大跨斜拉桥行车振动舒适性评价

为了提出适合于评价大跨桥梁行车振动舒适度的标准,对某大跨斜拉桥的行车振动进行现场实测,分析车辆驾驶员座椅处的振动特性以及不同车速下的车内振动加速度有效值;并以国际上通用的ISO2631标准为基础,结合车内人体的舒适感觉,提出行车振动舒适度评价标准,并对该桥的舒适性进行评价.     

垃圾车司机座椅振动舒适性评价

依据国际标准ISO2631、IS010326-2和国家汽车标准QC/T55的相关内容,以两辆垃圾车为研究对象,将垃圾车座椅处的振动加速度均方根值与人对垃圾车振动舒适性的主观感觉联系起来,对驾驶员全身振动进行了测量分析.     

山区简易刚性悬索桥振动舒适性评价

目前山区简易刚性悬索桥的振动舒适性问题越来越突出,而考虑车致桥梁振动影响行人行走舒适性的研究相对较少,因此分析通行车辆引起悬索桥振动响应的问题有着重要的现实意义。以某山区悬索桥为对象,分析了具有代表性的6种车辆荷载工况下的桥梁结构振动响应,并结合ISO2631标准和德国EN03规范对桥梁结构的振动舒适性进行了讨论。结果表明,按照ISO2631标准,所有车辆荷载工况下的桥梁振动加速度响应均方根值位于0.31～0.635 m/s²,处于“中度舒适”范围,结构的振动舒适性满足规范要求;而按照德国EN03规范,在工况1～4车辆荷载条件下,桥梁结构的竖向加速度峰值满足规范要求,行人行走处在“中度舒适”范围内,但是在工况5、6车辆荷载条件下,结构有部分位置竖向峰值加速度不满足规范要求。为了保证行人在桥上行走的舒适性,在未来设计当中应当限制过桥车辆的荷载以及车辆的行驶速度,同时要加强对桥面的养护,防止路面出现破损以致加大车辆对结构的振动作用,影响行人行走的舒适性。     

载货汽车随机输入行驶平顺性研究

货运是国民经济的动脉系统,它联结社会生产各个部分使之成为一个有机整体。在长途运输过程中,载货汽车平顺性对驾驶的舒适性和安全性有直接影响。文章结合GB/T 4970-2009和ISO 2631-1997对车辆平顺性的试验和评价方法,通过载货汽车随机输入行驶试验,分析了载荷状态和车速对车辆平顺性的影响。结果表明,车辆满载状态较空载状态行驶平顺性好,车速较低时车辆行驶平顺性变化不大,车速较高时平顺性大幅降低。此外,文章提出去除容易受坐姿影响的座椅靠背振动参数,在GB/T 4970的基础上,参照ISO 2631对坐垫处水平方向轴加权系数进行修正,对载货汽车平顺性试验和评价有指导意义。     

汽车座椅振动舒适性主客观测试及关联性分析

汽车座椅的振动特性直接影响乘坐舒适性。为综合评估座椅的振动舒适性,本文对座椅客观舒适性与乘员主观舒适性之间的关联性进行研究和分析。首先,进行不同激励幅值下的垂向振动试验,测量从座椅地板到与人体接触面的振动传递来表征人-椅耦合系统的动态性能。然后,设计相对幅值估计法用于主观评价,并进行主客观关联性分析。最后,提出一种能够表征座椅隔振性能的参数。结果表明:(1)随着振动量级的增大,人-椅耦合系统的共振频率会向低频移动,垂直同轴与交叉轴振动传递在第1阶共振频率处具有较强的关联性;(2)主客观测试关联性较好(拟合精度为99.05%),验证了相对幅值估计法的有效性;(3)提出的座椅隔振性能参数与主观评价一致性较好,可为汽车座椅振动舒适性的优化改进提供理论依据。     

出租汽车驾驶员振动剂量监测与评价

通过对ISO2631、GB4970等振动舒适性评价标准的研究,建立手动变速器出租汽车驾驶员振动舒适性评价方法。通过实车振动监测和测量驾驶员生理指标,找到了重庆市出租汽车驾驶员在实际行驶工况下达到疲劳的时间;并对他们进行有关疲劳的主观问卷调查,调查统计与试验的结果相吻合,由此得到出租汽车驾驶员达到疲劳时的“振动剂量极限值”。     

摩托车减震器道路振动对比试验研究

将2款不同示功特性和速度特性的减震器分别安装在同一辆摩托车上,并在典型坏路面、石块路面和平直路面上进行了振动对比测试,并按ISO 2631标准要求,对摩托车脚踏位置、座垫位置进行了分析计算及舒适性评价;对立管中部的振动响应进行了对比,为摩托车道路振动的测试和评价提供了参考。     

基于整车模型的路面不平度与行车舒适性关系的分析

鉴于目前尚未建立统一的行车舒适性的评价标准,通过建立符合车辆实际振动情况的十自由度整车模型,并以此模型为分析基础,以ISO2631—1：1997（E）《人体承受全身振动的评价标准》为依据,分析了路面不平度与行车舒适性的关系,评价了A、B、C三种等级路面的不平度对行车舒适性的影响,阐述了应从舒适性的角度对路面不平度分级进行调整的原因。     

摩托车平顺性评价研究

对几款具有代表性的摩托车进行了平顺性道路试验,研究分析了摩托车平顺性的实际特点,依据国际标准ISO2631、ISO5349,提出了摩托车平顺性客观和主观评价方法。通过主观调查和客观评价,探讨了手把处、座位处的客观评价指标和主观感觉之间的联系,座位处分析结果与ISO2631相吻合,说明该评价方法能较好地反映振动对人体的影响。     

风环境下大跨度斜拉桥上的车辆驾驶舒适性评价

建立了风环境下行驶于大跨度桥梁上的车辆驾驶舒适性评价体系.在综合考虑汽车-桥梁系统空间耦合关系的基础上,提出了能够考虑桥梁的静风响应、抖振响应、汽车-桥梁耦合振动、系统的时变特性以及结构几何非线性和气动荷载非线性影响的风-汽车-桥梁系统空间耦合分析模型,该模型可以预测风环境下桥梁上通行车辆的行驶安全性及驾驶舒适性;建立了车辆驾驶员位置处驾驶舒适性评价方法,并采用ISO 2631-1-1997标准对不同路面粗糙度下行驶于杭州湾跨海大桥的车辆驾驶舒适性进行了评价.评价结果表明:路况越差,车辆的驾驶舒适性越差,且所计算工况下车辆的竖向和侧向驾驶舒适性均满足ISO 2631-1-1997标准.     

参照国际标准ISO 2631的新草案修订汽车平顺性的评价方法

本文了国际标准ＩＳＯ ２６３１和我国汽车平顺性评价方法的基本情况与发展，分析了参照ＩＳＯ ２６３１新草案评价汽车平顺性的方法。     

汽车脉冲输入平顺性评价指标限值的研究

在分析了脉冲输入下人体所受到的振动速度响应到基础上，运用ＩＳＯ２６３１新草案对人体健康的评价指标和限值，提出了脉冲输入下汽车平顺性评价指标的限值，最后以东风ＥＱ２１０２Ｃ型军用越野汽车为例，说明了脉冲输入下汽车行驶平顺性的评价过程。     

Assessment of wheel loader vibration on the riding comfort according to ISO standards

Vibration accelerations were measured on a compact wheel loader during 11 operations with two drivers and with/without the activated boom suspension system (BSS). Two standards, ISO 2631-1 (1985) and ISO 2631-1 (1997), were used to assess the effect of wheel loader vibration on comfort. The assessment results of ISO 2631-1 (1985) showed that vibration in the frequency range from 4 to 20 Hz in the vertical direction and in the frequency range from 1.6 to 3.15 Hz in the vertical and driving directions plays an important role in comfort assessment. The overall total values of vibration measured on the wheel loader in all operations exceeded the ‘uncomfortable’ boundary specified in ISO 2631-1 (1997). The speed had a larger influence on the vibration intensity than the bucket load, the BSS or the driver biodynamic response during driving. During driving and V-cycle, the difference of vibration intensity with two drivers in the z-direction is larger than that in the x- and y-direction.     

Ride quality evaluation of a vehicle with a planar suspension system

The longitudinal connection between a chassis and a wheel in a conventional vehicle suspension system is commonly very stiff than the vertical connection. Such a mechanism can efficiently isolate vibrations and absorb shocks in the vertical direction but cannot sufficiently attenuate the impact in the longitudinal direction. In order to overcome such a limitation, a planar suspension system (PSS) with spring–damper struts in both the longitudinal and vertical directions is proposed so that the vibration along any direction in the wheel rotation plane can be isolated. In this paper, the dynamic responses of a vehicle with PSS due to a single bump and random road unevenness are investigated. The ride quality of the vehicle with PSS is evaluated in accordance with ISO 2631. A comparison with that of a similar conventional vehicle is conducted to demonstrate the promising potentials of the PSS in improving the vehicle ride quality.     

人体对1.0Hz以下低频振动的响应

ISO 2631/DP-1989修改草案[1]对原标准作了修改,推荐了一组频率加权函数曲线。本试验针对草案的0.25～1.0Hz低频垂直振动,通过对12名青年学生的胃电和人体不平衡的测试进行了试验分析,结果表明,胃电和人体质心不平衡的变化趋势与人体对低频振动的主观反应大体一致,为人对低频振动的反应提供了有效的客观指标。修改草案的低频振动的加权函数基本符合实际情况。     

对汽车平顺性评价方法的探讨与建议

首先分析了现行国家标准GB4970-1996<汽车平顺性随机输入行驶试验方法>与国际上通行的人体振动评价标准ISO2631-1997的区别.通过道路试验测量了驾驶员坐垫、靠背和脚部的平移振动以及坐垫的旋转振动共lO个方向的振动.分析发现汽车中人体振动的峰值因子一般小于9;而按照GB4970和ISO2631的试验数据对比表明,GB4970在一定程度上低估了人体振动.分析各方向振动所占的比例发现,坐垫垂向振动、靠背前后振动和坐垫侧倾振动影响最大.最后提出了对汽车平顺性评价方法的建议.     

Comparison between different sets of suspension parameters and introduction of new modified skyhook control strategy incorporating varying road condition

This study examines the uncertainties in modelling a quarter car suspension system caused by the effect of different sets of suspension parameters of a corresponding mathematical model. To overcome this problem, 11 sets of identified parameters of a suspension system have been compared, taken from the most recent published work. From this investigation, a set of parameters were chosen which showed a better performance than others in respect of peak amplitude and settling time. These chosen parameters were then used to investigate the performance of a new modified continuous skyhook control strategy with adaptive gain that dictates the vehicle's semi-active suspension system. The proposed system first captures the road profile input over a certain period. Then it calculates the best possible value of the skyhook gain (SG) for the subsequent process. Meanwhile the system is controlled according to the new modified skyhook control law using an initial or previous value of the SG. In this study, the proposed suspension system is compared with passive and other recently reported skyhook controlled semi-active suspension systems. Its performances have been evaluated in terms of ride comfort and road handling performance. The model has been validated in accordance with the international standards of admissible acceleration levels ISO2631 and human vibration perception.