• 제어로봇시스템학회논문지
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• 제11권7호
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• pp.633-643
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• 2005

An unmanned aerial vehicle (UAV) is an aircraft controlled by .emote commands from ground station and/o. pre-programmed onboard autopilot system. A navigation system in the UAV provides a navigation data for a flight control computer(FCC). The FCC requires accurate and reliable position, velocity and attitude information for guidance and control. This paper proposes an ADGPS/INS integrated navigation system for a UAV. The proposed navigation system comprises an attitude determination GPS (ADGPS) receive., a navigation computer unit, and a low-cost commercial MEMS inertial measurement unit(IMU). The navigation algorithm contains a fault detection and isolation (FDI) function fur integrity. In order to evaluate the performance of the proposed navigation system, two flight tests were preformed using a small aircraft. The first flight test was carried out to confirm fundamental operation of the proposed navigation system and to check the effectiveness of the FDI algorithm. In the second flight test, the navigation performance and the benefit of the GPS attitude information were checked in a high dynamic environment. The flight test results show that the proposed ADGPS/INS integrated navigation system gives a reliable performance even when anomalous GPS data is provided and better navigation performance than a conventional GPS/INS integration unit.

• Journal of Astronomy and Space Sciences
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• 제35권3호
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• pp.163-173
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• 2018

This paper presents relative navigation using intermittent laser-based measurement data for spacecraft flying formation that consist of two spacecrafts; namely, chief and deputy spacecrafts. The measurement data consists of the relative distance measured by a femtosecond laser, and the relative angles between the two spacecrafts. The filtering algorithms used for the relative navigation are the extended Kalman filter (EKF), unscented Kalman filter (UKF), and least squares recursive filter (LSRF). Numerical simulations reveal that the relative navigation performances of the EKF- and UKF-based relative navigation algorithms decrease in accuracy as the measurement outage period increases. However, the relative navigation performance of the UKF-based algorithm is 95 % more accurate than that of the EKF-based algorithm when the measurement outage period is 80 sec. Although the relative navigation performance of the LSRF-based relative navigation algorithm is 94 % and 370 % less accurate than those of the EKF- and UKF-based navigation algorithms, respectively, when the measurement outage period is 5 sec; the navigation error varies within a range of 4 %, even though the measurement outage period is increased. The results of this study can be applied to the design of a relative navigation strategy using the developed algorithms with laser-based measurements for spacecraft formation flying.

• 로봇학회논문지
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• 제4권3호
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• pp.169-176
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• 2009

Low-cost sensors have been widely used for mobile robot navigation in recent years. However, navigation performance based on low-cost sensors is not good enough to be practically used. Among many navigation techniques, building of an accurate map is a fundamental task for service robots, and mapping with low-cost IR sensors was investigated in this research. The robot's orientation uncertainty was considered for mapping by modifying the Bayesian update formula. Then, the data association scheme was investigated to improve the quality of a built map when the robot's pose uncertainty was large. Six low-cost IR sensors mounted on the robot could not give rich data enough to align the range data by the scan matching method, so a new sample-based method was proposed for data association. The real experiments indicated that the mapping method proposed in this research was able to generate a useful map for navigation.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2010년 춘계학술발표회 논문집
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• pp.7-8
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• 2010

무선인터넷 환경과 휴대용 장비의 발달로 차량 외부에서도 내비게이션이 가능하다. 특히, 보행자의 경우는 이동이 자유로와 기존의 차량 내비게이션에서 활용된 네트워크 데이터를 활용하는데 한계가 있다. 이에 본 연구에서는 기 구축된 공간정보에서 보행자 네트워크를 생성하는 방법에 대하여 제안하고자 한다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2017년도 추계학술대회
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• pp.115-116
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• 2017

본 논문에서는 이와같은 S-100 범용수로데이터모델(Universal Hydrographic Data Model)로 대별되는 차세대 전자해도가 e-Navigation 서비스 전략 지원은 물론이며 다양한 해양 정보, 서비스에서 발생되는 다양한 요구사항을 수용 할 수 있기 위한 차세대 전자해도 목적 다양성을 지원을 위한 표준화 전략을 제시하고 있다. IMO는 공통 해양 데이터 구조(Common Maritime Data Structure)로 IHO의 차세대 전자해도 표준인 S-100을 활용하고 있는데 이는 e-Navigation 실현을 위한 핵심 요소로 공통 데이터 모델이 필요함을 뜻하는 것으로써 e-Navigation은 해양안전뿐만 아니라, 해양 정보 및 서비스 관점에서도 새로운 ICT 융합 패러다임의 도입이 필요함을 적시하고 있다. 본 논문에서는 IMO는 공통 해양 데이터 구조로 활용되고 있는 S-100 표준의 내용 및 활용 방법을 이해하기 위해 모델 기반 데이터 표현 및 참조 모델에 대해 살펴보고 S-100 표준의 프로파일 기준 표준으로써 활용되었던 ISO/TC211 표준의 구성 및 역할을 살펴봄으로써 목적 다양성을 지원하는 차세대 전자해도 표준화를 위해 요구되는 표준화 항목이 무엇이며 상호간에 어떻게 연관되어 활용되는지 살펴본다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.337-342
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• 2006

The use of GPS receiver at outer space becomes common in low earth orbit. The KOrea Multi-Purpose SATellite-1 (KOMPSAT-1) which was launched in December 1999 has used GPS receiver's navigation solution to perform the Orbit Determination (OD) in the ground. At the circumstance of using only one ground station, the Orbit Determination using GPS receiver is good method. Because the accuracy of navigation solution acquiring directly from GPS receiver is not enough in satellite application such as map generation, post-processing concepts such as the Precise Orbit Determination (POD) are applied to satellite data processing to improve satellite position accuracy. The POD uses GPS receiver's raw measurement data instead of GPS receiver's navigation solution. The KOrea Multi- Purpose SATellite-2 (KOMPSAT-2) system newly uses the POD technique for large scale map generation. The satellite was launched in the end of July 2006. The satellite sends high resolution images in panchromatic band and multi-spectral bands to the ground. The satellite system uses GPS receivers as source of time synchronization and command reference in the satellite, provider of navigation solution for the OD, and provider of raw measurement data for the POD. In this paper, mechanical configuration and operations of the GPS receiver will be presented. The GPS data characteristics of the satellite such as time synchronization, command reference, the OD using GPS receiver's navigation solution, and the POD using GPS receiver's raw measurement data will be presented and analyzed. The enhancement of performance compared with it of the previous satellite will also be analyzed.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2017년도 추계학술대회
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• pp.22-24
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• 2017

한국형 e-Navigation 운영 시스템은 해양 안전과 관련된 다양한 서비스를 제공하도록 설계되고 있다. 이 서비스들은 하나의 소프트웨어에서 제공되는 것이 아닌, 별개의 소프트웨어로 구성된다. 한국형 e-Navigation 운영시스템에 탑재되는 서비스 소프트웨어들이 통합되기 위해서는 서비스 소프트웨어간 데이터를 교환할 수 있는 데이터 메시지의 정의가 필요하다. 또한 한국형 e-Navigation 운영시스템 서비스의 동작개념에 따라 짧은 시간에 많은 메시지가 네트워크를 통해 전송될 것으로 예상된다. 이와 같은 이유로 데이터 메시지를 효율적으로 관리하기 위해서는 고빈도, 고용량 메시지를 저장하기 위한 버퍼 또는 데이터 메시지 큐가 필요하다. 이에 본 논문에서는 한국형 e-Navigation 운영 시스템에 적용될 수 있는 데이터 메시지 큐인 AMQP(Advanced Message Queuing Protocol)의 특징을 분석하고 그 결과를 보였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2022년도 춘계학술대회
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• pp.44-45
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• 2022

국제항로표지협회(IALA)는 항로표지 데이터 교환을 위해 S-201 항로표지 정보표준을 2019년도부터 개발 및 제정하고 있다. 본 연구에서는 스마트 항로표지의 관리 및 서비스를 위해 IALA S-201 항로표지 정보표준체계를 활용하여 국내에서 관리되고 있는 항로표지 정보를 모델링하였다. S-201 항로표지 정보표준체계를 활용하여 국내 항로표지의 데이터 생산, 교환, 수집 등에 정보표준체계를 반영할 수 있는 기반을 마련하였으며 항로표지 조직, IALA 및 국가 간의 정보 교환체계 구축에 기여 하고자 한다.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2017년도 추계학술발표회
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• pp.211-211
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• 2017

• Journal of Positioning, Navigation, and Timing
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• 제3권3호
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• pp.99-105
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• 2014

A graphic processing unit (GPU) can perform the same calculation on multiple data (SIMD: single instruction multiple data) using hundreds of to thousands of special purpose processors for graphic processing. Thus, high efficiency is expected when GPU is used for the generation and correlation of satellite navigation signals, which perform generation and processing by applying the same calculation procedure to tens of millions of discrete signal samples per second. In this study, the structure of a GPU-based GNSS simulator for the generation and processing of satellite navigation signals was designed, developed, and verified. To verify the developed satellite navigation signal generator, generated signals were applied to the OEM-V3 receiver of Novatel Inc., and the measured values were examined. To verify the satellite navigation signal processor, the performance was examined by collecting and processing actual GNSS intermediate frequency signals. The results of the verification indicated that satellite navigation signals could be generated and processed in real time using two GPUs.