四轮定位仪校准技术

采用锥销插入组合车架的方法,配置1:1的"拆卸式模拟零位车架"的四轮定位仪校准,从而改善了目前市场上四轮定位仪校准装置无法保证四轮零位角度的准确性,并满足校准规范中的要求,开展了四轮定位仪的量值溯源工作。     

开展四轮定位仪检测工作的探析

车辆在出厂时,定位角度都是根据设计要求预先设定好的.这些定位角度共同用来保证车辆驾驶的舒适性和安全性.但是,由于车辆在售出并行驶一段时间后,这些定位角度会由于交通事故、道路坑洼不平造成的剧烈的颠簸(特别是高速行驶时突然遇到不平路面)、底盘零件磨损、更换底盘零件、更换轮胎等原因而产生变化.一旦定位角度由于任何一种原因产生变化,就可能产生诸如轮胎异常磨损、车辆跑偏、安全性下降、油耗增加、零件磨损加快、方向盘发沉、车辆发飘等不良现象的出现.这使得车辆在高速行驶时非常危险.     

四轮定位仪校准装置建立的探讨

论述建立四轮定位仪校准装置装置的基本步骤,主要讨论其数学模型的建立、不确定度的分析、重复性与稳定性验证的评价过程,并通过实验数据分析建立四轮定位仪校准装置装置。     

一种便携式四轮定位仪校准装置的技术研究

文章通过对JJF 1154—2014 《四轮定位仪校准规范》的详细研究及现场试验,结合目前四轮定位仪校准装置在主销模拟、定位参数零位确定、现场安装等方面的不足,介绍一种四轮定位仪校准装置采用四轮分体、组合使用的结构,由步进电机作为角度驱动器,通过高精度双轴倾角仪及绝对角度编码器实现角度闭环系统控制。文章对该装置的结构设计及校准原理进行了深入阐述,以期为四轮定位仪校准技术发展起到些许参考。     

四轮定位仪测量结果的不确定度评定

根据JJF1154-2006《四轮定位仪校准规范》,对四轮定位仪测量结果的不确定度评定进行分析。     

四轮定位仪示值误差测量结果不确定度的评定

本文介绍了四轮定位仪示值误差测量结果的不确定度评定方法。     

一种用于四轮定位仪的校准装置结构设计

汽车四轮定位仪校准装置是用于对汽车四轮定位仪的测量和校准。本文针对目前汽车四轮定位仪校准装置为一体式结构,采用涡轮蜗杆驱动模式,在检测过程中存在间隙大、测量准确度低、工作效率不高、不能涵盖对各类四轮定位仪的测量和校准,包括不便携带等使用缺陷,提出了汽车四轮定位仪校准装置采用四分体式结构,步进电机作为驱动器,圆光栅传感器作为测量标准的设计方案,提高了校准装置的测量准确度,仅供参考。     

汽车四轮定位仪检定技术的研究

通过对四轮定位仪检测车轮定位参数过程的分析,建立了检定装置的三维仿真模型,并开发了相应的检定设备.解决了对四轮定位仪测量车轮前束、车轮外倾、主销后倾及内倾的结果进行检定的问题,实现了四轮定位仪的全面正确检定.     

一种便携分体式四轮定位仪检定装置的研究

针对目前国内四轮定位仪的计量检定现状进行分析和论述,指出目前检定装置存在的不足之处,介绍一种既能满足定位精度要求又便于现场标定的便携分体式四轮定位仪检定装置,并对该定装置的检定原理、检定方法和设计特点进行分析,最后通过实验数据验证了该装置的正确性和可行性。     

Factors associated with the likelihood of injury resulting from collisions between four-wheel drive vehicles and passenger cars

The specific effects of vehicular type on the likelihood of an injury occurring are relatively unexplored. This study sought to assess the relative risk of injury to occupants of four-wheel drive vehicles and their counterparts in passenger cars.Data for 1143 occupants from all of the 454 crashes in Oklahoma, in 1995 that involved a four-wheel drive vehicle were used. Multiple logistic regression analysis determined the association between potential predictive factors and vehicular injury. Odds ratios revealed occupancy in a passenger car to be a major predictor of the likelihood of injury. Other factors include the driver being female, driving too fast, travel on curved or level roadways, and being hit laterally or from the rear.     

非接触式车轮定位仪测量原理及其标定

本文简述了车轮定位参数的定义；根据PNCA型非接触式车轮定位仪对车轮定位参数的测量过程，推导出其测量车轮前束角＆外倾角的计算公式——测量原理；分析了这类设备的标定方法，并以三坐标机测量为例介绍了设备主标定架的标定过程及其量值溯源方法；根据测量数据计算出标定架前、后、左、右各调整板的前束角＆外倾角。结果表明，当标定架各调整板上4个凸面块的平行度均小于0．05mm时，就能满足其作为PNCA型车轮定位仪测量基准的要求。     

Modeling the influence of Chevron alignment sign on young male driver performance: A driving simulator study

In China, the Chevron alignment sign on highways is a vertical rectangle with a white arrow and border on a blue background, which differs from its counterpart in other countries. Moreover, little research has been devoted to the effectiveness of China’s Chevron signs; there is still no practical method to quantitatively describe the impact of Chevron signs on driver performance in roadway curves. In this paper, a driving simulator experiment collected data on the driving performance of 30 young male drivers as they navigated on 29 different horizontal curves under different conditions (presence of Chevron signs, curve radius and curve direction). To address the heterogeneity issue in the data, three models were estimated and tested: a pooled data linear regression model, a fixed effects model, and a random effects model. According to the Hausman Test and Akaike Information Criterion (AIC), the random effects model offers the best fit. The current study explores the relationship between driver performance (i.e., vehicle speed and lane position) and horizontal curves with respect to the horizontal curvature, presence of Chevron signs, and curve direction. This study lays a foundation for developing procedures and guidelines that would allow more uniform and efficient deployment of Chevron signs on China’s highways.     

电能功率现场测量方法的计量性能

在功率测量原理的基础上,讨论了前端加源测值法和后端同步测值法的原理和特点,通过现场电能功率不同测量接入方式下的计量性能试验,并根据试验结果和不确定度的分析评定,指出两种方法的电能功率现场测量的计量差异,验证了两种现场功率测量方法计量性能一致性,对电能功率的现场测量工作具有参考价值。     

Models of the methods and instruments for the nondestructive testing of the hardness of articles

Models of the methods of nondestructive testing of the physical-mechanical properties of the materials of articles, for which integrated methods have limited application, are considered. The parameters of the amplitude-frequency characteristics obtained in instruments for the nondestructive testing of the hardness of articles are established on the basis of an analysis of the system of vibration-contact methods. __________ Translated from Izmeritel'naya Tekhnika, No. 1, pp. 27–30, January, 2006.     

Certification of instruments and devices of the threshold type

A program is described for determining and simulating the probit function reliability Probistics. __________ Translated from Izmeritel’naya Tekhnika, No. 10, pp. 70–71, October, 2007.     

Construction and alignment control of the middle steel pylon of Taizhou Bridge

In this paper, the general construction procedure of the steel middle pylon is briefly introduced. The alignment control of the pylon is carried out during the whole process of the construction. The control concept is extended to the manufacture stage. The manufacturing alignment errors are strictly controlled in the segments precast process in factory, and the errors are recognized and predicted precisely during the installation stage. The adjusting joints are employed to amend the accumulated errors, which ensure that the steel pylon alignment could satisfy the precision requirements after installation.     

触针式表面轮廓测量仪量值溯源方法研究

目前国内尚无开展检定或校准接触(触针)式表面轮廓仪的计量检定规程或校准技术规范,致使无法对接触(触针)式表面轮廓仪测量的二维形状、位置等参数的量值进行溯源,福建省大、中型机械加工企业和检验机构的机械加工、产品检验领域又需要对接触(触针)式表面轮廓仪量值溯源。为确保开展接触(触针)式表面轮廓仪量值溯源与检测数据准确可靠,根据接触(触针)式表面轮廓仪工作原理与计量技术特性,研究提出接触(触针)式表面轮廓仪计量性能的校准方法及其校准结果的不确定度评定方法,作为福建省在开展校准接触(触针)式表面轮廓仪的技术依据。     

反应源温度对ZnO纳米线阵列定向性及发光性能的影响

以Au薄膜为催化剂、ZnO与碳混合粉末为反应源,采用碳热还原法在单晶Si衬底上制备了ZnO纳米线阵列.通过扫描电子显微镜( SEM)、X射线衍射仪(XRD)、荧光分光光度计对样品的表征,研究了反应源温度对ZnO纳米线阵列的定向性和光致发光性能的影响.样品在源温度920℃条件下沿(002)方向择优生长,定向性最好,温度过低不利于ZnO纳米线阵列密集生长,而温度过高导致Zn原子二次蒸发,因而也不利于纳米线阵列的定向和择优生长;样品在源温度880℃有最强的近紫外带边发射,表明温度过高和过低都不利于ZnO晶体结构的优化;由于ZnO纳米线在缺氧氛围下生长,氧空位是缺陷存在的主要形式,因此所有样品都有较强的绿光发射.温度升高导致纳米线生长速度提高而增加了氧空位缺陷数量,从而使样品绿峰强度增强并在源温度920℃时达最大值,但温度的进一步升高可导致ZnO纳米线表面Zn元素的蒸发而降低氧空位缺陷的数量,从而抑制绿峰强度.     

无功电能计量理论技术及其发展

随着测量技术进步和电力系统管理水平的提高，无功电能计量理论技术得到了很大发展，一方面针对电力系统特性的变化提出了新的无功电能计量理论，另一方面随着微电子技术的进步形成了多种无功电能计量新技术。本文在阐述正弦无功功率理论与正弦无功电能计量技术的基础上，介绍亍非正弦无功功率理论和非正弦电能计量技术，并探讨了无功功率理论和无功电能计量技术的发展。