• Journal of Advanced Marine Engineering and Technology
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• v.37 no.8
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• pp.932-938
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• 2013

Recently, the Fingerprint, which is one of the methods of indoor localization using WLAN, has been many studied owing to robustness about ranging error by the diffraction and refraction of radio waves. However, in the signal gathering process and comparison operation for the measured signals with the database, this method requires time consumption and computational complexity. In order to compensate for these problems, this paper presents, based on proposed modified database, WLAN indoor localization algorithm using selective operation of collected signal in real time. The proposed algorithm reduces the configuration time and the size of the data in the database through linear interpolation and thresholding according to the signal strength, the localization accuracy, while reducing the computational complexity, is maintained through selective operation of the signals which are measured in real time. The experimental results show that the accuracy of localization is improved to 17.8% and the computational complexity reduced to 46% compared to conventional Fingerprint in the corridor by using proposed algorithm.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.397-399
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• 2005

무선 센서노드를 활용한 다양한 네트워크 설계 기술은 실생활의 각종 정보 수집에서부터 환경 모니터링까지 폭넓은 활용범위를 바탕으로 저전력 노드 설계 기술, 노드간 라우팅 프로토콜, 초소형 운영체제 및 미들웨어기술 등 관련 연구가 활발히 수행되고 있으며, 실내 센서네트워크에 분포된 노드의 절대위치를 측정하는 위치인식 시스템은 노드의 이동성, 다수성 그리고 환경의 제약성으로 인해 이를 보완할 시스템이 요구되고 있다. 이에 본 논문에서는 고정 센서노드의 배치밀도에 따라 위치정보를 선별적으로 처리하는 위치데이터 처리기와 다중 위치데이터의 발생을 원천적으로 차단하는 노드간 라우팅 기법을 통해, 센서노드의 이동성과 다중성을 효과적으로 보완하는 실내 이동객체 위치인식 시스템을 설계하고 서비스 구현을 위한 센서네트워크 플랫폼을 제안한다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1808_1809
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• 2009

이동 로봇이 이동하기 위해서는 시작위치와 목적위치까지 이동 경로를 계산해야한다. 특히 실내용 서비스로봇의 경우 상대적으로 저렴한 인공마크와 위치인식감지센서를 이용하여 현재 위치를 판단 할 수 있다. 이 센서의 인식마크를 이용해 노드 간의 이동 경로를 생성하고 목적노드까지 이동하는데 발생할 수 있는 외부의 변화를 포함하여 로봇의 이동경로를 빠르게 생성 할 수 있는 알고리즘을 제안한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.278-279
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• 2015

Recently, With the development of smart devices of interest in the intelligent indoor positioning service with a smart terminal it is increasing. The BLE(Bluetooth Low Energy) is an indoor location positioning technology has attracted the attention. However, there is no way to check the reliability of the position information collected by the smart terminal receiving a big location data. This is because the reliability of an indoor position information because of a signal interference to drop. In this paper, we propose a method of managing big data collected in order to obtain reliable position information from the position information of iBeacon.

• Journal of Practical Engineering Education
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• v.10 no.2
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• pp.119-124
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• 2018

Educational equipment that enables the user or device to recognize the indoor position by using the acceleration and angular velocity of the IMU (Inertial Measurement Unit) sensor is introduced. With this educational equipment, various position recognition and tracking algorithms can be learned and creative engineering design works can be realized. The data value of the IMU sensor is transmitted to the MCU (microcontroller unit) through $I^2C$ (Inter-Integrated Circuit), and the indoor position recognition algorithm is applied by processing the data value through the filter and numerical method. It is then designed to use wireless communication to send and receive processed values and to be recognized by the user. As an example using this equipament, the case of "Implementation and recognition of virtual position using computation of moving direction and distance using IMU sensor" is introduced, and various creative engineering design application is discussed.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.2
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• pp.13-25
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• 2008

In this paper, we propose the Location Awareness System adjusting Ranging Technology for CSS(Chirp Spread Spectrum) which is adopted on 2.45GHz standard in IEEE 802.15.4a and TOA(Time-of-Arrival) algorithm. The conventional methods have adopted RSSI, ultrasonic waves and infrared rays in Zigbee. RSSI measures strength indication of received signal and recognizes the position of nodes in RF boundary. However, this technology has the following problems; lots of error by the change of the channel environment and much power consumption. In this paper, adopting chirp pulse on 2.45GHz standard in IEEE 802.15.4a and SDS-TWR(Symmetrical Double Side-Two Way Ranging) method using the characteristic of Spread Spectrum, a new Location Awareness System is suggested. The distance and the coordinate are measured within ${\pm}\;5cm$ by TOA(Time of Arrival) algorithm and proposed algorithm and the data in error rate is decreased less than 1%. Through these results, the algorithm suggested in this paper is verified for its performance in a computer simulation.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.9
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• pp.959-966
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• 2015

In this paper, we propose an indoor visible light communication(VLC) localization using Walsh code which can identify overlapped signals transmitted from the different LED sources as each of orthogonal signal at a receiver and using Manchester code which can eliminate the flicker of LED light and maintain a constant brightness. The proposed system can estimate the relative position of the receiver by using Lambertian radiation properties and trilateration method that are applied to the location information of fixed LED sources and the received signals from them. In order to verify the feasibility of the proposed system, we carried out the simulation in an indoor space with $6{\times}6{\times}1.5m^3$ installed LED lamps of 16. The simulation result shows that the proposed method achieves an average positioning error of 0.0536 m and a maximum positioning error of 0.2977 m.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.430-433
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• 2006

Wireless sensor network plays a prominent role in tracking the location of the target outdoor and indoor. This paper describes the implementation of the passive indoor location tracking system using ultrasonic and RF technologies that provides accurate location in the form of user space and position in three dimensions. Our system used a combination of RF and ultrasonic technologies to provide a location-support service to users and applicants. Ceiling-mounted beacons were spread through the building, publishing location information on an RF signal. The person carried a listener and the listener determined the location by calculating the distance from three beacons using triangulation algorithm.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.01a
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• pp.227-228
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• 2012

실외에서의 위치추적은 GPS(Global Positioning System) 등의 다양한 방법이 활용가능하다. 하지만 실내에서는 사용이 어려워 비전, RFID 및 Zigbee 등을 활용한 다양한 연구가 진행되고 있다. 본 연구에서는 비교적 비용 효과적으로 구축이 가능한 수동형 RFID 태그를 기반 이동형 로봇의 위치 추적 알고리즘을 제안하도록 한다. 총 7 종의 태그에 대하여 각 태그가 가지고 있는 특성을 실험을 통하여 분석하고 분석한 결과에 따라 태그를 배치하여 효과적으로 로봇의 이동에 따른 위치 추적 및 이동방향 예측방법을 기술한다. 제안하는 방법을 실험실 환경에서 레고 마인드스톰을 활용하여 그 효용성을 나타내도록 한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.491-492
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• 2022

본 연구에서는 실내 공간 정보 획득을 위한 IMU/INS 항법장치에 관한 연구를 위한 선행연구를 수행 하였다. 최근의 GPS를 이용한 내비게이션의 경우 보통 5~10m의 위치 오차가 일어나지만 아파트나 대형시설과 같이 실내, 터널, 공장지대 및 산악 지대등 상당한 지역은 GPS의 사각지대 또는 오차 범위를 벗어난 지역으로 존재하고 있다. 따라서 GPS는 실내에서는 사용이 불가능 하므로 다른 방안이 제시되어야 한다. 현재 고속 연산을 위한 고성능 마이크로프로세서의 발전은 센서 분야에 적용되어 저 전력, 고 정밀, 소형의 IMU/INS, ARS/AHRS 센서가 개발되고 있다. 본 연구에서는 IMU(inertial measurement unit)와 INS(Inertial Navigation System)을 이용하여 IMU자체의 자이로 센서와 가속도 센서를 이용한 GPS의 위성신호가 감지되지 않는 지형에서도 속도의 적분값과 회전방향을 이용하여 위치인식이 가능하도록 정보를 계산하여 자기의 위치를 추적하는 방안을 연구하였다.