• 한국군사과학기술학회지
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• 제10권3호
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• pp.51-61
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• 2007

This paper concerns about the requirement analysis for night vision imaging system(NVIS), whose purpose is to intensify the available nighttime near infrared(IR) radiation sufficiently to be caught by the human eyes on a miniature green phosphor screen. The requirements for NVIS are NVIS radiance(NR), chromaticity, daylight legibility/readability, etc. The NR is a quantitative measure of night vision goggle (NVG) compatibility of a light source as viewed through goggles. The chromaticity is the quality of a color as determined by its purity and dominant wavelength. The daylight legibility/readability is the degree at which words are readable based on appearance and a measure of an instrument's ability to display incremental changes in its output value. In this paper, the requirements of NR, chromaticity, and daylight legibility/readability for Type I and Class B/C NVIS are analyzed. Also the rationale is shown with respect to those requirements.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.184-186
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• 2004

This paper is about vision system that exhibits automatic examination of the conditions of shaft's worm. The system is composed of three part : image acquisition, vision algorithm, and user interface. The image acquisition part is composed of motor control, illumination and optics. The vision algorithm examines the parts by labeling algorithm using shaft image. User interface is divided into two parts, user interface for feature registering with control value settings and user interface for examination operation. The automatic inspection system of this research is a tool for final examination of shaft worm. This tool can be practically used in production lines with simple adjustments.

• 한국산학기술학회논문지
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• 제11권5호
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• pp.1558-1563
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• 2010

본 논문에서는 생산 현장에서 작업자가 육안으로 하고 있는 자동차 부품의 전수(全數) 검사 방법을 대체하기 위한 머신 비전 시스템의 개발을 위한 검사알고리즘에 관한 연구이다. 생산 효율과 품질 향상을 위한 노력의 일환으로 플라스틱 압출 성형에서 생기는 여러 가지 불량품 유형을 PC를 기반한 머신 비전 시스템(Machine Vision System)을 구축하기에 앞서 생산된 부품을 실시간 검사하고 제품의 불량 유무를 판별하는 알고리즘을 개발하는 것이 본 연구의 목적이다. 검사방법에 사용된 소프트웨어는 NI-LabVIEW를 사용하였으며, LabVIEW Vision 이미지 함수를 사용하여 검사 프로그램을 개발하였다. 개발된 검사 알고리즘은 생산 부품의 실시간 검사에 적용 될 수 있으며, 검사 영역과 설정 값을 비전 시스템 운용자가 설정할 수 있도록 프로그램이 만들어져 검증되었다.

• Smart Structures and Systems
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• 제18권3호
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• pp.585-599
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• 2016

Steel cables serve as the key structural components in long-span bridges, and the force state of the steel cable is deemed to be one of the most important determinant factors representing the safety condition of bridge structures. The disadvantages of traditional cable force measurement methods have been envisaged and development of an effective alternative is still desired. In the last decade, the vision-based sensing technology has been rapidly developed and broadly applied in the field of structural health monitoring (SHM). With the aid of vision-based multi-point structural displacement measurement method, monitoring of the tensile force of the steel cable can be realized. In this paper, a novel cable force monitoring system integrated with a multi-point pattern matching algorithm is developed. The feasibility and accuracy of the developed vision-based force monitoring system has been validated by conducting the uniaxial tensile tests of steel bars, steel wire ropes, and parallel strand cables on a universal testing machine (UTM) as well as a series of moving loading experiments on a scale arch bridge model. The comparative study of the experimental outcomes indicates that the results obtained by the vision-based system are consistent with those measured by the traditional method for cable force measurement.

• International Journal of Aeronautical and Space Sciences
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• 제15권3호
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• pp.258-266
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• 2014

We present a system for the real-time visual relative navigation of a fixed-wing unmanned aerial vehicle in a GPS-denied environment. An extended Kalman filter is used to construct a vision-aided navigation system by fusing the image processing results with barometer and inertial sensor measurements. Using a mean-shift object tracking algorithm, an onboard vision system provides pixel measurements to the navigation filter. The filter is slightly modified to deal with delayed measurements from the vision system. The image processing algorithm and the navigation filter are verified by flight tests. The results show that the proposed aerial system is able to maintain circling around a target without using GPS data.

• Current Optics and Photonics
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• 제6권6호
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• pp.608-618
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• 2022

By analyzing the signal-to-noise ratio (SNR) theory of the conventional true color night vision system, we found that the output image SNR is limited by the wavelength range of the system response λ₁ and λ₂. Therefore, we built a double-channel four-band true color night vision system to expand the system response to improve the output image SNR. In the meantime, we proposed an image fusion method based on principal component analysis (PCA) and nonsubsampled shearlet transform (NSST) to obtain the true color night vision images. Through experiments, a method based on edge extraction of the targets and spatial dimension decorrelation was proposed to calculate the SNR of the obtained images and we calculated the correlation coefficient (CC) between the edge graphs of obtained and reference images. The results showed that the SNR of the images of four scenes obtained by our system were 125.0%, 145.8%, 86.0% and 51.8% higher, respectively, than that of the conventional tri-band system and CC was also higher, which demonstrated that our system can get true color images with better quality.

• 한국인터넷방송통신학회논문지
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• 제16권1호
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• pp.221-225
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• 2016

본 논문은 자동차용 퓨즈 및 릴레이 박스의 취부상태를 검사하기 위한 비전시스템의 구현 예를 보여준다. 검사를 위한 vision system은 영상 취득부와 검사 알고리즘, 그리고 사용자 인터페이스의 세 부분으로 구성된다. 영상 취득부는 box의 영상을 grabbing하는 부분으로 조명부와 광학부로 이루어진다. 검사 알고리즘은 영상을 이용하여 검사작업을 수행하는 부분이다. 사용자 인터페이스는 fuse & relay box의 모양과 부착되는 fuse와 relay를 등록하기 위한 사용자 인터페이스와 검사 작업을 수행하기 위한 사용자 인터페이스 두 부분으로 이루어진다. 본 연구에서 제시하는 검사 알고리즘은 신뢰도가 높아 실제 생산 현장에 사용이 가능하다.

• 한국전기전자재료학회논문지
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• 제34권5호
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• pp.371-381
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• 2021

A machine vision inspection system consists of a camera, optics, illumination, and image acquisition system. Especially a scanning system has to be made to measure a large inspection area. Therefore, a machine vision line scan camera needs a line scan light source. A line scan light source should have a high light intensity and a uniform intensity distribution. In this paper, an offset calibration and slope calibration methods are introduced to obtain a uniform light intensity profile. Offset calibration method is to remove the deviation of light intensity among channels through adding intensity difference. Slope calibration is to remove variation of light intensity slope according to the control step among channels through multiplying slope difference. We can obtain an improved light intensity profile through applying offset and slope calibration simultaneously. The proposed method can help to obtain clearer image with a high precision in a machine vision inspection system.

• 전자통신동향분석
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• 제39권4호
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• pp.1-9
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• 2024

As Advanced Air Mobility (AAM) technologies evolve, ensuring accurate navigation and localization in complex urban airspaces has become crucial. Because the Global Navigation Satellite System (GNSS) is prone to vulnerabilities in urban flight environment, an alternative localization technique is required. This paper examines vision-based localization technologies to enhance GNSS-free navigation. In addition, we explore various geo-referencing studies that utilize pre-existing spatial databases to improve the accuracy of vision-based localization under GNSS-denied conditions. This paper discusses the various types of onboard vision camera sensors, vision-based localization, spatial information databases, feature extraction methods, and matching techniques that contribute to the development of a vision-based localization and geo-referencing system for AAM, ensuring safety and reliability in urban operations.

• 조명전기설비학회논문지
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• 제23권10호
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• pp.134-142
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• 2009

본 논문에서는 인간의 시각을 가장 유사하게 구현한 스테레오 시스템을 이용하여 목표물의 크기를 얻을 수 있는 방법을 제시하고자 하였으며, 기존의 스테레오 시스템에서 발전한 방법으로 물체의 실체 크기에 가깝게 얻을 수 있는 시스템을 제시하고자 하였다. 이에 따라 기존의 교차식 스테레오 시스템에서 변형된 직각 스테레오 비젼 시스템을 제시하였으며, 제시한 시스템의 결과로서 실제 측정하고자 하는 목표물의 크기를 93[%]에서 103[%] 정도로 측정하는 좋은 결과를 얻을 수 있었다. 따라서, 본 논문에서 제시한 직각 스테레오 비젼 시스템은 기존의 로봇 시스템 등의 선비 시스템 분야에서 산업 전반에 걸친 영상 처리의 응용 기법으로서 그 다양성이 매우 많음이 기대된다.