A two-dimensional tire model on uneven roads for vehicle dynamic simulation1

This study proposes a comprehensive analytical tire model for handling and ride comfort in low frequency ranges. A contact algorithm that is developed in this study provides a two-dimensional contact pressure distribution on even and uneven road surfaces with reasonable computational cost. Shear stresses and strains during cornering and braking are estimated by direct measurement of tread deformations. The model is validated against experimental force and moment data for general handling simulations. Cleat tests are also conducted and validated under different forward velocity and vertical load conditions for a tire vibration study.     

基于能量解耦的汽车动力总成悬置系统优化设计

为了解决某款车的动力总成悬置系统振动问题,结合多自由度系统振动解耦和固有频率匹配理论,应用ADAMS建立动力总成悬置系统模型进行仿真分析。同时以解耦率目标函数,通过MATLAB软件中的遗传算法对悬置系统进行了优化。结果表明,对悬置刚度进行优化能有效提高解耦率,改善系统的NVH性能。     

新能源铝空电源电池介绍

1工作原理铝空气电池的化学反应与锌空气电池类似,铝空气电池以高纯度铝Al(含铝99.99%)为负极、氧为正极,以氢氧化钾(KOH)或氢氧化钠(Na OH)水溶液为电解质。铝摄取空气中的氧,在电池放电时产生化学反应,铝和氧作用转化为氧化铝。铝空气电池的进展十分迅速,它在EV上的应用已取得良好效果,是一种很有发展前途的空气电池。     

基于整车多自由度的电动助力转向系统建模与仿真

在电动助力转向系统（EPS）的数学模型和整车八自由度模型基础上,建立了基于Matlab／Simulink的电动助力转向系统仿真模型。基于扭矩输入对电动助力转向系统应用PID进行助力控制。仿真结果表明,所设计的电动助力转向系统在改善转向轻便型和路感的同时,具有很好的抗干扰性能,能提高汽车行驶的操纵稳定性和安全性。     

Velocity and normal tyre force estimation for heavy trucks based on vehicle dynamic simulation considering the road slope angle

A precise estimation of vehicle velocities can be valuable for improving the performance of the vehicle dynamics control (VDC) system and this estimation relies heavily upon the accuracy of longitudinal and lateral tyre force calculation governed by the prediction of normal tyre forces. This paper presents a computational method based on the unscented Kalman filter (UKF) method to estimate both longitudinal and lateral velocities and develops a novel quasi-stationary method to predict normal tyre forces of heavy trucks on a sloping road. The vehicle dynamic model is constructed with a planar dynamic model combined with the Pacejka tyre model. The novel quasi-stationary method for predicting normal tyre forces is able to characterise the typical chassis configuration of the heavy trucks. The validation is conducted through comparing the predicted results with those simulated by the TruckSim and it has a good agreement between these results without compromising the convergence speed and stability.     

动态交通分配中道路阻抗模型的研究

在分析道路阻抗构成的基础上，分析了运用传统的排除论确定交叉口前排队车辆数的局限和不足，根据交通流波动理论，提出了计算交叉口排除车辆数的模型，最后给出了计算路段和交叉口延误的模型。     

中国城市化战略目标

未来5 0年,中国的城市化率将从现在的37%提高到75 %以上。《2 0 0 2 2 0 0 3中国城市报告》提出中国城市化的战略目标主要内容有:用5 0年左右的时间,全面超出世界中等发达国这的城市水平;建成具有容纳1112亿人口的城市容量;形成结构合理、功能互补、整体效益最大化的大、中、小“城市体系”;城市化进程中土地占用面积不得超过国土总面积的2 % ,但其幅射带动的地理空间不得小于自身面积的5 0倍等中国城市化战略目标     

关于汽车取力器选型的几点建议

近几年,我国专用车迅猛发展,对汽车取力器的需求日益增大.但是,由于很多改装厂家和用户对取力器的性能不是很了解,因取力器选型与汽车使用工况不匹配而致使取力器使用寿命缩短,甚至造成质量事故的情况时有发生,给改装厂家及用户带来了诸多不便并造成经济上的损失.针对这些情况,现对汽车取力器的选型做一简单介绍,供改装厂家及用户参考.     

利用Cruise软件进行整车动力性和燃油经济性仿真分析

本文论述了利用CRUISE软件进行汽车建模的过程,并对某重型商用车的动力性和燃油经济性进行了仿真分析。     

汽车铅酸蓄电池SOC的实时估计方法

为应对汽车铅酸蓄电池荷电状态在线估计的需求,分析了现有SOC估计方法不足;在给出Thevenin电路模型基础上,结合铅酸电池的开路电压与SOC关系曲线,获得SOC估计线性化的输出方程,进而提出采一种基于卡尔曼滤波的铅酸电池SOC在线估计方法。通过卷绕式铅酸电池实验和计算结果表明,该算法能够实时估计电池SOC状态,最大误差小于5%,相比于传统的安时积分法更适合用于在线检测。     

电动汽车的新动力

技术专家们正在绞尽脑汁用各种各样方法让电池更新换代,一场电子设备的革命正悄悄来临。在不远的将来,可乐或许就可以帮助汽车行驶几百公里的路程。     

基于DYNAware的车辆稳定性控制仿真研究

使用车辆动力学仿真软件DYNAware／ve—DYNA,建立15自由度的参数化车辆模型,基于稳定性控制原理,以横摆角速度和质心侧偏角为控制变量,采用改进的横摆力矩决策计算方法,用Matlab／simulink建立控制器模型,并通过界面将其导入Ve—DYNA中。最后通过双移线和正弦延迟仿真实验验证了控制策略的有效性。     

特种车新增动力电源技术的应用

针对特种车功能装置动力电源问题,介绍了一种新增动力电源的技术.     

Prediction of ride quality of a Maglev vehicle using a full vehicle multi-body dynamic model

In magnetically levitated (Maglev) transportation systems, especially in electromagnetic suspension system (EMS) type Maglev systems, highly accurate prediction of ride quality is very important in order to reasonably relax guideway construction tolerances or constraints and stiffness while meeting the specification for ride comfort, thereby reducing guideway construction and maintenance costs. A full vehicle multi-body dynamic model is proposed, to facilitate a rigorous ride quality prediction of an EMS-type Maglev vehicle. Using the more realistic dynamic model proposed in this paper, the effects of guideway deflection limits, surface roughness, and levitation control system parameters on ride quality are studied numerically. The results obtained from the simulation studies are then used to facilitate a discussion of the trade-off between guideway smoothness and vehicle suspension. It can be expected that these studies could suggest cost-effective specifications for guideway construction tolerances and stiffness and EMS.     

基于ADAMS/Car汽车动力学仿真

随着计算机技术及计算方法的不断发展,汽车动力学仿真研究经历了由开环研究到闭环研究的过程。在这一过程中,人们根据不同的研究目的,建立了复杂程度不同的汽车模型。同时为了实际应用的方便性,相关科研人员编制了多种专门用于汽车动力学分析的软件,ADAMS/Car是众多软件中最具代表性的一个软件。通过介绍了ADAMS/Car,然后在ADAMS/Car中对某一具体的车型进行虚拟过弯道后撒手运行,并用ADAMS/Car所提供的后处理功能对运行过程中汽车轮胎受力进行分析。     

基于RS的某电源车故障的综合评价

简单介绍了粗糙集理论,在分析、确定某型武器系统电源车故障评判指标体系的基础上,运用粗糙集客观赋权法确定了权重,克服了主观赋权法的不足,建立了电源车故障的RS综合评价模型,得出故障度次序和评价等级。该方法具有一定的实用性,为部队和地方其它设备故障评估提供了一种参考。     

Evaluation of odometry algorithm performances using a railway vehicle dynamic model

In modern railway Automatic Train Protection and Automatic Train Control systems, odometry is a safety relevant on-board subsystem which estimates the instantaneous speed and the travelled distance of the train; a high reliability of the odometry estimate is fundamental, since an error on the train position may lead to a potentially dangerous overestimation of the distance available for braking. To improve the odometry estimate accuracy, data fusion of different inputs coming from a redundant sensor layout may be used. Simplified two-dimensional models of railway vehicles have been usually used for Hardware in the Loop test rig testing of conventional odometry algorithms and of on-board safety relevant subsystems (like the Wheel Slide Protection braking system) in which the train speed is estimated from the measures of the wheel angular speed. Two-dimensional models are not suitable to develop solutions like the inertial type localisation algorithms (using 3D accelerometers and 3D gyroscopes) and the introduction of Global Positioning System (or similar) or the magnetometer. In order to test these algorithms correctly and increase odometry performances, a three-dimensional multibody model of a railway vehicle has been developed, using Matlab-Simulink?, including an efficient contact model which can simulate degraded adhesion conditions (the development and prototyping of odometry algorithms involve the simulation of realistic environmental conditions). In this paper, the authors show how a 3D railway vehicle model, able to simulate the complex interactions arising between different on-board subsystems, can be useful to evaluate the odometry algorithm and safety relevant to on-board subsystem performances.     

适用于汽车转弯制动仿真的轮胎力学模型

通过对轮胎试验结果的分析,用统计拟合方法建立了一种适用于转弯制动联合工况仿真的轮胎力学模型。所建模型与实际情况接近,计算简便,在用理论分析建模困难时,而采用试验数据进行统计建模不失为一种有效的途径。     

基于数值模拟与动态监测的长大公路隧道施工支护优化研究

以河北省张石高速黑石岭隧道为研究对象,采用三维仿真数值模拟方法对隧道软弱破碎围岩段支护方案进行了优化分析研究。并采用现场监控量测对优化方案进行了动态监测,结果与数值模拟结论基本吻合,可见采用数值模拟方法在隧道工程分析上是可行的。     

Fuzzy energy management strategy for a hybrid electric vehicle based on driving cycle recognition

By considering the effect of the driving cycle on the energy management strategy (EMS), a fuzzy EMS based on driving cycle recognition is proposed to improve the fuel economy of a parallel hybrid electric vehicle. The EMS is composed of driving cycle recognition and a fuzzy torque distribution controller. The current driving cycle is recognized by learning vector quantization in driving cycle recognition. The torque of the engine and the motor is controlled by a fuzzy torque distribution controller based on the required torque of the hybrid powertrain and the battery state of charge. The membership functions and rules of the fuzzy torque distribution controller are optimized simultaneously by using particle swarm optimization. Based on the identification results of driving cycle recognition, the fuzzy torque distribution controller selects the corresponding membership function and rule to control the hybrid powertrain. The simulation research based on ADVISOR demonstrates that this EMS improves fuel economy more effectively than fuzzy EMS without driving cycle recognition.