• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.501-506
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• 1987

In this paper, we dealed development of analytic tools for strapdown inertial navigation system. It classified the constitution of strapdown inertial navigation system and the tests of productions. It is useful to high precision instrument.

• 한국항행학회논문지
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• 제27권1호
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• pp.50-56
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• 2023

관성항법장치는 내장된 관성센서만을 이용하여 외부의 도움 없이 항체의 가속도 및 각속도를 이용하여 항법 정보를 계산한다. 하지만, 장시간 운용 시 관성항법장치는 시간이 지남에 따라 오차가 누적되어 항법 성능이 저하된다. 이러한 관성항법장치의 누적 오차를 줄이기 위하여 관성센서조립체를 일정한 절차로 회전시켜 관성센서 오차가 회전을 통해 상쇄되도록 항법 성능을 개선 시키는 연구가 활발히 진행되고 있다. 본 논문에서는 2축 회전형 관성항법장치의 성능에 영향을 미칠 수 있는 오차 요소를 식별하고 각 오차가 항법 성능에 어떠한 영향을 미치는지 분석하였다. 오차 분석 수행 후 시뮬레이션을 통해 관성항법장치의 항법 성능분석 결과를 제시하였다.

• 로봇학회논문지
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• 제18권4호
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• pp.472-480
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• 2023

This paper describes the development of a test-equipment for the pre-verification of navigation performance in cluster-based AUVs (Autonomous Underwater Vehicle). In the development of an AUV, conducting hardware and software development sequentially is not efficient due to the limited research and development period. Therefore, in order to reduce the overall development time and achieve successful development results, it is essential to pre-validate the navigation system and navigation algorithms. Accordingly, this paper explains the test-equipment for pre-verification of navigation performance, and ultimately confirms the stability of the navigation system and the performance of the navigation algorithms through the analysis of five types of navigation sensor data stored during real-sea experiments. The results demonstrate that through the development and verification of the test-equipment, it is possible to shorten the overall development period and improvement of product quality in the process of developing multiple AUVs.

• 한국항행학회논문지
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• 제6권2호
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• pp.104-112
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• 2002

GPS를 항공기의 항법 장치로 사용하게 되면 기술적, 경제적인 면에서 많은 이익을 얻을 수 있다. 그런데 항공기는 어떤 시스템보다도 안전이 중요한 시스템이므로 개발된 항법 장치를 사용하기에 앞서 항법해의 신뢰성을 확보하는 것이 우선되어야 한다. 그에 따라 본 논문에서는 항공기 착륙 시에 사용하게 될 DGPS를 이용해서 측정치의 고장을 검출하고 고장이 검출된 측정치를 제거하는 시스템을 구현하고자 하였다. 또한 구현된 시스템의 성능을 평가하기 위해 여러 가지 상황에 대해서 실제 데이터를 사용하여 실험을 실시하였고, 그 결과 일부 구간을 제외하고는 고장의 검출 및 제거가 잘 이루어지는 것을 볼 수 있었다. 하지만 좀 더 완벽한 신뢰성을 확보하기 위해서는 측정치의 오차에 대한 분석, 다른 장치들과의 통합을 통한 가용성 확보 등에 대한 연구가 앞으로 많이 이루어져야 할 것으로 보인다.

• 대한전자공학회논문지TC
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• 제48권10호
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• pp.20-28
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• 2011

이 논문은 위성항법시스템의 문제점인 위치오차와 실외음영지역을 해소하기 위하여 위성항법시스템과 비전시스템을 융합한 신뢰성있는 고정밀 측위 기술을 제안하였다. 동적단독측위에서 이동체는 이동 위치에 따라 사용할 수 있는 위성항법시스템의 수가 변화한다, 위치 측위를 위해서는 최소 4개 이상의 위성항법시스템으로부터 위치정보데이터를 수신 받아야 한다. 그러나 도심지역에서는 고층건물이나 장애물 또는 반사파에 의해 정확한 위치측위가 어렵다. 이러한 문제점을 해결하기 위하여 비전 시스템을 이용하였다. 위성항법시스템을 사용하기 열악한 도심지역의 특정 건물에 정확한 위치값을 결정해 놓는다. 그리고 비전시스템을 통해 특정 건물을 인식하고, 인식된 건물을 이용하여 위치오차를 보정해 준다. 이동체는 이동하면서 비전시스템을 이용하여 특정 건물을 인식하며 위치 데이터값을 만들어내고, 위치계산을 수정하여 안정되고 신뢰성있는 고정밀 위치측위를 할 수 있다.

• Journal of Positioning, Navigation, and Timing
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• 제8권2호
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• pp.79-85
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• 2019

The mission tasks of polar exploration utilizing unmanned systems such as glacier monitoring, ecosystem research, and inland exploration have been expanded. To facilitate unmanned exploration mission tasks, precise and robust navigation systems are required. However, limitations on the utilization of satellite navigation system are present due to satellite orbital characteristics at the polar region located in a high latitude. The orbital inclination of global positioning system (GPS), which was developed to be utilized in mid-latitude sites, was designed at $55^{\circ}$. This means that as the user is located in higher latitudes, the satellite visibility and vertical precision become worse. In addition, the use of satellite-based wide-area augmentation system (SBAS) is also limited in higher latitude regions than the maximum latitude of signal reception by stationary satellites, which is $70^{\circ}$. This study proposes a local-area augmentation system that additionally utilizes Global Navigation Satellite System (GLONASS) considering satellite navigation system environment in Polar Regions. The orbital inclination of GLONASS is $64.8^{\circ}$, which is suitable in order to ensure satellite visibility in high-latitude regions. In contrast, GLONASS has different system operation elements such as configuration elements of navigation message and update cycle and has a statistically different signal error level around 4 m, which is larger than that of GPS. Thus, such system characteristics must be taken into consideration to ensure data integrity and monitor GLONASS signal fault. This study took GLONASS system characteristics and performance into consideration to improve previously developed fault detection algorithm in the local-area augmentation system based on GPS. In addition, real GNSS observation data were acquired from the receivers installed at the Antarctic King Sejong Station to analyze positioning accuracy and calculate test statistics of the fault monitors. Finally, this study analyzed the satellite visibility of GPS/GLONASS-based local-area augmentation system in Polar Regions and conducted performance evaluations through simulations.

• ETRI Journal
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• 제35권5호
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• pp.943-946
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• 2013

Instead of the extended Kalman filter, the unscented Kalman filter (UKF) has been used in nonlinear systems without initial accurate state estimates over the last decade because the UKF is robust against large initial estimation errors. However, in a multirate integrated system, such as an inertial navigation system (INS)/Global Positioning System (GPS) integrated navigation system, it is difficult to implement a UKF-based navigation algorithm in a low-grade or mid-grade microcontroller, owing to a large computational burden. To overcome this problem, this letter proposes a modified UKF that has a reduced computational burden based on the basic idea that the change of probability distribution for the state variables between measurement updates is small in a multirate INS/GPS integrated navigation filter. The performance of the modified UKF is verified through numerical simulations.

• 제어로봇시스템학회논문지
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• 제14권8호
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• pp.745-751
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• 2008

This paper presents a framework for GPS/INS/Vision based navigation system of helicopters. GPS/INS coupled algorithm has weak points such as GPS blockage and jamming, while the helicopter is a speedy and high dynamical vehicle amenable to lose the GPS signal. In case of the vision sensor, it is not affected by signal jamming and also navigation error is not accumulated. So, we have implemented an GPS/INS/Vision aided navigation system providing the robust localization suitable for helicopters operating in various environments. The core algorithm is the vision based simultaneous localization and mapping (SLAM) technique. For the verification of the SLAM algorithm, we performed flight tests. From the tests, we confirm the developed system is robust enough under the GPS blockage. The system design, software algorithm, and flight test results are described.

• Journal of Positioning, Navigation, and Timing
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• 제6권1호
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• pp.9-15
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• 2017

In this paper, results of a jammer detection and localization system operation are given. The system consists of receiver stations, a central tracking station, and a monitoring station and it was developed by our institute in 2014. Through real-time tests, it is confirmed that the developed system has an ability to estimate the location of interference sources with an accuracy of 50 m (CEP) even they was 10 km away. After verification, this system was installed in Incheon International Airport and operating results are being monitored by the airport and our institute continuously. In this year, there were some events that jamming signals were received from North Korea, so the data were analyzed and given here.

• 제어로봇시스템학회논문지
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• 제10권6호
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• pp.557-565
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• 2004

The Korean space program was marked by the successful launching of a KSR-III liquid propelled sounding rocket. The Inertial Navigation System (INS) which carries out critical mission functions of navigation, guidance and control was domestically developed and perfectly certified through the flight test. The system consists of a strapdown inertial measurement, an onboard computer and flight software. This paper will describes the development works of the inertial navigation system, including top level system design, hardware and software. And it summarizes flight results.