衡器国际建议认知与应用现状浅谈（一）--检定分度值e和实际分度值d

OIML国际建议为各成员国提供同等的计量器具评估方法，避免了技术标准不同产生的技术壁垒限制，目前已经被广泛的接受和任何， OIML证书制度也成为一种全球通用和认可的制度。对各成员国而言， OIML国际建议并非是强制要求采纳的，各成员国有权利做出符合国情的采用和修改。我国衡器领域多数等同采用国际建议，但在实际应用中出现一些不一致的状况，究竟原因何在。本文将在分度值、标定方法和计量器具软件三个方面展开探讨，以求较真实的认知和理解。     

电子皮带秤示值误差测量不确定度分析

随着韶钢铁前计量管理系统的正式运行,担负着铁前各单位工序之间物料输送计量用的电子皮带秤,在各单位成本核算,降低能源消耗,提高经济效益的需要作用日益主要。为此,对承担煤炭、焦炭、烧结矿等物料输送计量的电子皮带秤的计量性能提出了更高的要求,本文在对电子皮带秤进行计量检定,判断是否符合国家计量检定规程的要求之外,试对其计量检定过程中不确定度来源进行分析,从定量的角度分析计量皮带秤的计量性能。     

Investigations of piezoelectric force measuring devices for use in legal weighing metrology

In conjunction with low-drift charge amplifiers, static force and weighing measurements become increasingly important for piezoelectric force transducers if the measuring time and the time of load change are in the range of a few minutes. The investigations according to the international recommendation OIML R60 (International Recommendation OIML R60 for load cells, Edition 2000, Bureau International de Métrologie Légale, Paris, France), which are presented here illustrate that piezoelectric sensors can be used for static applications with low-accuracy requirements (e.g. class D for ordinary-accuracy weighing instruments). With suitable methods for the compensation or adjustment, the sensors even meet the higher requirements of medium accuracy class C (e.g. commercial scales). Especially for high-nominal loads, the piezoelectric measurement technology offers unused potential also for static precision measurements.     

Traceability of mass measurements in Estonia

Realization of the national mass scale for the optimal coverage of the industrial need for the mass calibrations at the Estonian national metrology institute, AS Metrosert, is described. The cost effective technical solutions to meet the calibration requirements of the advised OIML class E1 weights have been established. The traceability to the International Prototype Kilogram, the measurement capability achieved, and the results of participation in international comparisons are described in detail. The actual need for the mass calibrations in Estonia with respect to the measurement capability of the laboratory is estimated.     

Uncertainty of measurement by Monte-Carlo simulation and metrological reliability in the evaluation of electric variables of PEMFC and SOFC fuel cells

The aim of this work is presenting results of uncertainty of measurement calculations applied to both a low temperature PEMFC (proton exchange membrane fuel cell) and a high temperature SOFC (solid oxide fuel cell) by using Monte Carlo method simulations. The intention is correlating electric voltage, obtained in the technical literature, and energetic efficiency of the fuel cells studied in this work. In order to validate the Monte Carlo results achieved a comparison with the procedure for the evaluation of the uncertainty of measurement existing in the GUM 95 ”Guide to the Expression of Uncertainty in Measurement” (by BIPM, IEC, IFCC, ISO, IUPAC, IUPAP and OIML) is made. A reasoning of the balancing of the sources of uncertainty is presented as well. In last, it is discussed why the calibration process and traceability of the voltmeter are key factors in providing reliable metrological results in the production of electricity by fuel cell technology. This work is the first part of a broader study from which the next steps will be the validation of these presented simulations by fuel cell bench tests and the planning and development of Brazilian Conformity Assessment programs for PEMFC and SOFC fuel cells afterwards.     

Water density formulations and their effect on gravimetric water meter calibration and measurement uncertainties

In the gravimetric calibration method of water meters, the volume of water that has passed through the equipment under test (EUT) is generally collected into a tank and the quantity (mass) determined by weighing. The mass of water collected is then converted into a volume. This conversion of mass into volume requires knowledge of the water density, which can be estimated, measured directly or determined by other means. The error of measurement of the EUT is determined by comparing the volume recorded by the EUT and the volume collected in the tank. The density of water is, therefore, one of the major causes of measurement uncertainty in laboratory calibration of water meters using the gravimetric method. Water meter calibration facilities commonly use density formulations proposed by the International Standards Organisation (ISO) and the Organisation for International Legal Metrology (OIML). In Australia, additional guidance in water density determination is provided by the National Measurement Institute (NMI). In this study, testing was undertaken using ten positive displacement water meters arranged in series in the test rig to evaluate some of the common water density formulations used in Australia. The effect of these different formulations on the water meter error measurement was determined, as well as the effect on the measurement uncertainties. The results shows that the use of these different density formulations evaluated do not significantly affect the water meter error of measurement or the uncertainty of measurement. There was no apparent correlation between the water meter error and the meter position in the test rig. It was also determined that if the water density was adjusted only for temperature effects, a maximum of 0.05 and 0.15% drift in meter error and measurement uncertainty respectively, can be expected.     

一种新型混合动力总成的开发与应用

项目开发的系统为混联式驱动结构,双电机模式,混合程度深,更加适合复杂的城市工况;电机功率大,起步快,加速快;制动能量回收率高,节油潜力大。经过装车运行,试验结果证明系统的可靠性和先进性。     

Optimization of flow rate measurement using piezoelectric accelerometers: Application in water industry

This paper presents a method for measuring flow rates in pipelines based on the flow induced vibration principle using water as fluid, eliminating the need for interrupting the flow and opening of the pipeline for installation of traditional water flow meters. Experimental measurements are carried out in an accredited laboratory for calibration of rate flow meters and a metrological validation, followed by an uncertainty evaluation, are presented. Data analysis is accompanied by a method of optimization that minimizes adjustment errors of measurement using regression by parts and by the selection of the optimum period to estimate more accurately the flow rate. The results meet the specifications of Brazilian Metrology Institute.     

混合动力系统控制软件的开发

为提高混合动力电动汽车图形化算法人工编码的可靠性与快速性,以某型混联式混合动力电动轿车为研究对象,对以"驾驶员意图识别-能量管理-协调控制"为核心的多能源动力总成控制策略进行研究.按照混合动力系统多能源动力总成控制的特点,并针对不同的功能和性能需求,提出基于嵌入式实时操作系统μC/OS-Ⅱ和层次式状态机实现框架的"四层/两库/一框架"式软件体系结构:从而将软件的不同功能分开,减小模块间的耦合,便于并行协同开发,提高算法的可移植性及可维护性.解决在手工编码方式下快速实现Matlab/Simulink/Stateflow仿真模型中的层次式状态机算法这一难题.将所开发的控制算法应用到该车上,进行多种工况的试验,并对换挡及制动能量回收等典型工况做简要分析.经过系统的实车试验及可靠性考核,证明控制软件可以准确地控制目标车型实现多工况运行及工况切换,且具备较高的可靠性.     

关于谐波下电能计量方法的研究

首先从谐波环境下电能计量的基本原理出发，分析了谐波对不同电能表计量的影响，对谐波下电能计算和电能质量分析的方法进行了讨论，设计完成新型基波电能表，以改善电能计量的准确性与合理性。     

Metrological evaluation of skin conductance measurements

Electrodermal activity is a frequently measured physiological response in various applications. It is also being increasingly used in clinical applications. Numerous published papers report results of skin conductance measurements in absolute values, but few are concerned with the quality of results. This paper describes a procedure for metrological evaluation of skin conductance measurement. Three commercial devices for measuring skin conductance were calibrated by comparison with a precision digital ohmmeter used as a reference. Combined measurement uncertainty of skin conductance meters was calculated by means of uncertainty of reference instrument and uncertainties due to measurement repeatability, reproducibility, resolution and environmental condition. Additionally, a procedure for evaluation of the effect of electrode displacement and electrode gel was shown. A model of finger skin conductance profile was build. Measurement uncertainty analysis showed that contributions due to resolution and sensitivity of the measuring device, usually obtained from specifications, are negligible when compared to uncertainty of measuring method. Our results indicate that measurement uncertainty does not meet target uncertainty requirements for certain applications.     

柴油机燃油喷射系统高速电磁铁驱动特性研究

在分析喷油器高速电磁铁驱动电路结构和特点的基础上,设计了一种具有能量回收的喷油器高速电磁铁驱动电路。基于MATLAB/Simulink对该驱动电路进行仿真分析,根据仿真结果构成实际驱动电路。试验结果表明:改进后的驱动电路性能优异、运行可靠,能够实现电磁铁在高压下的迅速开启和快速关闭,可以满足精确控制喷油量的实际使用要求。     

基于灰色理论的继电器电接触可靠性预测

电接触可靠性是有触点电器产品可靠性的一个重要方面,所以评估触点的电接触性能及可靠性和预测其失效时间对提高有触点电器产品的使用可靠性具有重要的应用价值。针对继电器失效原因的复杂性,提出基于灰理论的电接触可靠性预测。通过建立单变量预测模型GM(1,1),较好地预测电接触失效的问题。并且用动态接触电阻测量系统进行HH52P型电磁继电器失效检测试验,证实灰预测模型的准确性。     

电力系统谐波对电能计量的影响

高压大功率电力电子电源容量的不断提高,给电力系统的电量计量带来了诸多问题.在分析电能表计量原理的基础上,对比分析了在谐波情况下电子式与电磁感应式电能表的计量差异,提出基于电力谐波的合理电能计量方法,并进行模拟验证.     

Probabilistic measurement evaluation for the implementation of the Measuring Instrument Directive

The approval of the European Measuring Instrument Directive (2004) constitutes a noteworthy novelty in legal metrology, since this Directive implements the so called “new approach” to technical normalization and harmonization and moves toward a “global approach” to evaluation and conformity. According to the principles of the new approach regulatory model, the Directive establishes some essential requirements for a wide class of measuring devices, subject to legal control, whilst leaving manufacturer free to develop proper technical solutions for meeting them. Moreover, the conformity of instruments to prescribed requirement may now be ensured through quality assurance procedures, in the context of a quality system. This increase in technical and metrological freedom on the manufactures side may promote innovation, social benefit and costumers’ satisfaction, provided that some recent advances in measurement theory are properly employed.In this paper, after a brief discussion regarding the philosophy of the Directive, a probabilistic approach to conformity assessment is presented. The proposed approach concerns some currently open issues such as measurement uncertainty due to the influence of operating conditions, the assessment and reduction of the risk related to measurement uncertainty in conformity decision and the costs of instrument uncertainty and of non-conformity, for both the manufacturer and the user. The approach is supported by a package of software codes that assists the application of verification procedures, with a user-friendly approach.All these aspects are discussed with reference to the case of water meters, considering both end-of-production acceptance tests and the performance of meters under operation.     

浅谈定量包装秤的应用

简单介绍了定量包装秤的结构及原理，并就OIMLR61号国际建议中对定量包装秤的主要计量指标进行了表述。同时对定量包装秤的一般故障、维护和在选择定量包装秤时应注意的几个问题进行了说明，以便用户更好地选用。     

基于PSф8的无线传输的太阳能衡器系统

本文介绍了集成高精度时间数字转换器(TDC)的PSф8单芯片衡器解决方案.阐述了PICOSTRAIN测量原理,给出了利用PSф8设计的符合OIML Ⅲ精度等级的衡器系统;本系统采用电阻应变式称重传感器,利用太阳能供电,通过2.4GHz频段进行数据无线传输.     

Evaluation of the uncertainty of an optical machine with a vision system for contact-less three-dimensional measurement

Optical machines with a vision system containing a video camera are designed to perform contact-less three-dimensional measurements. They are becoming more widely used in the industrial sector because of the many possibilities for automation they permit and because of the speed and economies in measurement tasks that can consequently be obtained. Within dimensional control these machines introduce significant characteristics of flexibility, savings and reliability. Therefore the purpose is to identify the principal metrological characteristics of such machines and so characterise the metrological traceability of the measurements obtained from them. The aim is to qualify each part of the optical machine as well as on the whole. Previously, no metrological traceability of this equipment has been provided in primary metrology, either at national (SIT—Sistema di Taratura in Italia—Calibration System in Italy) or at international level (EA–European co-operation for Accreditation). For this reason we develop a mathematical model that permits the evaluation of the measurement uncertainties in the use of such a device. The purpose is to obtain the certification of the measurement results furnished by the optical machine in as broad a context as possible. The experimental results of the tests are introduced for validating the proposed method. This paper provides the basis of the expression of the uncertainty of a measurement result obtained using the optical measurement machines and it shows the necessary requirements for the numerical evaluation of such uncertainty.     

SMP 及绝缘子类电连接器焊接质量改进方案研究

某工程大量应用某型电连接器（SMP 和绝缘子）,以实现高密度硬装互联,该类电连接器装配精度要求高,装焊难度大。为了满足产品的装焊质量及电性能要求,针对该类电连接器的装配问题,从焊前处理、焊接过程控制和机械加工质量控制等方面着手对该类电连接器焊接质量的改进方案进行了试验与探究,提出了4种改进方案,包括焊前去金处理、腔体焊前去毛刺与超声清洗、设计制作装焊夹持工装与机械加工专用特型刀具,并通过对比试验验证了各个方案对焊点质量提升的有效性。     

基于CAN总线电传动车辆辅助电气系统设计分析

电传动自卸车辆的辅助电气主要完成车辆仪表、灯光、雨刮、液压逻辑等控制功能以及为整车弱电设备提供电源,主要采用点对点模式,原理简单但存在着整车线束数量多、检修困难、难以维护保养等诸多弊端。针对存在的问题,提出分布集中式的辅助电气模式;对系统布线进行设计,根据各部分功能和布置的不同,采用分布式和传统点对点连接方式相结合的方法,降低整车线束的复杂程度;对辅助电气系统进行设计,设计控制器和端口程序,并对主控制器线路和液压控制器线路进行设计,使其满足整车的使用需求;对辅助电路进行仿真实验,选取机油压力检测和整车紧急双移线试验进行各辅助电路测试。结果可知:机油泵转速、机油温度和机油压力的检测准确度高,误差小于1%;整车实际运行轨迹与理想双移线运行轨迹有较好的吻合;辅助电路能够实现设计的控制机理,顺畅的信号流,CAN总线的网络能够保证正确的通信,准确性和实时性得到实现;为此类设计提供参考。