• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.237-240
• /
• 2003

Gas turbines are extensively used in flight propulsion, electrical power generation, and other industrial applications. During its life span, a turbine blade is taken out periodically for repair and maintenance. This includes re-coating the blade surface and re-drilling the cooling holes/channels. A successful laser re-drilling requires the measurement of a hole within the accuracy of ${\pm}0.15mm$ in position and ${\pm}3^{\circ}$ in orientation. Detection of gas turbine blade/vane cooling hole position and orientation thus becomes a very important step for the vane/blade repair process. The industry is in urgent need of an automated system to fulfill the above task. This paper proposes approaches and algorithms to detect the cooling hole position and orientation by using a vision system mounted on a robot arm. The channel orientation is determined based on the alignment of the vision system with the channel axis. The opening position of the channel is the intersection between the channel axis and the surface around the channel opening. Experimental results have indicated that the concept of cooling hole identification is feasible. It has been shown that the reproducible detection of cooling channel position is with +/- 0.15mm accuracy and cooling channel orientation is with +/$-\;3^{\circ}$ with the current test conditions. Average processing time to search and identify channel position and orientation is less than 1 minute.

• 센서학회지
• /
• 제4권4호
• /
• pp.41-46
• /
• 1995

세포의 흐름을 감지할 수 있는 감지 시스템을 반도체 공정과 EDM(Electro-chemical Discharge drilling Method)을 사용하여 설계 및 제작하였다. 이 감지 장치에서는 세포의 통로관 상하에 광을 투과시켜 감지하는 투과광 방법과 세포 통로관에 평형 전극을 만들어 세포의 흐름에 따른 임피던스의 변화를 측정하는 방법을 사용하였다. 담배잎의 세포를 이용하여 실험한 결과, 광을 이용한 방식에서는 세포의 유무에 따라 출력전압이 0.2V에서 0.7V의 변화를 보였고, 임피던스 방식에서는 0.2V에서 2V의 변화를 감지할 수 있었으나 노이즈의 영향을 받았다.

• Design & Manufacturing
• /
• 제16권1호
• /
• pp.43-49
• /
• 2022

As technologies in various industrial fields develop, high-quality parts are required. In the past, precision parts were produced by the contact machining method, but the contact machining method has clear limitations. In order to solve this problem, research on a non-contact processing method has been conducted, and laser processing and electric discharge processing are representative. However, the non-contact method has a problem in that productivity is insufficient, and there is a problem that it takes a lot of time to continuously process microholes. Researchers have developed an electron beam drilling equipment for continuous processing of fine holes, and a vaporization amplification sheet to increase the processing efficiency of the equipment. In this study, a cylindrical vaporization amplification sheet using room temperature curing type silicon was fabricated, and the metal distribution and thickness uniformity of the produced sheet were analyzed. In order to manufacture a cylindrical vaporization amplification sheet, an equipment capable of using centrifugal force was developed, and a sample in which metal powder was evenly distributed and a constant thickness was produced.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2005년도 춘계학술대회
• /
• pp.634-637
• /
• 2005

Multichannel seismic data acquired in Ulleung Basin of East Sea for gas hydrate exploration. The seismic sections of this area show strong BSR(bottom simulating reflections) associated with methane hydrate occurrence in deep marine sediments. Very limited information is available from deep sea drilling as the risk of heating and destabilizing the initial hydrate conditions during the processing of drilling is considerably high. Not so many advanced status of gas hydrate exploration in Korea, the most of information of gas hydrate characteristics and properties are inferred from seismic reflection data. In this study, The AVO analysis using the long offset seismic data acquired in Ulleung Basin used to explain the characteristics and structure of gas hydrate. It is used primarily P-wave velocity accessible from seismic data. To make a good quality of AVO analysis input data, seismic preprocessing including 'true gain correction', 'source signature deconvolution', twice velocity analysis and some kinds of multiple rejection and enhancing the signal to noise ratio processes is carried out very carefully. The results of AVO analysis, the eight kinds of AVO attributes are estimated basically and some others of AVO attributes are evaluated for interpretation of AVO analysis additionally. The impedance variation at the boundary of gas hydrate and free gas is estimated for investing the BSR characteristics and properties. The complex analysis is performed also to verifying the amplitude variation and phase shift occurrence at BSR. Type III AVO anomaly appearance at saturated free gas area is detected on BSR. It can be an important evidence of gas hydrate deposition upper the BSR.

• 한국산학기술학회논문지
• /
• 제21권8호
• /
• pp.26-35
• /
• 2020

터널공사는 국내 공공건설공사의 중요한 부분을 차지하고 있으며, 다양한 장비와 기술의 개발로 터널공사 시공방법이 발전하였고 현장에 적용되고 있으나 공사비산정기준은 아직까지 현장실태를 제대로 반영하지 못하고 있다. 본 연구에서는 현장실태를 반영한 공사비산정기준 수립을 위하여 관련 문헌조사 및 현장조사를 통해 합리적인 터널공사비 산정기준을 제시하였다. 먼저 현재 건설공사 표준품셈에서 정하는 터널공사비 산정기준의 각 항목들을 분석하고 현장조사를 통한 실제 현장시공의 실태와 비교 분석하였다. 주요 조사내용으로는 암판정 및 내공측량, 천공속도, 버력처리 장비조합 등 싸이클 시간과 관련된 작업 시간에 대한 조사와, 굴착 투입인원에 대한 현장별 적용실태를 확인하였다. 현장 조사결과를 바탕으로 터널굴착 1발파당 싸이클 시간, 천공기계의 천공속도, 버력처리 장비조합, 터널굴착 투입 작업인원에 대한 개선안을 제시하였다. 싸이클 시간의 경우 천공준비 시간에 암판정 및 내공측량 시간을 반영하였으며, 천공기계 속도는 컴퓨터 점보드릴의 천공속도를 반영하였다. 버력처리는 상차장비의 규격을 현장 시공실태에 맞추어 개정하였으며, 터널굴착 투입 작업조를 현장실태에 맞추어 개선안을 제시하였다. 본 연구를 통하여 현장 시공실태를 반영한 공사비산정기준이 제시되었으며, 터널공사 적정공사비 확보에 일조할 것으로 기대된다.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2016년도 추계학술발표대회
• /
• pp.783-784
• /
• 2016

천공위치 안내 시스템은 천공작업 Hole의 정확한 위치를 추적하는 시스템이다. 천공작업의 정확성과 안정성, 그리고 장비 조작의 용이성을 위하여 범지구 위성 항법 시스템(Global navigation satellite system, GNSS)을 이용하여 지표면의 천공위치를 찾아주는 안내 시스템을 연구 개발하였다.

• 한국레이저가공학회지
• /
• 제9권2호
• /
• pp.11-15
• /
• 2006

We report experimental results on the high-speed micromachining using a femtosecond laser (800 nm, 130 fs, 1kHz) and galvanometer scanner system (Raylase, Germany). Periodic hole drilling of silicon and glass with the scan speed of 1-20 mm/s is demonstrated. Finally, we demonstrate the utility of the femtosecond laser application to ITO patterning by using a high-speed femtosecond laser scanner system.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2021년도 춘계학술발표대회
• /
• pp.404-407
• /
• 2021

석유개발 현장에서 시추장비의 고장으로 인한 장비교체 및 시추시간 증가는 막대한 비용소모를 발생시킨다. 본 논문은 딥러닝 기반의 시추장비 중 드릴비트의 동력을 구동시키는 디젤엔진의 고장 요소를 분류하고 이 요소에 따른 고장여부를 판별하는 딥러닝 기반의 이상 예측 및 진단 모델을 개발하였다. 또한 제안한 모델의 우수성을 확인하기 위해 로지스틱 회귀분석 분류모델과의 예측성능 비교분석도 수행하였다.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2002년도 춘계학술대회 논문집
• /
• pp.23-28
• /
• 2002

This paper describes the machining characteristics of the $MoSi_2$ based composites by electric discharge drilling with various tubular electrodes, besides, Hardness characteristics and microstructures of $Nb/MoSi_2$ laminate composites were evaluated from the variation of fabricating conditions such as preparation temperature, applied pressure and pressure holding time. $MoSi_2$ -based composites has been developed in new materials for jet engine of supersonic-speed airplanes and gas turbine for high- temperature generator. Achieving this objective may require new hard materials with high strength and high temperature-resistance. However, With the exception of grinding, traditional machining methods are not applicable to these new materials. Electric discharge machining (EDM) is a thermal process that utilizes a spark discharge to melt a conductive material, the tool electrode being almost non-unloaded, because there is no direct contact between the tool electrode and the workpiece. By combining a nonconducting ceramics with more conducting ceramic it was possible to raise the electrical conductivity. From experimental results, it was found that the lamination from Nb sheet and $MoSi_2$ powder was an excellent strategy to improve hardness characteristics of monolithic $MoSi_2$. However, interfacial reaction products like (Nb, Mo)$SiO_2$ and $Nb_2Si_3$ formed at the interface of $Nb/MoSi_2$ and increased with fabricating temperature. $MoSi_2$ composites which a hole drilling was not possible by the conventional machining process, enhanced the capacity of ED-drilling by adding $NbSi_2$ relative to that of SiC or $ZrO_2$ reinforcements.

• Journal of Welding and Joining
• /
• 제25권3호
• /
• pp.78-84
• /
• 2007

Laser Material Processing has been replaced the conventional machining systems - cutting, drilling, welding and surface modification and so on. Especially, LTH(Laser Transformation Hardening) process is one branch of the laser surface modification process. Conventionally, some techniques like a gas carburizing and nitriding as well as induction and torch heating have been used to harden the carbon steels. But these methods not only request post-machining resulted from a deformation but also have complex processing procedures. Besides, LTH process has some merits as : 1. It is easy to control the case depth because of output(laser power) adjustability. 2. It is able to harden the localized and complicated a.ea and minimize a deformation due to a unique property of a localized heat source. 3. An additional cooling medium is not required due to self quenching. 4. A prominent hardening results can be obtained. This study is related to the surface hardening of the rod-shaped carbon steel applied to the lathe based complex processing mechanism, a basic behavior of surface hardening, hardness distribution and structural characteristics in the hardened zone.