重型汽车低附着路面制动稳定性的仿真研究

文章利用trucksim重型汽车动力学仿真软件,对六轮双轴重型汽车在低附着路面左右车轮附着系数不一致情况下进行紧急制动的行驶工况进行了仿真研究。研究结果表明在低附着路面进行紧急制动时,对制动轮进行制动压力控制,有ABS控制的重型汽车比没有ABS控制的重型汽车具有更好地行驶稳定性。但在低附着路面上,有ABS控制的重型汽车比没有ABS控制的重型汽车的制动距离增加了很多,这对重型汽车的行车安全性非常不利。     

基于客户关联的纯电动轻卡驱动电机可靠性台架试验研究

为研究轻卡BEV驱动电机可靠性台架试验标准与实际客户的关联,文章基于整车CAN网络,采集实际客户日常行驶过程中的电机扭矩、转速等数据,通过Ncode软件计算出电机的扭矩谱。根据Miner准则,计算出电机20万公里的疲劳伪损伤。对比电机可靠性台架试验的电机伪损伤,确定电机台架试验标准是否满足客户需求。     

Orchestration of driving simulator scenarios based on dynamic actor preparation and automated action planning

In driving simulation, a scenario includes definitions of the road environment, the traffic situation, simulated vehicles’ interactions with the participant’s vehicle and measurements that need to be collected. The scenarios need to be designed in such a way that the research questions to be studied can be answered, which commonly imply exposing the participant for a couple of predefined specific situations that has to be both realistic and repeatable. This article presents an integrated algorithm based on Dynamic Actor Preparation and Automated Action Planning to control autonomous simulated vehicles in the simulation in order to generate predefined situations. This algorithm is thus able to plan driving actions for autonomous vehicles based on specific tasks with relevant contextual information as well as handling longitudinal transportation of simulated vehicles based on the contextual information in an automated manner. The conducted experiment shows that the algorithm is able to guarantee repeatability under autonomous traffic flow. The presented algorithm can benefit not only the driving simulation community, but also relevant areas, such as autonomous vehicle and in-vehicle device design by providing them with an algorithm for target pursue and driving task accomplishment, which can be used to design a human-vehicle cooperation system in the coming era of autonomous driving.     

Measuring risk aversion to guide transportation policy: Contexts,incentives, and respondents

Road pricing may provide a solution to increasing traffic congestion in metropolitan areas. Route, departure time and travel mode choices depend on risk attitudes as commuters perceive the options as having uncertain effects on travel times. We propose that Experimental Economics methods can deliver data that uses real consequences and where the context can be varied by the researcher. The approach relies on the controlled manipulation of contexts, similar to what is done in the Stated Choice approach, but builds in actual consequences, similar to the Revealed Preference approach. This paper investigates some of the trade-offs between the cost of conducting Experimental Economics studies and the behavioral responses elicited. In particular, we compare responses to traditional lottery choice tasks to the route choice tasks in simulated driving environments. We also compare students (a low cost convenient participant pool) to field participants recruited from the driving population. While we see initial differences across our treatment groups, we find that their risk taking behavior converge with minimal repetition.     

城市快速路基本路段车辆运行特性调查与分析

快速路系统既承担大城市内部中长距离的机动车交通,又承担大城市与区域内其它城镇联系的对外交通。依托教育部高等学校博士学科点专项科研基金项目《城市快速路系统通行能力计算与服务水平评价方法研究》,对国内七个典型城市的快速路进行了交通调查,从交通量的变化特性、车速运行特性及交通组成特性方面对车辆运行特性进行了分析。     

多轴驱动车辆的扭矩优化分配

实践证明，制约多轴驱动车辆发展的问题之一是驱动扭矩的鸽合理分配技术。文中在假定所有轮胎具有个同滚动半径，同一车轴的左右轮胎爱力状态相同的前提下，以牵引功率最大，对多轴驱动车辆的驱动扭矩做了优化分配。通过分析得出，在一般路面正常行驶时，只有保证分配到各个驱动车轮的扭矩与各自的轴荷相匹配时，汽车才具有最小的功率循环及最高的牵引效率。     

纯氢燃料电池汽车性能的仿真

本文以由纯氢作燃料、采用串联式结构的燃料电池车用研究对象，通过仿真对车辆的部分参数和驾驶循环对车辆的性能影响进行了分析。在所分析的车辆参数中，动力系统效率的提高对车辆能量经济的改善最为有效，其次是车的总质量、空气阻力系数和滚动阻力系数减小的影响。在对原地起步加速特性的影响中，车重的减轻效果最为明显，其次是空气阻力系数和动阻力系数减小的影响。这些结论为燃料电池车动力系统的优化设计提供了依据。     

装甲车辆非稳定工况驱动性能仿真模型

基于发动机和传动系统的动态过程，本文开发了一个装甲车辆非稳定工况的驱动性能仿真模型。对一台装甲车辆的加速过程进行了实例仿真计算，计算结果与实测值符合较好。这个仿真模型可以方便地用于装甲车辆非稳定工况动力性能的研究。     

高速公路陡坡弯道路段安全性评价

结合运行车速理论,分析判定陡坡弯道的汽车行驶安全性,并在设计、管理等方面对存在安全隐患路段提出改进措施。     

Weather and road geometry impact on longitudinal driving behavior: Exploratory analysis using an empirically supported acceleration modeling framework

The objective of this paper is to quantify and characterize driver behavior under different roadway geometries and weather conditions. In order to explore how a driver perceives the rapidly changing driving surrounding (i.e. different weather conditions and road geometry configurations) and executes acceleration maneuvers accordingly, this paper extends a Prospect Theory based acceleration modeling framework. A driving simulator is utilized to conduct 76 driving experiments. Foggy weather, icy and wet roadway surfaces, horizontal and vertical curves, and different lane and shoulder widths are simulated while having participants driving behind a yellow cab at speeds/headways of their choice. After studying the driving trends observed in the different driving experiments, the extended Prospect Theory based acceleration model is calibrated using the produced trajectory data. The extended Prospect Theory based model parameters are able to reflect a change in risk-perception and acceleration maneuvering when receiving different parameterized exogenous information. The results indicate that drivers invest more attention and effort to deal with the roadway challenges compared to the effort to deal with the weather conditions. Moreover, the calibrated model is used to simulate a highway segment and observe the produced fundamental diagram. The preliminary results suggest that the model is capable of capturing driver behavior under different roadway and weather conditions leading to changes in capacity and traffic disruptions.