A Variable Free Control Characteristic Vehicle

A variable characteristic car (VCC) has been developed at Melbourne University for driverlvehicle handling research. The vehicle is unusual in that it has facilities for varying both its fixed control and free control dynamic characteristics over wide ranges. In this paper the servo systems used to effect these changes are described. The calibration methods used to relate the vehicle response characteristics to the variable servo settings are detailed. Sample calibration results are given for the fixed control parameters steering ratio, yaw response time and stability factor. Calibration of the free control parameters is also described and results are given for the steering torque gradient, and the time-to-peak and percentage overshoot of the steering wheel motion in response to a step input of torque.     

Development of a Strategy Model of the Driver in Lane Keeping

Based on vehicle constraints and known human operator characteristics, a strategy model was postulated for describing behavior in the lane keeping task. This model includes nonlinear thresholds operating on vehicle yaw and lateral translation, random input sources to account for spurious driver activity, and smoothing to account for driver response lag. The output of the model is steering wheel position

To determine model parameters and model suitability in describing driver behavior, recordings were made for driver-subjects performing a lane-keeping task in a moving base driving simulator having a computer generated display. A procedure involving both analytic and experimental techniques was then developed for determining the model parameters of each driver

Statistical comparisons and visual inspections made between driver-vehicle and model-vehicle time histories indicate a high degree of correspondence. Models such as these show promise in obtaining a better understanding of driver behavior and driver-vehicle response by incorporating nonlinear elements in the driver model.     

桥梁撞击问题研究的新方法

为了更准确地研究桥梁撞击问题,介绍了当前常用的计算最大撞击力的经验公式,指出它们的局限性。从动量和能量双重角度来分析和研究桥梁撞击问题,提出了一种研究桥梁撞击问题的新方法。认为桥梁在受到撞击后做阻尼简谐振动,提出了如等效振幅、等效弹性系数等概念。用高采样率高精度的RTK-GPS技术采集撞击瞬间及撞击后短时间段内的桥梁振动数据,利用动量守恒和能量守恒定理,得出桥梁所能承受的最大撞击,并通过现场试验对新方法的有效性进行了验证。试验结果表明,提出的方法具有一定的实用性,并得出了一些有益的结论。     

基于变压差稳流气道试验台数据采集与处理系统的设计

基于变压差试验方法，在稳流气道试验台上，测量涡流动量矩、气门升程、气道压差、温度及流量等参数，上述各参数可用相应的传感器及放大器转变为电信号，再经A／D转换由计算机进行处理和分析，从而得出流量系数、涡流比等参数，改变了以往的手工记录和传统测试方法。     

Effect of Frame Compliance on the Lateral Dynamics of Motorcycles

The lateral dynamics of an uncontrolled motorcycle, running on a straight, level road surface, is investigated in this paper. The structural compliances in the front and the rear frames of the motorcycle are taken into account by introducing additional degrees of freedom in the analysis. The kinematics of the tires is represented by linear differential equations which are based on the taut-string model of pneumatic tires. The linear differential equations of motion are solved to yield the eigensolutions of the system. Numerical results, obtained for parameters corresponding to a Honda CB750 motorcycle, are presented and discussed.     

Messungen von Fahrbahn-Unebenheiten paralleler Fahrspuren und Anwendung der Ergebnisse

Measurement of two track road inputs and theoretical application of the results

The calculation of vehicle response to road-surface irregularity inputs requires the spectral densities of the left and right longitudinal track and their statistical dependence

This paper presents some resluts of parallel profile measurements, three typical german roads have been chosen

Random vibration of two vehicle types are digital-simulated. The dynamic tire load shows that independent suspension systems are more advantageous than beam axles, because by wheel tramp this type increases the dynamic tire load.     

人体胸部侧向碰撞模型参数值确定方法

本文以人尸体胸部无反弹冲撞式滑车侧向碰撞试验为基础，建立与试验相适应的人体胸部侧向碰撞模型。通过导出试验与模型之间误差的函数关系和应用最小误差理论。探讨了如何根据测试胸部生物力学特性的试验数据确定定最佳参数的方法问题。     

A fuzzy approach to reconstructing vehicle–pedestrian collisions

Vehicle–pedestrian collision is one of the most frequent and most severe types of road accident. Many models, both theoretical and empirical, have been developed over the last 30 years to reconstruct this type of impact, but not all of them yield accurate results, with a spread averaging about ±10?km/h. Many multibody software systems have been developed as well. They are very accurate and, when all of the parameters required by the software are available, they are the best methods to reconstruct the collision. However, complete knowledge of the precise dynamics of pedestrian motion throughout the trajectory is not necessary. For a court expert, the data on conditions of pre-impact, impact and rest position are usually sufficient to make an adequate survey. The fuzzy approach presented in this paper is used to calculate the velocity of the impacting vehicle, considering the main parameters, all collectable at the scene of the accident, with a precision of about 3?km/h. Accordingly, this methodology represents a suitable tool for the purpose of accident reconstruction.     

发动机增压匹配的涡轮通流模型研究

建立了用于车用涡轮增压发动机匹配的涡轮通流模型。该模型根据进口条件和几何参数自动计算涡轮特性参数,能够有效地应用于可变截面涡轮与发动机的匹配;模型能够在整个工况范围内得到完整的涡轮特性,对涡轮增压发动机进行全工况匹配及优化,还可以应用于发动机开发阶段的涡轮增压器选型,指导涡轮增压器的开发设计工作。模型基于一维定常流体动力学质量守恒、动量守恒和能量守恒方程,结合了损失和阻塞预测值,并应用3款不同结构参数的混流涡轮试验数据验证了模型的有效性。     

工程车辆FOPS冲击试验中落锤塑性变形研究

为了对工程车辆的落物保护装置(FOPS)进行可靠性试验提供理论依据,采用冲击动力学的塑性波两侧的动量平衡理论对工程车辆FOPS受冲击时落锤的动态响应进行了研究,建立了锤头变形的基本方程,绘制了方程相应曲线;建立了锤头在冲击过程中任一瞬时变形长度和非变形长度的数学模型,找到了工程应变和冲击速度之间的曲线对于塑性大变形的突变点及影响落锤变形的各个因素和控制变形的依据。为减小落锤的蘑菇形尺寸,降低锤头的材料成本,多次重复使用落锤,进行合理的落锤结构设计指明了方向。     

A Two DOF Model for Jerk Optimal Vehicle Suspensions

Researchers have proposed various active suspension concepts to optimize the tradeoff between ride and handling in passenger vehicles. A few investigators suggested inclusion of the passenger jerk, the derivative of the passenger acceleration, as a measure of ride quality in the performance index. Minimization of a performance index then optimizes both the acceleration and jerk as well as other outputs representing handling quality and design constraints. This approach is called jerk optimal control.

This paper compares two different vehicle models of increasing complexity (the one and two DOF quarter car) using jerk optimal control. Different aspects of suspension performance are investigated, including the structure of the system transfer functions, the structure of the force control laws, and the tradeoffs between the various root mean square (rms) outputs defining system ride and handling performance. Tables compare the numerical results of the two models, allowing predictions of actual vehicle performance.

The results of the two models show the same basic trend for the tradeoff between ride and handling quality: at a constant level of rms passenger acceleration the rms passenger jerk can be reduced significantly, but only at a cost of increased rms tire deflections. In physical terms, a softer ride results in degraded handling performance. For a chosen level of ride improvement, the more realistic two DOF quarter car model predicts more severe degradation of handling. The latter nevertheless predicts a substantial increase in vehicle ride quality is possible through a 55% reduction in jerk. It is expected that actual suspensions could also produce significant increases in ride quality through jerk reduction. Jerk optimal suspensions could find use both in higher end passenger vehicles and in transports for vibration sensitive cargo.     

中国公路车-桥耦合振动车辆模型研究（双语出版）

为了提出适用于中国车-桥耦合振动分析的车辆动力分析模型,首先基于中国桥梁规范中的设计车辆荷载,结合大量调查统计数据和等效静力分析方法,初步拟定车辆动力分析模型的几何尺寸、质量、刚度、阻尼等参数取值,并与国内外广泛采用的几种车辆模型的参数取值进行对比。接着选取4座钢筋混凝土简支梁桥并建立其三维有限元模型,基于车-桥耦合振动数值模拟分析车辆模型的刚度、阻尼等参数对桥梁上动力冲击系数的影响,并对比几个不同车辆模型对动力冲击系数的影响。最后,选择中国湖南省境内一座实桥和几辆不同轴数的重车开展实桥试验,将实测动力冲击系数与所提车辆模型数值模拟获得的冲击系数进行对比。结果表明：动力冲击系数随车辆总质量的增大而减小,随车辆整体刚度的增大而增大,但随车辆整体阻尼的增大呈先减小后增大的趋势;单个车轴的刚度和阻尼对动力冲击系数的影响不明显;车辆总质量是导致不同车辆模型作用下动力冲击系数差异的主要因素;数值模拟结果与实测结果吻合良好,验证了所提车辆模型及参数取值的合理性;该车辆模型可用于中国的设计车辆荷载作用下桥梁的动力响应分析和相关研究,也可用于估算重量相当的不同类型车辆对桥梁的动力冲击效应。     

恶劣天气条件下城市快速路通行能力研究

通行能力是道路交通工程的重要参数。特别是在恶劣天气条件下,交通组织管理需要准确的通行能力数据支撑。基于上海市快速路监控中心采集存储的海量交通数据,结合气象局发布的天气状况信息,提取出恶劣天气条件下快速路的交通流参数。根据气象数据对交通流参数关系的影响程度,对气象条件进行了分级。提出了基于交通流模型拟合的通行能力计算模型,计算并标定了不同气象等级下通行能力的折减系数。     

A Comparison of Tyre Representations in a Simple Wheel Shimmy Problem

A simple system capable of wheel shimmy is analysed in three different ways and the results are compared. The tyre in each case is taken to be representable by a “taut string”, and the three ways involve (a) developing a digital tyre simulation which operates sequentially with a digital simulation of the mechanical system, (b) representing the tyre responses by linear constant coefficient differential equations derived empirically to match the string responses, and (c) as in (b) but employing fundamentally derived equations which approximate the exact string responses. The approximations are shown to give good results at reduced frequencies typical of the wheel shimmy phenomenon.     

基于摄动理论的汽车二维碰撞模型抗干扰性分析

目前国内外的汽车事故再现模型主要基于动量定理来分析的.通过对典型的汽车二维非对心点碰撞模型分析求解计算,并且基于摄动理论,应用数学方法分析模型的抗干扰能力.通过理论分析,提高模型计算的准确性和可靠性.     

基于Apriori算法对地面沉降影响因素的数据挖掘及分析

为有效利用盾构法施工过程中产生和积累的大量掘进历史数据、挖掘知识和信息,以优化掘进参数、控制地表沉降,采集某地铁相邻两区间的地面沉降数据及掘进参数,基于数据挖掘技术,通过对比优缺点,综合等宽离散和k-means聚类2种方法将数据离散化,并采用Aprioir算法进行关联规则挖掘。通过分析关联规则得到以下结论: 出土率、注浆填充率和俯仰角对沉降值影响较大,掘进速度和刀盘转矩对沉降值也有一定影响。根据数据离散区间和关联规则,给出穿越土层为圆砾和卵石时的注浆填充率建议值为185%~190%,注浆压力建议区间为0.16~0.22 MPa,同时建议俯仰角纠偏幅度宜平均每3环小于±0.2°。     

基于信息融合的轿车碰撞两轮车事故车速分析

在对北京市轿车与两轮车碰撞事故调研分析的基础上,深入分析车辆、路面遗留痕迹特征与汽车碰撞特点之间的联系,选择与轿车碰撞速度相关的人体-风窗玻璃接触、人体及车辆与路面接触的痕迹特征参数,运用人工神经网络方法建立了轿车与两轮车碰撞事故的车辆碰撞速度分类预测模型.该模型融合了人-车-路相互作用的痕迹特征信息,采用实际事故案例提取的可靠样本对其进行训练并应用于车速估算.     

Berechnung des extremen Lenk- und Bremsverhaltens von Sattelkraftfahrzeugen

Simulation of Steering and Braking Behaviour of Tractor-Semitrailer Vehicles in Extreme Situations

This paper deals with the simulation of the behaviour of tractor-semitrailer vehicles at braking on wet, slippery road surface. The nonlinear model used for the computation enables to simulate extreme situations at wheel locking and swerving

The instabilities during braking such as jackknifing and trailer swing as well as non steerability are investigated. Straightline braking shows the influence of cornering on the behaviour during braking in a turn.     

冲击压实后旧水泥混凝土路面作为垫层及其回弹模量的试验研究

在提出冲击压实后旧水泥混凝土路面作为加铺结构层之一的设计思路的基础上，阐述实测回弹模量的重要性；通过对大量实测承载板数据进行分析，获得了实施冲击压实处理后旧水泥混凝土板及板下基层回弹模量的量值范围和变化规律，作为加铺层设计的计算参数，并用来评价其残余承载能力。