激光三角法扫描测头特性的研究

在分析了激光三角法位移测量原理的基础上,以ＩＢ－１２型激光三角法位移传感器为实例,研究了激光三角法位移传感器的使用特性,补偿非线性误差、倾斜角误差,提高了测量精度,使其能够作为非接触式扫描测头用在三坐标测量机上,完成空间自由曲面的非接触扫描测量。     

激光位移传感器在自由曲面测量中的应用

以点激光位移传感器(HL-C211BE)为对象,研究它在自由曲面测量中的应用。针对激光位移传感器因测点倾角代入的测量误差,提出了一个可以量化的倾角误差模型。基于直射式点激光三角法原理,分析了激光光路的几何关系,从会聚光斑光能质心发生的偏移推导出倾角误差模型。随后,用高精度激光干涉仪和正弦规对激光位移传感器进行校对实验,并用误差模型对测量结果进行补偿。结果显示,补偿后激光位移传感器的测量精度得到明显提高。对一非球面凸透镜进行了实验测量,得到了自由曲面测点倾角的计算方法,并用倾角误差模型修正了测量数据。实验结果表明,量化的倾角误差模型可以将激光位移传感器的测量误差控制到小于10μm,满足激光位移传感器在自由曲面测量中应用的要求。     

单点激光三角测量系统不确定度评定

激光三角法测量是对于三维以及多维空间自由曲面非接触测量的主要方法之一,具有分辨力高、稳定性好、使用灵活、抗干扰能力强等优点,在光电检测和几何测量领域中得到广泛的应用.本文论述了激光三角法的测量原理,通过对DB-M72型激光位移传感器的实验,结合实验数据,对测量系统不确定度进行评定,达到了对测量系统进行误差分析目的.     

激光三角法内孔测量传感器的光学成像分析

为了实现对孔类零件特别是深孔零件的孔深测量,设计了一套激光内孔测量传感器.该传感器基于激光三角测量的方法,利用梯形棱镜的全反射特性将光路限制在狭窄的空间内,从而实现对深孔或盲孔的测量.针对该传感器的光学成像规律做出了深入的分析,并结合目前存在的问题提出了几种改进方案.实验结果表明:梯形棱镜能够较好地解决测量内孔时物理空...     

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。     

基于CMOS单点激光三角法测距系统设计

根据三角法测距原理,运用单片机技术对距离进行测量,设计了一套基于CMOS的单点激光三角法测距系统。详细地介绍了系统的硬件组成和软件结构,针对测量用的光敏传感器之标定曲线的非线性特征,提出了用逐段折线逼近该标定曲线的方法,最后给出实验结果,并分析了各个参数对实验精度的影响。实验结果表明方案切实可行,该方法的测量误差小于3%。     

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.     

激光隧道表面测量仪的研制

采用激光测距元件作为测量传感器,研制了一种隧道表面测量仪。该仪器可以实现绕两个相互垂直的轴旋转,对隧道表面的形状和物体的外形进行自动连续扫描测量,同时可以对所测量的数据进行处理,生成被测量曲面的形状图。对该仪器原理、硬件结构和组成进行了分析、研究,根据原理图设计了硬件电路图,并选择了相关的元器件,搭接了硬件电路,设计了硬件控制软件和数据后处理软件。应用该仪器对实际表面进行了测量并进行了处理,绘制出了所测表面的三维图形。实际使用表明,该仪器具有性能稳定、测量速度快、使用方便等优点。     

在役套管的激光测量法研究

介绍激光三角测量法在套损检测中的应用，激光三角法的测量原理、结构组成及CCD信号采集。提出双层4探头交叉测量方法对套管内壁腐蚀缺陷的检测，实现了单探头单通道测量，通过数据处理判断腐蚀缺陷的位置和深度。     

光学三角法在大面积体积测量中的应用

作者的研究目标是一种用于测量大面积物体体积的新系统。该测量系统是以获得距离信息的光三角原理为基础,它的位置传感器是线性CCD,它的显示和控制中心是微机。这种仪器可作实时显示、并能输出计算结果。文中详细讨论了光学系统的成像特性,给出了用于控制系统的软硬件设计。测量结果表明,系统的操作正常,测量精度在2%之内。最后给出测量误差的数学分析结果。     

The influence of incident angle, object colour and distance on CNC laser scanning

This article examines the influence of incident angle, object colour and measurement distance on the computer numerically controlled laser scanning process. To determine the physical background of these influences, the operation of the triangulation sensor, the surface reflection and the colour properties of the measured object were analysed. The various influences and their physical background are explained by using a test-measurement setup, which makes it possible to investigate a specific influencing factor. The article concludes with several guidelines that should be followed in order to obtain better measurement results.     

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.     

激光三角法在锥管螺纹轮廓测量中的应用

设计了基于激光三角测量原理的锥管螺纹轮廓测量系统,以非接触扫描的测量方法实现螺纹轮廓的自动测量。系统以ADu C845单片机为核心,采用激光三角位移传感器、精密丝杠和编码器分别获取螺纹垂直(Y轴)和水平(X轴)方向的原始数据,进而得到螺纹轮廓的坐标值。对数据进行相应的滤波和处理后综合得到螺纹轮廓,通过参数的算法模型得出螺纹的牙高、螺距和锥角等参数。     

轴类零件参数综合检测

以轴直齿类零件为例 ,提出一种快速、能同时测量轴向尺寸和径向尺寸的非接触、多参数综合测量方法。它利用基于光学三角法的激光位移传感器获得轴类零件的径向尺寸 ,利用半导体激光器与光电二极管组成的扫描式发讯传感器和光栅传感器的组合获得轴向尺寸。探讨了该系统的检测性能 ,给出了实测结果     

High-accuracy error-reduction method for 3D complex shape measurement with local-maximum-power-based technique of FMCW

To expand the measurement target from that containing simple cylindrical-shaped components to complex-shaped components that have several directional tilted surfaces, we determined an issue in measuring the rough surfaces with laser distance measurement. The issue is that laser speckle causes measurement error, which amount, we found, can be determined by the diameter and irradiation angle of the measurement laser beam. We then developed two error-reduction techniques that are based on the optical properties of a detected waveform and power. We conducted a basic experiment and a feasibility study with actual samples, to evaluate the distance measurement performance of targets with various surface roughness and irradiation angles. The roughness and angle range of the evaluation was determined considering actual measurement needs in parts manufacturing. We confirmed that the measurement error, whose maximum value was nearly 80 μm, decreased to less than 20 μm using our proposed local-maximum-power-based technique.     

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。     

Non-contact optical probing sensor — applying optical feedback effects in laser diodes

The possibility of a non-contact optical distance/displacement sensor, making use of optical intensity variations caused by optical feedback effects in laser diodes, was investigated. A compact sensor system and a simple signal processing technique were proposed to realise the sensor system. The experimental results indicated that the resolutions were of sub-mm order in distance measurements and about 40 nm in displacement measurements. The allowable maximum speed of displacement can be improved up to several cm/s. The influence of temperature variation on the measurement accuracy was discussed and the advanced sensing technique utilising a synthetic wavelength of laser diodes was proposed. These methods are applicable even to an object with rough surfaces.     

Effect of slice thickness on the profile accuracy of model maker rapid prototyping measured by a circular triangulation laser probe

The objective of this research is to investigate the effect of slice thickness on the profile accuracy of the model maker (MM) rapid prototyping (RP) system, layer by layer, through non-contact laser probe measurement. A circular triangulation laser probe, model OTM-3A20, made by Wolf & Beck Co., was mounted on a coordinate measuring machine (CMM), as the non-contact sensor. An adjustment device for the laser probe was designed to minimise the cosine error caused by assembly inaccuracy. The alignment test of the measuring laser beam was carried out using a calibrated specimen. The systematic accuracy of the circular triangulation laser probe with respect to the surface roughness and the surface slope of the RP workpiece was investigated using a HP5529A laser interferometer system. The maximum error of 21/2D RP part profile accuracy can be improved from 220 μm to 131 μm, and the average error can be improved from 78 μm to 46 μm as the slice thickness changed from 0.127 mm (0.005 in.) to 0.0127 μm (0.0005 in). However, the machining time increases by about seven fold based on the experimental results. An overall error of 197 μm as measured by the laser probe is attainable using the finest slice thickness 0.0127 mm (0.0005 in.) for the 3D profile accuracy. To verify the accuracy of non-contact laser probe measurement, the 3D profile of the RP part was also measured by a CNC CMM, with good consistency.     

用于旋转对称三角传感器的一种鲁棒的处理方法

旋转对称三角传感器由于其光学系统的旋转对称性而比其他的传统激光三角传感器具有更好的柔性，将旋转对称三角传感器应用于工业领域，相应的处理方法的性能是至关重要的。为了使传感器在复杂物体表面情况下仍具有较好的性能，我们设计了一种用于旋转对称三角传感器的鲁棒的处理方法。首先，分析旋转对称三角传感器图像的特性，这些特性取决于被测物体的表面特性，而这些图像特性将有助于传感器图像的处理方法的设计。其次，用一种由粗到精检测方法实现对传感器图像的处理。提出在精检测中，一种结合了自适应平滑和峰值法的方法，以实现检测的鲁棒性。在实际传感器图像上的实验结果证明，这种处理方法对于来自复杂表面的传感器图像具有很好的鲁棒性，从而提高了传感器的柔性。     

基于激光三角法的汽车同步带齿形轮廓参数测量

针对目前汽车同步带齿形轮廓参数测量过程中存在的测量效率低和人为因素影响大等问题,提出了一种基于激光三角法的汽车同步带齿形轮廓参数非接触式测量方案,并设计了相应的汽车同步带齿形测量装置。该装置通过激光位移传感器与汽车同步带传动速度的配合,对汽车同步带齿形轮廓数据进行采集,并提出一种改进后的分割算法对采集到的齿形截面轮廓数据进行特征分割。通过对分割后齿形数据的拟合,实现了齿形轮廓曲线特征的分段重构并获得被测带齿的轮廓参数。基于激光三角法对汽车同步带齿形轮廓参数进行测量,实现了对齿形轮廓参数自动测量提高了测量效率避免了人为因素的影响,保证了测量精度,有望在汽车同步带实际生产中得到应用。