於參數化和特徵模型的變形中保持幾何特徵是CAD建模中一項新的挑戰。這篇論文提出了一個以限制為基礎去進行變形的系統。此系統結合了自由曲面和特徵模型建模的好處，而且容許更自由的工程設計。 / 本方法可分為三個主要步驟。以常用的變形技術去改變一個模型的形狀，包括自由變形及軸向變形，然後參數特徵會根據用戶的要求去分拆為一系列基本的限制，最後目標特徵將會以逐步增量的優化技術去重建。 / 這篇論文提出了一個逐步增量的方法為優化中提供導引。這個優化是於維持所有提供的限制下盡量減少變形後模型的改變。另外，於一組的限制中以一個基准為參考，能使本系統更有效的運行。最後，我們也會展示一些使用本系統以限制為基礎去進行變形的結果。 / To retain geometric features in the deformation of a parametric and feature-based model is a new challenge for CAD modeling. This thesis presents a constraints based deformation framework. This framework combines the advantage of free-form modeling with feature based modeling, and allows engineering design to be performed in a free-form manner. / The proposed method can be divided into three major steps. An object is deformed by common deformation techniques such as FFD and axial deformation. Parametric features are divided into systems of primitive constraints based on user specification. The targeting features are reconstructed by the use of incremental optimization technique. / An incremental constrained deformation is introduced. It is used to provide hints for the optimization. The optimization is to minimize the changes in the deformed model subjected to all the provided constraints. For a structural constraint specified with a group of constraints, it would be better to use a reference datum for all its component constraints. We show numerous results of constraints retained models using our framework. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Tang, Wing Shing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 84-86). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese. / Chapter 1 --- INTRODUCTION --- p.3 / Chapter 1.1 --- Aims and Objectives --- p.4 / Chapter 1.2 --- Report Organization --- p.5 / Chapter 2 --- BACKGROUND AND LITERATURE REVIEW --- p.7 / Chapter 2.1 --- Mesh Editing Techniques --- p.7 / Chapter 2.1.1 --- Mesh Deformation Techniques --- p.7 / Chapter 2.1.2 --- Detail Preserving Techniques --- p.9 / Chapter 2.2 --- Optimization Techniques --- p.11 / Chapter 2.2.1 --- Optimization Techniques --- p.11 / Chapter 2.2.2 --- Linear Programming --- p.12 / Chapter 2.2.2.1 --- Simplex Method --- p.12 / Chapter 2.2.2.2 --- Interior Point Method --- p.12 / Chapter 2.2.2.2.1 --- Primal-Dual Interior Point Method --- p.13 / Chapter 2.2.3 --- Nonlinear Programming --- p.14 / Chapter 2.2.3.1 --- Sequential Quadratic Programming --- p.14 / Chapter 2.2.3.2 --- Reduced Gradient Methods --- p.14 / Chapter 2.2.3.3 --- Interior Point Methods --- p.15 / Chapter 2.2.4 --- Optimization Solver --- p.15 / Chapter 2.2.4.1 --- KNITRO --- p.16 / Chapter 3 --- SPECIFICATION OF CONSTRAINTS --- p.18 / Chapter 3.1 --- Constraints --- p.18 / Chapter 3.1.1 --- Constraints with Reference Points --- p.22 / Chapter 3.1.2 --- Constraints with Reference Variables --- p.24 / Chapter 3.1.3 --- Reference Vector Constraints --- p.26 / Chapter 3.1.4 --- Constraints with Reference Datum --- p.27 / Chapter 3.1.4.1 --- Planer Constraint with References --- p.28 / Chapter 3.1.4.2 --- Collinear Constraint with References --- p.29 / Chapter 3.1.4.3 --- Circular Constraint with References --- p.30 / Chapter 3.2 --- Redundant Constraints --- p.31 / Chapter 4 --- CONSTRAINED OPTIMZATION --- p.32 / Chapter 4.1 --- Objective Function --- p.32 / Chapter 4.2 --- Incremental Constrained Deformation --- p.39 / Chapter 4.3 --- The Scaling Problem --- p.43 / Chapter 5 --- CASE STUDIES --- p.44 / Chapter 5.1 --- Maintain Individual Engineering Features --- p.44 / Chapter 5.2 --- Maintain Pattern between Engineering Features --- p.49 / Chapter 5.3 --- Maintain Relationship between Engineering Features --- p.51 / Chapter 5.4 --- Implementation Issue --- p.66 / Chapter 6 --- TESTS AND RESULTS --- p.68 / Chapter 6.1 --- Constraints with References --- p.68 / Chapter 6.2 --- Level Of Detail --- p.71 / Chapter 6.3 --- Incremental Method --- p.73 / Chapter 6.4 --- Comparison --- p.76 / Chapter 7 --- FURTHER WORK AND CONCLUSIONS --- p.81 / Chapter 7.1 --- Recommendation for Further Work --- p.81 / Chapter 7.2 --- Conclusions --- p.82 / REFERENCES --- p.84
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_328219 |
| Date | January 2013 |
| Contributors | Tang, Wing Shing., Chinese University of Hong Kong Graduate School. Division of Mechanical and Automation Engineering. |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, bibliography |
| Format | electronic resource, electronic resource, remote, 1 online resource (5, 86 leaves) : ill. (chiefly col.) |
| Coverage | Data processing |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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