Transparent Micro-component Three-dimensional Measuring System Based On Line Laser Scanning

With the rapid development of modern digital manufacturing technology,in the field of industrial measurement,the high-precision measurement of products' size is required to reach the micron level,especially with the rise of smart phones numbers,the thickness measurement of transparent glass panel has gradually become the demand of industry.However,the existing measurement technology can not meet the standards of this special material and high precision measurement.In order to realize the precise measurement which is efficient,rapid and non-contact,in this paper,based on the theory of triangle measuring method,taking the advantages of the optical fiber coupled laser that energy conversion rate is high,monochromaticity is good,precision is high,a non-contact precise measuring system for transparent micro is set up and a use of optical fiber coupled laser and precision measurement method based on triangle measuring method with high accuracy is proposed mainly based on line of the laser projection imaging acquisition object,the pretreatment and extraction of laser line,geometrical parameter calibration,the camera calibration,data conversion,model reconstruction of key technology.Aiming at several problems in online structural light measurement,including system design structure,special optical path of laser in transparent glass,extraction of laser line,etc.,this paper has studied and analyzed them one by one.The main work is as follows:(1)Comparing the measurement schemes of several triangulation methods,analysing the optical path characteristics of the high frequency linear structured light reflected by the semiconductor laser in the glass and the imaging characteristics in the camera CCD,selecting the most suitable measurement scheme and deduce the formula to calculate the measurement thickness.(2)To do a detailed analysis of the laser line on the glass surface of special status,in the bilateral filtering pre-processing and gray centroid method based on the theory of this paper proposes a laser line extraction method based on seeds point search,and with the aid of hardware feedback value and the formula to calculate the real depth of pixel information and coordinate positioning information.(3)Using the 3D reconstruction of the existing mature technology and open source libraries to organize and complete the point cloud data visualization,based on the theory of triangle subdivision method to reconstruct the reconstruction of the object under test rest for another model,and finally get the thickness of the object under test on the model value,this paper carried out the reconstruction of the three forms of glass panel measuring contrast experiment to verify the validity of the measurement system and the accuracy of the measurement methods.