乘用车燃料消耗量检测不确定度评定

基于国内乘用车排放试验室现状,根据《测量不确定度评定与表示》(JJF 1059—1999)中对不确定度的定义和评定要求,将尾气排放测试系统、底盘测功机等仪器和设备、环境条件、标准物质、试验操作等影响测量结果的不确度用于评定汽车燃油消耗量测量精度,通过计算得到了碳平衡法油耗测试结果的扩展不确定度,且表明了该结果的置信范围和程度。     

车辆跟驰行为建模的回顾与展望

系统地回顾了跟驰理论60年的发展历程,依据建模思想将跟驰行为模型分为交通工程角度和统计物理角度。交通工程角度的跟驰模型包括刺激-反应类、安全距离类、心理-生理类及人工智能类模型;统计物理角度的跟驰模型包括优化速度模型、智能驾驶模型和元胞自动机模型。针对各类模型分别阐述了其建模思路、模型结构、参数标定及其扩展研究。最后,展望了跟驰行为建模的发展趋势与研究方向,为建立适合中国交通流特点的跟驰模型提供参考。     

An insight into linear quarter car model accuracy

The linear quarter car model is the most widely used suspension system model. A number of authors expressed doubts about the accuracy of the linear quarter car model in predicting the movement of a complex nonlinear suspension system. In this investigation, a quarter car rig, designed to mimic the popular MacPherson strut suspension system, is subject to narrowband excitation at a range of frequencies using a motor driven cam. Linear and nonlinear quarter car simulations of the rig are developed. Both isolated and operational testing techniques are used to characterise the individual suspension system components. Simulations carried out using the linear and nonlinear models are compared to measured data from the suspension test rig at selected excitation frequencies. Results show that the linear quarter car model provides a reasonable approximation of unsprung mass acceleration but significantly overpredicts sprung mass acceleration magnitude. The nonlinear simulation, featuring a trilinear shock absorber model and nonlinear tyre, produces results which are significantly more accurate than linear simulation results. The effect of tyre damping on the nonlinear model is also investigated for narrowband excitation. It is found to reduce the magnitude of unsprung mass acceleration peaks and contribute to an overall improvement in simulation accuracy.     

Vertical random vibration analysis of vehicle–track coupled system using Green's function method

A vertical vehicle–track coupled dynamic model, consisting of a high-speed train on a continuously supported rail, is established in the frequency-domain. The solution is obtained efficiently by use of the Green's function method, which can determine the vibration response over a wide range of frequency without any limitations due to modal truncation. Moreover, real track irregularity spectra can be used conveniently as input. The effect of the flexibility of both track and car body on the entire vehicle–track coupled dynamic response is investigated. A multi-body model of a vehicle with either rigid or flexible car body is defined running on three kinds of track: a rigid rail, a track stiffness model and a Timoshenko beam model. The results show that neglecting the track flexibility leads to an overestimation of both the contact force and the whole vehicle vibration response. The car body flexibility affects the ride quality of the vehicle and the coupling through the track and can be significant in certain frequency ranges. Finally, the effect of railpad and ballast stiffness on the vehicle–track coupled vibration is analysed, indicating that the stiffness of the railpad has an influence on the system in a higher frequency range than the ballast.     

汽车智能网联系统中的信息安全问题探究

汽车智能网联系统是当前智能化汽车发展的核心方向,对于汽车性能提升以及汽车使用安全都有非常重要的作用,本文笔者主要针对汽车智能网联系统进行了分析研究,文章中简要阐述了汽车智能网联系统及技术,并提出了汽车智能网联系统中存在的信息安全问题,并针对问题提出汽车智能网联系统的信息安全建设策略。     

基于ATmega16芯片的车用倒车测距系统设计

利用超声测距工作原理,以ATmega16单片机为主控芯片,采用超声波测距模块,数码管显示模块和蜂鸣器报警模块搭建的近距离报警系统,详细地叙述了各模块之间的控制电路和软件设计方案,实现系统实时显示汽车尾部与障碍物之间距离,并根据不同的距离发出不同频率蜂鸣的功能,达到提醒人员提高注意力的目的.测试结果表明测量精度达到1cm...     

基于显示屏EMC防护在汽车座舱控制系统研究

随着电子科技技术的进步及更新,传统意义上机械式操作的汽车音响,空调,仪表已经被越来越多的电子化产品所覆盖.在不断的电子技术变更过程中,对于各种电控产品的EMC要求也不断提高.基于此本文对于汽车音响,仪表等有TFT显示部分EMC的防护措施进行分析,并且围绕汽车音响显示屏部分EMC为中心诠释综合系统设计理念.提高汽车座舱控...     

浅析汽车车身无痕修复技术的重要性及方法

随着全球经济发展的不断加深,机动车的数量也不断增加,改革开放以来我国的汽车产业发展速度非常快,2018年中国机动车保有量差不多有3.27亿辆,从数字上来看汽车的量非常庞大,随之而来的是汽车售后服务的跟进,特别是随着近年来交通事故率的上升,使汽车维修业务量不断增多,其中汽车车身钣金修复是维修业务量的重要组成部分,现在很多...     

FSAE赛车前悬架运动学仿真及参数优化

运用Catia软件建立某FSAE赛车前悬架三维模型,并将Catia中的坐标转换成Adams软件中的坐标,建立Adams前悬架模型.针对该FSAE赛车前悬架进行双轮跳动运动学仿真,并对悬架传递比和前轮定位参数进行参数优化.