汽车操纵动力学十八自由度模型仿真研究

本文介绍了根据多刚体动力学中的凯恩方法建立的一般两轴汽车的十八自由度数学模型。     

车身内部布置CAD系统及其应用

介绍了自行开发的汽车车身内部布置的ＣＡＤ系统，并就系统在设计中的应用了说明。该系统是在通用图形软件基础上进行二次开发而成的，以ＳＡＥ标准，ＥＥＣ标准及为主要依据，将ＣＡＤ技术运用到车身内部布置设计中。     

三轴汽车前后轮角输入时的响应特性

本文详细推导了三轴汽车线性二自由度模型的运动微分方程，分析了汽车对前后轮角输入时的移居记响应特性。从汽车动力学的角度讨论了前后轮转应具备的比例关系。该方法同样适用于其它多轴汽车的建模分析。     

车辆行驶工况滚动阻力系数的测定

分析了车辆滚动阻力系数的影响因素，论述了车辆行驶速度对滚阻力系数的影响。依据车辆行驶的功率平衡原理，提出了滚动阻力系数的测试方法及测试时应注意的问题。并对实车测试值与经验公式估算值进行了比较。     

汽车操纵稳定性的广义汽车转向稳态响应模型

针对传统汽车操纵稳定性理论的线性二自由度模型的不足,构建了一个新的广义汽车转向稳态响应模型,并说明了该模型的广泛适用性。以某不足转向轿车模型的有关参数为例,仿真计算并比较了应用两种模型时该轿车等速圆周行驶时的稳态响应状况,验证了广义模型的正确性,同时得到了一条有别于传统汽车操纵稳定性理论的重要结论。     

磁导航车体运动数字控制系统数学模型研究

探讨磁导航车体运动数字控制系统的数学模型。用实验方法建立磁导航车体运动数字控制系统典型环节的时间连续数学模型,结合车体运动机械操纵环节的传统数学模型建立整个控制系统的时间连续数学模型。利用Z变换方法把控制系统时间连续数学模型转换成离散数学模型,引入数字控制系统典型环节的数学模型,建立磁导航车体运动数字控制系统的离散数学模型。设计数字控制系统的二次型最优控制器并进行计算机仿真。仿真分析结果验证了数学模型的有效性。     

基于视觉的前方车辆探测技术研究方法综述

对国内外关于车道上本车前方车辆检测方法进行了综述。根据探测车辆所采用的传感器不同,分别对采用单目视觉、双目视觉、视觉与其他传感器融合以及非视觉传感器的几种探测方法进行了比较与分析。同时,针对每种探测方法,进一步阐述了目前车辆识别的一些具体算法。最后,指出了每种方法存在的优点和一些不足。     

Fuzzy-logic applied to yaw moment control for vehicle stability

In this paper, we propose a new yaw moment control based on fuzzy logic to improve vehicle handling and stability. The advantages of fuzzy methods are their simplicity and their good performance in controlling non-linear systems. The developed controller generates the suitable yaw moment which is obtained from the difference of the brake forces between the front wheels so that the vehicle follows the target values of the yaw rate and the sideslip angle. The simulation results show the effectiveness of the proposed control method when the vehicle is subjected to different cornering steering manoeuvres such as change line and J-turn under different driving conditions (dry road and snow-covered).     

A rolling horizon algorithm for auto-carrier transportation

This paper introduces a rolling horizon algorithm to plan the delivery of vehicles to automotive dealers by a heterogeneous fleet of auto-carriers. The problem consists in scheduling the deliveries over a multiple-day planning horizon during which requests for transportation arrive dynamically. In addition, the routing of the auto-carriers must take into account constraints related to the loading of the vehicles on the carriers. The objective is to minimize the sum of traveled distances, fixed costs for auto-carrier operation, service costs, and penalties for late deliveries. The problem is solved by a heuristic that first selects the vehicles to be delivered in the next few days and then optimizes the deliveries by an iterated local search procedure. A branch-and-bound search is used to check the feasibility of the loading. To handle the dynamic nature of the problem, the complete algorithm is applied repeatedly in a rolling horizon framework. Computational results on data from a major European logistics service provider show that the heuristic is fast and yields significant improvements compared to the sequential solution of independent daily problems.     

Vehicle kilometers traveled reduction impacts of Transit-Oriented Development: Evidence from Shanghai City

The role of residential self-selection has become a major subject in the debate over the relationships between the built environment and travel behavior. Numerous previous empirical studies on this subject have provided valuable insights into the associations between the built environment and travel behavior. However, the vast majority of the studies were conducted in North American and European cities; yet this research is still in its infancy in most developing countries, including China, where residential and transport choices are likely to be more constrained and travel-related attitudes quite different from those in the developed world. Using the data collected from 2038 residents currently living in TOD neighborhoods and non-TOD neighborhoods in Shanghai City, this paper aims to partly fill the gaps by investigating the causal relationship between the built environment and travel behavior in the Chinese context. More specifically, this paper employs Heckman’s sample selection model to examine the reduction impacts of TOD on personal vehicle kilometers traveled (VKT), controlling for self-selection. The results show that whilst the effects of residential self-selection are apparent; the built environment exhibits the most significant impacts on travel behavior, playing the dominant role. These findings produce a sound basis for local policymakers to better understand the nature and magnitude toward the impacts of the built environment on travel behavior. Providing the government department with reassurance that effective interventions and policies on land use aimed toward altering the built environment would actually lead to meaningful changes in travel behavior.