• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.9
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• pp.891-897
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• 2008

GPS can provide precise relative navigation information. But it needs a reference station in a close range and is effected by satellite observation environment. In this paper, we propose INS and Vision sensor integrated system with a known landmark geometry. This system is supposed to overcome problems of GPS only system. Using the proposed method, a relative navigation is available without a GPS reference station. The only need for the proposed system is a landmark image which is drawn on the ground. We conduct simple simulation to check the performance of this method. As a result, we confirm that it can improve the relative navigation information.

• Journal of Advanced Navigation Technology
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• v.21 no.1
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• pp.138-144
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• 2017

A method for improving the integrated navigation performance in the INS/GPS navigation system by the considering that the condition that the geometric arrangement of the satellite is degraded due to limitation of the line of sight of the satellite such as geographic feature and GPS signal jamming is proposed. A variable covariance extended Kalman filter (VCEKF) that correlated to the measured covariance to the DOP of GPS is suggested. The navigation performance of integrated navigation system using EKF and VCEKF is analyzed by Monte-Carlo simulations. The result is verified that VCEKF has better estimation performance than EKF using fixed covariance on condition that DOP value is larger than the smaller value.

• 한국항공운항학회:학술대회논문집
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• 2004.11a
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• pp.295-301
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• 2004

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.1
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• pp.1-8
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• 2004

The INS(Inertial Navigation System) provides high rate position, velocity and attitude data with good short-term stability while the GPS(Global Position System) provides position and velocity data with long-term stability. By integrating the INS with GPS, a navigation system can be achieved to Provide highly accurate navigation Performance. For the best performance, time synchronization of GPS and INS data is very important in GPS/INS integrated system But, it is impossible to synchronize them exactly due to the communication and computation time-delay. In this paper, to reduce the error caused by the measurement time-delay in GPS/INS integrated systems, error compensation methods using separate bias Kalman filter are suggested for both the loosely-coupled and the tightly-coupled GPS/INS integration systems. Linearized error models for the position and velocity matching GPS/INS integrated systems are Int derived by linearizing with respect to its time-delay and augmenting the delay-state into the conventional state equations for each case. And then separate bias Kalman Inter is introduced to estimate the time-delay during only initial navigation stage. The simulation results show that the present method is effective enough resulting in considerably less position error.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1535-1536
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• 2008

GPS/INS/지자기 컴파스 통합 항법 시스템에서 지자기 컴파스의 이상 검출 방법을 제안하였다. 지자기 컴파스의 이상은 Hard iron과 Soft iron 효과에 의하여 발생하므로 이와 관련된 값을 통합 필터 측정치의 시험 통계치로 이용하여 검출하는 방법을 제안하였다. 제안한 방법의 효용성을 모의 실험과 차량 실험을 통하여 검증하였다.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.5
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• pp.190-196
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• 2015

In this paper, we propose multiple location error compensation algorithm for GPS/INS fusion using kalman filter and introduce the way to reduce location error in 9-axis navigation devices for implementing inertial navigation technique. When evaluating location, there is an increase of location error. So navigation systems need robust algorithms to compensate location error in GPS/INS fusion. In order to improve robustness of 9-axis inertial sensor(mpu-9150) over its disturbance, we used tilt compensation method using compensation algorithm of acceleration sensor and Yaw angle compensation to have exact azimuth information of the object. And it shows improved location result using these methods combined with kalman filter.

• The KIPS Transactions:PartA
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• v.8A no.4
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• pp.429-438
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• 2001

GPS (Global Positioning System) is the most ideal navigation system which can be used on the earth irrespective of time and weather conditions. GPS has been used for various applications such as construction, survey, environment, communication, intelligent vehicles and airplanes and the needs of GPS are increasing in these days. This paper deals with the design and implementation of the RTOS (Real-Time Operating System) for a GPS navigation computer in the GPS/INS integrated navigation system. The RTOS provides the optimal environment for execution and the base platform to develop GPS application programs. The key facilities supplied by the RTOS developed in this paper are priority-based preemptive scheduling policy, dynamic memory management, intelligent interrupt handling, timers and IPC, etc. We also verify the correct operations of all application tasks of the GPS navigation computer on the RTOS and evaluate the performance by measuring the overhead of using the RTOS services.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.1
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• pp.93-102
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• 2024

Global Navigation Satellite System (GNSS)/Inertial Navigation System (INS) integrated navigation systems provide highly accurate and reliable navigation solutions and are widely used as civil and military navigation systems. In order to facilitate the GNSS/INS integrated navigation system development task, a simulator can be used to provide inputs for the GNSS/INS integrated navigation system. In this paper, a simulator design using general-purpose Personal Computer (PC) and Off-The-Shelf (OTS) interface boards for a GNSS/INS integrated navigation system is proposed and implementation results are presented. Requirements of the GNSS/INS integrated navigation system simulator are presented and a design method that satisfies the requirements is described. In order to show the usefulness of the proposed design method, a simulator using a general-purpose PC and OTS interface boards for the GPS/INS integrated navigation system are implemented and verified. The implementation results show that the simulator designed by the proposed method generates the GPS L1 C/A signal and IMU data without any problems.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.6
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• pp.77-81
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• 2008

In the deeply coupled GPS/INS integrated systems, if the integration filter update period is longer than the period of GPS navigation data, the loss of correlation values occurs due to the bit transition. This problem can be resolved when data wipe off(DWO) is used. However, general DWO methods requires heavy computation or cannot be applied continuously. This paper proposes an effective DWO method using carrier phase discriminator In order to show validity of the proposed method, simulations were carried out. The simulation results show that the data bit is accurately estimated and conform that the loss of correlation values and the error of code phase is small.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.11a
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• pp.217-221
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• 2000

증강현실은 사용자가 보고 있는 실세계의 영상과 컴퓨터가 생성한 가상의 영상을 실시간으로 합성하여 제시해주는 기술로 사용자에게 실세계에 대한 이해 및 현실감을 높여 줄 수 있는 기술이다. 본 논문에서는 이러한 기술을 이용하여 조종사에게 항법관련 정보를 제공해줄 수 있는 헬리콥터 항법용 증강현실 인터페이스를 설계하는 것을 목적으로 한다. 증강현실 인터페이스는 위치 측위를 위한 GPS/INS 기술과 통합되어 조종사에게 실시간으로 항법관련 정보를 제공해줄 수 있도록 한다. 제안된 시스템에서는 조종사의 주시방향을 보다 정확하게 추출하기 위하여 레이저 방식의 트래커를 이용하며, 투시형 HMD(Head-mounted Display)를 이용하여 합성된 영상을 조종사에게 실시간으로 제공하도록 한다.