关于车辆方向盘摆振的补偿方法及补偿系统研究

研究电动助力转向系统对方向盘摆振补偿的功能,通过对影响方向盘摆振因素的分解,当整车基本参数确定的情况下可以采用EPS进行摆振补偿.通过摆振补偿功能开发到某车型实车测试验证,有效解决高速制动等工况下方向盘摆振问题.该研究为车辆方向盘摆振问题的解决提供采用EPS补偿万式提供方法及系统.     

车辆前轮摆振的原因分析与解决方法

简要介绍前轮摆振的现象;分析原因,并找出解决方法。     

鼓式制动器制动时前轮摆振的原因分析

针对某中型货车制动时前轮摆振现象,从理论上分析了前轮摆振的产生机理,先对振动现象进行检测分析,再改进制动器的结构,然后通过整车试验和制动器台架试验对改进进行了验证。试验和分析的结果表明：制动时前轮摆振是车辆制动过程中前制动器的制动力矩波动造成的,与制动器结构有关,通过改进制动器这个摩擦系中的摩擦体的刚性,不仅可以消除制动时的前轮摆振,同时还可大幅提高制动性能。     

干摩擦力矩对某独立悬架汽车前轮摆振影响研究

为了探究前轮摆振的影响因素,将运动副间隙处的干摩擦等效到前轮主销处．应用拉格朗日方程建立了3自由度摆振系统模型,并用Matlab对其进行了仿真计算。结果表明,汽车在较大的初始激励下才会激发摆振;较大的干摩擦力矩有利于抑制摆振。     

A study on the effect of different tyre imperfections on steering wheel vibration

Multibody dynamics and tyre models have made possible detailed analysis not only for ride and handling, but also for determining their effects on tyre nonuniformities. The aim of this paper is to analyse the steering wheel vibration, both shimmy and shake, excited by different tyre imperfections by using the commercial simulation package ADAMS/car 2005R2 and FTire. Different settings with respect to imperfection locations, amount, and the combined effects of defects have been studied. An interesting beat phenomenon is observed when all the wheels have imperfections. A procedure to determine the type of imperfections in the tyre from the results of the test rig has also been proposed.     

考虑万向节间隙的汽车摆振系统动力学建模

在经典三自由度前轮摆振模型的基础上,基于非线性动力学理论,建立了考虑万向节运动副间隙的三自由度摆振模型。利用Poincare截面法绘制了车轮摆角幅值随车速变化的分岔特性曲线,分析了车速变化引起的某非独立悬架汽车前轮自激摆振的Hopf分岔,验证了在特定车速范围内发生自激励摆振的运动特性。     

汽车操纵稳定性与前轮摆振的非线性仿真分析

以某轿车为例,建立3自由度整车系统动力学模型,利用常微分方程稳定性理论和数值仿真计算,详细研究整车的稳态转向特性和系统失稳后的前轮摆振特性。阐明汽车的操纵稳定性与前轮摆振特性同属汽车整车稳定性问题,前者是负刚度系统,后者是负阻尼系统。在一定的参数组合下,具有不同转向特性的汽车都或多或少地存在摆振现象,这与实际情况相符,建议适当增加转向系阻尼和刚度以减小甚至消除摆振的发生。     

制动时汽车前轮摆振试验研究

对某车型在制动时出现前轮摆振现象进行试验研究,经过对检测和数据处理分析,深入分析了该问题产生的原因,制动力不平衡是引起汽车摆振的直接原因,它会引起制动力的变化,从而形成摆振.     

某大客车转向轮摆振及影响因素的分析

考虑侧偏角和侧偏力之间的非线性关系,建立4自由度某大客车转向轮摆振模型。运用非线性动力学理论,确定转向轮发生自激摆振的Hopf分岔点：通过MATLAB＆Simulink软件建立大客车转向轮摆振仿真模型。通过仿真结果检验理论分析,并得到车速、转向系参数、横拉杆参数、质心位置、主销后倾角与转向轮自激摆振幅值或频率的关系曲线．找出影响自激摆振的敏感参数及敏感参数的适取范围,能有效减小或消除客车的自激摆振。     

Micro-shimmy of towed structures in experimentally uncharted unstable parameter domain

In this paper, the lateral instability of towed structures (trailers, caravans and articulated buses) is investigated with special attention to the small amplitude lateral vibration that leads to a higher energy consumption in certain parameter domains. A low degree-of-freedom mechanical model of a shimmying towed tyre is used that describes the dynamics of the tyre–ground contact patch by the time delayed differential equation. Stability charts are calculated and the theoretically predicted linear unstable islands of small amplitude shimmy motions are validated by laboratory experiments. A tyre is towed by a relatively long caster, and its temperature and the input current of the conveyor belt are measured in order to show the increased value of the rolling resistance.