【作者】 王春艳；

【导师】 谭庆昌；

【作者基本信息】 吉林大学 ， 机械设计及理论， 2014， 博士

【摘要】 在现代机械制造领域中，应用激光和光电测试技术进行测量已经成为一种实用、有效的非接触测量方法。该方法综合利用了激光优良的方向性、相干性、几何光学的成像规律和计算机技术高效处理数据的能力。其中，激光光条中心检测是实施视觉传感器校准、获取物体尺寸及轮廓信息的关键之一。因此，实际测量中需要在改进激光光束质量，寻找快速而精确的光条中心检测算法及精度评价等方面进行深入研究。本课题采用线激光进行尺寸测量，实验中选择半导体激光器来产生线激光。为提高测量精度，探索利用整形技术把高斯光束整形为平顶光束，使激光具有均匀的光强分布和窄线宽。根据能量守恒原理和折射定律，在I.Powell扩束棱镜实验的基础上，建立非球面柱透镜整形光学系统，推导入射光线与出射光线的函数关系式，并利用光路追迹方法确定并优化非球面柱透镜的矢高表达式。在此基础上，采用金刚石车床加工非球面柱透镜。通过实验把改进的线激光与传统线激光进行对比，证明优化后的线型光斑能量分布更均匀。由于改进的激光器投射到被测物体表面所形成的激光光条灰度呈现两个阶跃分布，首先利用亚像素边缘检测方法提取出光条的两个亚像素边缘，再根据检测到的边界线求得光条中心线。通过实验比较灰度矩法、多项式插值法、高斯拟合法进行光条边缘检测的效果，结果表明高斯拟合法对噪声具有良好的鲁棒性，在光条的边缘提取中能够获得较高的精度。分别采用传统的评价方法和本文的评价方法对线激光光条中心检测结果进行对比实验，证明本文方法有效。为验证本文提出的基于改进激光器所得到的线激光光条应用于尺寸测量的精度，构建基于改进激光器的线激光测量系统，进行量块对比实验。证明本文方法测量结果的相对精度波动较小，测量的稳定性较好，利用本文改进的光源及相应的光条中心提取方法能够提高测量精度。更多还原

【Abstract】 In the field of modern machinery manufacturing, laser and optical technology inmeasure has become a practical and effective non-contact measurement method. Thedirection and the coherence of laser were utilized in this method. The imaging law ofgeometrical optics and efficient data processing ability of computer technology wereused too. Among them, the laser stripe center detection is a key step in obtainingobject size information and the visual sensor calibration. Therefore, the actualmeasurement requires in-depth research in improving the quality of the laser beam,looking for the accurate algorithm of detecting laser stripe center, and precisionevaluation.The linear laser is used in size measurement of this issue. This kind of laser isusually made up by the semiconductor laser. To improve the measurement precision,the shaping technique that turn Gauss beam to the flattop beam is explored to makethe laser beam has a very uniform intensity distribution and narrow line width. Basedthe experiment of I.Powell prism, the beam shaping system and the expression ofaspheric lens is solved by the law of energy conservation and refraction rule. The raytracing and the optimization of the whole system will be performed by the opticaldesign software. According to the expression of the vector height, the aspheric columnlens can be fabricated through the diamond lathe. Comparing with the traditionallinear laser, the intensity distribution of this designed laser is more uniformity.The light strip gray that improved laser projects on the measured object surfacepresents distribution of two steps, so two edges were detected at first using thesub-pixel edge detection method, and then seek the centerline. Comparing with theeffects of the light strip edge detection using gray Moment Method, polynomialinterpolation method, and Gaussian fitting method, the experiment results show thatGaussian fitting method has good noise robustness. It can obtain higher precision inthe light strip edge detection.Respectively, using the traditional evaluation methods and evaluation methods inthis article to compared experiments on detecting laser strip center, the test resultsproved this method effective.Finally, in order to verify the accuracy of the size measuring used improved linelaser, constructed line laser measurement system based on improved laser for gauge blocks comparative experiments. Measurement results prove that relative accuracy isless volatile, and measurement stability is good using this method. The improved linelaser of this article and the corresponding light strip center extraction method canimprove the measure precision.更多还原