• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.6
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• pp.559-568
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• 2016

For the economic management of photovoltaic power plants, it is necessary to regularly monitor the panels within the plants to detect malfunctions. Thermal infrared image cameras are generally used for monitoring, since malfunctioning panels emit higher temperatures compared to those that are functioning. Recently, technologies that observe photovoltaic arrays by mounting thermal infrared cameras on UAVs (Unmanned Aerial Vehicle) are being developed for the efficient monitoring of large-scale photovoltaic power plants. However, the technologies developed until now have had the shortcomings of having to analyze the images manually to detect malfunctioning panels, which is time-consuming. In this paper, we propose an automatic photovoltaic panel area extraction algorithm for thermal infrared images acquired via a UAV. In the thermal infrared images, panel boundaries are presented as obvious linear features, and the panels are regularly arranged. Therefore, we exaggerate the linear features with a vertical and horizontal filtering algorithm, and apply a modified hierarchical histogram clustering method to extract candidates of panel boundaries. Among the candidates, initial panel areas are extracted by exclusion editing with the results of the photovoltaic array area detection. In this step, thresholding and image morphological algorithms are applied. Finally, panel areas are refined with the geometry of the surrounding panels. The accuracy of the results is evaluated quantitatively by manually digitized data, and a mean completeness of 95.0%, a mean correctness of 96.9%, and mean quality of 92.1 percent are obtained with the proposed algorithm.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.1
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• pp.97-104
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• 2014

Recently infrared cameras have been widely used to diagnosis degradation status of the power substitution system. At the place of high magnetic field, however, electronic parts of infrared camera take a place problem that is not reasonable working due to high magnetic field. In this paper, technique of design for reflector is proposed to perform degradation diagnosis without damage of infrared camera in a power substation system including the rectifier that is able to impact to the infrared camera by high magnetic field.

• Journal of Sensor Science and Technology
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• v.19 no.3
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• pp.246-257
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• 2010

Autonomous guided robot navigation which consists of following unknown paths and avoiding unknown obstacles has been a fundamental technique for unmanned robots in outdoor environments. The unknown path following requires techniques such as path recognition, path planning, and robot pose estimation. In this paper, we propose a novel sensor fusion system for autonomous guided robot navigation in outdoor environments. The proposed system consists of three monocular cameras and an array of nine infrared range sensors. The two cameras equipped on the robot's right and left sides are used to recognize unknown paths and estimate relative robot pose on these paths through bayesian sensor fusion method, and the other camera equipped at the front of the robot is used to recognize abrupt curves and unknown obstacles. The infrared range sensor array is used to improve the robustness of obstacle avoidance. The forward camera and the infrared range sensor array are fused through rule-based method for obstacle avoidance. Experiments in outdoor environments show the mobile robot with the proposed sensor fusion system performed successfully real-time autonomous guided navigation.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.700-703
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• 2021

Infrared cameras are widely used in recent research for automatic monitoring the abnormal behaviors of the pig. However, when deployed in real pig farms, infrared cameras always get polluted due to the harsh environment of pig farms which negatively affects the performance of pig monitoring. In this paper, we propose a real-time noise-robust infrared camera-based pig automatic monitoring system to improve the robustness of pigs' automatic monitoring in real pig farms. The proposed system first uses a preprocessor with a U-Net architecture that was trained as a GAN generator to transform the noisy images into clean images, then uses a YOLOv5-based detector to detect pigs. The experimental results show that with adding the preprocessing step, the average pig detection precision improved greatly from 0.639 to 0.759.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.96.4-96
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• 2002

Thermal infrared imaging is a highly promising technology for condition monitoring and predictive maintenance of electronic, electrical and mechanical elements in nuclear power plants. However, conventional low-cost infrared imaging systems suffer from poor spatial resolution compared to commercial CCD cameras. This paper describes an approach to enhance inspection performances for calandria reactor area of Wolsung nuclear power plant through the technique of superimposing thermal infrared image into real CCD image. In the occurrence of thermal abnormalities on observation points and areas of calandria reactor area, unusual hot image taken from thermal infrared camera is mapped upon re...

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.578-578
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• 2002

Thermal infrared imaging is a highly promising technology for condition monitoring and predictive maintenance of electronic, electrical and mechanical elements in nuclear power plants. However, conventional low-cost infrared imaging systems suffer from poor spatial resolution compared to commercial CCD cameras. This paper describes an approach to enhance inspection performances for calandria reactor area of Wolsung nuclear power plant through the technique of superimposing thermal infrared image into real CCD image. In the occurrence of thermal abnormalities on observation points and areas of calandria reactor area, unusual hot image taken from thermal infrared camera is mapped upon real CCD image. The performance of the technique has been evaluated in the experiment carried out at Wolsung nuclear power plant in the overhaul period. The results show that localizations of thermal abnormalities on calandria reactor face can be estimated accurately.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.1
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• pp.57-62
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• 2024

This study conducted a measurement method of high temeprature conditions using infrared termography. All objects emit infrared light, and this emissivity has a significant impact on the temperature measurements of infrared thermal imaging (IR) cameras. In order to measure the temperature more accurately with the IR camera, correction equations were derived by measuring the emissivity according to the temperature change of combustible metals in a high-temperature environment. Two combustible metals, Mg and Al, were used to measure emissivity with changing temperature. Each metal was heated, the emissivity was measured by comparing the temperature with IR camera and thermocouples so that the correlation between temperature and emissivity could be anslyzed. As a result of the experiment, the emissivity of the metals increases as the temperature increased. This can be interpreted as a result of increased radiation emission as the thermal movement of internal metal molecules increased.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.3
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• pp.285-293
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• 2009

Thermal infrared cameras have been conducted actively in various application areas, such as military, medical service, industries and cars. Because of their characteristic of sensing the radiant heat emitted from subjects in the range of long-wavelength($3{\sim}5{\mu}m$ or $8{\sim}12{\mu}m$), and of materializing a vision system, when general optics materials are used, they don't react to the light in the range of long-wavelength, and can't display their optic functions. Therefore, the materials with the feature of higher refractive index, reacting to the range of long-wavelength, are to be used. The kinds of materials with the characteristic of higher refractive index are limited, and their features are close to those of metals. Because of these metallic features, the existing producing method of optical systems were direct manufacturing method using grinding method or CAD/CAM, which put limit on productivity and made it difficult to properly cope with the increasing demand of markets. GASIR, a material, which can be molded easily, was selected among infrared ray optics materials in this study, and the optical system was designed with two Aspheric lenses. Because the lenses are molded in the environment of high temperature and high pressure, they require a special metallic pattern. The metallic pattern was produced with materials with ultra hardness that can stand high temperature and high pressure. As for the lens mold, GMP(Glass Molding Press) of the linear transfer method was used in order to improve the productivity of optical systems for thermal infrared cameras, which was the goal of this paper.

• Korean Journal of Optics and Photonics
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• v.34 no.3
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• pp.106-116
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• 2023

In this paper, we designed a coaxial dual camera incorporating two optical systems-one for the visible rays and the other for far-infrared ones-with the aim of capturing images in both wavelength ranges. The far-infrared system, which uses an uncooled detector, has a sensor array of 640×480 pixels. The visible ray system has 1,945×1,097 pixels. The coaxial dual optical system was designed using a hot mirror beam splitter to minimize heat transfer caused by infrared rays in the visible ray optical system. The optimization process revealed that the final version of the dual camera system reached more than 90% of the fusion performance between two separate images from dual systems. Multiple rigorous testing processes confirmed that the coaxial dual camera we designed demonstrates meaningful design efficiency and improved image conformity degree compared to existing dual cameras.

• Journal of the Ergonomics Society of Korea
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• v.16 no.3
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• pp.71-75
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• 1997

This paper presents the development of videobased 3-dimensional tracking system. Measurement of human motion is important in the application of ertonomics. The system uses advanced direct video measurement technology. Passive retro-reflecting markers are attached to a subject and movements of markers are observed by two CCD cameras. Infrared light emitted near the CCD cameras is reflected by the markers and is detected by the cameras. The images are captured by Samsung MVB302 board and the centers of markers are calculated by DSP program. The positions of markers are transferred from MVB02 board to the computer through AT bus. The computer then tracks the position of each marker and saves the data. This system has dynamic accuracy with 0.7% average error and 4.2% maximum error, and the sampling rate to 6 .approx. 10 Hz, and this system can analyse the trajectory and speed of the marker. The results of this study can be used for operator's motion analysis, task analysis, and hand movement characteristic analysis.