软弱地面上汽车牵引系数和牵引效率

牵引系数C_T和牵引效率E_T是描述汽车在软弱地面上行驶时的重要性能参数。本文根据汽车地面系统力学的方法建立了计算C_T和E_T的数学模型,并用实车的试验结果进行了验证。文中给出了三种典型的越野汽车在江边沙滩地、河床沙地及淤泥地上的试验结果,讨论了牵引系数和牵引效率对汽车性能的影响。     

红岩CQ4261、CQ4161半挂牵引汽车列车风洞试验

我厂和西南交通大学机械学院合作进行了CQ4261、CQ4161兰挂牵引汽车列车风洞试验，研究了影响汽车列车气动性能的因素。本文报告了这次试验的设施、试验方法、根据试验数据整理的列车气动性能参数；利用试验结果分析了降低气动阻力对降低油耗率和改善动力性能所起的作用。     

汽车弯道制动试验响应分析

汽车弯道制动是一种危险而复杂的工况，其复杂性表现在影响因素多和评价方法两方面。文中通过试验，分析了影响汽车弯道制动性能的主要因素。从试验结果来看，用稳定性和偏移量两个评价指标，可以较全面评价汽车弯道制动性能。     

一种车用高强球墨铸铁的疲劳性能

本文针对一种新研制的高强度，高延伸率球墨铸铁材料进行了疲劳性能方面的试验研究。本文简略地介绍了测试疲劳性能的试验方法，通过使用升降法试验获得了材料的弯曲疲劳极限，证明该材料具有良好的疲劳性能，通过低周疲劳试验获得了应力－应变曲线和应变－寿命曲线，这些都是汽车有关零件疲劳设计和寿命预测重要的数据资料。     

汽车半挂列车牵引座结构对汽车运行稳定性的影响

汽车半挂旬车具有半截质量大，转弯灵活，燃油单耗低，经济效益高等优点，介绍了目前普遍采用的牵引车与半挂车的连接方式，也就是仅有纵向摆动的牵引鞍座，并做了有关性能分析，同时也推荐了一种能增加稳定性的牵引鞍座。     

半挂汽车列车牵引联接装置牵引销受力分析

分析了半挂汽车列车在坡道上起点和紧急制动两种工况下，牵引联接装置牵引销的受力情况。     

国产稀土车用催化剂的试验评价和性能考察

采用国通用的发动机台架评比方法，对两种典型的国产稀土型车用催化剂进行了性能评比试验，包括空燃比特性试验，、起燃温度特性试验以及快速老化试验，通过理论和研究对催化剂失活的主要原因作了分析，同时对国内外催化剂的性能水平进行了地比。     

沙漠车在塔克拉玛干沙漠牵引通过性能的试验研究

设计制造了一套沙漠车模引的电测试验装置，对浙江省车在塔克拉玛干沙漠中行驶时的驱动桥扭矩，挂钩力，动裁，车速，车轮轮速等参数进行了现场测量，得出了沙漠车在不同轮胎气压下的牵引系数，牵引效率和动阻力系试验结果对沙性性能的评价和改进具有指导意义。     

基于碳平衡法测量汽车燃料消耗量的方法研究

碳平衡法测量汽车燃料消耗量符合汽车不解体和自动化检测的发展要求。本文在给出了碳平衡法测量原理后重点介绍了甲醇汽车、NG汽车和LPG汽车采用碳平衡法计算燃料消耗量的计算方法，弥补了我国现有《轻型汽车燃料消耗量试验方法》(GB／T19233—2003)国家标准只规定了汽油和柴油两种燃料的消耗量试验及其计算方法的不足。试验结果表明，使用碳平衡法计算汽车燃料消耗量具有较好的结果一致性、稳定性和准确性。文中给出的计算方法可作为汽研部门有关整车性能测试的主要参考依据。     

自卸汽车举升倾卸验方法探讨

根据在试验工作中的体会和理论分析，对现行标准ＪＢ４０４７．２－８５《自卸汽车性能试验方法》中有关最大举升角，举升时间，自降量，举升倾卸系统可靠性的试验条件有详细规定，并且试验操作复杂，造成在实际试验过程中，试验条件和试验方法不统一，试验结果和评定结果的对比性较差等问题进行了探讨，提出了一种较好的自卸汽车性能试验方法和可靠性和试验方法。     

驻车制动性能路试检验作业指导书

对于无法上制动检验台检验驻车制动性能的车辆及经台架检验后对其驻车制动性能有质疑的车辆,采用坡道检验驻坡时间或驻车制动性能测试仪检验牵引力。本文对这两种检验方法、步骤做了详细介绍,并对仪器使用注意事项作出规定。     

汽车跑偏测试系统中的相机标定技术研究

欲保证基于摄影测量的汽车行驶跑偏在线自动测试系统的测试精度,需对测试用CCD相机进行精确标定.CCD相机标定常用的算法有空间后方交会法和直接线性变换(DLT)法等2种.通过对2种相机标定方法基本原理的分析,结合汽车行驶跑偏在线自动测试系统的特点,从相机标定精度和稳定性出发,探讨了相机标定算法的选用原则及控制点类型对标定...     

基于力学分析的皮卡车牵引能力研究

本文介绍了一种基于力学分析的皮卡车(也称多用途货车)牵引能力的理论计算和试验方法,得出了决定皮卡车牵引能力的主要因素有:皮卡车动力传动系统能力、驱动形式、结构强度,挂车类型以及道路情况等。经验证,理论计算得到的牵引能力与试验结果一致性较好:通过皮卡车牵引能力的计算和验证,能够有效指导企业进行设计开发,充分发挥皮卡车较强的牵引能力特性,推动皮卡车市场发展。     

Re-adhesion control for a railway single wheelset test rig based on the behaviour of the traction motor

A method for detecting wheel slip/slide and re-adhesion control of AC traction motors in railway applications is presented in this paper. This enables a better utilisation of available adhesion and could also reduce wheel wear by reducing high creep values. With this method, the wheel–rail (roller) creepage, creep force and friction coefficient can be indirectly detected and estimated by measuring the voltage, current and speed of the AC traction motor and using an extended Kalman filter. The re-adhesion controller is designed to regulate the motor torque command according to the maximum available adhesion based on the estimated results. Simulations under different friction coefficients are carried out to test the proposed method.     

Comparative study of vehicle tyre–road friction coefficient estimation with a novel cost-effective method

This paper qualitatively and quantitatively reviews and compares three typical tyre–road friction coefficient estimation methods, which are the slip slope method, individual tyre force estimation method and extended Kalman filter method, and then presents a new cost-effective tyre–road friction coefficient estimation method. Based on the qualitative analysis and the numerical comparisons, it is found that all of the three typical methods can successfully estimate the tyre force and friction coefficient in most of the test conditions, but the estimation performance is compromised for some of the methods during different simulation scenarios. In addition, all of these three methods need global positioning system (GPS) to measure the absolute velocity of a vehicle. To overcome the above-mentioned problem, a novel cost-effective estimation method is proposed in this paper. This method requires only the inputs of wheel angular velocity, traction/brake torque and longitudinal acceleration, which are all easy to be measured using available sensors installed in passenger vehicles. By using this method, the vehicle absolute velocity and slip ratio can be estimated by an improved nonlinear observer without using GPS, and the friction force and tyre–road friction coefficient can be obtained from the estimated vehicle velocity and slip ratio. Simulations are used to validate the effectiveness of the proposed estimation method.     

沥青回收方法对沥青老化影响程度的对比试验分析

将原样沥青经过不同程度的老化,三氯乙烯进行溶解,然后采用阿布森法和旋转蒸发器两种沥青回收方法进行沥青的回收,为分析两种沥青回收方法在回收过程中对沥青老化的影响程度,对原样沥青、阿布森法回收的沥青以及旋转蒸发器法回收的沥青进行针入度、软化点、延度、粘度、动态剪切模量、相位角、低温弯曲蠕变劲度模量等性能指标的检测,通过试验分析可以得出,阿布森法和旋转蒸发器法在沥青的回收过程中都会使沥青产生一定程度的老化,但是老化程度都相对较低,在两种回收方法的比较中,阿布森法对沥青老化的影响要比旋转蒸发器法小,但是回收的试验过程要比旋转蒸发器法复杂,所以对两种回收方法的选择要结合具体实际情况恰当选取。     

Proposal for Testing and Rating of Traction and Stability Control Systems

Function and object of existing control systems for traction and stability are described. The problem of rating and objective evaluation of the influence of such slip control systems on vehicle dynamics is demonstrated. Closed-loop manoeuvres with subjective assessment and open-loop tests with measured data are shown. Analysis of correlation results in characteristic values which allow assessment of dynamic performance of slip control systems. Tests on natural and synthetic μ-low road surface with two passenger cars, equipped with different slip control systems, demonstrate the objective test method and show their results.     

Simulation of active steering control for curving under traction in hauling locomotives

Active steering control in the form of secondary yaw control (SYC) and actuated wheelset yaw (AWY) have been in prototype development. This paper presents a new active steering bogie design, actuated yaw force steering (AY-FS), that is able to steer under high traction loads in tight curves. The AY-FS bogie design is compared with the AWY design. The steering performance AWY under high traction loads has not been previously reported. This paper examines five control methods, three for AWY and two for AY-FS bogies and assesses the traction curving and stability control performance of the alternative designs and control methods compared with each other and to passive steering bogie designs. The curving performance results showed considerable advantage in the proposed AY-FS bogies over the AWY. It was shown that control must be applied to both the yaw angle and the steering angle of the bogie to achieve the best traction steering performance which was not possible with the AWY bogies. The proposed new bogie designs of AY-FS overall give better traction curving and stability performance than the AWY designs.     

基于外部火烧安全的车用动力电池箱优化研究

基于国标对车用动力蓄电池的外部火烧安全要求,文章针对某款车用动力电池箱外部火烧试验的表现情况进行分析,提出优化改进方案,并通过试验验证确定最终方案。试验结果表明,优化方案效果达到了预期,为车用动力电池箱的防火性设计与试验验证提供了可借鉴的思路。