汽车半挂列车稳态转向特性的研究

本文对汽车半挂列车的稳态转向特性进行了研究和分析;提出了评价方法,并得到了试验验证;它对汽车半挂列车操纵稳定性的研究和如何设计好汽车半挂列车的行驶方向稳定性有参考价值。     

汽车半挂列车稳态转向特性的研究

本文对汽车半挂列车的稳态转向特性进行了研究和分析;提出了评价方法,并得到了试验验证;它对汽车半挂列车操纵稳定性的研究和如何设计好汽车半挂列车的行驶方向稳定性具有参考价值。     

基于Matlab的半挂汽车列车侧倾稳定性分析

针对重型半挂汽车列车侧倾稳定性问题,在Matlab/simulink中建立了重型半挂汽车列车的数学模型及动力学仿真模型,并进行了转向盘阶跃转向输入下的牵引车驱动轴横向载荷转移仿真分析.仿真结果表明,牵引车驱动轴为侧倾稳定性危险车轴.通过分析不同车速和车辆结构参数时牵引车驱动轴载荷转移的变化情况,得到重型半挂汽车列车侧倾稳定性与车辆主要结构参数及不同车速间的关系.     

基于ADAMS/Car的半挂汽车列车转向瞬态响应试验仿真分析

运用多体动力学软件ADAMS/Car建立某半挂汽车列车虚拟试验整车模型,参照汽车操纵稳定性试验方法对该半挂汽车列车进行转向瞬态响应试验仿真,分析得到了半挂汽车列车在不同速度下的侧向加速度和横摆角速度响应、转向瞬态响应试验的极限车速及半挂汽车列车安全运行的最大侧倾角,为半挂汽车列车的设计和使用提供理论依据.     

半挂汽车列车操纵特性与横向稳定性的研究

采用牵引车和半挂车的不足转向梯度独立定义的方式对半挂汽车列车的操稳性进行了研究,分析了车辆的结构参数对不足转向梯度的影响.应用动态系统的稳定性理论,探讨了“折叠”和“横向摆振”失稳与其操纵特性间的关系.结果表明,与两轴单体汽车只会发生单调分歧失稳相比,半挂汽车列车还会发生“横向摆振”失稳,具体的失稳形式与牵引车和半挂车的不足转向梯度以及车辆结构参数密切相关.     

半挂牵引车牵引座强度设计及整车稳定性分析

文章以半挂牵引车牵引座强度设计及整车稳定性分析为研究对象,首先对半挂牵引车牵引座工作原理进行了简单的介绍,随后对半挂牵引车牵引座强度设计优化进行了系统的探讨与分析,最后讨论了影响半挂牵引车整车稳定性因素,以供参考.     

基于主动制动的半挂汽车列车横摆稳定性控制

为研究半挂汽车列车在高速大转向等极限操作工况下的横摆稳定性控制问题,建立了14自由度的半挂汽车列车非线性仿真模型;提出了牵引车与半挂车独立直接横摆力矩控制的横摆稳定性控制方案,通过牵引车和半挂车车轮的合理选择和主动制动实现横摆控制;以跟踪参考模型的稳态横摆响应为目标,设计了PI横摆稳定性控制器,对牵引车和半挂车分别设计了目标制动车轮的选择决策规则。单移线操作仿真结果表明,基于主动制动的横摆力矩控制可有效改善极限工况下半挂汽车列车的横摆稳定性,牵引车与半挂车进行独立横摆控制可以减小制动车轮选择决策的复杂性,而获得较好的控制效果。     

普通半挂牵引车驾驶室舒适性评价

由于传统半挂牵引车驾驶室采用的是半悬浮被动悬置,减振效果不好,对于经常进行中长途运输的半挂牵引车司机而言,连续较长时间的驾驶会使司机暴露于机械性全身振动(WBV)之中。由于目前还没有确凿的证据证明半挂牵引车司机的腰痛等职业病与全身振动有直接关联,故为探索有关驾驶半挂牵引车的健康风险程度进行了试验验证。对同一辆试验车在不同路面、载荷和车速的多工况下进行了研究,并将试验结果与标准GB/T 13441.1-2007附录B中的健康指南警告区域进行了对比。研究表明,在当前的行驶条件下,我国半挂牵引车司机每天的连续驾驶时间最多不应超过5.5 h。     

基于ADAMS的某重型牵引车操纵稳定性仿真分析

以某6×4重型牵引车为分析对象,采用ADAMS建立了整车的仿真模型,根据国标《汽车操纵稳定性指标限值与评价方法》,进行整车操纵稳定性仿真试验,从不同角度反映在运动过程中的稳态响应和瞬态响应,综合评价牵引车的操纵稳定性。同时,通过对牵引车的前悬架钢板弹簧刚度和整车载荷等参数参数的变化,研究了不同状态下参数的变化对操纵稳定性所造成的影响。     

转向盘转角阶跃输入下半挂汽车列车操纵稳定性仿真分析

基于包括任意载荷分布的非线性轮胎模型在内的半挂汽车列车整车模型,应用汽车列车动力学仿真软件Arc Sim,分析了半挂汽车列车在转向盘转角阶跃输入时的转向特性。通过在不同车速、不同结构参数等条件下的仿真计算,揭示了半挂汽车列车的转向特性与车速、结构参数之间的内在联系,给出了半挂汽车列车转向特性在这些条件下的表现特征,为半挂汽车列车操纵稳定性分析提供了参考和借鉴。     

High-speed optimal steering of a tractor–semitrailer

A high-speed optimal trailer steering controller for a tractor–semitrailer is discussed. A linear model of a tractor–semitrailer with steered trailer axles is described, and an optimal trailer steering controller is introduced. A path-following controller is derived to minimise the path-tracking error in steady-state manoeuvres using active trailer steering. A roll stability controller is introduced by adding the lateral acceleration of trailer centre of gravity as another objective in the steering controller, so as to improve roll stability in transient manoeuvres. A strategy to switch between these two control modes is demonstrated. Simulation results show that the steering controller can ensure good path tracking of articulated vehicles in steady-state manoeuvres and improve roll stability significantly in transient manoeuvres, while maintaining the path-tracking deviation within an acceptable range. Tests with an experimental tractor–semitrailer equipped with a high-bandwidth active steering system validate the controller design and simulation results. The roll stability controller reduces the measured rearward amplification by 27%.     

牵引车、半挂车ABS道路试验及计算方法

ABS试验作为强制实施项目，受到汽车生产企业和检测部门的关注，牵引车、半挂车ABS试验往往连接在一起进行，与其它的机动车试验相比具有一定的特殊性，尤其是计算方法有所不同。详细介绍了半挂车空载、半挂车满载、牵引车满载工况的试验和计算方法，并以实例进行了说明。     

Kinematic and dynamic analysis of a heavy truck with individual front suspension

The main focus of this work is on the characteristics of a commercial vehicle with individual front suspension (IFS). Both kinematic and dynamic properties of the vehicle are investigated through simulations and analytical expressions. Moreover, employing the model of the tractor semitrailer combination, the study presents the results of comparison between the trucks with IFS and rigid front axle with respect to comfort and handling. This is done by analysing the responses of the vehicles to different road and steering inputs. The obtained results show enhanced comfort and steering feeling for the truck with IFS.     

基于整车建模的半挂牵引车有限元分析

在调研国内外相关研究的基础上,对某半挂牵引车整车结构进行了建模,并对该牵引车进行了静态电测试验,为有限元分析提供实践依据,同时验证了有限元模型的正确性。利用已验证的有限元模型,分析了该牵引车在弯曲工况、扭转工况、紧急制动工况和紧急转弯工况下的应力分布和变形情况,同时对该牵引车整车结构进行了模态分析。     

牵引车和半挂车联合辅助制动设计

针对装有辅助制动装置的牵引车在下坡过程中不能与半挂车协调实现减速和制动常引起冲撞和折叠等不安全的现象,提出了一种可以实现牵引车和半挂车联合辅助制动的设计方案即通过控制器使半挂车预先制动,再按设定的速度实现汽车列车稳速下坡。     

A method to find correlations between steering feel and vehicle handling properties using a moving base driving simulator

There have been several investigations to find out how drivers experience a change in vehicle-handling behaviour. However, the hypothesis that there is a correlation between what the driver perceives and vehicle- handling properties remains to be verified. To define what people feel, the human feeling of steering systems was divided into dimensions of perception. Then 28 test drivers rated different steering system characteristics of a semi-trailer tractor combination in a moving base-driving simulator. Characteristics of the steering system differed in friction, damping, inertia and stiffness. The same steering system characteristics were also tested in accordance with international standards of vehicle-handling tests resulting in characteristic quantities. The instrumental measurements and the non-instrumental ratings were analysed with respect to correlation between each other with the help of regression analysis and neural networks. Results show that there are correlations between measurements and ratings. Moreover, it is shown that which one of the handling variables influence the different dimensions of the steering feel.     

Automotive Stability and Handling Dynamics in Cornering and Braking Maneuvers

SUMMARY

Automotive steering behaviour is classified for steady-state cornering and the definitions of over-/understeer and stability/instability are well known. In this paper it is intended to apply these definitions to combined cornering and braking maneuvers i.e. to extend the criteria to quasi-steady-state conditions. This way of investigation was chosen because it gives a clear idea of the typical handling behaviour. Furthermore, the vehicle behaviour is analyzed using the cornering stiffness of the axles and front/rear cornering stiffness ratio because this is always of primary significance. The following contribution is based on a theoretical analysis considering the most important non-linear vehicle properties.

The paper deals with two groups of vehicles: single vehicles (passenger cars) and combinations (passenger car/caravan and tractor/semitrailer). In the case of combinations the effect of trailers on the towing vehicles is examined. So, careful attention is paid to the coupling forces, which alter the wheel loads and influence steerability and stability.     

Sideslip estimation for articulated heavy vehicles at the limits of adhesion*

Various active safety systems proposed for articulated heavy goods vehicles (HGVs) require an accurate estimate of vehicle sideslip angle. However in contrast to passenger cars, there has been minimal published research on sideslip estimation for articulated HGVs. State-of-the-art observers, which rely on linear vehicle models, perform poorly when manoeuvring near the limits of tyre adhesion. This paper investigates three nonlinear Kalman filters (KFs) for estimating the tractor sideslip angle of a tractor–semitrailer. These are compared to the current state-of-the-art, through computer simulations and vehicle test data. An unscented KF using a 5 degrees-of-freedom single-track vehicle model with linear adaptive tyres is found to substantially outperform the state-of-the-art linear KF across a range of test manoeuvres on different surfaces, both at constant speed and during emergency braking. Robustness of the observer to parameter uncertainty is also demonstrated.     

EQ2102越野汽车前轮摆振影响因素试验分析及改进措施

针对东风EQ2102型独立悬架越野汽车的前轮摆振问题进行了道路试验分析,研究了前轮失衡量、转向系统阻尼和刚度对前轮摆振的影响。试验及分析表明,该车摆振主要为强迫振动,通过控制激振源、增大转向系统阻尼可抑制摆振。提出了采用阻尼轴承代替主销滚针轴承来增大转向阻尼的解决方案,同时评估了阻尼轴承对汽车操纵稳定性的影响。     

装备EPS系统特锐样车操纵稳定性客观评价

对装备电动助力转向(EPS)系统的整车操纵稳定性进行评价的必要性进行了分析,介绍了装备EPS的整车操纵稳定性评价的具体内容。给出装备EPS的特锐样车原地转向轻便性、转向盘中间位置操纵稳定性、转向回正性、转向瞬态响应特性(转向盘转角脉冲输入)的试验方法和标准,对其操纵稳定性进行了评价。评价结果表明,所采用的评价方法有效、可行。