【作者】 张晓；

【导师】 于洵；

【作者基本信息】 西安工业大学 ， 精密仪器及机械， 2012， 硕士

【摘要】 近几年来,激光打孔和激光切割在工业应用中的比例迅速增长。但是不管哪种加工类型,都存在一个缺点,即会产生一定量的废品。在激光加工中,对加工零部件的高质量要求只能通过监测生产过程以及控制生产部件的特殊特征来保证。要实现可靠的监测,监测系统必须能够对激光与材料作用区或邻近区域的实时条件进行准确的反映。这就意味着监测过程必须是无接触的操作,保证不对加工过程产生干扰。本论文主要研究超快激光微加工的实时监测技术。采用同轴监视的方法实现激光扫描微圆孔的孔径检测。论文中首先对激光微加工的监测信号,监测方法及监测手段进行了综合论述；然后,根据实际的激光微加工系统的加工光路,设计了同轴监视光路,根据加工微孔的孔径指标计算监视光路中成像中继镜组的各项参数,采用正负透镜系统组合的方式缩短监测光路,并利用zemax光学设计软件,设计了一套成像中继镜组。最后,搭建了实验光路,采集加工图像,通过图像测量的方法检测激光加工微孔的孔径尺寸。其中包括对CCD成像系统的尺度标定,以及对采集到的图像进行去除噪声,图像滤波,阈值分割等操作,最终通过最小二乘法进行圆拟合,得到微孔的尺寸。此外,由于激光加工是利用焦斑的能量与工件相互作用,因此,在加工时,工件必须设置于聚焦镜的焦平面上。本论文设计的监测系统,只需要再引入一个指示光源,可以实现被加工面与焦点位置的偏差测量。通过反馈机制对超差补偿,还可达到自动调焦的目的。更多还原

【Abstract】 In recent years, laser drilling and laser cutting in the proportion of industrial applications is growing rapidly. But no matter what type of processing, there is a drawback, that is, to produce a certain amount of waste. In the laser processing, only by monitoring the production process and control the special features of the production parts to ensure the high quality of the parts and components. To achieve reliable monitoring, the monitoring system must be able to accurately reflect real-time conditions in the area of the laser and material role or neighborhood. This means that the monitoring process must be non-contact operation to ensure that does not process the interference.This thesis focused on real-time monitoring of ultrafast laser micromachining technology. Laser scanning micro-hole aperture measurement by using coaxial monitoring method was achieved. Firstly, the monitoring signal of the laser micro-machining, monitoring methods and monitoring tools were discussed comprehensively:Secondly, according to the actual optical path of laser processing, the coaxial monitoring optical path was designed.According to the aperture indicators of the processed micro porous; the various parameters of the imaging lens group were calculated. By using the lens system of combination positive and negative lens the monitoring optical path was shortened. And a set of imaging relay lens group were designed by using optical design software zemax, Finally, the experimental optical path is build and get images. Through the image measurement method the aperture size of the laser processed micro porous was detected. Including the scale factor calibration of CCD imaging system, and the noise removal, thresholding segmentation of the images, and ultimately by the least squares method for circle fitting, the size of the microspores was calculated.In addition, because of the use of the focal spot energy interact with the work piece in laser processing, during the processing; the work piece must be set in the focal plane of the focusing lens. The monitoring system was designed in this thesis, just with an indicator light, can also achieve the machined surface and the focus position deviation measuring. And through feedback mechanisms can achieve the purpose of automatic focusing.更多还原