Repurposing Technology: An Innovative Low Cost Two-Dimensional Noncontact Measurement Tool by Linda L. Graham A Thesis Presented in Partial Fulfillment of the Requirements for the Degree Master of Science in Technology Approved October 2011 by the Graduate Supervisory Committee: Russell Biekert, Chair Narciso Macia Robert Meitz ARIZONA STATE UNIVERSITY December 2011 ©2011 Linda L. Graham All Rights Reserved ABSTRACT Two-dimensional vision-based measurement is an ideal choice for measuring small or fragile parts that could be damaged using conventional contact measurement methods. Two-dimensional vision-based measurement systems can be quite expensive putting the technology out of reach of inventors and others. The vision-based measurement tool design developed in this thesis is a low cost alternative that can be made for less than $500US from off-the-shelf parts and free software. The design is based on the USB microscope. The USB microscope was once considered a toy, similar to the telescopes and microscopes of the 17 th century, but has recently started finding applications in industry, laboratories, and schools. In order to convert the USB microscope into a measurement tool, research in the following areas was necessary: currently available vision-based measurement systems, machine vision technologies, microscope design, photographic methods, digital imaging, illumination, edge detection, and computer aided drafting applications. The result of the research was a two- dimensional vision-based measurement system that is extremely versatile, easy to use, and, best of all, inexpensive. i DEDICATION This thesis is dedicated to the friendship and memory of Patricia Anne McAllister Moffatt. 1942 – 2011 ii ACKNOWLEDGEMENTS This thesis took almost a year to complete. The first few months were spent proving that designing and building an inexpensive two-dimensional noncontact measurement tool was a feasible Master’s thesis topic. My thesis committee, I think, was a bit dubious about my proposed subject, but they went along with it. After that came several months of research, reverse engineering, dead ends, obstacles, and failed experiments. This last year was not much fun. It felt more like I was stumbling along in a dark tunnel not knowing if there would actually be light at the end. Along the way I encountered people who made my research very difficult and my time at ASU a horrible experience, but there were others who made the ordeal a little easier. I would like to thank the following: My Thesis Committee: Professors Russell Biekert, Narciso Macia and Robert Meitz for not trying to steer my thesis research or make ridiculous demands. I would also like to thank them for their kind words of encouragement. Professor Daniel Wilson for introducing me to the concept of disruptive technology. It took almost a year to figure out how to integrate the concept into my thesis. Mesa Community College instructors: Scott Shaw and Keith Evanson. Their enthusiasm about engineering and design made me decide to go for the Master’s degree. Most of all, I would like to thank my husband, Steven L. Graham, for his support, patience, and welding skills. iii TABLE OF CONTENTS Page LIST OF FIGURES .............................................................................................................vii LIST OF TABLES ................................................................................................................ x PREFACE ..........................................................................................................................xii CHAPTER 1. INTRODUCTION ....................................................................................................... 1 Thesis Organization ............................................................................................... 7 2. LITERATURE REVIEW ............................................................................................. 8 Machine Vision and Vision-Based Measurement Systems ................................... 9 Photographic Methods ......................................................................................... 12 Hardware .............................................................................................................. 15 Digital Imaging Software Topics .......................................................................... 31 Case Studies ........................................................................................................ 45 3. 2DNCMT SYSTEM DESIGN ................................................................................... 49 Project Requirements........................................................................................... 50 Project Budget ...................................................................................................... 50 Contrast ................................................................................................................ 51 Hardware .............................................................................................................. 51 Color, IR, UV, and polarizing Filters ..................................................................... 57 Software Selection Criteria .................................................................................. 57 Image Calibration Techniques ............................................................................. 60 4. TEST METHODS .................................................................................................... 64 iv CHAPTER Page Feasibility Studies ................................................................................................ 64 2DNCMT Equipment Tests .................................................................................. 64 Measurement Tests ............................................................................................. 65 5. TEST RESULTS AND ANALYSIS .......................................................................... 75 Feasibility Studies ................................................................................................ 75 Color, IR, and UV Filters ...................................................................................... 75 Color Reflection .................................................................................................... 76 Edge Detection Algorithms .................................................................................. 76 Illumination ........................................................................................................... 76 Software ............................................................................................................... 79 Measurement Test Results .................................................................................. 79 Measurement Test Analysis ................................................................................. 89 6. CONCLUSION ........................................................................................................ 93 REFERENCES .................................................................................................................. 95 APPENDIX A BUDGET ...................................................................................................................... 104 B MACHINE BUILD ......................................................................................................... 109 C DESIGN DATA ............................................................................................................ 135 D TEST DATA AND RESULTS ...................................................................................... 146 E 2DNCMT OPERATING PROCEDURE ....................................................................... 205 F SOFTWARE ANALYSIS .............................................................................................. 210 G MICROSCOPE DESIGN ............................................................................................. 213 v APPENDIX Page H LIGHTING SYSTEM ANALYSIS ................................................................................. 223 J IMAGE ANALYSIS AND HISTOGRAM STUDY ......................................................... 237 K DIFFERENCES BETWEEN CCD AND CMOS SENSORS ........................................ 249 L FEASIBILITY STUDIES AND RESULTS ..................................................................... 252 M ENGINEERING NOTES............................................................................................. 261 vi LIST OF FIGURES FIGURE Page 1.1 Completed Two-Dimensional Noncontact Measurement Tool ..................................... 3 1.2 Research Topic Relationships ...................................................................................... 5 2.1 Early Example of a Universal Photomicrograph Apparatus ........................................ 12 2.2 Reference Target with Micro Part ............................................................................... 14 2.3 Stereomicroscope with Rigid Frame and Illuminated Stage ...................................... 16 2.4 Boom Mounted Stereomicroscope .............................................................................. 16 2.5 Logitech QuickCam ..................................................................................................... 18 2.6 Brando USB Microscope ............................................................................................. 19 2.7 IntelPlay QX3 Plus Computer