• Journal of Positioning, Navigation, and Timing
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• 제7권3호
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• pp.155-163
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• 2018

This study examined methods to enhance navigation performance and reduce the divergence of navigation solutions that may occur in the event of global positioning system (GPS) failure by integrating the GPS/inertial navigation system (INS) with the three-dimensional (3D) magnetic vector measurements of a magnetometer. A magnetic heading aiding method that employs a magnetometer has been widely used to enhance the heading performance in low-cost GPS/INS navigation systems with insufficient observability. However, in the case of GPS failure, wrong heading information may further accelerate the divergence of the navigation solution. In this study, a method of integrating the 3D magnetic vector measurements of a magnetometer is proposed as a countermeasure for the case where the GPS fails. As the proposed method does not require attitude information for integration unlike the existing magnetic heading aiding method, it is applicable even in case of GPS failure. In addition, the existing magnetic heading aiding method utilizes only one-dimensional information in the heading direction, whereas the proposed method uses the two-dimensional attitude information of the magnetic vector, thus improving the observability of the system. To confirm the effect of the proposed method, simulation was performed for the normal operation and failure situation of GPS. The result confirmed that the proposed method improved the accuracy of the navigation solution and reduced the divergence speed of the navigation solution in the case of GPS failure, as compared with that of the existing method.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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• pp.107-110
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• 2008

In this study, we propose a system for setting a Destination on CNS(Car Navigation System) or PNS(Personal Navigation System). The present Navigation does set the destination by only static method like name search, address search and wire telegraph telephone number search. But, the kind of setting a static destination does not reflect the dynamic moving situation. So we suggest setting the destination of navigation using Identifier of moving terminal. And it includes privacy protection on personal position information

• 한국항공운항학회지
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• 제11권2호
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• pp.7-21
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• 2003

The objective of this study is to evaluate a feasibility of navigation systems appropriate for the Asia-Pacific region. As an independent navigation system, four, five, and six geosynchronous satellite constellations are simulated to provide a navigation system for the region and dilutions of precision of the proposed systems are analyzed and compared.

• 한국항행학회논문지
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• 제27권6호
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• pp.788-797
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• 2023

본 논문은 수직 이착륙 무인 항공시스템의 GPS (global positioning system) 불가 시 대체 항법 시스템으로의 영상보정항법 시스템을 시험하기 위한 검증환경 개발 내용을 소개한다. 개발 중인 영상보정항법 시스템의 시험 및 평가를 위해서는 가상 환경을 활용하는 것이 효율적이지만, 현재 국내에는 적합한 장비가 개발되어 있지 않다. 따라서 제안된 검증환경은 시험 대상 장비의 운용 환경을 모델링 및 시뮬레이션 하여 입력 신호를 생성하고, 출력 신호를 관측함으로써 대상 장비의 성능을 평가할 수 있도록 개발되었다. 연구 과정은 검증환경 요구도 생성, 검증환경 설계에서부터 구성품별 하드웨어 및 소프트웨어 설계, 제작까지 포괄적으로 기술되었다. 이를 바탕으로 제작된 검증환경을 개발 중인 영상기반 보정항법 알고리즘의 성능평가와 시뮬레이션 기반의 사전 비행시험 수행에 활용하였다.

• 대한임베디드공학회논문지
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• 제9권5호
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• pp.299-305
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• 2014

In this paper, a simple version of the hybrid navigation system using Kalman filter is proposed. The implemented hybrid navigation system is composed of a GPS to measure the position and the velocity, and a IMU(inertial measurement unit) to measure the acceleration and the posture of a mobile robot. A discrete Kalman filter is applied to provide the position of the robot by fusing both of the sensor data. When GPS signal is available, the navigation system estimates the position of the robot from the Kalman filter using position and velocity from GPS, and acceleration from IMU. During the interval until next GPS signal arrives, the system calculates the position of the robot using acceleration from IMU and velocity obtained at the previous step. Performance of the navigation system is verified by comparing the real path and the estimated path of the mobile robot. From experiments, we conclude that the navigation system is acceptable for the mobile robot.

• Journal of Positioning, Navigation, and Timing
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• 제1권1호
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• pp.45-49
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• 2012

The flight performance evaluation of navigation system is very significant because the reliability of navigation data directly affect the safety of aircraft. Especially, the high-level navigation system such as DGPS/INS, need more precise flight performance evaluation method. The performance analysis is evaluated by comparing between the navigation system in aircraft and reference trajectory which is more precise than navigation system in aircraft. In order to verify DGPS/INS performance of m-level, the GPS receiver, which is capable post-processed Carrier-phase Differential GPS(CDGPS) method of cm-level, have to be used as reference system. The DGPS/INS is estimated the Center of Gravity (CG) point of aircraft to offer precise performance while the reference system is output the position of GPS antenna which is mounted on the outside of aircraft. Therefore, in order to more precise performance evaluation, it needs to compensate the lever arm and coordinates transformation. This paper use quaternion and Direct Cosine Matrix(DCM) methods as coordinate transformation matrix in lever arm compensation of CDGPS reference trajectory. And it compares NED errors of DCM and quaternion transformation in lever arm of reference trajectory via DGPS/INS result.

• 한국항해항만학회지
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• 제43권6호
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• pp.353-360
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• 2019

Technology-driven development of a new system makes it difficult for users and stakeholders to identify or intervene in the development process, resulting in systems with unnecessary functions and poor quality services. Applying the software architecture design process to the initial design of the navigation system platform of autonomous ships enables the development of a system that reflects the required functions and service quality of the stakeholders. The design, which includes all of the subsystems that make up an autonomous ship platform, is close to an enterprise architecture. Thus, we strived to design a navigation system platform suitable for the design range of the software architecture. This study analyzed the definition of functional requirements, and quality attributes by applying the software architecture design procedure. This study was conducted to identify the characteristics of the navigation system and platform needs, and the stakeholders were identified. To derive the functional requirements and constraints of the platform, a quality attributes workshop was held engaging stakeholders, and the results of the analysis of functional requirements and quality attributes were listed. Based on the results of this study, the architect can establish the evidence and technical solutions that are integral for the architecture development, and will facilitate the creation of quality attribute scenarios.

• 한국해양공학회지
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• 제22권4호
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• pp.106-113
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• 2008

This paper presents an underwater navigation system based on range measurements from a known reference station fixed on the sea bottom or floated at surface with a buoy, for which the system is extended to 3-dimensional coordinates. We formulated a state equation in polar coordinates and constituted an extended Kalman filter for discrete-time implementation of the navigation algorithm. The autonomous underwater vehicle, lSiMl, cruising with a constant speed can estimate its trajectory using just range measurements and additional depth, heading and pitch sensors. Simulation studies were performed to evaluate the underwater navigation of the maneuvering AUV with range measurements. We modulated the sample rate of range measurements to evaluate the effect of the update rate, and changed the initial position error of the AUV to check the robustness to estimation errors. Simulation results illustrates that the extended navigation system provides convergence of the state estimates. The navigation system was conditionally stable when it had initial position errors.

• 한국항해항만학회지
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• 제30권10호
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• pp.833-837
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• 2006

해난사고를 억제하고 선박을 안전하게 운항하기 위해서는 선박을 조종하는 항해사와 항해사의 항해 수행을 보조하는 시스템의 효과적인 상호작용이 필수적이다. 본 연구에서는 항해사의 항해 수행을 지원하고 안전한 선박 운행을 확보하기 위해 개발된 SCMS(Ship Control and Management System)의 기능을 항해사의 수행과 관련지어 (1) 경계(watchkeeping), (2) 위치확인(positioning) 및 조종(maneuvering)의 측면에서 개관하고, 선박 조종 및 안전성 확보를 위해 항해사가 이 시스템과 어떠한 방식으로 상호작용하는지 기술하였다. 또한 실제 선박에 탑재된 것과 동일한 SCMS 시뮬레이터를 이용하여 항해사를 훈련할 경우 선박조종을 위한 교육시간이 훨씬 단축될 수 있다는 것과, 실제 항해 실습 과정에서 경험하는 선박조종에서의 안전 정도(특히 조종 부문에서)도 급격히 상승함을 경험적 자료를 통해 확인하였다.

• 품질경영학회지
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• 제49권1호
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• pp.1-15
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• 2021

Purpose: The purpose of this study was to propose a sensor fusion algorithm that integrates vehicle motion sensor(VMS) into the hybrid navigation system. Methods: How to evaluate the navigation performance was comparison test with the hybrid navigation system and the sensor fusion method. Results: The results of this study are as follows. It was found that the effects of the sensor fusion method and α value estimation were significant. Applying these greatly improves the navigation performance. Conclusion: For improving the reliability of navigation system, the sensor fusion method shows that the proposed method improves the navigation performance in a combat vehicle.