贯通测量误差预计在矿山测量中的应用

贯通误差点的多少,直接关系到整个矿井工程质量和使用。在矿山测量中就选择合理的贯通测量方案和合适的测量方法进行分析,提出贯通方案测量技术措施,并对误差预计方法用实例加以说明。     

关于大型容器几何尺寸测量的探讨

测量大型容器几何尺寸不仅有形状误差,还有位置误差问题,且测量精度高。我们利用工业尺寸三坐标测量系统(MetroIn)掌握了轴对准输入虚拟点坐标测量法,先投影后平移测量法,反射靶与搬站技术相结合测量法,虚拟点拟合筒体测量等检验方法;该测量方法满足了公司大型容器产品几何尺寸测量精度的要求,缩短检验周期,实现了多项测量技术国内领先的目标。     

基于神经网络的游梁式抽油机示功图软测量研究

游梁式抽油机示功图是悬点载荷和悬点位移的关系图,示功图可以诊断油井的工作状况。至今没有一种有效方法实时测量示功图,主要原因是载荷传感器容易老化及使用寿命短。针对游梁式抽油机的示功图实时测量难问题,总结了现有的示功图间接测量方法后,提出了基于神经网络的示功图软测量方法。该方法的核心是实时测量游梁式抽油机的相关物理量,如电机功率、游梁摆动角度,利用神经网络的非线性逼近功能,预测抽油机悬点载荷。通过数据通信手段,把相关的现场数据传到数据中心,数据中心的示功图测量单元由神经网络预测抽油机悬点载荷,加上悬点位移,得到抽油机示功图。实验仿真表明基于神经网络的示功图软测量方法是可行的,有推广应用价值。     

座面角度测量精度的分析

介绍了几种座面角度的测量方法,并根据孔板和针阀体座面角度的具体结构,利用误差分析的方法,分析了每种测量方法的测量精度及其满足公差要求的程度,为不同零件不同公差要求下座面角度测量方法的选择提供了依据,同时也为解决测量方法和测量手段的选择问题提供了一种基本方法。     

叶片型面CMM测量与误差处理技术

介绍了汽轮机叶片的测量方法,并着重叙述了三坐标测量机(CMM)测量的原理;在对叶片截面进行测量过程中,分析了影响CMM测量精度的误差源,列出了CMM测量中经常出现的问题,并提出了相应的误差处理方法。     

磷酸铁锂电池内阻连续动态测量与分析

磷酸铁锂电池内阻测量目前大多存在耗时长、测量结果不连续等问题。文章提出一种新型的内阻测量方法——双倍率曲线法。基于该方法,对不同温度下电池内阻进行测量并进行误差分析。结合误差分析结果发现,该测量方法的适用放电状态（state of discharge, SoD）区间为5% ~ 90%。对该区间内平均内阻与温度之间的关系进行定量分析,得到平均内阻随温度变化的关系式。相比于以往的其他测量方法,该方法的提出能够有效缩短内阻测量时耗,可为在线内阻测量的实现提供一定的研究基础。     

曲轴连杆轴颈中心距测量方法改进

介绍了柴油机曲轴连杆轴颈中心距的测量方法,分析了传统中心距检测的方法所带来的误差。详细介绍了专用检具的结构设计,材料选择,并对综合误差进行了分析。改进后的专用检具可以有效保证曲轴连杆中心距测量的精确度,而且操作简便。     

三维激光点云支持下的变电站立柱倾斜变形监测

水利工程中常用立柱支撑上部结构，为保证上部结构稳定，需监测立柱变形，确保立柱倾斜角度在允许范围内。通过全站扫描仪的波形数字化测距技术进行非接触式测量，采集高精度点云数据，采集过程中通过后方交会法计算各观测站的三维坐标，将观测数据统一到一个坐标系统中，无需数据配准，避免了观测误差的传递。提出利用点云的立柱倾斜形变算法，采集两期点云数据后基于真配对点计算形变量，并通过点面优化算法减少误差，计算得到立柱的倾斜角度。为验证形变算法的精度，设计了仿真试验模拟立柱倾斜变形。试验结果发现，实际倾斜角为0°16′49″,计算倾斜角为0°16′57″,算法误差小于20″,满足高耸结构的变形监测要求。所提形变算法可应用于立柱倾斜变形监测领域。     

浅谈气缸套同轴度在三坐标上的正确测量

本文介绍了气缸套同轴度在三坐标上的正确测量方法,利用三坐标测量机进行检测,三坐标测量既直观又方便,且测量精度高,可以大幅度的降低生产成本,缩短生产周期,但由于不正确的评价方式,可能会出现测量结果误差很大,从而误导生产过程的控制。     

粗加工曲轴相位专用测量工具的设计与应用

简要介绍ZD30四缸曲轴粗加工相位的测量方法及其检具的设计.并使用曲轴综合测量机测量曲轴,其测量数据和检具测量数据进行对比分析,为检具准确性的确认提供了依据.检具操作简单,满足了现场快速测量的需要,测量数据直接可指导加工机床的精度调整.     

Use of autoregressive models to generate a series of daily averaged point cloudiness values

Analysis of observed data for 10 years in two Romanian localities showed that the daily averaged point cloudiness in a given day mainly depends on the cloud cover amount from the past two days. Hence, first or second order autoregressive (AR) processes can be used to generate a point cloudiness time series. The second order models are slightly better than the first order models. The AR models generate data whose mean and standard deviation are close to those of the observed data. Good agreement between the skewness of the observed and synthetic data occurs during the warm season. No concordance was emphasized between the kurtosis of observed and generated daily averaged point cloudiness values.     

风速计安装间距对其测量偏差的影响研究

以某风场1．5MW风电机组作为研究对象,根据流体力学以及风速的空间相关性特性对机组两个风速计测量偏差进行研究。研究表明,叶根后部湍流在不同风速下,其影响区域宽窄不同,两相距一定距离的风速计不能迅速处于同一流体状态,从而导致所测的风速值不同。另外,不同两点间风速空间距离越大,相关性越低,数值差异越大,因此,两个风速计间的安装距离是影响测量结果偏差的主要原因之一。     

输电线路多旋翼无人机激光雷达点云数据自动分类技术研究及应用

  [目的]  旨在提高输电线路激光点云数据处理的效率和质量，为输电线路树障检测提供数据保障。  [方法]  基于自主研发的激光雷达无人机，提出了一种新的点云自动分类算法；基于该算法，研发了一款树障隐患分析软件，实现了一键式点云自动分类。  [结果]  研究表明:点云分类的正确率可达到95%以上，点云自动分类的效率可达60 km/h，且在杆塔与电力线、杆塔与植被相互交叉的复杂区域，也取得了较好的分类效果。  [结论]  本方法为树障隐患的分析提供了高效率、高质量、全自动、智能化的数据处理手段，有效地提高了地理空间三维信息数据的获取精度和处理效率。     

Sampling and estimation of better defined cloudiness for Dar es Salaam

We report on one year of special point cloudiness observations at the University of Dar es Salaam Radiation Calibration Station. The data are compared with long term averages and simultaneous observations at a nearby basic network station and analyzed for influences of sampling rate. Monthly and seasonal averages and seasonal diurnal trends indicate that adding more observations to the two daily routine ones will for our cases not improve the accuracy of average point cloudiness data for use in relationships with solar energy flux densities. The addition of percentage of point cloudiness and percentage of possible sunshine from Campbell-Stokes duration measurements shows values much higher than 100%. This overestimation of cloud shade area, the seasonal trend and the high average of this overestimation are explained from objective observation problems and cloud/sky conditions. Comparison with areal cloudiness data obtained from satellite observations shows that cloud shade area is on the average also in the tropics more representative for areal cloudiness. Such data do not suffer from inaccuracy due to variability in overestimation, as does point cloudiness. Such results explain a large part of the inaccuracy of using empirical average point cloudiness/solar energy flux densities relationships. The overestimation problem did not influence the conclusions on sampling rates. The Campbell-Stokes derived cloud shade area is recommended for use as ground truth for satellite cloudiness, rainfall, solar energy and energy balance studies in the tropics.     

高拱坝边坡开挖面质量快速评定与实践

以我国西部某高拱坝边坡开挖面为例,利用三维激光扫描技术快速、全面地获取开挖面点云数据信息,制定合理的数据采集流程,对所采集的开挖面空间数据信息进行处理并建立数据库。在施工现场直接利用点云数据对边坡开挖质量进行实时评价,实现了高拱坝边坡开挖质量快速评价的目标,对加快施工进度和保障施工质量具有重要的工程意义。     

Application of beta distribution model to Malaysian sunshine data

Malaysian sunshine data covering a ten-year period were fitted to a beta distribution model. Most of the months follow mount shape distributions. The K–S statistics indicated that the distributions fitted well the Petaling Jaya and Subang stations. All months could not be rejected at 5% level. For the Bayan Lepas and Kota Bharu stations, some months were significantly different. Our data showed a weak empirical relationship between the mean and standard deviation and this rules out the possibility of using tabulated mean sunshine data to estimate the standard deviation. The standard deviation must therefore be calculated from the measured data. For Malaysia, measured daily sunshine data must be made available before the model can be used.     

Estimation of height-dependent solar irradiation and application to the solar climate of Iran

An explicitly height-dependent model has been used to estimate the solar irradiation over Iran which has a vast range of altitudes. The parameters of the model have been chosen on general grounds and not by parameters best fitting to any of the available measured irradiation data in Iran. The estimated global solar irradiation on the horizontal surface shows a very good agreement (4.1% deviation) with the 17-year long pyranometric measurements in Tehran, and also, is in good agreement with other, shorter available measured data. The entire data base of the Iranian meteorological stations have been used to establish a simple relation between the sunshine duration records and the cloud cover reports which can be utilized in solar energy estimations for sites with no sunshine duration recorders.Clear sky maps of Iran for direct solar irradiation on tracking, horizontal, and south-facing vertical planes are presented. The global solar irradiation map for horizontal surface with cloudiness is zoned into four irradiation zones. In about four-fifths of the land in Iran, the annual-mean daily global solar irradiation on horizontal surface ranges from 4.5 to 5.4 kWh/m².     

内河运营船舶技术经济参数的模拟计量及仿真研究

本文对内河运营船舶技术经济参数的模拟法进行了研究，编制了相应的计算功率、燃油耗率、航速等参数的计算机仿真程序．运用这些程序可以得到船舶任意工况下的主要参数．结果表明，模拟计量结果与用仪器直接测量所得结果误差小于7．5％，与理论设计参数的相对误差小于4％．     

破坏性测量系统稳定性分析初探

介绍了破坏性测量系统稳定性分析的具体运作方法,并通过连杆表面硬度测量的实际案例,分别运用均值-极差法和单值-移动极差法,详细阐述了样本选择、原始数据的采集及数据的计算与分析等。     

含易挥发组元炉渣的高温性能检测

冶金炉渣常含有易挥发组元,在加热过程中,这些组元的挥发使得炉渣成分发生变化,导致炉渣性能测定误差(或称为测不准),如炉渣的熔点、粘度等测定。基于对挥发机制和炉渣性能测定过程,探讨了现行冶金炉渣性能测定中易于造成误差的原因,提出了对现行测定方法中冶金炉渣成分进行修正进而与高温性能测定结果对应的方法。对含易挥发组元的炉渣,如高氟化物含量、高钾钠氧化物含量以及高铅锌氧化物含量的炉渣性能测定具有参考价值。