、加速度等参数对其排放特征的影响规律,并与国内主要大城市城市道路机动车不同行驶工况排放特征相比较。研究结果表明,改善城市交通状况和优化机动车综合行驶工况点的燃烧质量是减少深圳市机动车大气污染的关键所在。     

Experimental study on mobility of a vehicle with CTIS in soft soil

Recently, the domestic military vehicles currently being developed are installed with a central tire inflation system (CTIS) to control the pressure of tires to increase the contact area between the tires and the ground and improve mobility on soft soils. On the other hand, it is difficult to find technical data based on experiments for designing a CTIS. In this study, to obtain the technical data to set proper pressures according to road conditions a range of mobility tests were performed on soft soil roads, such as sand and clay, according to the CTIS operating modes to obtain the technical data to set proper pressures according to the road conditions. The characteristics of the mobility and its correlation with the tire pressures in each operating mode were analyzed. The results confirmed that a wheeled vehicle with a CTIS showed better performance on soft soil than a vehicle without a CTIS.