• Title/Summary/Keyword: Landmarks

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Gait Analysis System Using Infrared LED Landmarks (적외선 LED 랜드마크를 이용한 보행분석 시스템)

  • Nhut, Do-Tri;Suh, Young-Soo
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.7
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    • pp.641-646
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    • 2011
  • A low cost gait analysis system, which can measure stride length, walking speed, and ground reaction force, is proposed. A gait analysis system is used for medical evaluation of patients and rehabilitation assistance. Low cost cameras are attached to a shoe and movement of a shoe is estimated using infrared LED landmarks. Ground reaction force is measured from pressure sensors, which are installed inside a shoe. Through experiments, it is shown that the proposed system can be used to obtain stride length, walking speed, and ground reaction force.

Conservative neural symmetry of the caprine mandible

  • Pares-Casanova, Pere M.
    • Korean Journal of Veterinary Research
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    • v.53 no.4
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    • pp.207-210
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    • 2013
  • Fifteen dry dentate and complete mandible samples from the White Rasquera goat breed were studied for symmetry. Thirty-one landmarks were digitally located on the images of the lateral and medial aspects of each hemimandible. Distances between these landmarks allowed the evaluation of the whole hemimandible and also the neural mandible. In the studied samples, the mandible was rather symmetrical, especially in the medial neural part, and in general, there was no side dominance. Only the diastema differed significantly between the sides, and this was related to the rostral part (incisive arch). The incisive region was the least symmetrical region of the caprine mandible, indicating a modular structure more conservative for the neural part. If unsigned asymmetry is interpreted as a measure of developmental stability, then the studied breed presented a marked ability to develop in good fitness despite the harsh environment. The measurements presented here can also be used as a reference for researchers designing experimental studies, especially on mandibular catch-up growth, and as an aid for zooarchaeologists comparing results from dead animals with those from living goat populations.

Self-Positioning of a Mobile Robot using a Vision System and Image Overlay with VRML (비전 시스템을 이용한 이동로봇 Self-positioning과 VRML과의 영상오버레이)

  • Hyun, Kwon-Bang;To, Chong-Kil
    • Proceedings of the KIEE Conference
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    • 2005.05a
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    • pp.258-260
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    • 2005
  • We describe a method for localizing a mobile robot in the working environment using a vision system and VRML. The robot identifies landmarks in the environment and carries out the self-positioning. The image-processing and neural network pattern matching technique are employed to recognize landmarks placed in a robot working environment. The robot self-positioning using vision system is based on the well-known localization algorithm. After self-positioning, 2D scene is overlaid with VRML scene. This paper describes how to realize the self-positioning and shows the result of overlaying between 2D scene and VRML scene. In addition we describe the advantage expected from overlapping both scenes.

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Navigation of a mobile robot using active landmarks (능동 표식을 이용한 이동 로봇의 운행)

  • 노영식;김재숙;권석근
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.916-919
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    • 1996
  • An real-time active beacon localization system for mobile robots is developed and implemented. This system permits the estimation of robot positions when detecting light sources by PSD(Position Sensitive Detector) sensor which are placed sparsely over the robot's work space as beacons(or landmarks). An LSE(Least Square Estimation) method is introduced to calibrate the internal parameters of a model for the beacon and robot position. The proposed system has two operational modes of position estimation. One is the initial position calculation by the detection of two or more light sources positions of which are known. The other is the continuous position compensation that calculates the position and heading of the robot using the IEKF(Iterated Extended Kalman Filter) applied to the beacon and dead-reckoning data. Practical experiments show that the estimated position obtained by this system is precise enough to be useful for the navigation of robots.

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Mobile Robot Localization Based on Hexagon Distributed Repeated Color Patches in Large Indoor Area (넓은 실내 공간에서 반복적인 칼라패치의 6각형 배열에 의한 이동로봇의 위치계산)

  • Chen, Hong-Xin;Wang, Shi;Han, Hoo-Sek;Kim, Hyong-Suk
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.4
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    • pp.445-450
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    • 2009
  • This paper presents a new mobile robot localization method for indoor robot navigation. The method uses hexagon distributed color-coded patches on the ceiling and a camera is installed on the robot facing the ceiling to recognize these patches. The proposed "cell-coded map", with the use of only seven different kinds of color-coded landmarks distributed in hexagonal way, helps reduce the complexity of the landmark structure and the error of landmark recognition. This technique is applicable for navigation in an unlimited size of indoor space. The structure of the landmarks and the recognition method are introduced. And 2 rigid rules are also used to ensure the correctness of the recognition. Experimental results prove that the method is useful.

Intertester and Intratester Reliability of Tape Measurement on Lower Extremities (줄자를 이용한 하지부피 측정시 부위별 검사자간, 검사자내 신뢰도 측정)

  • Kim, Seng-Jung;Yang, Hoi-Song;Yi, Chung-Hwi
    • Physical Therapy Korea
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    • v.7 no.1
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    • pp.38-45
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    • 2000
  • Tape measurement for evaluating edema is frequently used by clinicians. The primary purpose of this study is to determine the intertester and intratester reliability of tape measurement carried out by two physical therapists on lower extremities. The intertester and intratester reliability of six anatomical landmarks measurements were determined in six healthy subjects. The measurements were taken in five sessions by each tester. The intraclass correlation coefficients (2,1) were between .87 and .99 for intertester reliability. Intratester reliability was .93 and .99 for A tester and .82 and .99 for B tester. The average range of variation was .13 to .54 in six landmarks. The reliability of six volume measurements was very high. These results support the use tape measurement as a reliable tool for measuring limb girth.

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Mobile Robot Localization using Ceiling Landmark Positions and Edge Pixel Movement Vectors (천정부착 랜드마크 위치와 에지 화소의 이동벡터 정보에 의한 이동로봇 위치 인식)

  • Chen, Hong-Xin;Adhikari, Shyam Prasad;Kim, Sung-Woo;Kim, Hyong-Suk
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.4
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    • pp.368-373
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    • 2010
  • A new indoor mobile robot localization method is presented. Robot recognizes well designed single color landmarks on the ceiling by vision system, as reference to compute its precise position. The proposed likelihood prediction based method enables the robot to estimate its position based only on the orientation of landmark.The use of single color landmarks helps to reduce the complexity of the landmark structure and makes it easily detectable. Edge based optical flow is further used to compensate for some landmark recognition error. This technique is applicable for navigation in an unlimited sized indoor space. Prediction scheme and localization algorithm are proposed, and edge based optical flow and data fusing are presented. Experimental results show that the proposed method provides accurate estimation of the robot position with a localization error within a range of 5 cm and directional error less than 4 degrees.

Computer control of wheel chair by using landmarks

  • Wang, Hongbo;Tanaka, Shin-ichirou;Kang, cheolung;Ishimatsu, Takakazu
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.388-391
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    • 1995
  • This paper describes computer control of a wheel chair by using landmarks. Firstly, the approach of landmark detection and recognition is described and the image coordinates are obtained by the primary component analysis method. Subsequently, the self-localization of the wheel chair is determined on the basis of a three-dimensional image processing method. Finally, the control system of the wheel chair is described and a navigation experiment is given. Experimental results indicate the effectiveness of our approah.

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Development of Active Stereo Surveillance System with the Human-like Visual Selective Attention (인체의 상향식 선택적 주의 집중 시각 기능을 모방한 능동 스테레오 감시 시스템의 개발)

  • Jung, Bum-Soo;Lee, Min-Ho
    • Journal of Sensor Science and Technology
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    • v.13 no.2
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    • pp.144-151
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    • 2004
  • In this paper, we propose an active stereo surveillance system with human-like convergence function. The proposed system uses a bottom-up saliency map model with the human-like selective attention visual function to select an interesting region in each camera. and this system compares the landmarks whether the selective region in each camera finds a same region. If the left and right cameras successfully find a same landmarks, the implemented vision system focuses on the landmark. Using the motor encoder information, we can automatically obtain the depth information and resultantly construct a depth map using the depth information. Computer simulation and experimental results show that the proposed convergence method is very effective to implement the active stereo surveillance system.

Two-Dimensional Navigation Error for Geometry of Landmark in Line-Of-Sight Measurement Based Vision Navigation System (시선각 측정기반 비전항법시스템에서 랜드마크의 기하학적 배치에 대한 2차원 항법오차)

  • Kim, Young-Sun;Ji, Hyun-Min;Hwang, Dong-Hwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.3
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    • pp.479-484
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    • 2012
  • Geometric effect of landmarks to the navigation error is investigated in the two-dimensional line-of-sight measurement based vision navigation system. DOP is derived between line-of-sight measurement error and navigation solution error. For cases of three landmarks in an area, variations of the DOP were observed through computer simulations. Vision navigation system experiments were performed for the cases. Simulation and experimental results show that navigation solution errors have similar trend to DOP values of the simulation.