High Precision Cutting Technology Of Optical Glass Based On Machine Vision

Optical glass block is often widely used in military and civil fields,when it becomes a standard optical glass components through the molding process.Its weight is the key factor that affects the size of the pressed element.Therefore,the improvement of cutting precision of optical glass strip is a key factor in the manufacture of optical glass element,which is also the starting point and the end point of this paper.At present,the research on optical glass by scholars at home and abroad mainly focuses on the mechanism,surface morphology and cutting assistance,etc.However,less research has been done on the precision of the cutting weight of optical glass.Based on the development for high-precision fixed-weight cutting equipment of optical glass,the realtime visual weight-accumulation method adopted by photo tangent is mainly researched.The main contributions in this thesis are as follows:1.The establishment of hardware platform for equipment was completed,which mainly included wiring of control mechanism,hardware and actuator construction.The coordinated operation between the control parts based on the IPC and the execution parts was completed,which achieved the goal of workpiece flow and cutting.2.The linear structure light mode was introduced to obtain the image of the cross section profile of the optical glass strip.And the image was pre-processed by denoising.The image edges were detected by five algorithms,such as Sobel,Roberts operators.However,these traditional algorithms could not work very well for edge line continuity and denoising.Therefore,mathematical morphology theory was introduced,and then the image was successively calculated as follows,including closure operation,Otsu threshold processing and contour extraction,which can obtain continuous,smooth and noise-free curves of cutting contour for the optical glass and PSNR is relatively high.The simulation results proves the validity of the proposed method.3.The limited weight measurement system was established based on light-cut measurement theory.Firstly,the cross-section profile of the left and right half of the optical glass strip were measured by three linear lasers and two CCD cameras.Secondly,the highprecision centre line linear equation was extracted combining Hough transform with least square method,and the cross section area can be known by obtaining the contour feature points based on the intersection of straight lines.Thirdly,the volume between each frame section can be calculated by cross section area and the feed rate of optical glass strip.Finally,the limited weight was obtained by cumulative volume and density under the experience environment.A non-contact method for fixed-weight cutting of optical glass strip through machine vision and image processing technology can provide some help for the realization of the intellectualization and practicability of fixed weight cutting of optical glass strip.