• 한국CDE학회논문집
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• 제11권5호
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• pp.375-383
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• 2006

Presented in this paper is a new fast and robust algorithm generating NC tool path for 2D pockets with islands. The input shapes are composed of line segments and circular arcs. The algorithm has two steps: creation of successive offset loops and linking the loops to a tool path. A modified pairwise technique is developed in order to speed up and stabilize the offset process, and the linking algorithm is focused on avoiding thin-wall cutting and minimizing tool retractions. The proposed algorithm has been implemented in C++ and some illustrative examples are presented to show the practical strength of the algorithm.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
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• pp.223.1-223.1
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• 2005

• 한국CDE학회논문집
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• 제10권6호
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• pp.455-464
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• 2005

This paper discusses the methods of computing tool-paths for machining free-form surfaces on 3-axis CNC machines in die and mould making. In computational view this paper describes the characteristics and issues of the geometric information and the shape, which make computing tool-paths difficult. Important points that should be considered in devising a computing method are also discussed. A newly implemented method is explained and compared with an old method for a commercial CAM system. The implemented method is used in a commercial CAM system and the computing time for an example is presented.

• 한국정밀공학회지
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• 제10권2호
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• pp.48-53
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• 1993

At present, the manufacturing industry is in a process of a great change. There is a demand for a variety of types and shorter product life. The change increases the number of different tools and frequencies of tool changes. For the most part, the tools are presetted and offset values are entered manually or via punched tapes to NC machines. Thus a large amount of capital is tied up in the tool area and considerable productive time is lost. Consequently, there is a need for improvement in tool management. This paper describes a computer controlled tool data management system which include: 1) tool identification with bar code. 2) computer aided management and updating of tool data. 3) tool data communication with tool presetter, CNC, etc.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.329-330
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• 2010

• 대한전자공학회논문지TC
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• 제47권10호
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• pp.49-56
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• 2010

이 논문에서는 pipeline CORDIC(COordinate Rotation DIgital Computer)을 이용한 저전력 주파수 옵셋 동기화기 구조를 제안하였다. 주파수 옵셋 동기화기의 핵심 블록은 주파수 옵셋 추정부와 보상부이다. 제안된 주파수 옵셋 추정부에서는 sequential CORDIC을 사용하여 구현면적을 감소시켰으며 한번에 2 단계씩 CORDIC을 수행하는 방식을 사용하여 연산 속도를 높였다. 또한 제안된 주파수 옵셋 보상부에서는 pipeline CORDIC을 사용하여 구현면적을 줄임과 동시에 계산 속도를 향상시킬 수 있었다. MatLab을 사용하여 제안 구조가 주파수 옵셋을 추정 및 보상하는 function을 검증하였다. 제안 구조에 대하여 Verilog-HDL로 코딩하고 Synopsys tool을 사용하여 합성하여 구현면적을 실험하였다.

• 대한기계학회논문집A
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• 제30권2호
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• pp.141-148
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• 2006

In this paper, a new offset algorithm for closed 2D lines with islands is introduced and the result is illustrated. The main point of the proposed algorithm is that every point is set to be an offset by using bisectors, and then invalid offset lines, which are not to be participated in offsets, are detected in advance and handled with an invalid offset edge handling algorithm. As a result, raw offset lines without local invalid loops are generated. The proposed offset method is proved to be robust and simple, moreover, has a near O(n) time complexity, where n denotes the number of input lines. In addition, the proposed algorithm has been implemented and tested with 2D lines of various shapes.

• 대한기계학회논문집A
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• 제24권12호
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• pp.3018-3025
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• 2000

It is possible to shorten developing process by making model using polyurethane foam in the area of automobile development process, etc. However, this skill is too difficult to be of practical use because machining is not easy due to characteristic of polyurethane foam. Domestic and foreign automobile company use clay, polyurethane foam. etc,, those are easy to handle and to make model after completing design sketch. But these materials is difficult to the machined and be worked by humans hand, There are so many difficult problem for machining by making model using polyurethane foam since cutting of elastic body like polyurethan foam has never been studied. Therefore, in this study, it is investigated to measured cutting force that is generated in case of polyurethane foam machining, and to make systematize tool compensation of polyurethane foam cutting work on automobile model by modification of tool offset method on existing steel.

• Journal of Advanced Marine Engineering and Technology
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• 제21권4호
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• pp.381-386
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• 1997

The offsetting method using geometric properties of B-spline control polygon is more faster than using of general normal vector in offset processing. But this method itself does not solve the prob¬lems of loop removal in normal offsetting. Generally the distance between neighborhood spans of B-spline control polygon is greater than the offset distance, the loops are occurred in offsetting. For generating of the more precision tool-path in NC machining, the loops of offset must be removed. In this paper, two methods for loop removal are introduced in offsetting of B-spline curve. One is using the intersection of B-spline control span which being occurred of the loop. The other is using two B-spline curve divisions divided from original B-spline curve or its offset curve. After the inter¬section point of loop was searched, the loop being removed to cusp. Also the method for filleting of cusp is inspected to more precision cutting. It is shown that the offsetting using B-spline control polygon is more effective in the sculptured surface machining.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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• pp.200-207
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• 2003

Presented in this paper is a new fast and robust algorithm generating NC tool path for 2D pockets with islands. The input shapes are composed of line segments and cricular arcs. The algorithm has two steps: creation of successive offset loops and linking the loops to tool path. A modified pair-wise technique is developed in order to speed up and stabilize the offset process, and the linking algorithm is focused on minimizing tool retractions and preventing thin-wall rotting The proposed algorithm has been implemented In C++ and some illustrative examples are presented to show the practical strength of the algorithm.