• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.683-684
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• 2010

• 대한기계학회논문집A
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• 제20권3호
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• pp.891-900
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• 1996

The vision sensor which is based on the optical triangulation theory with the laser as an auxiliary light source can detect not only the seam position but the shape of seam. In this study, a vision sensor using the scanning laser beam was investigated. To design the vision sensor which considers the reflectivity of the sensing object and satisfies the desired resolution and measuring range, the equation of the focused laser beam which has a Gaussian irradiance profile was firstly formulated, Secondly, the image formaing sequence, and thirdly the relation between the displacement in the measuring surface and the displacement in the camera plane was formulated. Therefore, the focused beam diameter in the measuring range could be determined and the influence of the relative location between the laser and camera plane could be estimated. The measuring range and the resolution of the vision sensor which was based on the Scheimpflug's condition could also be calculated. From the results mentioned above a vision sensor was developed, and an adequate calibration technique was proposed. The image processing algorithm which and recognize the center of joint and its shape informaitons was investigated. Using the developed vision sensor and image processing algorithm, the shape informations was investigated. Using the developed vision sensor and image processing algorithm, the shape informations of the vee-, butt- and lap joint were extracted.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.597-599
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• 2006

In this paper, we propose an artificial intelligence method to compensate the nonlinearity error which occurs in the heterodyne laser interferometer. Some superior properties such as long measurement range, ultra-precise resolution and various system set-up lead the laser interferometer to be a practical displacement measurement apparatus in various industry and research area. In ultra-precise measurement such as nanometer or subnanometer scale, however, the accuracy is limited by the nonlinearity error caused by the optical parts. The feedforward neural network trained by back-propagation with a capacitive sensor as a reference signal minimizes the nonlinearity error and we demonstrate the effectiveness of our proppsed algorithm through some experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.234-236
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• 2006

Because of its long measurement range and ultra-precise resolution. the heterodyne laser interferometer systems are very common in various industry area such as semiconductor manufacturing. However the periodical nonlinearity property caused from frequency mixing is an obstacle to improve the high measurement accuracy in nanometer scale. In this paper to minimize the effect of nonlinearity, we propose an adaptive nonlinearity compensation algorithm. We first compute compensation parameters using least square (LS) with the capacitance displacement sensor as a reference input. We then update the parameters with recursive LS (RLS) while the values are optimized to modify the elliptical phase into circular one. Through comparison with some experimental results of laser system, we demonstrate the effectiveness of our proposed algorithm.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 춘계학술대회 논문집
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• pp.414-419
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• 1995

The wire displacement of wire electric discharge machine has been measured using He-Ne laser. A measurement system consisted of He-Ne laser, A/D converter, 4 divided photodiode, amplifier, sensor process instrument, and personal computer. The processing parameters were varid with feed rate, wire tension, wire speed and voltage. The laser beam intensity transmitted on a 4 divided photodiode was varied by processing wire electric descharge machine with various process parameters. The 4 divided photodiode and amplifier were used to change the detected beam intensity into voltage. Variation of wire displacement was between 11 and 125 .mu. m. The wire tension was dominant on the variation of wire displacement among many parameters.

• 융합신호처리학회논문지
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• 제11권4호
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• pp.338-344
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• 2010

선박 블록의 용접 공정에서는 용접선의 양쪽 끝이 벽에 의해 막혀있는 경우가 많다. 본 연구에서는 이러한 벽이 있는 환경에서 맞대기 용접의 자동화를 위한 용접선 검출 시스템을 개발하였다. 용접선 검출 시스템은 벽에서 캐리지의 위치를 측정하고, 초층의 용접선을 검출하게 된다. 시스템은 레이저 변위센서와 초음파센서로 구성되어 있다. 레이저 변위센서는 모터에 의해 회전 왕복 운동하며 용접 모재까지의 거리를 측정하게 되고, 초음파센서는 양쪽 벽면까지의 거리를 측정한다. 초음파센서로 측정된 거리정보를 활용하여 용접선의 X(주행)좌표와 용접 시작 및 끝 위치를 판별한다. 그리고 레이저 변위센서에 의해 측정된 거리정보와 센서의 자세정보를 활용하여 용접선의 Y(위빙), Z(높이)좌표를 검출하게 된다. 용접선 검출 시스템은 용접 캐리지와 독립적인 구동을 위해 DSP를 이용하여 별도의 제어기를 구성하였다. 용접 도중 용접선 검출 시스템과 용접 토치(Torch)와 간섭을 피하고, 측정 불가능한 구간이 발생하지 않도록 용접선 검출 시스템을 캐리지의 양쪽에 부착할 수 있게 설계하였다. 최종적으로 용접 캐리지에 부착하고 실험을 수행하여 개발된 용접선 검출 시스템의 효용성을 확인하였다.

• International Journal of Precision Engineering and Manufacturing
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• 제6권3호
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• pp.45-50
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• 2005

This paper proposed an efficient manufacturing system using the OMM (on-machine measurement) system. The OMM system is software-based 3D modeler for inspection on machine, and it is interfaced with machine tools via RS232C. The software is composed of two inspection modules; one is touch probe operating module, and the other is laser displacement sensor operating module. The module for touch probe needs the inspection feature extracted from CAD data. The touch probe moves to workpiece by three operating modes as follows: manual, general and automatic mode. The operating module of the laser displacement sensor is used to inspect profiles and very small holes. An advantage of this inspection method is the ability to execute on-line inspection during machining or afterward. The efficiency of proposed system which can predict and define the machining errors of each process was verified, so the developed system was applied to inspect a mold-base (cavity, core).

• 한국건설관리학회논문집
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• 제23권1호
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• pp.64-72
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• 2022

흙막이 공사는 지하굴착을 수행하는 건설공사에서 필수적으로 적용되는 공사 기법으로, 공사 규모와 관계없이 흙막이의 계측관리는 필수적이다. 그러나 굴착깊이 10m 미만에 해당되는 소규모 건축현장(총 공사비 20억 내외)의 경우에는 1) 시공업체의 영세성, 2) 현장관리자의 역량 부족, 3) 계측기기 설치·해체 및 변위분석의 복잡성 등의 문제점으로 인해 흙막이의 계측 관리가 제대로 수행되고 있지 않는 실정이다. 상기 문제점을 해결하는 선행연구 분석 결과, 대부분의 선행연구에서는 값비싼 3D 스캐너를 활용하거나 다수의 계측기기를 설치해야 되는 문제점이 있어 소규모 건설현장에 이를 적용하는 것은 어려운 것으로 분석되었다. 따라서 본 연구의 목적은 하나의 계측기기를 활용하여 흙막이 구조체의 변위를 파악할 수 있는 레이저 센서 기반 흙막이 구조체 변위 계측 시스템의 개념 디자인을 제안하고 개념 디자인에 적용된 요소기술의 변위 인식 성능을 검증하는 것이다. 요소기술은 2D 레이저 스캐너가 선정되었으며, 선정된 2D 레이저 스캐너를 활용하여 개념디자인이 제안되었다. 2D 레이저 스캐너의 변위 인식 검증 결과, 15mm의 변위는 충분히 파악 가능한 것으로 분석되었다. 추후, 제안된 개념디자인이 개발되고 현장에 적용될 경우 소규모 건설현장의 안전사고 저감에 기여할 것으로 분석된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1038-1041
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• 2003

The magnetic suspension system is used in many areas, because it has great advantages. such as no friction, no noise, no lubrication and so on, but it is a unstable system in natural. It must have a feedback control with the position is measured for a stable levitation. There are an eddy-current sensor, a capacitive sensor, an inductive sensor, and an optical sensor with a laser as the sensor which measures displacements without contact. Among them, an inductive sensor is made with lower price than others. And it has a good linearity. In this paper, a magnetic circuit leads a linear equation between an input as a displacement and an output as a voltage. Experiments establish that voltage change according to displacement is linear. This paper presents the preliminary study of an inductive position sensing for self-sensing magnetic suspension system.

• 제어로봇시스템학회논문지
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• 제15권11호
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• pp.1122-1129
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• 2009

Recently taping robot with smart recognition function have been studied in the coil manufacturing field. Due to the difficulty of 3D surface processing from the complicated working environment, it is not easy to accomplish smart tape attachment motion with non-contact sensor. To solve these problems the applicable surface recognition algorithm and a flexible sensing device has been recommended. In this research, the fusion method between 1D displacement and 3D laser scanner is applied for robust tape attachment about cold rolled coil. With these sensors we develop a two-step exploration and the smart algorithm for the awareness of non-aligned coil's information. In the proposed robot system for tape attachment, the problem is reduced to coil's radius searching with laser displacement sensor at first, and then position and orientation detection with 3D laser scanner. To get the movement at the robot's base frame, the hand-eye compensation between robot's end effector and sensing device should be also carried out respectively. In this paper, we examine the auto-coordinate transformation method in the calibration step for the real environment usage. From the experimental results, it was shown that the taping motion of robot had a robust under the non-aligned cold rolled coil.