3차원 비접촉 측정 및 자유곡면 모델링 = Three Dimensional Noncontact Measurement and Free-Form Surface Modeling

다국어 초록 (Multilingual Abstract)

As the measuring data of physical object can be easily obtained in large quantities and of high precision, the importance of surface reconstruction from the these data is rapidly increasing in many application domains such as reverse engineering, CAD/CAM, geographic data process, and 3D visualization.
In this study, the noncontact measuring algorithm has been described for data measurement using the CCD carmera and the laser slit beam. Also, the NURBE surface approximation method has been introduced for creating the surface patches from the data points.
Data obtained from noncontact measurements using CCD carmera and laser slit beam and they have noises and are not regular due to the dispersion of light. therefore, the surface reconstruction mehtod form scattered data is required for surface modeling. But, this method is complex, difficult and needs much of calculation time. This study proposes the regulation method and the interpolation algorithm of measuring data to increase the efficiency of data processing such as filtering and extraction of interest. The regulated data are converted to either triangle mesh surface or NURBS surface. Furthermore, the research explains each step of the modeling process.
This study is implemented using C++ language and Open Inventor and the results of this study are as follows.
1) Noncontact measuering device using CCD camera and laseer enabled us to swift 3D measurement.
2) By regulating measured data from the step of measurement, it is possible efficient data process and we can obtain more complete model through applying data interpolation at overlapped data,
3) By developing a system witch can be applied to either triangle mesh or NURBS surface model form measurment data, we were able to stand on the basis of reverse engineering. Also, we can implement efficient reverse engineering process by integrating measuring system and modeling system,
* A thesis submitted to the Committee of Graduate School, Chungnam National University in partial fulfillment of the requirements for the degree of Master of Mechanical Design Engineering in February 1999.

목차 (Table of Contents)

• 목차
• LIST OF FIGURES = IV
• LIST OF TABLES = VI
• 1. 서론 = 1
• 1.1 연구의 필요성 = 1
• 1.2 국내외 연구 동향 = 3
• 1.3 연구의 목적 = 4
• 2. 비접촉 3차원 측정 = 5
• 2.1 영상처리 알고리즘 = 5
• 2.1.1 디지털영상의 경계값(Threshold valve) 설정 = 6
• 2.1.2 잡음제거 및 슬릿광 균일화 = 8
• 2.1.3 슬릿광 윤곽 추출 = 9
• 2.2 3차원 위치 측정 = 11
• 2.2.1 카메라 교정 = 12
• 2.2.2 좌표 측정 = 13
• 3. 자유곡면 생성 = 15
• 3.1 곡선 보간 = 15
• 3.1.1 NURBS 곡선 보간 = 15
• 3.1.2 곡선 데이터 추출 = 17
• 3.2 자유곡면 보간 알고리즘 = 18
• 3.2.1 NURBS 곡면의 정의 = 19
• 3.2.2 NURBS 곡면 보간 = 22
• 3.3 데이터 처리 = 25
• 3.3.1 측정 데이터의 중복 = 25
• 3.3.2 필터 설계 = 26
• 3.3.3 점열 데이터 보간 = 27
• 3.3.4 모델링 표면 추출 = 29
• 4. 시스템 구성 = 31
• 4.1 시스템 모듈의 구조 = 31
• 4.2 측정 시스템 = 33
• 4.3 데이터 처리 및 모델링 시스템 = 38
• 5. 적용 사례 및 고찰 = 40
• 5.1 데이터 측정 = 40
• 5.2 곡면 모델링 = 42
• 6. 결론 = 50
• REFERENCES = 52
• ABSTRACT = 54
• APPENDEX = 57