On-machine profile measurement of a micro cutting edge by using a contact-type compact probe unit

A new contact-type on-machine measurement system is designed and developed for the evaluation of a micro cutting edge profile. The measurement system is composed of a compact probe unit having a sharp stylus mounted on a flexible beam, an inner displacement sensor for the detection of the stylus displacement, and a two-axis precision positioning system. For the evaluation of tool faces having a steep slope, a new probing procedure with the enhancement of the inner displacement sensor integrated into the probe unit is newly proposed. After the design and development of the probe unit, the feasibilities of the developed measurement system and the proposed probing procedure are demonstrated through some basic experiments. Regarding the out-of-straightness and angular error motion of the two-axis positioning system employed in the developed measurement system, a pair of length gauges is newly employed to reduce the influences of error motions of the stage system. The topographic profile of the micro cutting edge obtained by the measurement system with the modified probe unit is then compared with those obtained by a commercial stylus profiler and a laser confocal microscope. The feasibility and effectiveness of the developed on-machine tool edge profile measurement system are also demonstrated through uncertainty analysis based on the GUM with the Monte-Carlo method.     

光电内窥参数检测装置

报导一种新的光电内窥参数测量装置。将一半导体激光器发出的光束经柱面镜汇聚成一细线,通过特殊设计的折反棱镜将其沿轴线方向投影到管孔内壁,得到管孔内壁的光截轮廓,该轮廓经物镜成像到CCD光敏面,通过图像卡采集到计算机。在计算机图像测量及辅助提示下,完成参数测量。此外,该装置还可在测量显微镜横向移动导轨及读数手轮的配合下测量内孔中径。实验结果表明轴向测量的重复精度为±17μm;中径测量的重复精度为±12μm.它在工业制造领域内具有广阔的应用前景。     

基于ASODVS的全景相机运动估计及管网3D重构技术

针对地下管网的空间三维测量、三维形貌重构难等问题,提出了一种基于主动式全方位视觉传感器(ASODVS)的相机运动估计及管网3D重构解决方案。通过携带有ASODVS的管道机器人进入管道内部,实时获取管道内壁纹理全景图像和全景激光扫描图像;首先对全景激光扫描图像处理解析出投射在管道内壁上的激光中心点,通过计算得到管道横截面的点云数据;另一方面,对全景纹理图像进行处理,首先利用快速鲁棒性特征(SURF)算法快速提取特征点并进行匹配,然后采用随机抽样一致性(RANSAC)算法去除误匹配点,接着利用全景相机的极几何原理估计相机运动位姿,并利用光束法平差(BA)进行优化,最后利用相机运动位姿将相机坐标系下的点云坐标实时转换到世界坐标系下,完成对地下管网的三维重构。实验结果表明,所提出的方案能够精确估计相机运动位姿,实时对管道内部进行三维重构,实现了管道检测机器人边行走、边采集数据、边检测分析处理、边三维建模的设计目标。     

点激光测头激光束方向标定

为了使点激光测头能在任意方向上实现测量功能,提出一种逆向工程中标定激光束方向的方法,设计了一种标定面方向可调的标定块配合标定。标定过程中,让激光测头在标定面上分别沿X、Y、Z3个轴方向做等间距运动,根据进给步长与激光束长度变化量之间的关系确定激光束的方向。以三坐标测量机为平台,给出了以任意方向安置点激光测头时,测量值从传感器坐标系到基准坐标系的转换过程,并对标定算法及整个标定过程进行了详细描述。最后,通过与接触式测量进行对比实验,验证标定后点激光测头的测量效果。实验结果表明,用该方法标定的点激光测头在3σ范围内沿任意方向的测量误差为(0.0452±0.0168)mm,满足逆向工程的测量要求。     

基于球形目标的激光位移传感器光束方向标定

搭建了非接触式的三坐标测量系统以便精密测量三维型面。将激光位移传感器通过具有两个回转轴的回转体安装在测量机的Z轴上,从而可根据待测表面的形状来调整传感器的方位。为了使传感器在各个方位上实现测量功能,提出了基于球形目标的光束方向标定方法,并详细阐述了其数学原理。标定时,驱动测量机使传感器分别沿测量机的X,Y和Z轴做等间距步进,根据步长和激光束长度的变化建立方程组求解出激光束所在直线的单位方向向量。最后,多次测量尺寸参数已知的六面体标准块规,检验了该测量系统的重复性。结果显示,该系统的测量不确定度为0.048mm;测量另一直径已知的被测球时,传感器在各个方位上的误差小于0.05mm,表明所提出的标定方法使测量系统达到了逆向工程的使用要求。得到的数据表明,本文所提出的方法有较高的标定精度和较好的重复性,为实现三维型面的快速扫描测量奠定了基础。     

宽光束光电传感器

本文介绍了一种宽光束光电传感器测量原理。试验表明，该传感器具有很大的测量范围和转好的灵敏度。     

移动式油管纵横缺陷检测系统的研制

根据磁性无损检测基本原理，对油管纵横向缺陷检测实现方法进行了研究，研制出移动式油管纵横缺陷检测系统。该系统在油管局部实施轴向和周向磁化，油管由电机主轴带动旋转，检测探头紧贴油管直线运动，从而实现对腐蚀坑、腐蚀孔等横向缺陷和杆状损伤、劈缝等纵向缺陷的综合检测。     

Study and industrial evaluation of mass flow measurement of pulverized coal for iron-making production

This paper described a measurement system for mass flow measurement of pulverized coal in a blast furnace coal injection system. The system mainly consists of a volumetric concentration sensor and a velocity sensor. The concentration sensor is a capacitance sensor which has two pairs of concave electrodes placed axially on a piece of pipe of oxide of aluminum with different orientation to get being less affected by flow regime; the velocity sensor is also based on capacitance sensing principle, but uses “passing time difference method” which records the time at which each flowing cloud of coal powder passes through upstream and downstream sensor and then calculates the time difference to get the transit time for the cloud to travel between the two sensors. Both of the experiments in the laboratory and on the spot showed the measurement system has industrially acceptable performance.     

城轨车辆轮对尺寸在线测量系统的研制

针对城轨车辆轮对测量费时费力的问题,基于激光轮廓扫描传感器技术,开发了一种城轨车辆轮对尺寸在线测量系统。系统采用将激光轮廓扫描仪和激光位移传感器布置在钢轨的内外两侧。将轮廓扫描仪发射的激光线投射到车轮踏面上,实时测量经过测量区域内的车轮踏面外轮廓,并对测量结果进行插值运算、数据平滑运算等算法处理,获得车辆轮对的轮缘高度、轮缘厚度、车轮直径等主要参数。通过对测量结果数据分析,该系统可以完成运行中地铁车辆轮对参数的自动测量。     

基于双环电阻传感器的管道内壁腐蚀监测技术研究

为实现管道内壁腐蚀的全周向在线监测并提高测量精度,在传统电阻法的基础上提出一种基于双环电阻探针的腐蚀监测方法。双环电阻探针解决了由于几何限制和管道内外壁温差所带来的测量误差。通过对双环探针进行多象限分区,求解各分区的电阻比值,实现了管道全方位的在线腐蚀监测。通过双环探针可以同时实现对管道内外壁的温差计算与实时监测,为湿蒸汽管道冷凝液膜的形成起到预报作用。基于以上研究基础,在实验室X65模拟管路中,分别布置四象限分区双环电阻传感器、传统丝状电阻传感器和高精度热电偶对管道的腐蚀和内外壁温差进行实时监测。试验结果表明：基于新型双环探针的管道内壁腐蚀监测方法,可以完成管道内外壁温差和局部分区腐蚀状态的在线监测,并在腐蚀深度和腐蚀速率的测量上比传统丝状电阻探针具有更高的监测精度。     

基于结构光的微细管孔内表面三维重建

介绍了一种适于空间曲线型微细管孔内表面三维重建的系统。该系统主要由管道机器人、形貌检测器和曲率检测器等部分组成。形貌检测器在管道机器人的带动下潜入管孔内部进行内壁截面图像采集，曲率检测器负责测量管孔中心轴线在检测器采样位置处的局部几何性质。对管道内壁截面图像进行适当的处理，结合形貌传感器的标定参数和结构参数，可以计算出在检测器局部坐标系下的管道截面三维轮廓；同时，根据传感器采样位置处的管道中轴线局部几何性质、管道机器人的前进步长，建立局部坐标系与全局坐标系的关系，从而将被测全部截面的局部坐标转化为全局坐标，实现管道内表面的三维重建。实验结果表明，利用该技术检测的管道内表面三维形貌与实际情况是一致的。     

A laser sensor with multiple detectors for freeform surface digitization

An integrated laser scanning sensor for freeform surface digitization is presented. The sensor consists of a diode laser light source and four position-sensitive device (PSD) detectors. The stand-off distance of the sensor is 180 mm and the measurable range is 90 mm. The Lambert model is applied to calculate the displacement between the sensor and the measured point on the object surface along the optical axis, under the assumption of a diffusive surface. The inclination angle of the measured point from the vertical plane of the laser beam is calculated by mathematical inference. Those data are used in error compensation to improve system precision. The new design of multiple detectors could increase the measurable angle and could solve the dead space problem in single point laser of triangulation measurement. The computer simulation and actual measurements show that the displacement resolution reaches 50 μm, and the system performs well in regards to stability and repeatability. The sensor system could be mounted on the NC machine orX-Y platform for freeform surface digitization.     

Calibration of laser beam direction for optical coordinate measuring system

For the purpose of measuring free form surfaces of some key parts in the aviation field accurately and effectively, such as blades, a non-contact optical coordinate measuring system is set up in the paper. A laser displacement sensor is mounted on the Z axis of a CMM via a turntable and adjusted to the suitable orientation according to the shape of the target surface. The combination of optical sensor and CMM can reach the full potential of them both. To enable the laser sensor to perform measurement in every direction, a calibration method used to determine the laser beam direction based on a standard sphere is proposed, the principle of which is analyzed in detail in the paper. In the calibration procedure, the sensor moves at an equal step along X, Y and Z axes respectively and then equation sets are established to calculate the unit direction vector of the line which the laser beam is on. In the process of solving the unknown quantities, a new parameter substitution method is applied. Finally, a gauging block and a sphere with known size are used to verify the method. As the experimental results show, the measuring errors in several directions are all smaller than 0.05 mm, which manifests that the calibration method proposed can meet the requirements of reverse engineering.     

基于主动式全景视觉的管道内部缺陷检测方法

针对管道内表面检测空间受限的约束以及同时需要检测管道内壁功能性缺陷和结构性缺陷等需求,基于主动式全景视觉检测原理提出了一种既能视觉检测管道横截面几何尺寸又能获取和分析管道内壁表面缺陷的管道内部全方位视觉检测方法。利用携带有主动式全景视觉传感器的爬行机器人进入管道内部,分别实时获取内壁全景图像及激光横断面扫描全景图像。本文重点介绍基于管道内壁全景图像的缺陷检测方法,对管道内壁全景图像进行展开、预处理并提取管道病害区域的几何特征,最后判定缺陷类别及危害程度。经本文方法获取的缺陷几何特征实验数据验证,管道内表面存在的较为普遍的裂缝、腐蚀缺陷几何特征差异明显：腐蚀缺陷的圆形度较大,而裂缝缺陷的圆形度趋于0;腐蚀缺陷的凸度普遍大于裂缝缺陷;裂缝缺陷由于弯曲程度不同其边界离心率变化率大,而腐蚀缺陷的边界离心率趋于1。实验结果表明：该系统能够有效提取疑似缺陷区域并计算各几何特征,可通过合适的阈值判定其所属类别,为管道内表面缺陷检测提供了一种新的手段。     

Nanometer edge profile measurement of diamond cutting tools by atomic force microscope with optical alignment sensor

This paper describes an atomic force microscope (AFM) based instrument for nanometer edge profile measurements of diamond cutting tools. The instrument is combined with an AFM unit and an optical sensor for alignment of the AFM probe tip with the top of the diamond cutting tool edge in the submicrometer range. In the optical sensor, a laser beam from a laser diode is focused to generate a small beam spot with a diameter of approximately 10 μm at the beam waist, and then received by a photodiode. The tool edge top and the AFM probe tip are brought to the center of the beam waist, respectively, through monitoring the variation of the photodiode output. To reduce the influence of the electronic noise on the photodiode output so that the positioning resolution can be improved, a modulation technique is employed that modulates the photodiode output to an AC signal by driving the laser diode with a sinusoidal current. Alignment experiments and edge profile measurements are carried out.     

大直径内孔自动测量机构倾斜度测量研究

为了实现对大直径内孔自动测量机构倾斜角度的连续、自动测量,建立了倾斜度测量系统.系统主要由半导体激光器、光学系统与位置敏感探测器(PSD)等元件组成,以激光光束和光学系统光轴分别表征被测机构的参考轴线与大直径内孔的轴线,同时PSD测量经过光学系统折射后激光光点的位置,由此测量两轴线构成的夹角,确定机构倾斜程度.论文分析了系统的测量误差,并进行了相关的实验,对测角误差进行校正,结果表明:系统的测角精度为±0.02°,分辨率为0.000 3°.系统稳定可靠,能够基本满足测量机构在大直径内孔中倾斜度测量的要求.     

Modeling and verification of a five-axis laser scanning system

Today several new kinds of laser beam sensors appear with high resolution and accuracy and find their applications in reverse engineering and quality control. Due to the incapability of changing their orientations continuously in response to the surface fluctuation of a part to be measured, they are not competent for measuring parts with complicated structures. In this paper a five-axis laser scanning system integrated with a CMM, a laser beam sensor and a PH10 rotary head is proposed, which can measure complicated parts by frequently indexing the laser sensor approximately consistent with the normal direction of the surface. As the laser value is a 1-D data and the measured data must be given in 3-D expression in the world coordinate system, a system model for coordinate transformation is established. An “equivalent probe” approach is presented for system verification, and an iterative verifying process is adopted to eliminate the verification error caused by the inclination error of the laser sensor. Experiment study shows that the system can measure a part from any direction with an accuracy of 30 μm.     

A laser sensor with multiple detectors for freeform surface digitization

In this paper, an integrated laser scanning sensor for freeform surface digitization is presented. The sensor consists of a diode laser light source and four position-sensitive device (PSD) detectors. The stand-off distance of the sensor is 180 mm and the measurable range is 90 mm. The Lambert model is applied to calculate the displacement between the sensor and the measured point on the object surface along the optical axis, under the assumption of a diffusive surface. The inclination angle of the measured point from the vertical plane of the laser beam is calculated by mathematical inference. Those data are used in error compensation to improve the system precision. The new design of multiple detectors could increase the measurable angle and could solve the dead-space problem in the single-point laser of triangulation measurement. The computer simulation and actual measurements show that the displacement resolution is around 50 μm, and the system performs well in terms of stability and repeatability. The sensor system could be mounted on the NC machine or on the X–Y platform for freeform surface digitization.     

基于激光三角法的零件表面粗糙度在线测量

介绍了一种零件表面粗糙度的激光在线测量方法,该测量方法具有测量速度快且能够显示被测表面的具体形貌等优点．在测量中引入激光三角测量系统,用无衍射激光光束作光源,用高精度的摄像机作位移传感器,通过计算机数据处理得到表面粗糙度值,使表面粗糙度在线检测成为可能。     

双波长集成光栅干涉微位移测量方法

介绍了一种基于双波长激光的集成光栅干涉位移检测方法,利用该方法对硅-玻璃键合工艺制作的集成光栅位移敏感芯片进行了测试实验。实验系统主要由敏感芯片、波长为640nm和660nm的双波长半导体激光器、双光电二极管及检测电路组成,敏感芯片则由带反射面的可动部件和透明基底上的金属光栅组成。入射激光照射到光栅上产生衍射光斑,衍射光的光强随可动部件与光栅之间的距离变化,通过分别测量两个波长的衍射光强信号并交替切换选取灵敏度较高的输出信号,实现了一定范围内的扩量程位移测量,并得到绝对位置。实验结果表明,利用双波长集成光栅干涉位移检测方法测得敏感芯片可动部件与基底光栅的初始间隙为7.522μm,并实现了间隙从7.522μm到6.904μm区间的高灵敏度位移测量,其噪声等效位移为0.2nm。