• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.06a
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• pp.296-297
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• 2010

본 연구는 비디오카메라와 GPS/MEMS IMU를 이용하여 동영상과 위치/자세 데이터를 동시에 취득하는 방법을 제안하고 시스템을 구축하였다. 구축된 시스템에 실시간 영상 georeferencing 알고리즘을 적용한다면 데이터 취득과 동시에 georeferenced 동영상을 획득할 수 있을 것으로 기대된다. 또한 이로부터 신속하게 대상물의 3차원 모델 등의 다양한 공간정보를 구축하여 증강현실 등에 활용될 수 있을 것이다. 향후 정확도 검증을 통해 시스템의 효용성을 입증할 것이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.447-450
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• 2006

최근 국내외에서 재래식 폭탄의 정확도와 사거리를 향상시킨 정밀 유도 무기에 관한 연구가 활발하게 진행 중에 있다. 국내에서는 국방과학연구소의 주도로 재래식 폭탄에 GAK(GPS Adapter Kit)를 장착하는 연구가 진행 중이다. GAK는 GPS/INS 복합 항법 모듈을 내장한 사거리 연장 유도 키트의 일종으로 폭탄이 투하되면 접혀 있던 날개가 전개되고 이후 날개의 플래퍼론을 구동하여 유도 조종을 수행한다. 복합 항법 모듈은 상용의 MEMS IMU, 내장형 GPS 수신기 및 항법 컴퓨터와 실시간 운영 체제에서 구동되는 항법 소프트웨어로 구성된다. 본 논문에서는 복합 항법 모듈의 비행 시험 결과를 제시하였다. 시험 결과 항법 모듈이 실시간으로 정상적인 동작을 수행하였으며 GPS 유도 폭탄의 유도 조종에 적합한 항법 정보를 제공하였음을 확인하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.6
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• pp.637-643
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• 2010

In this study, we developed a Portable Multi-sensor System, which consists of a video camera, a GPS/MEMS IMU and a UMPC to acquire video images and position/attitude data. We performed image georeferencing based on the bundle adjustment without ground control points using the acquired data and then evaluated the effectiveness of our system through the accuracy verification. The experimental results showed that the RMSE of relative coordinates on the ground point coordinates obtained from our system was several centimeters. Our system can be efficiently utilized to obtain the 3D model of object and their relative coordinates. In future, we plan to improve the accuracy of absolute coordinates through the rigorous calibration of the system and camera.

• Journal of Positioning, Navigation, and Timing
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• v.3 no.2
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• pp.53-62
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• 2014

In the guided missile and unmanned vehicle system, the navigation system is one of the most important components. Recently, low-cost effective smart projectiles and guided bomb are being developed using MEMS based navigation system which has high-G, low-cost and small size. In this paper, locally developed MEMS based GPS/INS integrated navigation system will be introduced in comparison with the state of the art of MEMS based navigation system. And technical design and development method is described to satisfy the required performance of GPS receiver, MEMS inertial sensor assembly, navigation computer and software.

• Journal of Advanced Navigation Technology
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• v.25 no.1
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• pp.68-77
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• 2021

In this paper, a GPS/MEMS IMU integrated navigation receiver module capable of operating in a high dynamic environment is designed and fabricated, and the results is confirmed. The designed module is composed of RF receiver unit, inertial measurement unit, signal processing unit, correlator, and navigation S/W. The RF receiver performs the functions of low noise amplification, frequency conversion, filtering, and automatic gain control. The inertial measurement unit collects measurement data from a MEMS class IMU applied with a 3-axis gyroscope, accelerometer, and geomagnetic sensor. In addition, it provides an interface to transmit to the navigation S/W. The signal processing unit and the correlator is implemented with FPGA logic to perform filtering and corrrelation value calculation. Navigation S/W is implemented using the internal CPU of the FPGA. The size of the manufactured module is 95.0×85.0×.12.5mm, the weight is 110g, and the navigation accuracy performance within the specification is confirmed in an environment of 1200m/s and acceleration of 10g.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.475-478
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• 2006

본 논문에서는 소형 무인항공기의 정확한 위치, 속도, 자세 정보를 제공하기 위해 저급의 MEMS IMU를 이용한 항법 시스템을 제안한다. 제안하는 시스템은 비행체의 직선운동과 회전운동을 측정할 수 있는 관성측정기와 위성신호를 수신하여 항체의 위치, 속도 정보를 제공하는 GPS 수신기, 지구 자기장 정보를 이용하여 방향각 정보를 제공하는 지자기 센서들로 구성되었다. SDINS와 약결합 방식의 칼만필터를 이용한 항법 시스템은 초기정렬 알고리즘과 센서 오차 보상 알고리즘, 자력계 보상 알고리즘 및 복합항법 알고리즘으로 나뉘며, 설계된 항법 알고리즘들은 시뮬레이션과 차량 실험을 통해서 성능을 분석하였다.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.7
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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 the Korean Society for Aeronautical & Space Sciences
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• v.35 no.3
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• pp.260-267
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• 2007

GPS adapter kit (GAK) is a GPS/INS guided range extension system to improve the accuracy and availability of existing dumb bombs. In this paper, a van test result of GPS/INS navigation module (NM) for guided bomb with GAK has been presented. The NM consists of a commercial MEMS IMU, embedded GPS receiver and navigation computer unit (NCU). The GPS receiver of NM was designed to use multiple antennas for satellite visibility and GPS attitude determination. The real-time navigation software was designed by modularized structure to guarantee the maintainability and extensibility. In order to evaluate the performance of the NM, a van test was preformed by using a high performance INS - Honeywell H-726 MAPS(Modular Azimuth Position System).The van test results show that the GAK NM with GPS attitude measurement gives better navigation performance than a conventional GPS/INS integration and good coasting capabilities under jamming environment.

• Journal of Korean Society for Geospatial Information Science
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• v.14 no.3 s.37
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• pp.47-53
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• 2006

In this contribution, an integration of seamless navigation system for the pedestrian is introduced. To overcome the GPS outages in various situations, multi-sensor of GPS, INS, electronic barometer and compass are considered in one Extented Kalman filter. Especially, the integrated system is designed for low-cost for the practical applications. Therefore, a MEMS IMU is considered, and the low quality of the heading is compensated by the electronic compass. In addition, only the pseudoranges from GPS measurements are considered for possible real-time application so that the degraded height is also controlled by a barometer. The mathematical models for each sensor with systematic errors such as biases, scale factors are described in detail and the results are presented in terms of a covariance analysis as well as the position and attitude errors compared to the high-grade GPS/INS combined solutions. The real application scenario of GPS outage is also investigated to assess the feasible accuracy with respect to the outage period. The description on the current status of the development and future research directions are also stated.

• Journal of Advanced Navigation Technology
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• v.23 no.3
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• pp.228-236
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• 2019

Recently, multi-sensor integration techniques have been actively studied to obtain reliable and accurate navigation solution in GPS (Global Positioning System)-denied harsh environments such as urban canyons, tunnels, and underground roads. In this paper, we propose a low-cost ultrasonic-speedometer utilizing the characteristics of the ultrasonic propagation. An efficient integrated INS (inertial navigation system)/ultrasonic-speedometer navigation system is also proposed to improve the accuracy of positioning in GPS-denied environments. To evaluate the proposed system, car experiments with field-collected measurements were performed. By the experiment results, it was confirmed that the proposed INS/ultrasonic-speedometer system bounds the positioning error growth effectively even though GPS signal is blocked more than 10 seconds and a low-cost MEMS IMU (micro electro mechanical systems inertial measurement unit) is utilized.