Large-caliber Optical Element Laser Pretreatment System Of Image Processing And Algorithm Research

Inertial confinement fusion (IGF) is the most hopeful way which to achieve the under controlled nuclear fusion.Nowadays, in many countries, the research of ICF has been considered very important. In large system of inertial confinement fusion, due to the high power of the lasers, the defects of the optical components which has been used in the system are likely to endanger the security of the system during the normal operation.Also, in the course of the low threshold portion may be generated to new defects, so the optical components are needed to be pretreated that can find out the low threshold portions. Rely on the traditional visual inspection for defect treatment can not meet the requirements, so using the method which combine machine vision and motion control to realize the automation of optical element preprocessing.Firstly, from the dissertation, explain the necessity and feasibility about the use of machine vision which replace the conventional visual to detect the large size optical component.Then, the components and fuctions of laser preprocessing system are introduced in detail and the design of the module is descripted.To obtain the image which is suitable the image processing, the dissertation detailed introduces the control of the camera which is used to image acquisition.The dissertation focuses on defect detection image processing algorithms which are used to detect the defect in images of the optical components and the algorithm of the camera calibration. Through a two-dimensional platform grating motion, the collected optical component images are spliced to a complete image. On target pixel connectivity search, using optimized region labeling algorithm, which can reduce memory and improve processing speed. In this image, the defects are detected by using optimized region labeling algorithm which can check the pixels’connectivity, use this algorithm can aslo saving memory and improve processing speed. It can be detected by edge detection to certify the rounded edge of isometric circle etalon in the process of camera calibration. Use rectangle frame and distance variance methods to determine whether target pixels getting from boundary tracing could form circle, which can improve the accuracy of the camera calibration.In the actual application, if the optical component’s diameter is430X430mm2, through the image processing algorithm, the defects in optical component also could be automatic detected and located. After the image process, the defects could be repaired by CO2laser which is guided by preprocessing system. To enhance the optical component’s anti-damage threshold, the system is used for large size optical components automatic laser preprocess in domestic has not seen the report.