• Title/Summary/Keyword: 증강 상태 칼만 필터

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A Real-time Particle Filtering Framework for Robust Camera Tracking in An AR Environment (증강현실 환경에서의 강건한 카메라 추적을 위한 실시간 입자 필터링 기법)

  • Lee, Seok-Han
    • Journal of Digital Contents Society
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    • v.11 no.4
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    • pp.597-606
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    • 2010
  • This paper describes a real-time camera tracking framework specifically designed to track a monocular camera in an AR workspace. Typically, the Kalman filter is often employed for the camera tracking. In general, however, tracking performances of conventional methods are seriously affected by unpredictable situations such as ambiguity in feature detection, occlusion of features and rapid camera shake. In this paper, a recursive Bayesian sampling framework which is also known as the particle filter is adopted for the camera pose estimation. In our system, the camera state is estimated on the basis of the Gaussian distribution without employing additional uncertainty model and sample weight computation. In addition, the camera state is directly computed based on new sample particles which are distributed according to the true posterior of system state. In order to verify the proposed system, we conduct several experiments for unstable situations in the desktop AR environments.

Roll Angle Estimation of Slowly Rolling Guided Munition With Time-delayed Measurement and Its Verification Through Flight Experiment (지연된 측정치를 가진 저속 회전 유도형 탄약의 롤각 추정 및 비행 실험을 통한 검증)

  • Park, Junwoo;Ahn, Hyungjoo;Jung, Sungmin;Noh, Junyoung;Hong, Kyungwoo;Jang, Kwangwoo;Kim, Sungjoong;Bang, Hyochoong;Kim, Jin-Won;Heo, Junhoe;Pak, Chang-Ho;Seo, Songwon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.49 no.5
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    • pp.373-381
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    • 2021
  • This paper details the result of flight experiment that examines performance of roll angle estimation algorithm of slowly rolling munition taking time delay of measurement into account when measurement comes in delayed fashion. As the measurement is passed through low pass filter for numerical stabilization and de-noising purpose which induces time delay, we design augmented state Kalman filter that incorporates distribution models of stochastic delay over time. Flight experiment was conducted to verify the algorithm at around 250m high AGL(Above Ground Level) conveying velocity of 28m/s from fixed-wing mother plane to the munition. Munition was made spun with respect to its roll axis using internal reaction wheel afterward. Numerical comparison of proposing method's roll estimation performance with that of commercial aerospace graded GPS/INS shows that proposed filter design can effectively compensate time delay of measurement.

Design and Implementation of Walking Activity Prediction Service for Exercise Motive (운동 동기 부여를 위한 걷기 활동량 예측 서비스 설계 및 구현)

  • Kim, Bogyeong;Lee, Cheolhyo;Kim, DoHyeun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.5
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    • pp.99-104
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    • 2016
  • The walking exercise can alleviate stress and also it can improve health fortheir lifetime. Recent development in Information and Communication Technologies (ICT) has laid the foundation for Internet of Things (IoT) to become the future technology. IoT has many applications in industry automation, security, smart homes and cities, education, health etc. In personal health-care domain, IoT is mainly used for monitoring fitness condition by observing current activity of individual. In this paper, we have proposed a novel IoT based personal wellness care system. Proposed system not only keep track of current fitness level but also provide future activity prediction based on history data along with standard recommendations. Predicted activity helps in motivating the individual to achieve the desired fitness level. Initially, we consider only walking activity for testing purpose and later, other types of activities/exercise will be captured for improved health care support.