基于LabVIEW的疲劳试验机同轴度检测仪设计

针对传统疲劳试验机同轴度检测设备接线繁琐、计算复杂等不足,提出了一种基于LABVIEW的疲劳试验机同轴度检测仪的设计方案,并对该检测仪的硬件和软件设计进行了分析。此检测仪具有低成本、设计灵活、界面友好、应用简单等特点。实践证明该检测仪运行稳定、可靠。     

正交试验在优化气体容积式流量计检定条件中应用

针对气体流量计检定影响因素较多的问题,以容积式气体流量计为例,提出以示值误差为优化综合指标,采用正交试验法分析检定过程中主要影响因素,包括温度、湿度、同轴度、取压方式等。确定各因素对示值误差影响的主次顺序,找出相对最优的检定条件。实验结果表明：采用正交试验方法优化检定条件方案具有可行性和有效性。     

量块双频激光干涉坐标测量系统的设计

目前,对于尺寸小于300 mm的四等及以下的非标称尺寸量块可以采用高精度万能测长仪测量,而对于尺寸大于300 mm的三等及以下非标称尺寸量块,则没有很好的测量方法。为此,提出了基于坐标测量机的双频激光干涉量块检定系统,对700 mm三等量块进行测量并对校准系统进行不确定度分析。通过与量块附带检定证书和JJG 146-2003量块检定规程的比对,验证了量块检定系统的准确性与可靠性。     

立柱缸筒加工内止口同轴度超差的控制措施

缸筒内止口同轴度超差会影响液压油缸的性能,针对缸筒加工中造成同轴度超差的原因是定位基准与工序基准不重合以及普通中心架定位调整不精确,提出了保证缸筒加工中同轴度超差的控制措施,改进装夹方式和控制中心架位的尺寸公差带,提高内止口与缸筒内孔的同心度.     

压力表测量不确定度评定及检定调压速率研究

指针压力表因具有稳定可靠的特点而被广泛应用于工业生产中，为确保其测量结果准确可靠需进行定期检定。该文针对手动检定指针压力表过程中示值误差的测量不确定度进行分析和评定，采用表示指南法，根据检表过程中可能的因素分析各不确定度的来源，计算各个不确定度分量，再得到合成不确定度评定结果；并进行手动操作检定装置检定压力表打压速率实验，探究检定过程中检定点之间的压力变化规律，得出适宜的升、降压速率。研究结果可以反映被测量值的误差波动范围，利于对检测结果的质量进行合理判断，为自动化的压力控制速率提供参考依据。     

压力测量不确定度评定基础知识讲座(四)第四讲油罐中油量测量不确定度评定

采用静压法原理测量罐内油品质量的方法有国标GB/T 18273-2000标准和国家检定规程JJG 759-1997.本文所采用的测量方法均符合国家标准和国家检定规程.     

噪声系数的测量方法

介绍了噪声系数的几种测量方法,重点分析了实际工程中常用的基于噪声分析仪的Y因子法测量噪声系数的原理和基于频谱分析仪的增益测量方法。测量不确定度是噪声系数测量中的一个关键指标,在增益测量法的论述中,从理论的角度详细阐述了影响噪声系数不确定度的因素和测量不确定度的定标方法,并介绍了使用该方法测量噪声系数的一些注意事项。     

浊度计示值相对误差不确定度的评定分析

按照JJG 880-2006《浊度计检定规程》对浊度仪进行示值相对误差的检定,对检定结果的不确定度来源进行了分析,对各不确定度分量进行了评定并合成了标准不确定度.当浊度仪的示值12NTU时,检定结果的扩展不确定度U=3.2％(k=2).     

圆柱工件同轴度非接触测量方法

应用精密激光位移测量技术、电机控制技术,结合精确的信号处理技术,设计了圆柱工件同轴度非接触测量系统,并推导了同轴度误差的计算方法,阐述了系统的组成和总体结构,并通过实验对测量系统进行了验证。     

双LD-双PSD同轴度测量技术研究

介绍了双LD-双PSD同轴度测量仪的结构：在主、从动轴上相向各固定一支半导体激光准直光源（LD）和光斑位置传感器（PSD）,激光束在对方的PSD光敏面上形成测量光斑;据该结构建立了测量过程的数学模型,讨论了所存在的主要系统误差以及为消除系统误差的影响所应采取的措施;结论：若激光器不存在安装倾斜误差,PSD传感器也不存在安装平移误差,则在任意一个转角位置进行测量可得到4个同轴度偏差参数,否则要在任意两个转角位置进行测量方能消除激光器和PSD传感器的安装误差对测量结果的影响。     

结合小波消噪的捷联惯导系统传递对准性能改进

针对机载捷联惯导系统的传递对准问题,给出了一种速度+姿态匹配算法,旨在强调姿态失准角和惯导器件误差参数估计性能的改善.并基于惯导测量单元 (inertial measurement unit,IMU)原始测量信号的频谱特征,引入了小波串级消噪算法,拟通过对IMU测量进行消噪,进一步提高传递对准的性能.仿真结果验证了所提算法的可行性.     

基于陀螺仪的炮塔角速度测量装置的设计

针对国内炮控系统性能参数测试中对角速度测量的成本较高、操作复杂、时间较长等问题,设计了一种基于MEMS陀螺仪的炮塔角速度高精度测量装置,通过中值滤波、均值滤波以及加权平均融合的方法,抑制了测量噪声等因素对炮塔角速度值的影响.通过在转台和坦克上对该装置进行标定和测试,分析了滤波和融合前后的实验结果,其对炮塔角速度的测量精度可达0.02°/s.该装置操作简单、灵敏度高、成本较低、实用性强,能有效地提高测试精度,节省了人力物力,缩短了测量时间,满足实际应用的需求,具有很高的实用价值.     

Camera calibration issues in robot calibration with eye-on-hand configuration

One of the possible methods for accurate, fast, low-cost and automated robot calibration is to employ a single camera rigidly mounted to the robot end-effector together with a single camera calibration board. The end-effector pose is measured by calibration of the camera at every robot measurement configuration. This paper contends that, with several modifications, Tsai's radial alignment constraint (RAC) camera calibration method can be made a fast and sufficiently accurate pose measurement technique. This paper focuses on speed, accuracy and cost enhancement of RAC-based camera calibration. A fast RAC-based algorithm is proposed, which cuts the computation time of Tsai's original algorithm by about a 5: 1 ratio while keeping its accuracy within the tolerances required for a successful robot calibration. A low-cost method for estimation of the ratio of scale factors of the camera/vision system is also proposed. This method does not require a precision vertical micrometer stage to provide non-coplanar calibration points data for camera calibration. Finally, the phenomenon of perspective projection distortion of circular camera calibration points is fully analyzed and error compensation methods are proposed.     

基于HMM/ KF 滤波的捷联惯组快速标定方法

提出一种快速标定捷联惯组常值零偏的六位置测试法.首先在传统解析式粗对准的基础上引入HMM/KF滤波器,利用HMM/KF滤波器滤除对准环境中的干扰噪声,实现捷联系统粗对准;然后分析利用粗对准的对准精度与惯性器件误差之间的关系,推导出求取捷联惯组常值零偏的数学表达式.对比实验分析结果表明,采用滤波技术的对准方法能够提高方位对准精度,而且能够快速有效地标定和补偿上一标定阶段残留的惯性器件常值零偏,改善导航性能.     

基于SPAN系统的姿态检测方法的研究

介绍了一种新型惯性组合导航系统-SPAN,阐述了SPAN的工作原理、系统组成、对准技术及在转台上的测试方法和数据处理方法,采用静态、连续匀速运动和正弦运动不同的测试方法,通过同步采集SPAN数据和转台数据,应用MATLAB数据处理软件对系统的输出数据和转台数据进行比对和分析,结果证明,此系统的姿态精度满足所给定的精度指标,具有广泛的应用前景和推广价值。     

基于PC的直线度误差自动测量与评定系统

介绍了一种新颖的直线度误差自动测量系统———便携式激光准直仪。直线度误差评定软件设计时 ,考虑了直线度误差的两类测量方法和两种评定方法 ,具有运算速度快、适合直线度误差测量仪器多等特点     

基于光学扫描的高精度基准孔测量方法研究

飞机部件装配连接孔的位置精度对飞机装配质量和使用寿命有重要影响。提出了一种高精度基准测量技术,利用伺服电机和光学扫描仪组成基准找正装置对基准孔进行扫描得到基准孔三维点云数据;然后对测量数据进行基准孔边界提取并通过最小二乘法计算出基准孔中心坐标;最后利用基准找正装置坐标系和数控机床坐标系的标定关系,计算得到基准孔中心在机床坐标系下的坐标。通过实验验证,证明了该方法能够对基准孔三维坐标进行精确测量,且具有一定的鲁棒性。     

Dynamic registration selection for fingerprint verification

Information fusion is a powerful approach to increasing the accuracy of biometric authentication systems, and is currently an active area of research. The majority of studies focus on combining the results from multiple verification systems at the match score level using either a classification or combination scheme. However, there are advantages to performing the fusion at an earlier stage of processing. Fingerprint registration involves finding the translation and rotation parameters that align two fingerprints; a challenging problem that can be approached in a number of ways. The fusion of fingerprint alignment algorithms is introduced in the form of dynamic registration selection. A Bayesian statistical framework is used to select the most probable alignment produced by competing algorithms. The results of the proposed technique are tested on multiple FVC 2002 databases, and are shown to outperform methods based on match score combination.     

Automated Alignment of Robotic Pan-Tilt Camera Units Using Vision

In this paper we show how to carry out an automatic alignment of a pan-tilt camera platform with its natural coordinate frame, using only images obtained from the cameras during controlled motion of the unit. An active camera in aligned orientation represents the zero position for each axis, and allows axis odometry to be referred to a fixed reference frame; such referral is otherwise only possible using mechanical means, such as end-stops, which cannot take account of the unknown relationship between the camera coordinate frame and its mounting. The algorithms presented involve the calculation of two-view transformations (homographies or epipolar geometry) between pairs of images related by controlled rotation about individual head axes. From these relationships, which can be calculated linearly or optimised iteratively, an invariant line to the motion can be extracted which represents an aligned viewing direction. We present methods for general and degenerate motion (translating or non-translating), and general and degenerate scenes (non-planar and planar, but otherwise unknown), which do not require knowledge of the camera calibration, and are resistant to lens distortion non-linearity.Detailed experimentation in simulation, and in real scenes, demonstrate the speed, accuracy, and robustness of the methods, with the advantages of applicability to a wide range circumstances and no need to involve calibration objects or complex motions. Accuracy of within half a degree can be achieved with a single motion, and we also show how to improve on this by incorporating images from further motions, using a natural extension of the basic algorithm.     

力传感器在发动机推力试验工况下的技术特性分析

力传感器是工业测控领域的常见测量仪器,其数据准确程度是应用效果的重要保证.力传感器在航空发动机试车台等推力测量场合的受力工况比较复杂,与实验室校准时的工作状态存在明显差异,由此引入的数据偏差需要进行分析和校准.通过对发动机推力试验中常用的应变式力传感器的使用工况进行分析,并与实验室校准条件进行比较,对力传感器在不同的环...