Fast Full Field Measurement Method Of Large Size Grind Wheel Surface Topography Based On Line Array Camera

Grinding wheel as the main grinding tool for grinding,its surface morphology has an important impact on grinding performance and processing quality.The rapid full-field measurement method of grinding wheel surface topography has important practical significance for obtaining the characteristic distribution of grinding wheel surface abrasive particles,optimizing the grinding processing technology,and promoting the development of ultra-precision grinding processing technology.In this paper,a line-field camera is used to construct a full-field measurement system for large-scale grinding wheel surface to quickly obtain the whole-field abrasive grain image on the grinding wheel surface.Through the processing of the abrasive grain image,the two-dimensional topography characteristics of the grinding wheel surface are extracted and analyzed.parameter.The main research work includes:(1)The overall design of the measurement system.The principle of full-surface measurement and detection of grinding wheel surface topography is described.Based on the measurement requirements,the overall structure design ideas of the system are determined,and the hardware components such as optical system,motion control system and auxiliary mechanism are analyzed and designed.(2)Calibration of the measurement system.Explain the significance of system alignment and propose a system alignment scheme;elaborate the principle of image sharpness evaluation function,and compare the performance of different image sharpness evaluation functions;use sobel sharpness evaluation function as the evaluation function of this project,and introduce The gray gradient threshold improves the accuracy of the evaluation function,improves the search strategy of the hill-climbing algorithm,improves the overall ability of the algorithm,reduces the probability of the algorithm falling into the local peak,and improves the focusing performance of the system;analyzes the causes of image motion distortion and the motion distortion of the measurement The influence of the system proposes a method for obtaining a motion-free distorted image.(3)Two-dimensional feature extraction and analysis of surface abrasive particles.The original image is scaled to speed up the processing of the image;according to the characteristics of the image,an appropriate image enhancement method is determined;the principles of some classical graph segmentation algorithms are described,and Otsu is determined as the project segmentation algorithm;and the classic Otsu algorithm is performed.Improve the image segmentation effect;use morphological algorithm to remove the small holes in the abrasive particles and bonding agent,smooth the edge of the abrasive particles,and obtain the effective abrasive grain area;analyze the azimuthal information of the abrasive grain centroid and abrasive particles and extract the geometry of the abrasive particles.Characteristic parameters,statistics and analysis of two-dimensional distribution information of the wheel surface topography.Using the system,the brazed diamond grinding wheel with the diameter of 120 mm and the sintered diamond grinding wheel with the thickness of 8mm and the diameter of 250 mm were tested for 80 s and 295 s respectively.The experimental results show that the measurement and inspection system studied in this project is better.Realize rapid measurement of the surface topography of large wheels.