• 한국지리정보학회지
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• 제26권4호
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• pp.130-144
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• 2023

최근 실내에 대한 정확한 위치정보 취득을 위해 신호기반측위와 영상기반측위를 기반으로 다양한 측위기술이 연구되고 있다. 이 중 카메라를 통해 획득된 영상과 필요에 따라 수집된 센서데이터를 이용하여 모바일 단말의 위치를 결정하는 영상측위 기술에 대한 연구가 다양하게 진행되고 있다. 영상기반측위를 위해서는 모바일 단말사진과 가상의 랜드마크 영상과의 매칭을 통해 실내위치 결정하는 방법이 사용되며, 이를 위해 광고판, 자판기, ATM기기 등 다양한 랜드마크에 대한 실내 공간정보구축이 필요하다. 다양한 랜드마크에 대한 실내공간정보 구축을 위해 한국전자통신연구원(ETRI) 13동을 대상으로 지상라이다 측량을 통해 로드뷰 형태의 파노라마 이미지와 정확한 3D 측량성과를 취득하였다. 3차원 토탈스테이션 결선성과와 지상라이다 파노라마 이미지 좌표상호간 비교시 약 0.10m 이내로 좌표 및 거리 성과가 취득되어 실내측위에 활용하기 위한 정확한 랜드마크 구축이 가능함을 확인하였다. 이러한 지상라이다 성과를 활용하여 영상측위에 필요한 3차원 랜드마크 모델링을 수행함으로써 기존 준공도면을 이용한 3차원 모델링만으로 구축할 수 없는 랜드마크 정보에 대해 보다 빠르게 모델링이 가능하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.451-454
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• 2006

Ultrasonic Positioning System (UPS) is an absolute positioning system using ultrasonic waves and has better performance in low price than the other absolute positioning systems. UPS can be further used as pseudo-satellites in the place where GPS is not available. This study aims to evaluate the efficiency and effectiveness of using UPS as a 3D free-hand writing or drawing tool. The process includes the design and testing of VPS as an efficient 3D free-hand writing or drawing tool in the air. The paper will further explain the system architecture of the UPS and how to use GPS as 3D free-hand writing or drawing tool. The efficiency and effectiveness of the system was confirmed by a computer software simulation. The software will further display the result of drawing or writing from the user by graphics. As a result, it is possible to implement UPS as a 3D free-hand writing or drawing tool in the air.

• 대한전자공학회논문지
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• 제27권8호
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• pp.1188-1200
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• 1990

In this paper, the 3-D positioning problem for a quadruped walking robot is investigated. In order to determine the robot's exterior position and orentation in a worls coordinate system, a stereo 3-D positioning algorithm is proposed. The proposed algorithm uses a Guide-Mark Pattern (GMP) specialy designed for fast and reliable extraction of 3-D robot position information from the uncontrolled working environment. Some experimental results along with error analysis and several means of reducing the effects of vision processing error in the proposed algorithm are disscussed.

• Journal of Positioning, Navigation, and Timing
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• 제12권3호
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• pp.323-332
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• 2023

Today, services using Positioning, Navigation, and Timing (PNT) technology are provided in various fields, such as smartphone Location-Based Service (LBS) and autonomous driving. Generally, outdoor positioning techniques depend on the Global Navigation Satellite System (GNSS), and the need for positioning techniques that guarantee positioning accuracy, availability, and continuity is emerging with advances in service. In particular, continuity is not guaranteed in urban canyons where it is challenging to secure visible satellites with standalone GNSS, and even if more than four satellites are visible, the positioning accuracy and stability are reduced due to multipath channels. Research using Low Earth Orbit (LEO) satellites is already underway to overcome these limitations. In this study, we conducted a trend analysis of LEO-PNT research, an LEO satellite-based navigation and augmentation system. Through comparison with GNSS, the differentiation of LEO-PNT was confirmed, and the system design and receiver processing were analyzed according to LEO-PNT classification. Lastly, the current status of LEO-PNT development by country and institution was confirmed.

• Journal of Positioning, Navigation, and Timing
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• 제5권3호
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• pp.145-156
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• 2016

A variety of methods for indoor positioning systems have been underway to ensure the safety of emergency rescuers who are working in dangerous situations such as fire fighters. However, since most systems display locations of rescue workers in two-dimension (2D)-based maps, it is difficult for a commander located in the outside to recognize locations of rescuers inside the building intuitively. An augmented reality (AR)-based indoor positioning monitoring system can display locations of rescuer inside the building that can be seen by commanders to help intuitive recognition of positioning. To monitor AR-based indoor positioning, it is necessary to have an estimation technique of line of sight vector of observers. In the present study, an estimation technique of a line of sight vector using ultra-wide band tranceiver installed inside the indoor to trace locations is presented.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2010년 춘계학술발표회 논문집
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• pp.169-171
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• 2010

The goal of this study is to evaluate the performance of different solution types(a GPS-only, a GLONASS-only, and a GNSS solution) on GNSS positioning modes which are point positioning and relative positioning(DGNSS-, Static-, and Kinematic-solutions). I started with GNSS sites of seoul metropolitan government's RTK network which providing combined GPS/GLONASS observations : Gangseo(GANS), Dobong(DBON). The positioning accuracy of different solution types on positining modes are compared. Considering the compared results of all cases, can find not only the difference of the performance between the GNSS solution and the GPS-only solution is very small, but also the GLONASS-only solution is not far from the other solution types taking into consideration that GLONASS system is not (yet) a complete system.

• 수산해양교육연구
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• 제3권2호
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• pp.19-28
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• 1991

1988년 1월과 8월에 나가사키, 하코다테 및 하마다(Hamada)에서 GPS 수신기로써 선위를 측정하여 그 측정정도(測定精度)를 분석한 결과, 1일의 측위시간(測位時間)은 하코다테에서는 8시간 50분, 하마다에서는 8시간 30분, 그리고 나가사키에서는 1월이 약 9시간, 8월이 약 6시간 30분으로, 8월에는 1월보다 약 2시간 반 감소하고 있다. 이것은 수신된 위성수(衛星數)는 6월까지는 7개였지만, 나가사키에서의 8월의 측정에서는 No.8의 위성신호(衛星信號)를 수신할 수 없게 되어 위성수(衛星數)가 6개로 줄었기 때문이다. 각 측정점(測定點)에서 다소의 차가 생긴 것은, 전체의 위성수(衛星數)가 적다는 것과, 궤도상(軌道上)의 배치의 관계로서, 측정점(測定點)의 위도(緯度)와 측정시기(測定時期)에 의해 측정 가능한 시간이 변화하고, 더우기 측정점(測定點)의 지형(地形)에 따른 영향을 받기 때문이라고 여겨진다. 이번에 시험적으로 고안정발진기(高安定發振機)를 장착하여 두 위성(衛星)에 의한 2차원의 위치를 측정했는데, H level에서는 2L와 거의 같은 정도였으므로 이것을 이용하면 측위 시간은 약 3시간 반 정도 길게 된다. 나가사키에 있어서 1월과 8월의 측정 결과는 3H 이외의 각 level에서는 어느 것이나 1월의 측정에서 측위오차(測位誤差)가 크고, 측정시각(測定時刻)의 상이에 따른 전리층(電離層)의 전자밀도(電磁密度)의 상이가 영향을 미치는 것으로 여겨진다. 3D에서는 각 측점 모두 거의 같은 정도의 오차로, 현저한 지역차(地域差)는 확인되지 않았다. 2D에서는 각 level모두 측위오차(測衛誤差)는 0.1해리 이하이지만, 그의 크기 및 자료 수에는 큰 변동을 보였다. 위성(衛星)의 궤도 주기가 약 11시간 58분이고 측위 가능한 시간대(時間帶)가 1년간의 주기로 변화하기 때문에, 거기에 따른 측위정도(測位精度)도 변동하는 것으로 여겨진다. 따라서, 금후의 과제로서 동일한 시기에 수개소(數個所)의 측점(測點)에 일정한 간격을 두고 측정을 행하여 시기에 따른 정도(精度)의 변화 및 PDOP값과 위성(衛星)의 배치(配置)에 의한 측위오차(測位誤差)의 경향 등을 확인하는 것이 필요할 것이다.

• Journal of Positioning, Navigation, and Timing
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• 제6권1호
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• pp.27-33
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• 2017

GPS provides the positioning solution in most areas of the world. However, the position error largely occurs in the urban area due to signal attenuation, signal blockage, and multipath. Although many studies have been carried out to solve this problem, a definite solution has not yet been proposed. Therefore, research is being conducted to solve the vehicle localization problem in the urban environment by converging sensors such as cameras and Light Detection and Ranging (LIDAR). In this paper, the precise vehicle localization using 3D LIDAR (Velodyne HDL-32E) is performed in the urban area. As there are many tall buildings in the urban area and the outer walls of urban buildings consist of planes generally perpendicular to the earth's surface, the outer wall of the building meets at a vertical corner and this vertical corner can be accurately extracted using 3D LIDAR. In this paper, we describe the vertical corner extraction method using 3D LIDAR and perform the precise localization by combining the extracted corner position and GPS/DR information. The driving test was carried out in an about 4.5 km-long section near Teheran-ro, Gangnam. The lateral and longitudinal RMS position errors were 0.146 m and 0.286 m, respectively and showed very accurate localization performance.

• 로봇학회논문지
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• 제12권1호
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• pp.78-85
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• 2017

This paper presents the development of a 3D printer based piezo-driven vertical micro-positioning stage. The stage consists of two flexure bridge structures which amplify and transfer the horizontal motion of the piezo-element into vertical motion of the end-effector. The stage is fabricated with ABS material using a precision 3D printer. This enables a one-body design eliminating the need for assembly, and significantly increases the freedom in design while shortening fabrication time. The design of the stage was optimized using response surface analysis method. Experimental results are presented which demonstrate 100nm stepping in the vertical out-of-plane direction. The results demonstrate the future possibilities of applying 3D printers and ABS material in fabricating linear driven motion stages.