【摘 要】
：
Based on structured-light vision measurement technology, we study a measuring method for microdiameter. The measurement principle and mathematical model are described. A novel grayscale barycenter extraction algorithm along the radial direction is propose
【机 构】
：
StateKeyLaboratoryofPrecisionMeasuringTechnologyandInstruments,TianjinUniversity,Tianjin300072,China
【出 处】
：
ChineseOpticsLetters
论文部分内容阅读
Based on structured-light vision measurement technology, we study a measuring method for microdiameter. The measurement principle and mathematical model are described. A novel grayscale barycenter extraction algorithm along the radial direction is proposed, which can precisely gather the image coordinates of the ellipse-shaped light-stripe centers. The accuracy of the measurement result shows marked improvement by using the algorithm. The method executes circle fitting to the measured three-dimensional (3D) data using linear least square method, which can acquire the diameter, surface profile, and other information of the object effectively. On the scene, a line-structured light vision system using the presented method is applied to measure the curvature radius of metal blades. Experimental results show that the measurement precision of the system is higher than 2 \mu m.
其他文献
1982年3月11~12日在加利福尼亚新港海滩召开的美国航空和宇航协会激光与纤维光学会议上讨论了军事电-光学领域的方向、目标、应用及需要。会上介绍了20多篇论文，其题目从高能激光设计到纤维光学市场展望。
Recent advances in power scaling of fiber lasers are hindered by the thermal issues, which deteriorate the beam quality. Anti-Stokes fluorescence cooling has been suggested as a viable method to balance the heat generated by the quantum defect and backgro
美国海军研究实验室的戈尔德（S. H. Gold),利用锥形摆动器场，将4毫米波长的自由电子激光器早期实验2.5%的效率提高至6%。此种激光器以超辐射模运转，产生75兆瓦的脉冲，聚焦后可造成空气击穿。改变摆动器电压，从而改变磁场，其波长可在1.5至6毫米间调谐。
飞溅是激光深熔焊接中最严重的缺陷之一。本文通过熔池原位光学观察和板材质量亏损计算,研究了高功率光纤激光深熔焊接过程中的飞溅行为以及离焦量对飞溅的影响。结果表明:飞溅的形成可分为三步,熔池凸起→凸起部位拉长形成液体柱→液体柱克服表面张力断裂形成飞溅;飞溅的直径主要分布在
可用激光技术区分进袭弹道导弹弹头与假目标。此种技术在通过畸变介质观察时，可产生目标的良好图像。如在远距离上也获得成功，则会大大改进反弹道导弹的能力。
当光源为高斯型光谱，非平衡光路中考虑介质色散时求出双光束干涉的光强度解析解。分析了干涉条纹可见度和可见范围与介质的厚度、色散及光谱线宽度的关系；干涉光强度变化的相位关系。据此得出：白光干涉法除用来测量群折射率外还可用作介质色散的测量；高测量精度下谱线宽度应满足的关系式；干涉条纹可见度最大的位置与光强度最大的位置并不重合；若以最大光强度位置作为零光程差，会出现四分之一中心波长的系统误差。并用不同谱线宽度的光源对部分结论进行了实验验证。
In this Letter, ceramic Nd:YAG is charactrizeby electron spin resonance (ESR) measurements. The ESR results indicate that the polycrystalline ceramic Nd:YAG has barely native defects and impurity ions localization defects, compared to an Nd:YAG crystal wi
A single-frequency pulsed all-fiber laser with a master oscillator power amplifier configuration is presented. While maintaining the properties of single mode, linear polarization, and narrow linewidth, a single-pulse energy of 260 μJ and over 500-W peak
Functional near infrared spectroscopy (fNIRS) is a technique that is used for noninvasive measurement of the oxyhemoglobin (HbO2) and deoxyhemoglobin (HHb) concentrations in the brain tissue. Since the ratio of the concentration of these two agents is cor
Samples with nodular defects grown from gold nanoparticles are prepared, and laser-induced damage tests are conducted on them. Nodular defects, which are in critical state of damage, are cross-sectioned by focusing on the ion beam and by imaging using a f