轮胎滚动阻力试验系统研究

许多汽车性能试验均在底盘测功机上进行，而轮胎滚动阻力是影确测试精度的重要原因。由于目前我国大多数企业均使用双滚筒式底盘测功机，所以设计双滚筒式测功机上轮胎滚动阻力测试系统，将为台试轮胎滚动阻力特性研究奠定基础。双滚筒式试验台上测试轮胎滚动阻力采用反拖法实现，滚动阻力测试系统由双滚筒式底盘测功机改制而成。通过对加载方式、误差处理方法、系统测试精度等问题的探讨，验证了系统的可靠性和准确性。     

汽车轮胎滚动阻力试验机测试方法分析

为了对汽车轮胎滚动阻力测试方案的可行性进行预先评估,基于检测设备的结构模型,提出了一种运用位移量对轮胎滚动阻力进行仿真分析的新方法。在简述滚动阻力有限元测试模型构建过程的基础上,通过改变轮胎的外部使用参数,分析传感器板在不同工况下位移场的分布情况,制定了设备的测试方案。以传感器的安装位置作为目标检测点,建立轮胎滚动阻力位移场与控制参数之间的关系曲线。最后将采集的数据经过平均滤波处理,与实验室的实测数据进行了趋势性对比。结果表明：采用该测试方法,轮胎滚动阻力随着轮胎负载和速度的增加而增大,随着气压的变大而减小;仿真结果和试验数据在相同工况下的变化趋势基本一致;该测试方法合理、可行。     

轮胎滚动阻力有限元仿真模拟研究

近年来随着汽车产业的飞速发展,汽车制造商开始对轮胎提出降低滚动阻力的要求,低滚动阻力轮胎已成为各大轮胎公司重点关注的课题。本文采用ABAQUS软件,开发轮胎滚动阻力有限元仿真模型,用于预测轮胎的滚动阻力和滚动阻力系数,并和试验结果进行对比,验证了模型的可靠性。     

台试轮胎滚动阻力研究

双滚筒上轮胎滚动阻力损耗功率对汽车动力性测试精度起关键作用，本文建立了轮胎滚动阻力与胎压、车速、载荷、双滚筒试验台滚筒直径及间距之间的函数关系，实现了用数学模型表述轮胎滚动阻力与这些影响因素的内在关系，为汽车动力性评价奠定了基础。     

双滚筒上轮胎滚动阻力模型

双滚筒上轮胎滚动阻力损耗功率对汽车动力性测试精度起关键作用，本文建立轮胎滚动阻力与胎压、车速、栽荷、双滚筒试验台滚筒直径及间距之间的函数关系，实现用数学模型表述轮胎滚动阻力与这些影响因素的内在关系：试验表明，各因素对轮胎滚动阻力的影响是非线性的，且影响程度及规律也各不相同。本文研究为汽车动力性评价奠定了基础。     

基于神经网络方法的台试轮胎滚动阻力模型研究

采用反拖测试方法,在双滚筒式底盘测功机上进行了大量有关轮胎滚动阻力影响因素(包括胎压、速度、载荷、胎温及轮胎的型号等)的交叉试验。以这些因素作为神经网络的训练输入参数,建立了台试轮胎滚动阻力神经网络模型。通过试验验证,用神经网络模型预估基于双滚筒测试的轮胎滚动阻力误差小于4%,为利用底盘测功机准确测试汽车动力性等工作奠定了基础。     

利用轮胎模态参数模型对滚动阻力的模拟

利用轮胎模态参数模型对稳态工况下的轮胎滚动阻力进行模拟.计算了不同胎面阻尼下的滚动阻力,所得结果与实际的趋势相符,数值合理.对不同半径转鼓下轮胎滚动阻力的模拟结果与按ISO 181964推荐的公式计算的结果有良好的一致性.表明了该轮胎模型的合理性.     

充气轮胎的滚动阻力与汽车燃料消耗的关系

本文分析了轮胎滚动阻力产生的原因,详尽地探讨了轮胎结构、材料及其使用条件对滚动阻力的影响,指出了降低轮胎滚动阻力的途径。     

客车轮胎滚动阻力与电动客车续驶里程关联性研究

文章简单概括了轮胎滚动阻力产生的机理及滚动阻力对车辆经济性的影响,采用轮胎台架试验与实车试验相结合的方法,针对轮胎滚动阻力的大小对电动车续驶里程的影响进行了探究,结果表明,降低轮胎滚动阻力是增加电动车续驶里程的重要方法之一。     

降低阻力 节能减排

轮胎滚动阻力 轮胎滚动阻力主要是由于车轮滚动时轮胎与路面的变形而产生的。弹性车轮沿硬路面滚动时,路面变形小、轮胎变形大;车轮沿软路滚动时,路面变形大、轮胎变形小。车轮滚动时产生的变形要消耗发动机的动力,从而形成滚动阻力,其数值与汽车的总重,轮胎的结构和气压,以及路面性质有关。     

Design of a signal transducer for direct conversion of wheel linear accelerations into tire lateral forces

This paper describes a design of a real-time conversion system of wheel linear accelerations into tire lateral forces. Though the tire lateral forces are important elements for analyzing vehicle dynamic control performances, they cannot be easily measured in real-time owing to the non-linearities of tire dynamics, friction, and slippage on road. In this paper, we propose a practical direct method using wheel linear accelerations in order to estimate tire lateral forces transmitted into the vehicle in real-time. A simplified vehicle model based on force-acceleration analysis is proposed to assure the real-time performance. The acceleration values are obtained using three-axis accelerometers attached on each wheel location. For conditioning and rectifying the acceleration signals, a signal transducer is designed using a digital filter. And in order to investigate the feasibility and real-time performance, a prototype of signal transducer is fabricated using a digital signal processor. The experimental results and performance are validated with the road test results using six-component wheel force transducers.     

Electronic stability control for electric vehicle with four in-wheel motors

The electric vehicle with four direct-driven in-wheel motors is an over actuated system. A three-level control strategy of electronic stability control (ESC) is proposed to achieve optimal torque distribution for four in-wheel motors. The first level is a gain-scheduled linear quadratic regulator which is designed to generate the desired yaw moment command for ESC. Control allocation is the second level which is used to distribute the desired longitudinal tire forces according to the yaw moment command while satisfying the driver’s intent for acceleration and deceleration. The associated weighting matrix is designed using the work load ratio at each wheel to prevent saturating the tire. The third level is slip ratio control (SRC) which is employed at each wheel to generate the desired longitudinal tire force based on a combined-slip tire model. Simulation results show that the proposed method can enhance the ESC performance for the test maneuvers. Since the tire model is often unknown for practical implementation, the effectiveness of the SRC is studied using the sine with dwell test. It is found that the SRC is not crucial for achieving performance similar to the proposed method with SRC, if the slip ratio can be maintained in the stable region using traction control system/anti-lock braking system.     

Approximate Dynamic Shimmy Response of Pneumatic Tires*

An improved approximation of the theory of the dynamic frequency response of side force and aligning torque acting upon the rolling wheel when the latter is moved laterally and swivelled about the vertical axis, is presented. The method is particularly suitable for application in vibration problems of steering and suspension systems of automobiles and aircraft where relatively high speed and high frequency phenomena play a role. The theoretical results show satisfactory agreement with experimental data. Calculations indicate that the inertia of the tire decreases the tendency to shimmy at higher frequencies and speeds of travel. For castered wheels however, tire inertia may have an adverse effect due to its unfavorable influence upon the side force response to swivel motions.     

The Wheel Shimmy Problem: Its Relationship to Wheel and Road Irregularities

The equations of motion are derived for a single wheel steerable pneumatic tire system. Included in this system are a built-in wheel wobble and wheel-tire irregularities which produce oscillation of the normal load. Special emphasis is placed on the dynamic characterization of the tire cornering force and aligning torque. The results show that the built-in wheel wobble causes a steady shimmy which is large when the wheel rotation frequency is close to the natural shimmy frequency. The results also show that a normal load oscillation which has a frequency approximately twice the natural shimmy frequency causes a decrease in shimmy stability.     

面向越野汽车通过性虚拟试验的有限元轮胎模型研究

分析了胎压与粘弹性对轮胎模型的影响,提出利用系数修正胎压对刚度和有效接地面积的影响来提高精度的方法。推导了三参数标准线性粘弹性模型的本构关系,得到了四节点等参单元有限元的刚度矩阵,建立了轮胎平面应力状态下的有限元模型。以轮胎六分力传感器为核心构建了轮胎模型的标定和验证系统,标定并验证了该轮胎模型的正确性。     

基于环模型的轮胎有限元建模与仿真研究

为了提高仿真模型的计算效率,基于环模型理论系统研究了轮胎二维有限元模型的建模技术、参数确定方法和轮胎包容特性分析技术.从试验与仿真结果对比分析可知,利用有限元方法基于轮胎REF模型建模,在对轮胎胎侧弹性进行非线性模型修正后,得到的轮胎低速滚动仿真结果与试验结果基本吻合,验证了轮胎模型的有效性,同时为车辆一地面系统虚拟试验提供了一种实时高精度的轮胎面内特性仿真建模方法.     

The Wheel Shimmy Problem: Its Relationship to Wheel and Road Irregularities

SUMMARY

The equations of motion are derived for a single wheel steerable pneumatic tire system. Included in this system are a built-in wheel wobble and wheel-tire irregularities which produce oscillation of the normal load. Special emphasis is placed on the dynamic characterization of the tire cornering force and aligning torque. The results show that the built-in wheel wobble causes a steady shimmy which is large when the wheel rotation frequency is close to the natural shimmy frequency. The results also show that a normal load oscillation which has a frequency approximately twice the natural shimmy frequency causes a decrease in shimmy stability.     

Method for measuring force transmitted from road surface to tires and its applications

The force transmission from road surface to a rolling tire has been successfully measured by force measurements on suspension parts and correction for interia forces of suspension parts. The results of the measurement have shown that the force from road to tire has a sharp directivity, which is inclined rearward in side view, within the frequency range between 5 and 15 Hz. And the inclination angle of the direction of action has been found to be dependent on the vehicle velocity. As the application of the finding, the optimal wheel center locus inclination in side view has been studied, to minimize the longitudinal force transmission. And the optimum angle has been confirmed to exist.     

用于公路车-桥系统振动分析的精细化轮胎模型

为了解决当前公路车桥耦合振动模型中轮胎模型过于简化、车轮-路面接触力与桥梁响应计算结果不够精确的问题,提出了一种精细化轮胎模型.首先基于车辆橡胶轮胎的几何、力学特征,建立了径向弹簧力学模型并进行了理论推导;然后考虑轮胎与路面接触面的刚度分布特征和高速状况下轮胎的惯性力,提出了轮胎接触面分布刚度的计算方法,保证了轮胎接触...