بهينه سازي و طراحي روش اسكن x-ray براي كنترل ابعادي و عيب يابي اتوماتيك قطعات متقارن پر تيراژ

چكيده انگليسي :

Design and Optimization of X ray Scanning Method for Automatic Dimensional Check and Defect Detection of Mass Produced Symmetrical Parts Mohammad Hassan Karimi mohamadhasankarimi@gmail com 2011 7 7 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSeyed Mohsen Safavi mosafavi@cc iut ac irAbstractThis research investigates the automatic dimensional check of symmetrical parts thoroughradiography and image processing To do an applicable research studies are carried out on avery sensitive part that has a 200000 parts per year production rate Despite intensivecontrols during production process All manufactured parts undergoes manually dimensionalchecks through go no go gauges snap gauges and spherical pellets for respectively internal external and conical surfaces due to their high sensitivity Automating dimensional checkingprocess needs automatic feeding of parts which is achieved using vibratory bowl feeder anddesigning suitable traps thorough feeder s part track that orients the parts into desiredorientation Necessary bowl feeder s parameters are calculated to reach the obligatory feedrate Part releasing oriented parts transmission to x ray imaging section and measured part sescapement mechanisms have been integrated and designed Designed Separationmechanism separates measured parts into three batches accepted rejected and modifiable Reducing cost efficiency and simplicity has been considered in design process so that the fullautomation has been achieved with only two electromagnet and four pneumatic jacks Monte Carlo based software MCNPX is used to simulate radiographic images to study theeffects of various factors on the radiographic image To confirm the performance ofsimulation software radiographic images have been taken by a digital mammography system Comparing the taken images with simulated ones show a good agreement By consideringpenumbra effect on reducing image quality minimum requirements to reach the 0 01 mmprecision in dimensional check have been introduced Laplacian of a tow dimensionalGaussian distribution is used to define Image edge detection algorithm Slope value of zerocrossing in second derivative histogram of each row of the image is defined as a criterion foredge detection Effect of variables such as source voltage part s axis distance to the source sfocal spot and secondary filters on images is simulated and for the first time in this study optimum value of each factor was obtained Algorithms based on finding edge position andsubtracting taken image by stored image derived from obtained dimensions is defined todetect structural and geometrical concentricity and elliptical surface defects respectively Edge detection algorithm has been implemented in industrial software Labview and itsperformance on taken images has been investigated Cylindrical and angular correctionfactors are applied on measured values to obtain real dimensions Despite 422 528 pixelimage resolution 0 03 mm precision is reached comparing calculated values derived from thealgorithm with real ones It is shown that accessing the research objective measurementprecision 0 01 mm is possible through using appropriate X ray generator and the detector Output precision of image processing algorithm for computing internal and external angleand diameters is reached to 0 1 degree and 0 005 mm respectively from simulated imageswith 4096 3328 pixel detector resolution using suggested optimum conditions for thesource type voltage and distances This accuracy would cover a wide range of industrial partswhich makes automatic dimensional check of symmetrical parts using radiography andimage processing Usability of the optimization criterion introduced in this study has beenprovided for other parts Key wordsDimensional check automation radiography image simulation MCNPX image processing

كريمي، محمد حسن

بهينه سازي و طراحي روش اسكن x-ray براي كنترل ابعادي و عيب يابي اتوماتيك قطعات متقارن پر تيراژ

اتوماسيون , راديو گرافي , شبيه سازي تصوير , MCNPX , مولد اشعه X , پردازش تصوير , قدرت لبه