• Journal of Biosystems Engineering
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• 제24권1호
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• pp.67-74
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• 1999

A prototype cut-flower sorter was developed and tested for its performance with five varieties of roses. Support plates driven by a chain mechanism transported the roses into an image inspection chamber. Color image processing algorithms were developed to evaluate the length, thickness, and straightness of stem and color, height, and maturity of bud. The average absolute errors of the system for the measurements of stem length, stem thickness, and height of bud were 19.7 mm, 0.5 mm, and 3.8 mm, respectively. The results of classification by the sorter were compared with those of a human inspector for straightness of stem and maturity of bud. The classification error for the straightness of stem was 8.6%, when both direct image and reflected image by a mirror were analyzed. The accuracy in classifying the maturity of bud varied among the varieties, the smallest for‘Nobless’(1.5%) and the largest for‘Rote Rose’(13.5%). The time required to process a rose averaged 2.06 seconds, equivalent to the capacity of 1,600 roses per hour.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 춘계학술대회 논문집
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• pp.181-186
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• 1999

Recently the machining technique have been progressed rapidly according to developments of the product technique in the machine tool and new tools. But in the case of vertical machine center(VMC), to become visible there is the appearance of bending because of the structural problems of x-axis guide way, and this would effect directly on accuracy of form of the straightness, parallelism and flatness. In this paper, I purpose to check the appearance of bending with the experiment and improve the working accuracy. Under the constant working conditions, the appearance of bending of x-axis guide way was measured to confirm the effectiveness of the compensation method in the vertical machine center(VMC). By using this method the results show that the accuracy of form of the straightness, parallelism and flatness could be reduced to 20% compared with ordinary method.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.551-552
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• 2013

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1998년도 추계학술대회 논문집
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• pp.54-59
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• 1998

In order to minimize straightness error of deflected shafts, a automatically bending process control system is designed, fabricated, and studied. The multi-step straightening process and the three-point bending process are developed for the geometric adaptive straightness control. Load-deflection relationship, on-line identification of variations of material properties, on-line springback prediction, and studied for the three-point bending processes. Selection of a loading point supporting condition are derved form fuzzy inference and fuzzy self-learning method in the multi-step straighternign process. Automatic straightening machine is fabricated by using the develped ideas. Validity of the proposed system si verified through experiments.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.712-717
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• 2000

Hydrostatic bearings have been applied to high precision machine tools and instruments, because the bearing has high stiffness, high damping and excellent straightness. This paper treats a procedure for designing a high precision press with linear hydrostatic bearings.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1996년도 춘계학술대회 논문집
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• pp.137-142
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• 1996

Magnetic-electrolytic-abrasive polishing system(MEAPS) was developed for machining national standard electrode and its finishing characteristics was analyzed. The paper describes the operational principle of MEAP system by experimental results. The finishing characteristics and optimal finishing condition for national standard electrodes were experimented and analyzed. As a result, MEAPS can improve straightness as well as surface roughness.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.141-142
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• 2011

• 한국정밀공학회지
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• 제28권8호
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• pp.904-914
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• 2011

The volumetric errors of CNC machining centers are determined by 21 errors, including 3 linear errors, 6 straightness errors, 3 perpendicular errors, 9 angular errors and non-rigid body errors of the machine tool. It is very time consuming and hard to measure all of these errors in which laser interferometer and other parts are used directly. Hence, as many as 21 separate setups and measurements are needed for the linear, straightness, angular and perpendicular errors. In case of the 5-axis machining centers, two more rotary tables are used. It can make 35 error sources of the movement. Therefore, the measured errors of multi movements of the 5-axis tables are very complicated, even if the relative measured errors are measured. This paper describes the methods, those analyze the error sources of the machining centers. Those are based on shifted diagonal measurements method (SDM), R-test and Double ball bar. In case, the angular errors of machine are small enough comparing with others, twelve errors including three linear position errors, six straightness errors and three perpendicular errors can be calculated by using SDM. To confirm the proposed method, SDM was applied to measuring 3 axes of machine tools and compared with directly measurement of each errors. In addition, the methods for measuring relative errors of multi-axis analysis methods using R-test and Double Ball Bar are introduced in this paper.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 추계종합학술대회
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• pp.561-564
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• 2007

사람이 걸을 때와는 달리 차량으로 이동할 경우 좌회전, U턴 동의 방향 전환시 교통신호를 받거나 속도를 줄여야만 하는 지연시간이 존재한다. 동일한 거리를 이동한다면 방향전환이 많은 경로보다 직진 구간이 많은 경로가 목적지에 더 빨리 도착할 가능성이 높다. 기존의 연구 중 이러한 직진성을 고려한 경로탐색은 연구되어 지지 않았다. 이 논문에서는 방향전환이 이루어지는 경로에 대해 가중치를 부여하여 직진성을 높인 경로 탐색 방법을 소개한다. 또한, 기존의 $A^*$ 알고리즘에서 맨하탄 거리를 휴리스틱으로 사용할 때와 제안하는 휴리스틱을 이용한 방법으로 탐색된 경로를 비교해 보았다. 실험결과 직진성이 약 30% 가량 향상되었으며 이동거리는 약 3.3%가량 축소되는 결과를 보였다.

• 대한기계학회논문집A
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• 제37권10호
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• pp.1269-1278
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• 2013

엔드밀링 공정은 형상창성기구의 특성 상, 절삭면적의 주기적인 변화를 피할 수 없다. 그러므로, 본 연구에서는, 가공 중 절삭날과 공작물 사이의 간섭영역에 해당하는 절삭면적의 모델을 확립하여, 가공면 형상 특성과 절삭면적의 관계를 규명하고자 한다. 대상 가공면은 측벽을 선정하였으며, 형상 특성은 축 방향 진직도를 선택하였다. 절삭면적 및 축방향 진직도에 영향을 미치는 특이점 추정 모델의 타당성은 반경 방향 및 축 방향 절삭깊이를 변화시키며 엔드밀링 가공을 수행하여 검증하였다. 연구 결과, 배분력이 음의 값을 갖지 않는 안정적인 엔드밀링 가공의 경우, 상향절삭은 절삭면적이 증가했다. 일정해지는 영역에서, 하향절삭은 절삭면적이 일정했다 감소하는 영역에서 가공면을 창성하며, 영역이 변화될 때 가공면에 특이점이 발생하는 것이 확인되었다.