• Title/Summary/Keyword: Active beacon

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A study on the PSD sensor system for localization of mobile robots (이동 로봇의 위치측정을 위한 PSD 센서 시스템에 관한 연구)

  • Ro, Young-Shick
    • Journal of Institute of Control, Robotics and Systems
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    • v.2 no.4
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    • pp.330-336
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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 robots 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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The Development and Implementation of Ward Monitoring Service Using Bluetooth Low Energy Scanners for Infectious Disease Response (감염병 대응 비콘 스캐너 기반의 병실 모니터링 서비스 개발)

  • Lee, Kyu-Man;Park, Ju-young
    • Journal of Digital Convergence
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    • v.15 no.3
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    • pp.287-294
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    • 2017
  • This study attempted to develop a beacon scanner based ward monitoring service in order to respond to the new paradigm of medical environment which is trying to introduce ICT technology as medical service to track and manage the spread path of large infectious diseases such as MERS. The study also included beacon hardware development, firmware development for the beacon low-power bluetooth 4.0, and server and web-based dashboard UI development. Using these, we have developed a customized monitoring system that provides functions such as locating patients by location based service and monitoring based on web UI. It is possible to maximize the efficiency of offline hospital services and to value active infection control and patient safety by integrating online technology into the area where online technologies such as beacons are not properly integrated.

Indoor Localization Scheme of a Mobile Robot Applying REID Technology (RFID 응용 기술을 이용한 이동 로봇의 실내 위치 추정)

  • Kim Sung-Bu;Lee Dong-Hui;Lee Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.12
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    • pp.996-1001
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    • 2005
  • Recently, with the development of service robots and with the new concept of ubiquitous world, the position estimation of mobile objects has been raised to an important problem. As pre-liminary research results, some of the localization schemes are introduced, which provide the relative location of the moving objects subjected to accumulated errors. To implement a real time localization system, a new absolute position estimation method for a mobile robot in indoor environment is proposed in this paper. Design and implementation of the localization system comes from the usage of active beacon systems (based upon RFID technology). The active beacon system is composed of an RFID receiver and an ultra-sonic transmitter: 1. The RFID receiver gets the synchronization signal from the mobile robot and 2. The ultra-sonic transmitter sends out the traveling signal to be used for measuring the distance. Position of a mobile robot in a three dimensional space can be calculated basically from the distance information from. Three beacons and the absolute position information of the beacons themselves. In some case, the mobile robot can get the ultrasonic signals from only one or two beacons, because of the obstacles located along the moving path. Therefore, in this paper, as one of our dedicated contribution, the position estimation scheme with less than three sensors has been developed. Also, the extended Kalman filter algorithm is applied for the improvement of position estimation accuracy of the mobile robot.

Precise Indoor Localization System for a Mobile Robot Using Auto Calibration Algorithm (Auto Calibration Algorithm을 이용한 이동 로봇의 정밀 위치추정 시스템)

  • Kim, Sung-Bu;Lee, Jang-Myung
    • The Journal of Korea Robotics Society
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    • v.2 no.1
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    • pp.40-47
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    • 2007
  • Recently, with the development of service robots and with the new concept of ubiquitous world, the position estimation of mobile objects has been raised to an important problem. As pre-liminary research results, some of the localization schemes are introduced, which provide the absolute location of the moving objects subjected to large errors. To implement a precise and convenient localization system, a new absolute position estimation method for a mobile robot in indoor environment is proposed in this paper. Design and implementation of the localization system comes from the usage of active beacon systems (based upon RFID technology). The active beacon system is composed of an RFID receiver and an ultra-sonic transmitter: 1. The RFID receiver gets the synchronization signal from the mobile robot and 2. The ultra-sonic transmitter sends out the traveling signal to be used for measuring the distance. Position of a mobile robot in a three dimensional space can be calculated basically from the distance information from three beacons and the absolute position information of the beacons themselves. Since it is not easy to install the beacons at a specific position precisely, there exists a large localization error and the installation time takes long. To overcome these problems, and provide a precise and convenient localization system, a new auto calibration algorithm is developed in this paper. Also the extended Kalman filter has been adopted for improving the localization accuracy during the mobile robot navigation. The localization accuracy improvement through the proposed auto calibration algorithm and the extended Kalman filter has been demonstrated by the real experiments.

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Position Estimation of Mobile Robots using Multiple Active Sensors with Network

  • Jin, Tae-Seok
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.11 no.4
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    • pp.280-285
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    • 2011
  • Recently, with the development of service robots and the concept of ubiquitous, the position estimation of mobile objects has received great interest. Some of the localization schemes are introduced, which provide the relative location of the moving objects subjected to accumulated errors. To implement a real time localization system, a new absolute position estimation method for a mobile robot in indoor environment is proposed. Design and implementation of the localization system comes from the usage of active beacon systems (based upon RFID technology). The active beacon system is composed of an RFID receiver and an ultra-sonic transmitter. The RFID receiver gets the synchronization signal from the mobile robot and the ultra-sonic transmitter sends out the traveling signal to be used for measuring the distance. Position of a mobile robot in a three dimensional space can be calculated basically from the distance information from three beacons and the absolute position information of the beacons themselves. In some case, the mobile robot can acquire the ultrasonic signals from only one or two beacons, due to the obstacles located along the moving path. In this paper, a position estimation scheme using fewer than three sensors is developed. Also, the extended Kalman filter algorithm is applied for the improvement of position estimation accuracy of the mobile robot.

An Transmission Time Allocation Scheme in ZigBee Network (지그비 네트워크에서의 전송 시간 할당 방법)

  • Choi, Hyo-Hyun
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.4
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    • pp.119-126
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    • 2011
  • When ZigBee network supports beacon transmission mechanism, ZigBee devices have the restriction of the transmission range from the coordinator. On the contrary, when it does not support beacon transmission, it is not easy to save the energy through turning into sleep mode. This paper proposes active slot allocation method that allocates a transmission time and does not use the beacon transmission mechanism. It is based on the ZigBee's distributed address assignment mechanism and supports the scalability. This paper explains the active slot structure and the allocation order and describes the operation of ZigBee devices. We verify the proposed mechanism through the simulation and show the performance evaluation. It can be useful on the industrial automation and the environmental surveillance.

Three-Dimensional Location Tracking System for Automatic Landing of an Unmanned Helicopter (무인 헬기 자동 착륙을 위한 3차원 위치 추적 시스템)

  • Choo, Young-Yeol;Kang, Seong-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.6
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    • pp.608-614
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    • 2008
  • This paper describes a location tracking system to guide landing process of an Unmanned Helicopter(UMH) exploiting MIT Cricket nodes. For automatic landing of a UMH, a precise positioning system is indispensable. However, GPS(Global Positioning System) is inadequate for tracking the three dimensional position of a UMH because of large positioning errors. The Cricket systems use Time-Difference-of-Arrival(TDoA) method with ultrasonic and RF(Radio Frequency) signals to measure distances. They operate in passive mode in that a listener attached to a moving device receives distance signals from several beacons located at fixed points on ground. Inevitably, this passive type of implementation causes large disturbances in measuring distances between beacons and the listener due to wind blow from propeller and turbulence of UMH body. To cope with this problem, we proposed active type of implementation for positioning a UMH. In this implementation, a beacon is set up at UMH body and four listeners are located at ground area at least where the UMH will land. A pair of Ultrasonic and RF signals from the beacon arrives at several listeners to calculate the position of the UMH. The distance signals among listeners are synchronized with a counter value appended to each distance signals from the beacon.

Robust Positioning-Sensing for n Ubiquitous Mobile Robot (유비쿼터스 모바일 로봇의 강인한 위치 추정 기법)

  • Choi, Hyo-Sik;Hwang, Jin-Ah;Lee, Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.11
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    • pp.1139-1145
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    • 2008
  • A robust position sensing system is proposed in this paper for a ubiquitous mobile robot which moves indoors as well as outdoors. The Differential GPS (DGPS) which has a position estimation error of less than 5 m is a general solution when the mobile robot is moving outdoor, while an active beacon system (ABS) with embedded ultrasonic sensors is reliable as an indoor positioning system. The switching from the outdoor to indoor or vice versa causes unstable measurements on account of the reference coordinates and algorithm changes. To minimize the switching time in the position estimation and to stabilize the measurement, a robust position sensing system is proposed. In the system, to minimize the switching delay, the door positions are stored and updated in a database. Using the database, the approaching status of the mobile robot from indoor to outdoor or vice versa has been checked and the switching conditions are prepared before the mobile robot actually moves out or moves into the door. The reliability and accuracy of the robust positioning system based on DGPS and ABS are verified and demonstrated through the real experiments using a mobile robot prepared for this research.

Design and Implementation of Healthcare Game Content in IOT Environment

  • Yoon, Seon-Jeong
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.9
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    • pp.29-34
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    • 2019
  • In Recently, as the interest in health has increased and the spread of smart phones has become common, the development of smart health care related contents has been active. In this paper, we introduce the design, implementation and effects of game-based content that can make walking exercise fun in the Internet of Things environment. This content calculates the consumed calories by walking the stairs with the Beacon installed, and incorporates games to encourage continuous fun activities. It also provides event functions that enable on-off-line coordination. The goal of this content is to enable busy modern people to exercise lightly, funly, and constantly in the surrounding activity space. The effect of this content has been confirmed through the review of many users participating in offline events. This content is expected to be able to converge with various types of healthcare systems with the expansion of the application space.

The Study of Microwave Propagation Model for the Active ETC System (능동방식 ETC 시스템을 위한 마이크로파 전파 모델 연구)

  • 배창호;정희창;김영주;장호성
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 1999.11a
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    • pp.101-105
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    • 1999
  • Electronic Toll Collection(ETC) System makes the telecommunication possible between the Beacon and the On Board Unit(OBU) in vehicle at the highway. In this paper, the propagation path of microwave is modelled and the induced voltage of receiving antenna is analyzed numerically according to multi-path fading effort. In this modelling, we consider the weather condition, polarization and antenna radiation pattern. Also, we suggest the diversity technique in order to re duce the fading effect. In the result, the lading effort is reduced significantly in case of the vertical polarization at the rain condition. The circular polarization is the most desirable in this application. The antenna which has the high directivity, is also desirable. Using the space diversity technique at the Beaten, the fading effect is reduced as the distance increases between the Beacon and OBU. These results are presented at the graphs whose axes are related to the magnitude of received voltage(dB) and the distance of the beacon and a vehicle.

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