高精度机动车GPS测速仪模拟校准技术研究

介绍了高精度机动车GPS测速仪的模拟测速误差校准技术,分别基于Labsat以及GSS6700两种GPS信号模拟器建立了GPS测速仪模拟校准系统。在20～200km·h^-1范围内特定速度点,对同一台高精度机动车GPS测速仪,使用两种模拟校准系统分别进行了模拟测速误差的校准。结果表明,使用两种GPS信号模拟校准装置测得的高精度机动车GPS测速仪的模拟测速误差相近,均在±0．05km·h^-1或±0．05％范围内,校准不确定度分别优于0．024％（k=2）和0．030％（k=2）,均能够满足高精度机动车GPS测速仪的溯源要求。     

高精度机动车GPS测速仪校准技术研究

为了建立针对高精度机动车GPS测速仪的溯源途径,本文介绍了高精度机动车GPS测速仪的两种实验室校准技术,在(40~180)km/h范围内特定速度点,对同一台高精度机动车GPS测速仪分别进行了实验室模拟测速误差校准、现场道路实际测速误差校准和实验室GPS信号回放校准,并分别提供了采用该校准方法的不确定度评定实例结果,验证了高精度机动车GPS测速仪的模拟测速误差校准不确定度优于0.02%(k=2),卫星信号回放测速误差校准不确定度优于0.10%(k=2).两种校准方法均能够对高精度机动车GPS测速仪进行有效校准.经过校准的高精度机动车GPS测速仪在可用卫星数不少于6颗的使用环境下,能够满足现场测速标准器具的使用要求,具有广阔的应用前景.     

基于多普勒频移观测值的机动车GPS测速仪校准技术的研究

提出了一种基于现场GPS信号定标的实验室校准方法.利用3光束光遮挡测速标准装置在测试现场对卫星GPS信号直接进行速度实测定标,通过GPS记录仪保存,然后在实验室进行GPS信号回放来完成高精度机动车GPS测速仪在40～180km/h范围内特定速度值的实验室精确校准,溯源至长度和时间计量基本单位.对同一台高精度机动车GPS测速仪的现场道路实际检测和实验室GPS信号回放检测的比对试验,车速在180km/h时采用该方法的速度校准不确定度优于0.1%(k=2).     

一种基于双天线测速雷达的新型机动车现场标准测速仪

在介绍常规单天线测速雷达工作原理的基础上,分析其在实际工作中存在着由安装偏差所带来的且无法修正的现场测速误差的原因,提出了双天线测速雷达工作原理、安装偏差自修正方法以及天线结构模型,并通过实验室模拟试验以及与高精度机动车GPS测速仪进行道路实测比对试验,验证了其测速技术指标能够满足检定规程中对现场标准测速仪的要求,可作为车载机动车现场标准测速仪进行使用。     

移动式机动车激光测速仪的校准

针对移动式红外机动车激光测速仪的测量原理,详细描述了一种基于时间延迟的校准方法.采用虚拟仪器技术的机动车激光测速仪校准系统,能够将激光测速仪发射的905nm测量脉冲激光光束进行特定时间量的延迟以模拟其在空气中对应的传播距离,完成机动车激光测速仪在(20～250)km/h时速范围内任意速度值的实验室准确校准,模拟速度不确定度优于0.5%(k=2).     

移动式机动车激光测速仪的校准

针对移动式红外机动车激光测速仪的测量原理,详细描述了一种基于时间延迟的校准方法。采用虚拟仪器技术的机动车激光测速仪校准系统,能够将激光测速仪发射的905nm测量脉冲激光光束进行特定时间量的延迟以模拟其在空气中对应的传播距离,完成机动车激光测速仪在(20~250)km/h时速范围内任意速度值的实验室准确校准,模拟速度不确定度优于0.5%(k=2)。     

固体火箭发动机旋转试验速度测试仪

本文根据固体火箭发动机旋转试验速度测量特声点,在分析国内外测速仪现状后,研制出新型的多功能测速仪。输入可以配接感应式和光电式测速传感器,输入电压信号有两种形式,方波信号和正弦波信号。输出三路电压信号,其中第一路接光线示波器记录,第二路接计算机数据采集记录,第三路输出由该机数字记录表显示测量结果。该仪器中设计有标准信号源,用于校验本机及检验速度记录系统性能,数字记录表示仪可以记录测速,还可以当作高精度频率计使用,测量100kHz以下的频率信号,该仪器运用于火箭发动机旋转试验速度测量及其它机械旋转速度的测量。是一种多功能式测速仪。 本文介绍了该测速仪的设计原理,工作原理,应用及分析,技术指标,为正确地选用测速仪提供了参考依据。     

基于GPS的道路测速系统校准仪器的研制

设计研制了一个基于GPS的道路测速系统校准仪器。该仪器可通过一个GPS接收机记录运动载体的行驶速度及时间、行驶路程,工作人员还可以方便地从软件中提取任意时间、任意地点的速度或任意时间段、任意路段的区间速度,并将其与其他测速系统的测量值进行比对校准,从而完成对其他测速系统如雷达测速仪的校准溯源。     

声学多普勒测速仪标校技术研究

为了提高声学多普勒测速仪输出速度的准确度,安装过程中测速基阵与载体之间的偏差角不可忽略,安装偏差角包括航向偏角,横摇角及纵摇角三类。介绍了一种三维空间上的多普勒标定技术,通过高精度的GPS导航仪以及多普勒测速仪对海底测速,利用速度比值差校准航偏角。通过纵向剖面的几何关系,从航偏角出发进而获得纵摇角和横摇角的大小,完成了三维方向上多普勒测速仪的校准,使多普勒测速仪坐标系与载体坐标系能够进行精确转换,从而提高了声学多普勒测速仪输出速度的准确度。外场试验较好地证明了该方法的有效性,分析结论看出在二维平面上,造成误差的原因主要在于安装偏角的航向偏角,而在三维空间上,尤其垂向速度,误差主要由纵摇角和横摇角产生。该方法可以快速地对三维安装偏角进行校准,运算量小,并且在对海水测速后续研究中可以形成一套体系。     

机动车超速监测系统现场测速误差检定装置研制

为更准确地检测机动车超速监测系统现场测速误差,以社会车辆为目标速度源,在机动车超速监测系统的临近位置,架设更高精度的测速装置,对相同速度监测和图像采集区域内的社会车辆,进行同步测量和同步图像采集,通过对比两者的速度量值实现对超速监测系统的检定校准。该装置用于检定道路超速监测系统的速度量值线性与误差,可以测量足够多的社会车辆样本,重点选取限速点附近的速度测量值进行对比分析。装置安装简单,使用方便,可以大幅提升检定效率与操作安全性。     

基于多目标三维跟踪雷达的移动式机动车在线测速标准装置

为了推广在线检定方法在机动车测速仪现场实车检定中的应用,研制了一套基于多目标三维跟踪雷达的移动式机动车在线测速标准装置.首先介绍了该套移动式在线测速标准装置的设计要求;其次分析了标准装置中的速度、距离和角度测量工作原理,描述了标准装置速度测量值的溯源方法,并对速度测量误差的不确定度进行了评定;最后进行了实验室全量程模拟...     

基于真实交通状况的固定式机动车现场测速标准装置

为了满足机动车测速仪现场检测新方法的需要,研制了基于真实交通流量状态下的固定式机动车现场测速标准装置。介绍了该套现场标准装置的设计思路与设计方案,分析了现场标准装置中所用的现场标准测速仪的工作原理,并对其现场速度测量的不确定度进行评估。不确定度评估结果表明:在20～250km/h速度测量范围内,现场标准测速仪的相对扩展不确定度为0.12%(k=3)。通过2款机动车雷达测速仪样品的大样本现场试验数据,验证了机动车测速仪现场检测新方法的可行性,以及该套现场标准装置在真实交通流量状态下的实际测速性能。     

A Methodology for the Evaluation of a GPS Receiver Performance in Telematics Applications

This paper presents a methodology to evaluate the position availability of automotive grade global positioning system (GPS) receivers intended for Telematics applications utilizing a multichannel GPS satellite signal simulator in a controlled laboratory environment. Initially, field testing of two distinct GPS receivers was conducted in an urban canyon environment and a foliage environment to assess each receiver's position availability performance. Test scenarios were then developed on a multichannel GPS satellite signal simulator in order to create controlled and repeatable stimuli to the GPS receivers. The scenarios take into account the actual satellite constellations at the same day, time, and locations of the field data collections. Furthermore, the number of visible satellites and power levels was adjusted in order to stimulate the hardware tracking sensitivity, hardware acquisition sensitivity, dynamic range, and navigation filter design, all of which impact position availability for GPS receivers. Quantitative results demonstrated good correlation between the results obtained using the developed test scenarios and the results from the field testing. The proposed methodology will result in reducing validation cost and time to market for automotive Telematics products     

The validity and reliability of a portable slip meter for determining floor slipperiness during simulated heel strike

A previously developed test rig was used as starting point for designing a portable slip meter with two new features. First, an inflatable pneumatic test wheel, consisting of six slider units, was introduced as the impacting contact element relative to floor surface. Second, an inductive trigger was built into the system to facilitate a precise timing of the slider-floor contact during the test. This new test rig was designed to measure transitional friction properties of contaminated floor surfaces during simulated heel strike, which is considered the most critical phase of gait from the slip and fall point of view. Another objective was to quantify the validity and reliability of this test method in the laboratory, but not yet in the field. The measurement process was evaluated on eight wet and oily floor surfaces (vinyl and ceramic tile floorings) using two slider materials (plain, profiled), two normal loads (100, 200 N), and two sliding velocities (0.15, 0.30 m/s) as independent variables. The outputs of the portable slip meter, in terms of transitional friction coefficients, were compared to force platform-based friction values and to slip resistance values obtained with a slip simulator apparatus for laboratory testing of shoes and floor surfaces. The outputs were also evaluated against slipperiness ratings made by three male subjects in paired comparison trials, in which the subjects walked over eight wet floor surfaces wearing shoes with the plain soling material. The results showed that test option 200 N and 0.15m/s led to optimum validity despite its tendency to promote frictional vibrations (stick-slip) in the contact surface. Compared to the lower sliding speed, the higher speed reduced both stick-slip and measurement bias. Test option 200 N and 0.30 m/s was the most reliable one in this experiment. It yielded lower friction coefficients than any other test option and reduced the likelihood of underestimating slip and fall hazards. The results implied that the minimum friction coefficient was 0.25 for preventing a fall on wet floor surfaces, whereas the limit for preventing a slip was in the range 0.30-0.35. Transitional friction measurement was found to be a valid and reliable indicator for slip resistance. A more accurate control of the normal force during testing is needed for actual field use of the test method.     

GPS浮标测高精度影响因素研究

海洋二号(HY-2)卫星高度计已在轨运行两年多,亟需深入开展海面高度定标工作,基于全球定位系统(GPS)浮标的高度计海面高度定标法是主要的定标方法。GPS浮标定标法的定标精度受到时间窗口、浮标姿态、温盐以及相位中心等因素影响。为了提高高度计海面高度GPS定标法的定标精度,本文对影响GPS浮标测高精度的主要因素进行了分析研究。结果表明,在充分考虑影响因素基础上自主研制的GPS浮标高程测量精度可以达到1 cm,满足高度计海面高度定标要求。     

医用诊断X射线非介入电流仪校准技术研究

为保障我国目前使用的X射线诊断光机曝光电流量值的准确性,开展医用诊断X射线非介入电流测量仪计量校准的研究,分析国内电流仪的校准方法和诊断辐射源检定规程,结合非介入电流仪测量的物理环境条件,提出非介入电流仪的计量指标要求、校准测试设备的技术要求。详细介绍开展校准工作的测试原理和数据处理方法,将诊断辐射源首次引入到电流仪的校准工作中作为触发信号,利用标准电流源,采用多台非介入电流测量仪进行实验研究和分析,证明校准工作的科学性、可操作性、有效性。     

基于经验模态分解的载货汽车载荷动态检测策略研究

针对载货汽车载荷动态检测问题,仿真分析了汽车不同车速和载荷状态下悬架的动态特性。基于车辆载荷与悬架变量的关系,设计了一种高精度带过载保护的汽车载荷动态检测装置,采用经验模态分解法（Emprical Mode Decomposition,EMD）构建了汽车载荷动态检测装置数据处理算法。以解放赛龙Ⅱ载货汽车为试验车、MC9S12XEP100单片机为车载终端构建了车辆载荷动态检测试验平台,并对系统进行了静态标定和动态检测试验。试验结果表明：该装置在试验车车速为40和60km/h、装载量分别为空载、半载和满载状态下对车辆总重检测结果误差均小于5.0%;车速为90km/h、相同装载量状态下,检测结果误差分别为3.12%,7.616%和6.75%;由此可见,随着试验车速增大,该装置对车辆载荷动态检测精度波动范围增大,但是总体满足工程的实际需求,它为车辆载荷动态实时检测提供了一种新方法。     

Driving simulator for speed research on two-lane rural roads

The paper reports on a validation study of the interactive fixed-base driving simulator of Inter-University Research Center for Road Safety (CRISS) that was effectuated in order to verify the CRISS driving simulator's usefulness at a tool for speed research on two-lane rural roads. Speeds were recorded at eleven measurement sites with different alignment configurations on a two-lane rural road near Rome. The real world was reproduced in the CRISS driving simulator. Forty drivers drove the simulator. The results of the comparative and statistical analysis established the relative validity and also revealed that absolute validity was obtained in nine measurements sites. Only in two non-demanding configurations, were the speeds in simulator significantly higher than those recorded in the field. In these sites the mean speed in simulator was equal to or greater than 94 km/h. For these configurations, the higher speeds recorded in simulator appeared to stem from the different risk perception on the simulated road as opposed to that on the real road. The study's results should be considered for driving speed behavior research, in which simulator equipment with similar features of the CRISS driving simulator is used.     

基于间歇励磁和信号重构的电磁水表变送器研制

针对电磁水表低功耗的要求,提出间歇励磁方式,每周期进行一次三值波励磁;针对电磁水表需要在励磁电流小、传感器输出信号非常微弱的条件下实现极低测量下限的要求,提出信号重构滤波的处理方法,将幅值解调后的信号重构为矩形波信号,以便对信号进行梳状带通滤波,从而保证电磁水表的测量准确度.研制了基于MSP430低功耗单片机的变送器,...     

基于机器视觉的指针式压力表智能检定系统研究

针对传统的指针式压力表检定装置工作效率低、数据无法保存追溯等问题,设计了一种基于机器视觉技术的指针式压力表智能化检定系统。首先介绍了系统的硬件架构与软件设计,然后对其图像解析的技术原理与解决方案进行了阐述,同时提出了系统的智能控制流程与检定数据的追溯复核方法,实现了2～10块相同检定点的压力表同时进行计量检定的技术方案。实测结果表明,系统图像解析平均速度为467 ms/帧,检定效率较人工检定可提升2倍以上;对于量程2.5 MPa的0.4级精密压力表和1.6级一般压力表,系统读数相对误差分别为0.08%、0.2%。