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Knowledge Guided Non-Uniform Rational B-Spline (NURBS) for Supporting Design Intent in Computer Aided Design (CAD) Modeling

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Knowledge Guided Non-Uniform Rational B-Spline (NURBS) for Supporting Design Intent in Computer Aided Design (CAD) Modeling University of South Florida Scholar Commons Graduate Theses and Dissertations Graduate School 2011 Knowledge Guided Non-Uniform Rational B-Spline (NURBS) for Supporting Design Intent in Computer Aided Design (CAD) Modeling Khairan Rajab University of South Florida, [email protected] Follow this and additional works at: https://scholarcommons.usf.edu/etd Part of the American Studies Commons, and the Computer Sciences Commons Scholar Commons Citation Rajab, Khairan, "Knowledge Guided Non-Uniform Rational B-Spline (NURBS) for Supporting Design Intent in Computer Aided Design (CAD) Modeling" (2011). Graduate Theses and Dissertations. https://scholarcommons.usf.edu/etd/3302 This Dissertation is brought to you for free and open access by the Graduate School at Scholar Commons. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. Knowledge Guided Non-Uniform Rational B-Spline (NURBS) for Supporting Design Intent in Computer Aided Design (CAD) Modeling by Khairan D. Rajab A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Department of Computer Science and Engineering College of Engineering University of South Florida Major Professor: Les A. Piegl. Ph.D. Susanna Lai-Yuen, Ph.D. Miguel Labrador, Ph.D. Dewey Rundus, Ph.D. Arthur Shapiro, Ph.D. Date of Approval: June 9, 2011 Keywords: NURBS Model exchange, CAD robustness, CAD incompatibility, Design intent exchange, Data migration Copyright © 2011, Khairan D. Rajab Acknowledgements First and foremost, my highest gratitude goes to my advisor, Dr. Les A. Piegl. To work with and be mentored by a renowned expert in the area of NURBS has truly been an honor and privilege. He is a generous and conscientious mentor who was always there when I needed advice and guidance. I thank the members of my committee: Dr. Susanna Lai-Yuen, Dr. Arthur Shapiro, Dr. Dewey Rundus, and Dr. Miguel Labrador. I appreciate their valuable time and comments. They have been inspiration in many ways. I would also like to thank Dr. Steve Permuth for taking the time to serve as the Committee Chair. My appreciation is also extended to the seminar members who listened to my research presentations on numerous occasions. Thanks to Dr. Daniel Simkens and to Olya Grove for the lively and rewarding discussions about my research ideas. I have thanked many yet also have left many out. Thanks to all whom I left out but were available to help and encourage. Special thanks to Dr. Yousef AL-Marshad for his relentless encouragement throughout most of my studies as an undergraduate and graduate student. Thanks to Dr. Fahd Rajab for the many comments he provided at the time of writing this dissertation. Dedication I most certainly thank and dedicate this work to my family for all their love and unconditional support. Without them my graduation would have been impossible. Table of Contents List of Tables ............................................................................................................. iv List of Figures ...............................................................................................................v Abstract ............................................................................................................. ix Chapter 1 --- Introduction ....................................................................................................1 1.1 Motivation and Problem Formulation ..............................................................1 1.1.1 Why isn't Design Intent Supported Yet? ............................................7 1.2 Prior Works .......................................................................................................9 1.2.1 Design Intent ...................................................................................10 1.2.1.1 Exisiting Design Intent System ....................................... 11 1.2.2 CAD Models Repair ........................................................................16 1.2.3 Design Intent Exchange ...................................................................18 1.2.4 CAD Model's Data Exchange..........................................................20 1.2.4.1 Efforts for Standardization ...............................................21 1.2.4.2 IGES: Initial Graphic Exchange Specification .................23 1.2.4.2.1 Shortcomings of IGES.....................................25 1.2.4.3 STEP: STandard for the Exchange of Product Model Data .......................................................................27 1.2.4.4 Quasi Industry Standards ..................................................30 1.3 Contributions ..................................................................................................31 1.4 Organization of the Dissertation .....................................................................32 Chapter 2 --- NURBS Fundamentals .................................................................................34 2.1 Mathematical Representations of Curves and Surfaces .................................35 2.1.1 Explicit ............................................................................................35 2.1.2 Implicit ............................................................................................36 2.1.3 Parametric ........................................................................................37 2.2 NURBS Basics ...............................................................................................38 2.2.1 NURBS Curve .................................................................................43 2.2.1.1 Knot Vectors .....................................................................44 2.2.1.2 Basis Functions .................................................................46 2.2.2 NURBS Surface ..............................................................................48 2.2.3 NURBS with Higher Dimensions ...................................................50 2.3 Modelling Techniques ....................................................................................51 i 2.3.1 NURBS Modeling Techniques ........................................................52 2.4 NURBS Model Representation ......................................................................58 2.5 NURBS Data Export to Other CAD Systems and Storage ............................60 2.5.1 NURBS within Standards ................................................................61 Chapter 3 --- Knowledge Guided Desing Intent Systems ..................................................64 3.1 What is Knowledge? ......................................................................................65 3.1.1 Knowledge Acquisition and Representation ...................................67 3.2 What is Design Intent? ...................................................................................68 3.2.1 Design Alternatives .........................................................................69 3.2.2 Design Functions .............................................................................69 3.2.3 Design Decisions .............................................................................70 3.2.4 Design History .................................................................................70 3.3 What Information Needs to be Retained? ......................................................71 Chapter 4 --- Knowledge Guided NURBS ........................................................................75 4.1 Knowledge Guided NURBS ..........................................................................76 4.1.1 Identification ...................................................................................77 4.1.2 Classification ...................................................................................80 4.1.2.1 Type ..................................................................................80 4.1.2.2 Origin ................................................................................82 4.1.2.3 Destination ........................................................................82 4.1.3 Definition .........................................................................................83 4.1.4 Representation .................................................................................84 4.1.4.1 Parametrization Factor .....................................................85 4.1.4.2 Level of Continuity ..........................................................87 4.1.4.3 Irregularities .....................................................................88 4.1.5 Geometry .........................................................................................88 4.1.6 Relationship Maps ...........................................................................90 4.1.6.1 Proper Naming .................................................................92 4.1.6.2 Participating Objects ........................................................93 4.1.6.3 Parameters ........................................................................94 4.1.6.4 Conditions ........................................................................94 4.2 Knowledge Acquisistion Manager .................................................................95 4.2.1 Construction ....................................................................................96 4.2.2 Design Intent Enforcment ...............................................................96
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