• Title/Summary/Keyword: Vision sensor

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A Study on the protection of false alarm in the UV/IR flame detector (불꽃 감지기에서 오동작 방지에 관한 연구)

  • Lim, Byung-Hyun;Park, Sung-Jin;Lim, Jong-Yeon;Hwang, Jong-Sun;Kim, Young-Min
    • Proceedings of the KIEE Conference
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    • 2001.04a
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    • pp.209-212
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    • 2001
  • A flame detector responds either to radiant energy visible to the human eye or outside the range of human vision. Such a detector is sensitive to glowing embers, coals, or flames which radiate energy of sufficient intensity and spectral quality to actuate the alarm. An infra-red detectors can respond to the total IR component of the flame alone or in combination with flame flicker in the frequency range of 5 to 30 Hz. A major problem in the use of infrared detectors receiving total IR radiation is the possible interference of solar radiation in the infrared region. When detectors are located in places shielded from the sun, such as vaults, filtering or shielding the unit from the sun's rays is unnecessary. In this study, we proposed method for redue a false alarm with using filtering & sensor technology for distinguish of causes of raise a false alarm and pure flame.

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Improvement of Gesture Recognition using 2-stage HMM (2단계 히든마코프 모델을 이용한 제스쳐의 성능향상 연구)

  • Jung, Hwon-Jae;Park, Hyeonjun;Kim, Donghan
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.11
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    • pp.1034-1037
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    • 2015
  • In recent years in the field of robotics, various methods have been developed to create an intimate relationship between people and robots. These methods include speech, vision, and biometrics recognition as well as gesture-based interaction. These recognition technologies are used in various wearable devices, smartphones and other electric devices for convenience. Among these technologies, gesture recognition is the most commonly used and appropriate technology for wearable devices. Gesture recognition can be classified as contact or noncontact gesture recognition. This paper proposes contact gesture recognition with IMU and EMG sensors by using the hidden Markov model (HMM) twice. Several simple behaviors make main gestures through the one-stage HMM. It is equal to the Hidden Markov model process, which is well known for pattern recognition. Additionally, the sequence of the main gestures, which comes from the one-stage HMM, creates some higher-order gestures through the two-stage HMM. In this way, more natural and intelligent gestures can be implemented through simple gestures. This advanced process can play a larger role in gesture recognition-based UX for many wearable and smart devices.

3D Environment Perception using Stereo Infrared Light Sources and a Camera (스테레오 적외선 조명 및 단일카메라를 이용한 3차원 환경인지)

  • Lee, Soo-Yong;Song, Jae-Bok
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.5
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    • pp.519-524
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    • 2009
  • This paper describes a new sensor system for 3D environment perception using stereo structured infrared light sources and a camera. Environment and obstacle sensing is the key issue for mobile robot localization and navigation. Laser scanners and infrared scanners cover $180^{\circ}$ and are accurate but too expensive. Those sensors use rotating light beams so that the range measurements are constrained on a plane. 3D measurements are much more useful in many ways for obstacle detection, map building and localization. Stereo vision is very common way of getting the depth information of 3D environment. However, it requires that the correspondence should be clearly identified and it also heavily depends on the light condition of the environment. Instead of using stereo camera, monocular camera and two projected infrared light sources are used in order to reduce the effects of the ambient light while getting 3D depth map. Modeling of the projected light pattern enabled precise estimation of the range. Two successive captures of the image with left and right infrared light projection provide several benefits, which include wider area of depth measurement, higher spatial resolution and the visibility perception.

Localization Using 3D-Lidar Based Road Reflectivity Map and IPM Image (3D-Lidar 기반 도로 반사도 지도와 IPM 영상을 이용한 위치추정)

  • Jung, Tae-Ki;Song, Jong-Hwa;Im, Jun-Hyuck;Lee, Byung-Hyun;Jee, Gyu-In
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.12
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    • pp.1061-1067
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    • 2016
  • Position of the vehicle for driving is essential to autonomous navigation. However, there appears GPS position error due to multipath which is occurred by tall buildings in downtown area. In this paper, GPS position error is corrected by using camera sensor and highly accurate map made with 3D-Lidar. Input image through inverse perspective mapping is converted into top-view image, and it works out map matching with the map which has intensity of 3D-Lidar. Performance comparison was conducted between this method and traditional way which does map matching with input image after conversion of map to pinhole camera image. As a result, longitudinal error declined 49% and complexity declined 90%.

Development of Wide-Range Brightness Controller of LED Backlight for Avionic Displays (항공기 디스플레이용 LED 백라이트의 광대역 휘도 제어기 개발)

  • Lim, Soo-Hyun;Lim, Jeong-Gyu;Chung, Se-Kyo;Shin, Hwi-Beom;Shin, Min-Jae;Sohn, Seung-Gul
    • The Transactions of the Korean Institute of Power Electronics
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    • v.13 no.4
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    • pp.287-294
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    • 2008
  • This paper describes an implementation of a wide-range dimming controller of a LED backlight for Avionics applications such as a control display unit(CDU) and multi-function display(MFD). The digital dimming controller employing a current controlled buck converter and light sensor feedback is proposed. The proposed system provides a wide dimming control range of from 150fL to 0.05fL(3000:1) required for avionic displays. The experimental results are provided to show the control performance.

Mobile Robots for the Concrete Crack Search and Sealing (콘크리트 크랙 탐색 및 실링을 위한 다수의 자율주행로봇)

  • Jin, Sung-Hun;Cho, Cheol-Joo;Lim, Kye-Young
    • The Journal of Korea Robotics Society
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    • v.11 no.2
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    • pp.60-72
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    • 2016
  • This study proposes a multi-robot system, using multiple autonomous robots, to explore concrete structures and assist in their maintenance by sealing any cracks present in the structure. The proposed system employed a new self-localization method that is essential for autonomous robots, along with a visualization system to recognize the external environment and to detect and explore cracks efficiently. Moreover, more efficient crack search in an unknown environment became possible by arranging the robots into search areas divided depending on the surrounding situations. Operations with increased efficiency were also realized by overcoming the disadvantages of the infeasible logical behavioral model design with only six basic behavioral strategies based on distributed control-one of the methods to control swarm robots. Finally, this study investigated the efficiency of the proposed multi-robot system via basic sensor testing and simulation.

A Performance Analysis of Video Smoke Detection based on Back-Propagation Neural Network (오류 역전파 신경망 기반의 연기 검출 성능 분석)

  • Im, Jae-Yoo;Kim, Won-Ho
    • Journal of Satellite, Information and Communications
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    • v.9 no.4
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    • pp.26-31
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    • 2014
  • In this paper, we present performance analysis of video smoke detection based on BPN-Network that is using multi-smoke feature, and Neural Network. Conventional smoke detection method consist of simple or mixed functions using color, temporal, spatial characteristics. However, most of all, they don't consider the early fire conditions. In this paper, we analysis the smoke color and motion characteristics, and revised distinguish the candidate smoke region. Smoke diffusion, transparency and shape features are used for detection stage. Then it apply the BPN-Network (Back-Propagation Neural Network). The simulation results showed 91.31% accuracy and 2.62% of false detection rate.

Robust Terrain Classification Against Environmental Variation for Autonomous Off-road Navigation (야지 자율주행을 위한 환경에 강인한 지형분류 기법)

  • Sung, Gi-Yeul;Lyou, Joon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.5
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    • pp.894-902
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    • 2010
  • This paper presents a vision-based robust off-road terrain classification method against environmental variation. As a supervised classification algorithm, we applied a neural network classifier using wavelet features extracted from wavelet transform of an image. In order to get over an effect of overall image feature variation, we adopted environment sensors and gathered the training parameters database according to environmental conditions. The robust terrain classification algorithm against environmental variation was implemented by choosing an optimal parameter using environmental information. The proposed algorithm was embedded on a processor board under the VxWorks real-time operating system. The processor board is containing four 1GHz 7448 PowerPC CPUs. In order to implement an optimal software architecture on which a distributed parallel processing is possible, we measured and analyzed the data delivery time between the CPUs. And the performance of the present algorithm was verified, comparing classification results using the real off-road images acquired under various environmental conditions in conformity with applied classifiers and features. Experiments show the robustness of the classification results on any environmental condition.

Structural and temperature coefficient of resistance characteristics of colossal magnetoresistance Mn oxides prepared by RF sputtering

  • Choi, Sun-Gyu;Ha, Tae-Jung;Reddy, A.Sivasankar;Yu, Byoung-Gon;Park, Hyung-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.361-361
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    • 2007
  • A lot of efforts have been paid to develop infrared imaging systems in last decades. Bolometer has a wide range of applications from military to commercial, such as military night vision, medical imaging system and so on. Bolometer is a resistive sensor that detects temperature changes through resistance change. To improve detecting ability, bolometer should have a good resistive film which has high temperature coefficient of resistance (TCR) value. Colossal magnetoresistance (CMR) $L_{1-x}A_xMnO_3$ (where L and A are trivalent rare-earth ions and divalent alkaline earth ions, respectively.) are received attention to apply bolometer resistive film because it has a high TCR property which was discovered in the metal to semiconductor phase transition temperature region. In this work, CMR films were deposited on various substrates in relative low substrate temperature by RF magnetron sputtering. The influence of deposition parameters such as substrate temperature, gas partial pressure, and so on have been studied. The structural and TCR properties of the films were also investigated for applying to microbolometer.

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Tracking of Single Moving Object based on Motion Estimation (움직임 추정에 기반한 단일 이동객체 추적)

  • Oh Myoung-Kwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.6 no.4
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    • pp.349-354
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    • 2005
  • The study on computer vision is aimed on creating a system to substitute the ability of human visual sensor. Especially, moving object tracking system is becoming an important area of study. In this study, we have proposed the tracking system of single moving object based on motion estimation. The tracking system performed motion estimation using differential image, and then tracked the moving object by controlling Pan/Tilt device of camera. Proposed tracking system is devided into image acquisition and preprocessing phase, motion estimation phase and object tracking phase. As a result of experiment, motion of moving object can be estimated. The result of tracking, object was not lost and tracked correctly.

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