• 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.

• Aerospace Engineering and Technology
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• v.6 no.2
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• pp.150-156
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• 2007

In this paper, we focus on the fault detection and isolation(FDI) method for inertial navigation system with three two-degree of freedom dynamically tuned gyros(DTG) on orthogonal sensor configuration. we propose the FDI method which can detect the fault of each DTGs rather than the fault of each sensing axis. The proposed FDI method is separated into two FDI modules according to the fault magnitude in order to improve the reliability of fault detection information. For large fault detection, only instantaneous DTG measurement is used to detect a fault DTG within a short time. For small fault detection, the integrated value of DTG measurements are used to detect a fault DTG. It takes a more time to detect a fault but it serves more reliable fault detection information. Using the proposed FDI method with consideration of DTG fault characteristic, we could find out a fault DTG successfully.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.10 no.1
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• pp.35-44
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• 2002

Inertial Navigation System(INS) has been used in the field of air navigation for a long time but is not popular in general aviation due to high price. Recently low-price GPS is available but vulnerable to radio interference. As an alternative on these problems, GPS/INS integrated navigation system has been considered. GPS/INS is capable of implementing navigation with low-price inertial sensors but its accuracy is dependent upon how much drift of INS may be calibrated by using GPS. In order to apply GPS/INS to air navigation, it must be investigated how long drift of INS in case of no GPS aiding will be bounded within requirements for safe flight. From the above motivation, the flight test for GPS/INS navigation system was conducted in order to make sense its performance in air navigation and its result was shown.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.10
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• pp.1822-1829
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• 2008

Calibration of an MEMS inertial measurement unit is very important process for obtaining precise navigation performance. In this paper, one method is proposed to overcome a limitations on cost and efficiency using a relatively higher grade sensor and a rate table. The same dynamic input is applied to both the reference and the target sensors during and after calibration process, then the results are analyzed. The experimental results show that the proposed method is very effective and useful in practice.

• Journal of Advanced Navigation Technology
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• v.16 no.5
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• pp.738-743
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• 2012

Kalman filter is generally used in INS/GPS integrated navigation filter. However, the INS with low performance inertia sensor can not find accurate azimuth in initial alignment stage because sensor noise level is too large compare to Earth rotation rate, therefore the performance and stability of Kalman filter can not be guaranteed. In this paper, the extended Kalman filter and particle filter combined filter structure which can be overcome large initial azimuth error is proposed.

• ICROS
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• v.19 no.1
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• pp.19-31
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• 2013

본 고는 국내외의 지형참조항법시스템 관련 기술의 발전 동향을 살펴보고자 한다. 지형참조항법은 국외에서 1940년대부터 그 필요성이 대두된 학문으로 잠수정, 군용 전투기 등 다양한 분야에서 주로 군사목적으로 연구가 진행되었다. 1950년 ATRAN의 개발을 시작으로 1990년대 PTAN 지형참조항법기술까지 발전되어 무인기뿐만 아닌 Tomahawk 같은 유도무기에도 그 활용 범위를 넓혀가고 있다. 하지만 하드웨어적인 제약과 GPS의 발달로 관련 연구가 주춤하였으나 컴퓨터 기술의 발달, 지형측정센서의 정확도 향상과 더불어 GPS 교란 가능성 등이 부각되면서 최근 다시 관성항법시스템(INS)을 보조하는 대체 항법으로서 주목받고 있다. 주로 다중 측정치를 이용하는 방법과 비선형 필터를 이용하여 항법해 성능을 향상시키거나 병렬 다중필터를 이용하여 항법해의 신뢰성을 향상시키는 방향으로 연구가 진행 중이다. 그리고 다양한 지구물리데이터와 통합한 데이터베이스기반 복합항법 기술로 발전하고 있다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.6
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• pp.463-472
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• 2017

Inertial Navigation System Alignment is the process to determine direction cosine matrix which is the transformation matrix between the INS body frame and navigation frame. INS initial position value is necessary to INS attitude calculation, so that user should wait until he get such value to start the INS alignment. To remove the waiting time, we propose an alignment algorithm that immediately starts after the INS power on by using pseudo initial position input and then is completed with attitude error compensation by entering true position later. We analyse effect of INS sensor error on attitude in process of time and verify the performance and usefulness of the close-loop alignment algorithm which corrects attitude error from the change of initial position.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.6
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• pp.438-445
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• 2019

In this paper, we present a new approach to extract the g-sensitivity scale-factor error for a MEMS gyroscope. MEMS gyroscopes, based on the use of both angular momentum and the Coriolis effect, have a g-sensitivity error due to mass unbalance. Generally, the g-sensitivity error is not considered in general use of gyroscopes, but it deserves our attention if we are to develop for tactical class performance and reliability. The g-sensitivity error during vehicle flight increases navigation error; so it must be analyzed and compensated for the use of MEMS IMU for high dynamics vehicle systems. Therefore, we analyzed how to extract the g-sensitivity scale-factor error from the inertial sensor error model. Furthermore we propose a new method to extract the g-sensitivity error using flight motion simulator. We verified our proposed method with experimental results.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2270-2273
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• 2001

This paper presents calibration and alignment algorithms for low-cost inertial sensors. The error models for gyro and accelerometer are presented with a study of their effects. A navigational Kalman Filter is derived based on those error models. Test results are presented, which shows the initial calibration and alignment scheme and the proposed filter configuration effectively reduce the drift of the sensors and provide improved accuracy for its practical use for navigation.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.3
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• pp.108-118
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• 2017

This paper presents experimental results of realtime sonar-based SLAM (simultaneous localization and mapping) using probability-based landmark-recognition. The sonar-based SLAM is used for navigation of underwater robot. Inertial sensor as IMU (Inertial Measurement Unit) and DVL (Doppler Velocity Log) and external information from sonar image processing are fused by Extended Kalman Filter (EKF) technique to get the navigation information. The vehicle location is estimated by inertial sensor data, and it is corrected by sonar data which provides relative position between the vehicle and the landmark on the bottom of the basin. For the verification of the proposed method, the experiments were performed in a basin environment using an underwater robot, yShark.