Research On End Coupling Detection Technology Of Long Optical Fiber

After the Internet era of the 21 st century,the demand for information dissemination has increased significantly.With the surge of demand,the output of optical fiber is bound to go further.After fully understanding the research status of optical fiber end cutting,optical fiber coupling detection and machine vision detection at home and abroad.The project aims to design and produce a machine detection equipment to replace manual work and improve the efficiency of long optical fiber coupling detection,and verify its feasibility,so as to meet the urgent needs of enterprises for automatic detection system.The principle of optical fiber brittleness is studied.The optical fiber cutting method is designed,that is,using the cutting tool to act an initial crack on the optical fiber,the crack propagation leads to the fracture of the optical fiber.At the same time,the simulation software is used to simulate the crack growth process of two kinds of cutting length(15mm,20mm)optical fiber under different crack depths,and the stress concentration and maximum stress are observed and recorded to find the most suitable cutting length and initial crack depth in theory.Then,the content of fiber coupling detection is introduced.The influence of three kinds of misalignment(transverse offset,longitudinal gap and angle error)on the coupling detection is studied theoretically,and the relevant experimental verification is carried out by relying on the experimental machine.It is concluded that the transverse offset error has the greatest influence on the fiber coupling detection.In the actual detection process,the existence of transverse offset error should be minimized.After determining the fiber cutting mode and fiber coupling detection device,the whole detection machine needs to be designed,including fiber coating removal device,fiber cleaning device,fiber cutting device and visual detection device.Finally,the software design composition of the whole system is explained.According to the requirements of the thesis,it is necessary to collect clear and prominent optical fiber end face images.This thesis selects the appropriate visual acquisition software,and constantly carries out relevant optimization and debugging to ensure the stability and efficiency of the acquisition system.In the research of image enhancement algorithm,the first step is to remove noise,enhance histogram and sharpen image.In the research of image segmentation algorithm,firstly,ROI processing is used to reduce the influence of irrelevant background on image detection.Secondly,Otsu is used to binarize the image after contrast selection to enhance image features.In the image defect detection algorithm,several different edge detection operators are compared,and Canny edge detection operator is selected to detect the crucial gradient features in the image,so as to prepare for two kinds of defect detection(scratch and edge collapse)in the optical fiber end face image.Finally,the Hough circle detection algorithm and Hough line detection algorithm are selected as the main algorithms to detect the end defects of optical fiber,and the region growing algorithm based on gradient feature is used as the supplementary detection algorithm of line defects.The feasibility of the cutting method is explored,and the end face image of the optical fiber is obtained by using the microscope.Through the whole machine detection system,the optical fiber with different cutting length and crack depth is pre-processed and visually detected.The defect situation is counted to explore the relationship between cutting parameters and defect situation and select the optimal cutting parameters.Finally,the detection machine is used to detect and couple the optical fiber samples,and the designed mechanism and image detection algorithm are improved according to the experimental data.There are 76 figures,22 tables,and 82 references in this thesis.