The Light-pen Detection Technology Of The Large Size Bearing

With the increasing demands of the large bearing products as well as the increasingvariety and precision of the bearing products,which stimulate the quick developmentof the industry of bearing products.Nowadays,bearing industry usually adopts thetraditional measurement method of combining semi-automatic and manual test whichcan not effectively and precisely control the bearing product quality,which can easilycause the existence of low detective efficiency、precision、high reject rate.It isdifficult to meet high precision of the large bearing detection.So it is very necessary todesign a convenient and high precision of testing tools of bearing products.Vision measurement is also known as the digital photogrammetry,which is a kind ofstereo vision-testing technology,and it has the capability of the online、real-time ofthree-dimensional measurement,especially suitable for3D point position,size or largeworkpiece contour detection.This paper researches the light-pen measuring system isto use CCD camera fixing on the marks of the light-pen to develop a image.Byextracting these signs point in the camera image plane corresponds to the pixelcoordinates of the image plane then indirectly to obtain three-dimensional coordinatesof the measured point.System is simple,mainly equipped with a landmark-measurement of the luminous point pen also with a visual measurement system and thecore of one or two CCD cameras as well as a portable computer equipped with asupporting measurement software.The main research work in this thesis includes：1.The comparative analysis the measuring principle,range of applications,measurement accuracy,the advantages and disadvantages when apply the method ofthe traditional mechanical measurement,the optical electronic measurement andmodern optical measurement in measuring the huge bearing.Then propose the subjectof research and solution.2.Research the composition of the light pen measuring system and measurement principle.3.Analysis of the development process and the mathematical model of the PNPproblem,examining only one solution to the situation,examining The particular casesolving P3P validation collinear solution unique,whereby redundant structure toestablish a practical model of the measurement system of this research project the lightpen,and solved to verify the accuracy and practicality.to prove the unicity of thespecial condition solution on verifying the threepoint collineation’s P3Pissue,accordingly utilize redundant structure to establish the practical model of lightpen mesuring system on this research project,and solve and verify the correctness andpractical utility.4. Analysis of the imaging characteristics of the light pen luminous point, basedon VC++development supporting the light pen image processing software, this paperpresents the method of the image pretreatment、 image denoising、 imagesegmentation、the expansion corrosion handle、least squares curve fitting featureextraction、gravity center point coordinates extraction、3D reconstruction based onMatlab, the effect of experimental verification is obvious.5. According to the date-result of the development of supporting software and thereconstruction of the three dimensionalof the Matlab software,the make a more perfectthe contours of the cylinder,and accurately calculate the diameter of the testingbearing.6.To build the experimental system,to maintain a test bearing roller fixed,usingthe coordinate measuring machine.Under three methods of light pen measuring systemfor the development of the subject and Canada Creaform hand-held light pencoordinate measuring system C-Track780to do analysis of data acquisition andcomparison of experiments to verify the practicality and feasibility of this researchproject,provides a theoretical basis and practical basis for further study...