全挂汽车列车制动防抱死系统的协调控制

以某型全挂汽车列车为研究对象,分别安装牵引车及挂车两套制动防抱死系统,并建立相关协调模块使两套系统协调工作。运用Matlab/Simulink软件对未安装及安装ABS系统的全挂汽车列车在高附着系数路面上进行直线制动仿真。分析对比仿真结果,证明协调模块使得两套ABS系统顺利工作,挂车与牵引车制动强度相协调,显著提高了列车制动稳定性。     

拖挂式房车制动稳定性的研究

在建立6自由度拖挂式房车转弯制动数学模型的基础上,对拖挂式房车的制动过程进行了仿真计算,分析了转向角、转向角速度和房车车轮制动力对房车横摆角速度的影响以及各参数之间的协调优化。为寻求房车车轮制动力与转向角、转向角速度、制动时间等因素的最优关系,达到拖挂式房车在行驶过程中实时控制房车制动力,提高拖挂式房车行驶的稳定性奠定了基础。     

Ride Vibration Measurements of Agricultural Tractor and Trailer Combinations

SUMMARY

Tractor ride vibration levels have been measured when operating with and without a two wheel (2W) unbalanced and a four wheel (4W) balanced trailer. Measurements were made in the vertical, pitch, longitudinal and roll directions with the trailers unladen and laden over four typical farm surfaces

The results showed that tractor ride vibration levels were usually increased in all directions-particularly the longitudinal direction- when operating with the laden trailers. But for the unladen trailers, they were increased only in the longitudinal direction. Predominant tractor frequencies tended to be lower with the trailers attached, and coupling between the tractor longitudinal, vertical, roll and pitch co-ordinates was generally increased

Comparisons of the results with the trends predicted by a simplified theoretical model of a tractor and 2W trailer, suggested that the model should be extended to include, (a) the roll direction, (b) more realistic ground inputs, and (c) a 4W trailer     

Ride Vibration Measurements of Agricultural Tractor and Trailer Combinations

Tractor ride vibration levels have been measured when operating with and without a two wheel (2W) unbalanced and a four wheel (4W) balanced trailer. Measurements were made in the vertical, pitch, longitudinal and roll directions with the trailers unladen and laden over four typical farm surfaces

The results showed that tractor ride vibration levels were usually increased in all directions-particularly the longitudinal direction- when operating with the laden trailers. But for the unladen trailers, they were increased only in the longitudinal direction. Predominant tractor frequencies tended to be lower with the trailers attached, and coupling between the tractor longitudinal, vertical, roll and pitch co-ordinates was generally increased

Comparisons of the results with the trends predicted by a simplified theoretical model of a tractor and 2W trailer, suggested that the model should be extended to include, (a) the roll direction, (b) more realistic ground inputs, and (c) a 4W trailer     

汽车电子机械制动系统

电子机械制动系统（EMB）,以电驱动元件为制动执行器,取代传统的液压或气压制动执行器.是一种全新的制动理念.它具有的没有制动液体、反应快速、性能可靠及安全环保等特点使其拥有令人看好的前景.在国外.EMB的研究取得初步的成绩,Bosch、Siemens公司已经研制出了自己的部分试验成果,而国内的研究刚刚开始.文章阐述了电子机械制动系统的概念、结构组成、工作原理及性能特点,论述了其关键技术及发展.     

制动管路对整车制动系统的影响

针对商用车整车制动系统的管路进行了分析,对不同材料的制动管路进行了试验,在试验的基础上分析了制动管路对整车制动系统的影响因素,通过对整车试验结果的分析研究,找出了因制动管路的原因对整车制动的影响。并采取措施解决了整车制动的某些问题。     

Improvement of Vehicle Dynamics by Rear Braking Force Control

A study on effective use of rear braking force to improve a brake performance and vehicle dynamics are carried out. On a ordinary condition, the rear braking force could be more increased to a conventional braking force distribution. Based on this thought, the brake performances are estimated. The results show the effects not only improve the brake performance but also reduce a pitching at braking and moderate a vehicle OS behavior in a turn during braking. These are verified by experimental test vehicle equipped with a rear braking force control system.     

Improvement of Vehicle Dynamics by Rear Braking Force Control

SUMMARY

A study on effective use of rear braking force to improve a brake performance and vehicle dynamics are carried out. On a ordinary condition, the rear braking force could be more increased to a conventional braking force distribution. Based on this thought, the brake performances are estimated. The results show the effects not only improve the brake performance but also reduce a pitching at braking and moderate a vehicle OS behavior in a turn during braking. These are verified by experimental test vehicle equipped with a rear braking force control system.     

A Theoretical Analysis of the Ride Vibration of Agricultural Tractor and Trailer Combinations

SUMMARY

A six degree of freedom model of an agricultural tractor and trailer combination has been developed. Results from eigenvalue and frequency response calculations indicated that tractor operator vibration levels will be higher when operating with a trailer than for the tractor alone, due mainly to increased tractor pitch motion.

Although minor improvements could be made to present tractor and trailer combinations by moving the hitch forward of the tractor rear axle or providing some damping at a sprung hitch, the scope for a significant improvement in ride lies in changing the configuration. If higher speed specialised transport vehicles prove economical for agriculture, there are some advantages in ride vibration to be gained by changing the layout of the tractor and trailer combination to resemble an off-road version of a commercial articulated lorry.     

商用车网络营销“组合拳”

<正>1月15日,《第25次中国互联网络发展状况统计报告》显示,截至2009年底,中国网民规模达到3.84亿人,较2008年增长28.9%,在总人口中的比重从22.6%提升到28.9%,互联网普及率在稳步上升。目前依然保持着快速增长的势头。中国互联网络信息中心主任毛伟表示,持续蔓延的全球金融危机对我国互联网总体影响不大,我国网民规模、宽带网民数、国家顶级域名注册量(1296万)三项指标仍然     

Vibration of the Pulsatory Braking Vehicle

The braking vehicle model considering the changes of the suspension stiffness was investigated. It was described by the stochastic matrix differential equation. The variances of the vibration responses obtained by solving this equation with Green's multi-dimensional function were compared with the experimental results.     

A Theoretical Analysis of the Ride Vibration of Agricultural Tractor and Trailer Combinations

A six degree of freedom model of an agricultural tractor and trailer combination has been developed. Results from eigenvalue and frequency response calculations indicated that tractor operator vibration levels will be higher when operating with a trailer than for the tractor alone, due mainly to increased tractor pitch motion.

Although minor improvements could be made to present tractor and trailer combinations by moving the hitch forward of the tractor rear axle or providing some damping at a sprung hitch, the scope for a significant improvement in ride lies in changing the configuration. If higher speed specialised transport vehicles prove economical for agriculture, there are some advantages in ride vibration to be gained by changing the layout of the tractor and trailer combination to resemble an off-road version of a commercial articulated lorry.     

Traction/Braking Force Distribution for Optimal Longitudinal Motion During Curve Following

The optimal tire force distribution to maximize acceleration/deceleration of a four-wheel vehicle during cornering is studied. The objective of this research is to investigate the improvement one can expect from the implementation of different vehicle steering and driving mechanisms. We first identify the upper limit imposed by physical laws by assuming all the four wheels can be individually steered and driven. Practical vehicle configurations such as four-wheel-steering (4WS) and four-wheel-drive (4WD) are then considered. The optimization involves equality and inequality constraints and are solved by nonlinear programming techniques.     

汽车制动性能的简易评价方法

为方便购车者对市场上在售汽车的制动性能有较为直观的认识和清晰的比较,文章提出了汽车制动性能的简易评价方法,以百分制为标准,运用MATLAB软件进行数值拟合,根据各指标得分方程得到汽车的制动性能,并运用该方法对10辆样车进行评价分析。评价结果表明,该方法可以准确反映汽车的实际制动性能,具有较好的实用性。同时,该方法还可以作为专业人员进行更深层次研究的理论参考。     

天兴洲公铁两用斜拉桥主梁纵向地震、列车制动及行车移动荷载响应的混合控制

针对天兴洲公铁两用斜拉桥提出"MR阻尼器 液体粘滞阻尼器"的混合控制方案,并建立了对该桥主梁纵向地震、列车制动和行车移动荷载响应混合控制的基本方程、控制策略和仿真分析方法,分析结果表明采用该混合控制方案能有效地抑制大桥主梁纵向地震、列车制动及行车移动荷载的振动响应.     

再生制动技术在汽车中的应用

再生制动技术是一种有效的节能方式。传统的汽车制动,是将车辆的动能变为摩擦片的热能浪费了,而再生制动技术的目的就是使这部分能量储存起来再利用,此种技术节约了能源,并降低了废气排量。文章对再生制动技术进行了理论研究,分析了再生制动技术的节能原理;从传动方式和能量存储方式上对再生制动技术汽车的名称作出定义,同时对再生制动汽车的功率流进行了分析。指出再生制动汽车在达到回收制动能量目的的同时,具有很多优点,是当前汽车发展的方向。     

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.     

汽车纵向加/减速度多模型分层切换控制

针对汽车纵向动力学模型的大不确定性,设计了一种基于鲁棒控制理论的汽车纵向加速度多模型分层切换控制系统。通过分析汽车纵向动力学特性,用4个不确定模型覆盖对象不确定性,并应用LM I方法设计对应的鲁棒性能控制器集合。考虑鲁棒控制系统的特点,设计了一种对不确定性的系统增益进行估计的切换指标函数,以选择控制器进行控制。实验表明,提出的方法在大不确定性下可以对纵向加速度有效控制。