轻型货车轮胎接地压力分布实测

利用自主开发的轮胎接地压力测试仪,进行了轻型货车不同花纹和不同使用年限轮胎,在不同轮胎胎压和不同负荷作用下,轮胎的接地压力分布规律测量。实测结果发现:轻型货车轮胎与路面的接触形状更接近于矩形;新胎比旧胎的接地压力要均匀些;轮胎胎压与平均接地压力、轮胎负荷与平均接地压力、轮胎负荷与有效接地面积基本上呈线性关系。     

An optical tire contact pressure test bench

An optical tire contact pressure test bench developed by the IMMa group is described. The measurement system is based on the frustration of total internal reflection (FTIR) of light. The test bench allows performing normal pressure distribution and patch contact shape measurements on passenger car tires. The system is based on the use of a laterally illuminated glass on which the tire leans. Between them a plastic interphase is located that will cause the FTIR of light. A video camera catches the formed shining image through the glass. The brightness level in each pixel of the image can be related to the existing normal pressure. The study of the contact patch provided by the bench makes it possible to characterize tire behaviour under different loading states, inflation pressure, tire defects and toe and camber angles. The bench incorporates a computerized load and control system of the tire operation parameters, an image acquisition module and a data acquisition system that allow monitoring and acting on the experimental variables of interest in the tests such as load on the tire and environmental conditions. A supporting mechanical system incorporated to the bench allows providing the tire with variable toe and camber angles. From the images obtained with this system, the maximum normal pressure points, total force, size and shape of the patch can be determined, which are related to the tire-use conditions. As an application example, results that show the patch size and shape under different load and tire inflation pressures are presented. A further application, which is the use of the system for the detection and study of defective tires is also presented.     

An optical tire contact pressure test bench

An optical tire contact pressure test bench developed by the IMMa group is described. The measurement system is based on the frustration of total internal reflection (FTIR) of light. The test bench allows performing normal pressure distribution and patch contact shape measurements on passenger car tires. The system is based on the use of a laterally illuminated glass on which the tire leans. Between them a plastic interphase is located that will cause the FTIR of light. A video camera catches the formed shining image through the glass. The brightness level in each pixel of the image can be related to the existing normal pressure. The study of the contact patch provided by the bench makes it possible to characterize tire behaviour under different loading states, inflation pressure, tire defects and toe and camber angles. The bench incorporates a computerized load and control system of the tire operation parameters, an image acquisition module and a data acquisition system that allow monitoring and acting on the experimental variables of interest in the tests such as load on the tire and environmental conditions. A supporting mechanical system incorporated to the bench allows providing the tire with variable toe and camber angles. From the images obtained with this system, the maximum normal pressure points, total force, size and shape of the patch can be determined, which are related to the tire-use conditions. As an application example, results that show the patch size and shape under different load and tire inflation pressures are presented. A further application, which is the use of the system for the detection and study of defective tires is also presented.     

Two-Dimensional Contact Area of a Pneumatic Tire Subjected to a Lateral Force

A mathematical model of a two-dimensional contact patch of pneumatic tires rolling over a rigid flat road surface at arbitrary slip and camber angles has been developed. The model is simple in concept, contains few parameters and is applicable to any tire simulation models. In addition to tire geometric parameters and vertical deflection, the carcass camber angle is introduced in the model. This angle is alone responsible for the asymmetric shape of the tire contact patch when the tire undergoes a lateral force. The computed contact patches agree well with the measured patches of an automotive tire at different slip and camber angles. Lastly, the influence of the contact patch geometry on the tire cornering and aligning properties has been discussed through a computational example. It has been shown that the effect of tire contact patch geometry on the steady state behavior is rather remarkable.     

轮胎制动力—滑移率特性的动态模型研究

轮胎制动力及滑移率对制动力矩的响应存在着显著的低频衰减振荡现象，这从制动力－滑移率特性曲线上看，表现为一系列的以稳态点为中心的旋涡状过渡曲线。这是稳态的轮胎模型所不能描述的。本文在稳态ｂｒｕｓｈ轮胎模型基础上，通过印迹前端蹼处胎冠一阶变形模型，建立了轮胎制动力－滑移率的动态模型，并根据转鼓试验台上的轮胎制动试验，验证了该模型的仿真效果。     

A Motorcycle Multi-Body Model for Real Time Simulations Based on the Natural Coordinates Approach

This paper presents an eleven degrees of freedom, non-linear, multi-body dynamics model of a motorcycle. Front and rear chassis, steering system, suspensions and tires are the main features of the model. An original tire model was developed, which takes into account the geometric shape of tires and the elastic deformation of tire carcasses. This model also describes the dynamic behavior of tires in a way similar to relaxation models. Equations of motion stem from the natural coordinates approach. First, each rigid body is described with a set of fully cartesian coordinates. Then, links between the bodies are obtained by means of algebraic equations. This makes it possible to obtain simple equations of motion, even though the coordinates are redundant. The model was implemented in a Fortran code, named FastBike . In order to test the code, both simulated and real slalom and lane change maneuvers were carried out. A very good agreement between the numerical simulations and experimental test was found. The comparison of FastBike 's performance with those of some commercial software shows that first is much faster than others. In particular, real time simulations can be carried out using FastBike and it can be employed on a motorcycle simulator.     

基于逆向工程技术的轮胎3D模型设计研究

以195/65R15规格的轮胎为例,利用三维激光扫描仪对轮胎进行扫描,通过CATIA软件对所得点云数据进行处理,实现曲面重构,建立了轮胎的3D模型.对依据逆向工程技术建立的轮胎3D模型特征尺寸与轮胎实物测量尺寸比较分析表明,所建模型与实际轮胎外形吻合良好,可为进行轮胎特性研究提供参考.     

基于TPMS的轮胎自动降压技术的研究

设计了TPMS系统并提出了一种新型的先导式自动降压电磁阀的设计思想。该系统可实现胎压的实时监测并基于TPMS获得的实时数据实现轮胎的自动降压。     

直接式TPMS在某款乘用车上的应用介绍

直接式的胎压检测系统(TPMS)能精确测量轮胎内的压力和温度,该系统在一个或多个轮胎气压不足时能提醒驾驶员。本文介绍胎压检测系统总览,主要零部件功能,TPMS在某款乘用车上的匹配应用、故障诊断及问题的处理。开发的TPMS样件,其性能测试结果达到了技术要求。样件在某款样车上实际试装测试,结果符合设计要求,可以批量生产。     

基于车路系统的事故现场轮胎印迹强度参数化研究

为明确事故现场可视轮胎印迹强度与车辆动力学特性、轮胎橡胶磨损特征及道路表面灰度之间的关联特性,提出基于车路耦合的事故现场轮胎印迹强度参数化研究方法。通过结合动态滑动摩擦因数模型及轮胎非线性模型,建立车辆路面9 DOF非线性系统动力学模型,运用VBOX惯性测量技术验证模型的有效性。运用胎面磨损能量模型,从车路系统角度确定车辆、轮胎和路面特性对轮胎全局摩擦力及胎面磨损特性的影响。结合印迹强度特征模型提出轮胎印迹强度参数研究方法,选取不同制动、转向角工况及3组路面、胎面特性对轮胎路面接地力学特性、胎面橡胶磨损量、可视轮胎印迹特征进行仿真分析。结果表明：印迹强度仅与全局摩擦力大小有关,与轮胎路面滑移方向无关;滑移工况下胎面橡胶磨损量随着全局摩擦力和滑移速度的增大而增大,而印迹强度变化不明显;制动力矩和道路表面灰度对产生可视轮胎印迹起决定作用,转向角主要影响不规则可视轮胎印迹的产生;前轮轮胎最先出现可视印迹,且可视印迹长度和强度均高于后轮轮胎;采取可视印迹起点作为事故车辆速度判定具有一定的误差,应根据具体情况进行具体分析;研究成果能够为基于可视轮胎印迹的交通事故重建提供理论基础。     

基于径向刚度法的车辆翻新轮胎使用寿命判定

为了有效判定车辆翻新轮胎的剩余使用寿命，需要科学确定废旧轮胎胎体橡胶老化程度对翻新轮胎使用寿命的影响。在分析废旧轮胎胎体橡胶老化规律的基础上，通过橡胶老化试验测试及回归分析，确定了胎体弹性模量随着橡胶老化年限增加近似线性增大的影响规律；结合计算机仿真技术及试验测试技术，基于轮胎径向刚度法提出了翻新轮胎剩余使用寿命不安全系数计算方法，其计算数值大小与翻新轮胎径向刚度和新轮胎径向刚度之差成正比，与新轮胎径向刚度值成反比；构建了由橡胶加速老化系统、弹性模量测取系统、承载-变形计算机模拟系统和承载-变形测试系统等组成的翻新轮胎剩余使用寿命判定系统；基于径向刚度法和判定系统提出了车辆翻新轮胎剩余使用寿命判定规则，确定了翻新轮胎胎体剩余使用寿命判定具体流程；根据剩余使用寿命不安全系数计算方法和判定规则，将翻新轮胎确定为可正常使用、需降速使用和需报废处理3个级别，并利用11.00R22.5载重车辆翻新轮胎进行了剩余使用寿命判定与评价，依据判定规则分别计算了不同使用年限3条翻新轮胎的剩余使用寿命不安全系数，确定出3条翻新轮胎所对应的级别，判定与评价结论与实际使用情况相吻合。研究结果表明：废旧轮胎胎体橡胶老化程度对翻新轮胎剩余使用寿命影响显著，翻新轮胎径向刚度与剩余使用寿命之间存在较大影响关系；废旧轮胎胎体橡胶老化程度越严重和径向刚度越大，翻新轮胎的剩余使用寿命将会越短。     

高速滚动汽车轮胎稳态温度场分布的数值研究

建立了滚动轮胎热平衡状态下的简化传热数学模型。应用自行开发的传热和热弹性力学分析有限元软件对中型载货车用9．OO一20(12P．R)尼龙斜交胎进行了稳态温度场仿真计算，获得了胎体内部的稳态温度场分布。分析了轮眙的速度、几何结构参数及材料特性参数对轮胎最高温升的影响，通过回归分析建立了该轮胎速度与最高温升的经验计算公式。     

Scaled vehicle tire characteristics: dimensionless analysis

This article demonstrates the use of dimensional analysis for scaled vehicle tires. The motivation for this approach is the understanding of realistic nonlinear tire behavior in scaled vehicle control studies. By examining the behavior of vehicle tires within a dimensionless framework, several key tire parameters are developed that allow for an appropriate relationship between full-sized tires and scaled tires. Introducing these scalings into vehicle dynamics studies allows for the development of scaled vehicles that have a high degree of dynamic similitude with full-sized vehicles, but are safer and more economical testbeds on which to develop experimental control strategies. Experimental data are used to compare the nonlinear characteristics for sets of scaled and full-sized tires. Finally, design of a scaled vehicle based on tire characteristics is demonstrated.     

浅谈中央充放气系统充放时间计算

本文针对不同容积轮胎及充气压力下充放气系统所需充放时间进行计算,使其根据气温,路面状况的不同,自动调节控制轮胎气压,产生最大附着力而又不至于产生过大阻力,保证汽车始终保持最合理的运动状态,提高车辆的地面通过性和工作效率。     

Experimental study on mobility of a vehicle with CTIS in soft soil

Recently, the domestic military vehicles currently being developed are installed with a central tire inflation system (CTIS) to control the pressure of tires to increase the contact area between the tires and the ground and improve mobility on soft soils. On the other hand, it is difficult to find technical data based on experiments for designing a CTIS. In this study, to obtain the technical data to set proper pressures according to road conditions a range of mobility tests were performed on soft soil roads, such as sand and clay, according to the CTIS operating modes to obtain the technical data to set proper pressures according to the road conditions. The characteristics of the mobility and its correlation with the tire pressures in each operating mode were analyzed. The results confirmed that a wheeled vehicle with a CTIS showed better performance on soft soil than a vehicle without a CTIS.     

工程车辆翻新轮胎承载变形特性

为了进一步明确工程车辆翻新轮胎的力学性能,提高其使用寿命,通过构建工程车辆翻新轮胎计算机几何模型、有限元分析模型、承载变形特性试验系统,对工程车辆翻新轮胎承载变形特性进行有限元分析及试验研究,并与同型号新轮胎进行对比分析,获得静态接地工况下工程车辆翻新轮胎的载荷-变形、载荷-刚度、载荷-压缩率等特性规律,构建26.5R25工程车辆翻新轮胎径向承载变形数学模型。研究结果表明：工程车辆翻新轮胎的径向变形、侧向变形变化规律与新轮胎接近,径向与侧向变形均比同型号新轮胎稍小;当胎压一定时,随着载荷的增加,工程车辆翻新轮胎径向变形呈线性增大,当胎压较低时侧向变形呈线性增大,当胎压较高时侧向变形呈非线性增大;工程车辆翻新轮胎的径向刚度及压缩率受径向载荷和胎压的影响较大,载荷一定时,径向刚度随胎压的增大而增大;胎压一定时,工程车辆翻新轮胎的压缩率随径向载荷的增大而增大,且稍小于同品牌、同型号新轮胎的压缩率;旧胎体的不同老化程度对工程车辆轮胎翻新后的承载-变形特性会产生较大的影响;在低载工况下,工程车辆翻新轮胎和新轮胎径向刚度差异不大,在接近标准载荷及高载工况下,工程车辆翻新轮胎径向刚度较新轮胎大,且随着载荷的增大,工程车辆翻新轮胎和新轮胎径向变形差异不断加大。     

Sideslip angle estimation based on input–output linearisation with tire–road friction adaptation

An adaptive sideslip angle observer considering tire–road friction adaptation is proposed in this paper. The single-track vehicle model with nonlinear tire characteristics is adopted. The tire parameters can be easily obtained through road test data without using special test rigs. Afterwards, this model is reconstructed and a high-gain observer (HGO) based on input–output linearisation is derived. The observer stability is analysed. Experimental results have confirmed that the HGO has a better computational efficiency with the same accuracy when compared with the extended Kalman filter and the Luenberger observer. Finally, a road friction adaptive algorithm based on vehicle lateral dynamics is proposed and validated through driving simulator data. As long as the tires work in the nonlinear region, the maximal friction coefficient could be estimated. This algorithm has excellent portability and is also suitable for other observers.     

客车轮胎建模和对侧倾稳定性的影响研究

客车轮胎与客车整车的侧倾稳定性有密切联系,ADAMS是典型的动力学虚拟样机仿真软件。介绍了在ADAMS中建立非线性轮胎的方法,在ADAMS中建立客车整车模型,通过改变整车模型中轮胎的刚度和阻尼,研究客车轮胎对整车侧倾稳定性的影响,从而为设计出符合性能要求的客车轮胎提供一定的理论依据。     

Dynamic Properties of Motorcycle and Scooter Tires: Measurement and Comparison

Summary Results of an experimental research program dealing with motorcycle and scooter tires are presented. Experimental tests were carried out by means of a rotating disk test machine, which is particularly suited to test tires in the presence of large camber angles. First, the capabilities of the rotating disk machine are discussed and results are compared with the ones obtained by means of other test machines. Then the properties of several motorcycle and scooter tires are presented and compared. The advantage of presenting results in terms of camber and sideslip stiffness is highlighted. The effect of tire working conditions (inflation pressure, load and temperature) is analyzed. Finally the measurement of tire torques is discussed and some results dealing with self-aligning, twisting and rolling resistance torques are presented.     

Dynamic Properties of Motorcycle and Scooter Tires: Measurement and Comparison

Summary Results of an experimental research program dealing with motorcycle and scooter tires are presented. Experimental tests were carried out by means of a rotating disk test machine, which is particularly suited to test tires in the presence of large camber angles. First, the capabilities of the rotating disk machine are discussed and results are compared with the ones obtained by means of other test machines. Then the properties of several motorcycle and scooter tires are presented and compared. The advantage of presenting results in terms of camber and sideslip stiffness is highlighted. The effect of tire working conditions (inflation pressure, load and temperature) is analyzed. Finally the measurement of tire torques is discussed and some results dealing with self-aligning, twisting and rolling resistance torques are presented.