汽车制动系统试验装置的开发及应用

研究和开发了基于GB12676－1999标准的汽车制动系统试验装置，该试验装置所测量的参数有：车轮的转速、转矩，整车速度，制动管路压力，踏板力，制动蹄片的温度等。为具备这些功能，本装置由传感器部分、信号处理部分、数据采集部分构成。对汽车制动时车轮转矩的测量进行了深入分析，并编制了相应的采集处理软件，进行了系统的实车试验。     

高速列车及其速度目标值的探讨

根据铁路运输高速化的发展趋势,初步分析了旅行速度、票价、运输管理、高速列车等因素和速度目标值的关系。提出高速列车是影响速度目标值的关键问题。从高速列车的牵引、能耗、制动能力和噪音方面对轮轨方式和磁悬浮方式的高速列车按不同速度目标值进行分析比较。以正在设计中的京沪高速铁路为例,在京沪高速列车运行仿真研究的基础上,按直达方式和沿线停站方式,对不同速度目标值的地面干线运输系统其旅行时间和能耗的经济问题进行简要的计算对比。提出选择我国高速铁路速度目标值的建议。     

Vehicle stability control system for enhancing steerabilty,lateral stability,and roll stability

The Vehicle stability control system is an active safety system designed to prevent accidents from occurring and to stabilize dynamic maneuvers of a vehicle by generating an artificial yaw moment using differential brakes. In this paper, in order to enhance vehicle steerability, lateral stability, and roll stability, each reference yaw rate is designed and combined into a target yaw rate depending on the driving situation. A yaw rate controller is designed to track the target yaw rate based on sliding mode control theory. To generate the total yaw moment required from the proposed yaw rate controller, each brake pressure is properly distributed with effective control wheel decision. Estimators are developed to identify the roll angle and body sideslip angle of a vehicle based on the simplified roll dynamics model and parameter adaptation approach. The performance of the proposed vehicle stability control system and estimation algorithms is verified with simulation results and experimental results.     

Influence of shock absorber wearing on vehicle brake performance

In order to safely maintain a vehicle, it is necessary to verify the most important systems that affect safety during Periodic Motor Vehicle Inspections (PMVIs). In a previous paper, a test method and validation criteria were suggested by the authors to verify shock absorber status during PMVIs, as they are a fundamental component that may wear out during a vehicle’s life. In this paper, variations of the performance of the vehicle’s brakes resulting from shock absorber wearing have been analyzed, in order to confirm whether the suggested criteria is valid for taking into account longitudinal forces and pitch movement on the vehicle. A simulation-based study was conducted with several configurations of a worn damper on a vehicle driving on two virtual roads: smooth and undulating. The results confirmed that the damping coefficient established as an acceptable value to verify the shock absorber status in PMVIs is also valid considering the forces involved in a braking maneuver.     

载货汽车中后翻动气室串气故障分析

介绍载货汽车中后桥制动气室的工作原理,分析其串气故障。     

简述汽车行人保护的现状与发展方向

近年来汽车碰撞安全的发展一日千里。但相对于日臻完善乘员保护研究,对行人的保护在过去并没有受到同等的重视。为此,欧洲自2005年开始把行人保护要求视为车辆设计必须考虑的因素。本文将从各个方面简要介绍汽车工业在行人保护上的发展现状,面临的挑战及未来可能的发展方向。     

汽车制动颤鸣现象的仿真分析

汽车的制动颤鸣现象是制动盘与摩擦块间的相对运动引起的两个摩擦表面间的粘滑运动,且由于其非线性振动的特性导致高自由度下的粘滑运动难以进行解析计算.建立了一个6自由度的制动颤鸣模型,通过数值仿真分析了汽车低速时制动压力、初始时刻制动盘与摩擦块之间的相对运动速度对制动颤鸣现象的影响,并指出通过合理控制这两个要素,可抑制制动颤鸣现象的产生.     

发动机制动工况下汽车制动器摩擦性能分析

建立了基于恒速制动车辆纵向力平衡方程、制动器耗散功率及其温度变化微分方程、管路压力调节等子模型的恒速长下坡汽车制动器摩擦性能分析系统.以两轴中型汽车为例,对前后制动器在不同挡位发动机制动时的温度、制动副摩擦因数、制动力分配及管路压力变化进行了计算.结果表明,在不影响车速情况下,合理使用各挡发动机制动可改善汽车前、后制动器热负荷,减小或避免制动摩擦力矩热衰退,保证汽车下长坡安全行驶.     

新型汽车液压增力制动控制器

为了提高汽车制动效率开发一种汽车液压增力制动控制器（HBI）.它主要由增压缸等组成,串联于汽车制动主缸与前制动轮缸之间,将制动主缸输出压力制动液增压,送往前制动轮缸.同时还将压力制动液直接送往后制动轮缸,实现汽车增压制动,其制动效率高于现有减压分配阀组成的制动系统效率10%以上.对具有HBI系统的制动性能检测表明,HBI可用于多种车型的制动系统中,制动踏板力明显下降100 N左右,制动稳定性明显提高.     

轿车制动性能的控制方法

针对目前轿车开发以逆向开发为主体,对整车制动性能控制能力较弱的实际问题,文章提出了一套制动性能控制方法,即以整车设计参数、制动强制性法规适应性及制动系统零部件尺寸系列化等为制动性能控制的输入约束条件,在设计初期预测新开发轿车的9项主要制动性能,经过多辆轿车制动系统的开发实践验证,此性能控制方法不仅可保证制动系统设计质量,而且缩短了轿车制动系统的设计周期。