• 제목/요약/키워드: Free-form Surface

검색결과 402건 처리시간 0.032초

역설계를 이용한 자유곡면 모델링 시스템 개발 (Development of Free-Form Surface Modeling System Using the Reverse engineering Technology)

  • 명태식
    • 한국생산제조학회지
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    • 제9권3호
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    • pp.111-122
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    • 2000
  • It is difficult to make shape library for featrue-based modeling because free-form surface is various shaped complicated To make modeling using similar shape feature-based model is easy and fast. Recently RE(Reverse Engineering) technolo-gy is very convenient method to get free-form surface. This study develops surface editor which makes surface modeling to manipulate control points and this study We study on the effective model data management using database system.

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3차 Ball 곡선을 이용한 자유 형태 곡면 근사 방법 (The Approximation of Free-form Surface using Cubic Ball Curve)

  • 이아리;심재홍
    • 한국정보처리학회논문지
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    • 제7권4호
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    • pp.1271-1278
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    • 2000
  • A general curve and surface is a basic method to generate Free-form object using the fundamental properties of blending function. In typical method, there is an overhead of calculating to present Free-form object with the line segments and interpolation algorithm, In this paper, for resolving this problem efficiently, it will propose the flexible Free-form curves/surfaces using Ball curve shape-preserving property. This method includes Geometric Continuity that is needed to design Free-form Surface of high degree consisted with many curves. Also, when lots of data are reduced using Geometric Property of Free-form curves, the shape-preserving property of resulting object can be maintained, then it can represent any Free-form object with less calculating .

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평행이동곡면과 자유곡면 사이의 교차곡선 계산 (Intersection between a Surface of Extrusion and a Free-Form Surface)

  • 김구진;김명수
    • 한국컴퓨터그래픽스학회논문지
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    • 제6권4호
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    • pp.29-34
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    • 2000
  • 이 논문에서는 평행이동곡면 (surface of extrusion) 과 임의의 자유곡면 사이의 교차곡선의 구조를 분석하고 이를 계산하는 방법에 대해 설명한다. 평행이동곡면의 이동방향에 대하여 다른 곡면의 윤곽곡선 (silhouette curve) 을 구하고, 이를 평행이동곡면의 기준곡선과 교차시킴으로써 교차곡선의 구조를 분석한다. 또한, 교차곡선이 존재하는 범위와 특이점을 구함으로써 교차곡선 전체를 안정적이고 효율적으로 계산하는 알고리즘을 제시한다.

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볼엔드밀 고속가공에서 곡면형상에 따른 절삭속도 일정제어기법 가공기술 (The Machining Technique of Curved Surface through Constant Control of Cutting Speed Method in Ball End Milling)

  • 김경균;문성준;강명창;이득우;김정석
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집A
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    • pp.753-759
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    • 2001
  • The purpose of this study is to suggest the machining technique of the constant control of cutting speed in order to improve precision machining and tool life in high speed machining using ball end mill. Cutting speed is changed in machining free form surface like free form surface. So, we don't have supreme surface form and toll life on machining. The way to solving this problem is that we should be settled to optimal cutting speed in free form surface machining. And, to improve precision machining is executed high speed machining method to output optimum NC data with developed constant control of cutting speed program after modeling of CAD/CAM. In this paper, a comparison was made of the cutting precision and tool life in conventional cutting and those in free form surface machining applying the program developed.

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볼 엔드밀을 통한 자유곡면의 고속가공에서 절삭방향에 따른 가공성 평가 (Machinability Evaluation with Cutting Direction in High Speed Machining of Free Form Surface through Ball End Milling)

  • 김경균;강명창;이득우;김정석
    • 한국정밀공학회지
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    • 제18권2호
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    • pp.84-89
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    • 2001
  • In recent years, there is increasing demand of esthetic design and complex function in aerospace, automobile and die/mold industry, which brings into limelight high-precision, high-efficient machining of sculptured surface. This paper deals with the establishment of the optimal tool path on free form surface in high speed ball end milling. Ball end milling is widely used for free form surface die and mold. In this machining, the cutting direction was changed with tool path. The cutting characteristics, such as cutting force and surface form are varied according to the variation of cutting directions. In this paper, the optimal tool path with down cutting in free form surface cutting is suggested.

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Automatic Panelizing Algorithms of Free-form Buildings

  • Lee, Donghoon;Lim, Jeeyoung;Habimana, Gilbert;Lee, Taick-Oun;Kim, Sunkuk
    • 국제학술발표논문집
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    • The 6th International Conference on Construction Engineering and Project Management
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    • pp.425-428
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    • 2015
  • New technologies using a CNC machine are being developed to reduce the production cost of free-form buildings. For production of free-form members using such technologies, vast free-form buildings should be first split into multiple panels that are productible. Taking into consideration of the curved surface of free-form members, the segmented free-form panels may vary in shape and size, which may cause a lot of errors. In addition, it is time-consuming for the work. However, the current panelizing work is completed with the trials and errors of engineers and architectural designers even in large-scale projects, which results in increased construction duration and cost. Thus, it is necessary to develop a technology for panelizing free-form panels so as to maximize the economic feasibility of production technologies for free-form concrete members. The study intends to develeop automatic panelizing algorithms of free-form buildings considering the curved surface and size of free-form panels and the production conditions. The developed algorithms will be useful in applying the production technologies of free-form buildings using CNC machine and reducing the cost.

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3차원 측정 데이터를 이용한 자유곡면 가공물의 오차해석 (Error Analysis of Free-Form Artifact using 3D Measurement Data)

  • 김성돈;이성근;양승한;이재종
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.439-442
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    • 2001
  • The Accuracy of a free-form artifact is affected by machine tool errors, machining process errors, environmental causes and other uncertainty. This paper deals with methodological approach about machine tool errors that are defined the relationship between CMM and OMM inspections of the free-form artifact. In order to analyze the measurement data, Reverse engineering was used. In other words, Surface of Free-Form Artifact is generated by NURBS surface approximation method. Finally, Volumetric error map is made to compare surface of CMM data with that of OMM data.

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3차원 자유곡면 가공에 있어서의 공구간섭방지에 관한 연구 (A Study on the Avidance of Tool Interference in Free form Surface Machining)

  • 양균의;박윤섭;이희관
    • 대한기계학회논문집
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    • 제19권8호
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    • pp.1832-1843
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    • 1995
  • Tool interference is one of the most critical problems in sculptured surface machining. When machining cavities and concaves, the tool frequently overcuts the portions of the surface, which cause inaccuracy in machining. So tool interference-free paths must be generated for rough cutting more efficiently. In this paper a software using SSI(Surface/Surface intersection) algorithm is developed for eliminating tool interference which occurs in an offset surface in 3-dimensional free form surface modeling. this work consists of two stages : using the offset data, the intersection curves are rapidly checked by this algorithm at the first stage. CL(cutter location) data are obtained by deleting the loop section of intersected offset patches at the second stage. This algorithm can reduce the amount of memory required to store machining data and also easily check region which have the possibility of intersection. Also, This software is verified to be useful in machining a curved object on a DNC milling machine.

3차원 자유곡면식을 이용한 LED 비대칭 렌즈 설계 및 성능 비교 분석 (Analysis of Performance on Asymmetric LED Lens Design Using Three-Dimensional Free-Form Surface Expression)

  • 이창수;이수영;현동훈
    • 한국생산제조학회지
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    • 제26권3호
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    • pp.328-336
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    • 2017
  • The exit surface of a lens is designed using a three-dimensional free-form expression in order to easily modify a curved surface. This enables the design of numerical values and mathematical things using three-dimensional free-form expression, and enhances precision because it can be fine-tuned via numerical control. The standard of "Classification of Luminaire Light Distribution" for outdoor lighting fixtures by IESNA is adopted in order to examine the correlation between three-dimensional free-form surface expression and lighting performance. The variation of light distribution type and range is analyzed using the values of maximum light intensity and 50% light intensity. The actual tolerance occurs owing to parameters such as the thickness of the lens, the distance between LEDs, and the movement of the center of the incident surface; the effects of changes in these parameters on the performance are compared and analyzed.

볼 엔드밀에 의한 정밀 가공에 관한 연구 (A stydy on the precision machining in ball end milling system)

  • 양민양;심충건
    • 한국정밀공학회지
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    • 제11권2호
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    • pp.50-64
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    • 1994
  • Cutter deflections in the ball-end milling process is one of the main causes of the machining errors on a free-form surface. In order to avoid machining errors in this process, a methodology avoiding these machining errors on the free-form surfaces has been developed. In this method, feedrates in the finish cuts are adjusted for the prevention of machining errors. A model for the prediction of machining errors on the free-form surface is analytically derived as a function of feed and normal vector at the surface of contact point by the cutter. This model is applied to the dertermination of the adjusted feedrates which satisfy the machining tolerance of the surface. In the finish cuts of a simple curved surface, the suggested model is examined by the measurements of the generated machining error on this surface. And also, this surface is machined with the adjusted feedrates for the given machining tolerance. The measured machining errors on this surface are compared with the given tolerance. In this comparisons, it is shown that the predicted errors are fairly good agreement with the test results.

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