• 한국해양공학회지
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• 제17권6호
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• pp.83-90
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• 2003

This paper presents an underwater hybrid navigation system for a semi-autonomous underwater vehicle (SAUV). The navigation system consists of an inertial measurement unit (IMU), and a Doppler velocity log (DVL), accompanied by a magnetic compass. The errors of inertial measurement units increase with time, due to the bias errors of gyros and accelerometers. A navigational system model is derived, to include the scale effect and bias errors of the DVL, of which the state equation composed of the navigation states and sensor parameters is 20. The conventional extended Kalman filter was used to propagate the error covariance, update the measurement errors, and correct the state equation when the measurements are available. Simulation was performed with the 6-d.o,f equations of motion of SAUV, using a lawn-mowing survey mode. The hybrid underwater navigation system shows good tracking performance, by updating the error covariance and correcting the system's states with the measurement errors from a DVL, a magnetic compass, and a depth sensor. The error of the estimated position still slowly drifts in the horizontal plane, about 3.5m for 500 seconds, which could be eliminated with the help of additional USBL information.

• 한국항행학회논문지
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• 제21권1호
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• pp.138-144
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• 2017

본 논문에서는 INS/GPS결합 시스템에서 GPS가 기만신호 또는 지형지물에 의한 가시선이 제한되어 위성의 기하학적 배치가 저하되는 조건을 고려하였고, 통합항법 성능을 향상시키기 위한 방법을 제안하였다. 먼저 GPS의 DOP에 측정 공분산 이 연동되는 가변 공분산 확장 칼만필터(VCEKF)를 제시하였다. 그리고 몬테칼로 시뮬레이션을 통하여 EKF와 VCEKF를 사용한 통합항법 시스템의 항법성능을 분석하였다. DOP 값이 낮은 경우보다 DOP값이 높을 경우에 VCEKF가 확정 공분산을 사용하는 EKF보다 우수한 추정 성능을 보임을 확인할 수 있었다.

• Journal of Construction Engineering and Project Management
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• 제6권2호
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• pp.30-39
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• 2016

This research presents the development of a self-governing mobile robot navigation system for indoor construction applications. This self-governing robot navigation system integrated robot control units, various positioning techniques including a dead-reckoning system, a UWB platform and motion sensors, with a BIM path planner solution. Various algorithms and error correction methods have been tested for all the employed sensors and other components to improve the positioning and navigation capability of the system. The research demonstrated that the path planner utilizing a BIM model as a navigation site map could effectively extract an efficient path for the robot, and could be executed in a real-time application for construction environments. Several navigation strategies with a mobile robot were tested with various combinations of localization sensors including wheel encoders, sonar/infrared/thermal proximity sensors, motion sensors, a digital compass, and UWB. The system successfully demonstrated the ability to plan an efficient path for robot's movement and properly navigate through the planned path to reach the specified destination in a complex indoor construction site. The findings can be adopted to several potential construction or manufacturing applications such as robotic material delivery, inspection, and onsite security.

• 한국시뮬레이션학회논문지
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• 제18권4호
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• pp.9-20
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• 2009

자동차 내비게이션 시스템은 경로탐색 및 길안내 등의 기능을 제공하는 대표적인 운전자 지원 시스템의 하나로서 그 사용성이 크게 증가하고 있다. 대부분의 자동차 내비게이션 시스템은 2차원 지도에 기반하고 있는데 이는 기본적으로 지도가 지니는 함축화된 정보 표현 패러다임에 기반하고 있음으로 인해 실세계 정보로의 변환에 인지적 부담이 작용하게 된다. 최근에 개념적으로 대두되고 있는 새로운 내비게이션의 형태는 자동차에 장착된 카메라로부터 실시간으로 취득되거나 자동차 전면 유리창에 투영되는 실제 영상위에 내비게이션 정보를 그래픽으로 표현하는 증강현실의 모습을 취하고 있다. 차량 내에서의 정보 제공 장치로서 내비게이션 시스템은 그것이 함축화된 그래픽이든 아니면 실사 영상이든 궁극적으로 운전자의 운전부하를 줄이고 빠른 직관력을 제공함으로써 주의분산을 최소화 시킴이 중요하다 할 수 있다. 본 논문에서는 증강현실 내비게이션 시스템인 RACE(Reality-Augmented Car-navigation Environment)를 설계 및 구현하고 그것이 실제적으로 운전자의 운전 수행과 인지 및 주의 분산에 어떠한 영향을 미치는지, 그리고 증강현실 내비게이션이 기존의 2차원 지도 기반 내비게이션에 비해 갖는 효용성이 무엇인지에 대하여 운전자 행동에 기반한 인지심리학적 실험을 통하여 분석한다. 이러한 작업들을 바탕으로 정보처리 관점에서 운전자의 운전 수행과 인지적 수행을 위한 최적의 내비게이션 정보 제공 방법은 무엇인지 고찰해본다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 춘계학술대회
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• pp.872-875
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• 2012

Recently, China officially declared to operate its satellite positioning system, Beidou so called Compass. The system is currently having 10 orbiting satellites which regionally cover from Australia to Russia in the north. Moreover, the system will be planed not only to launch 6 navigation satellites in its orbit in 2012 but also to complete the system with 35 satellites in 2020. The China satellite navigation system can affect to the current circumstance of global satellite navigation world in terms of navigation parameters. In this paper, we investigate characteristics of multi-integrated GNSS involving Beidu-Compass system and discuss general issues involving visibility and GDOP.

• 제어로봇시스템학회논문지
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• 제11권5호
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• pp.429-434
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• 2005

In this paper, the maze navigation system using image recognition for autonomous mobile robot is proposed. The proposed maze navigation system searches the target by image recognition method based on ADALINE neural network. The infrared sensor system must travel all blocks to find target because it can recognize only one block information each time. But the proposed maze navigation system can reduce the number of traveling blocks because of the ability of sensing several blocks at once. Especially, due to the simplicity of the algorithm, the proposed method could be easily implemented to the system which has low capacity processor.

• 한국항행학회논문지
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• 제23권4호
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• pp.289-295
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• 2019

국제항로표지협회에서는 해양 분야에서 활용하는 백업항법시스템의 경우 항만 입출항시 10 m의 수평정확도를 보장하도록 요구하고 있다. 대표적인 해양분야의 백업항법시스템인 eLoran은 10 m 이내의 수평 정확도를 만족함이 증명되었지만, 수신환경에 따라 항법성능이 저하되기도 한다. 특히 수신 안테나 주변의 잡음 및 멀티패스 등으로 인한 요인으로 인해 특정 상황에서는 항법 자체가 불가능해지기도 한다. 본 논문에서는 이러한 환경에서 항만입출항 조건의 수평정확도 요구성능을 만족하기 위하여 UAV(unmanned aerial vehicles)를 활용한 선박의 백업항법시스템을 설계하였다. eLoran 신호 수신에 영향을 주는 주변 환경의 영향을 감소시키기 위하여 UAV에 카메라, IMU센서, eLoran 안테나 및 수신기를 장착하였으며, 선박의 안테나보다 높은 곳에서 카메라를 이용하여 랜드마크를 추적하고 일정 범위 내에서 eLoran 신호 수신과 위치 및 자세를 제어하도록 설계하였다. 선박에서는 UAV로부터 수신한 영상 및 자세 정보와 eLoran 신호를 이용한 선박기반 측위결과를 이용해 항만 입출항 시 수평정확도 요구성능을 만족할 수 있다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.1274-1281
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• 2010

Cut Slope Management System(CSMS) is a systematic maintenance and management system designed to prevent the collapse of cut slopes located along national roads and to minimize damages caused by slope collapse related accidents. In order to implement a maintenance and management system that will ensure safe road operation, the Korean government has started the inventory of cut slopes and developed a cut slope database since 2006. The study on the application of cut slope database is on-going and part of this study is the development of cut slope database management system (Slope-navi) using GIS technology and navigation system for the effective and efficient cut slope management using Information Technology. Using the Navigation Cut Slope Data Management System the previously developed database was checked and verified. The converted cut slope inventory data and field investigation reports of about 20,000 cut slopes were loaded in the navigation map. Through the development of the navigation's cut slope data search system, a systematic and efficient cut slope database management and operation in the prevention of slope collapse and remedial measure selection was established.

• 제어로봇시스템학회논문지
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• 제7권9호
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• pp.774-782
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• 2001

In this paper, we propose a new approach to the autonomous and high-speed indoor navigation of wheeled mobile robots using hybrid system controller. The hierarchical structure of hybrid system presented consists of high-level reasoning process and the low-level motion control process and the environmental interaction. In a discrete event system, the discrete states are defined by the user-defined constraints and the reference motion commands are specified in the abstracted motions. The hybrid control system applied for the nonholonomic mobile robots can combine the motion planning and autonomous navigation with obstacle avoidance in the indoor navigation problem. For the evaluation of the proposed algorithm, the algorithm is implemented to the two-wheel driven mobile robot system. The experimental results show that the hybrid system approach is an effective method for the autonomous navigation in indoor environments.

• 제어로봇시스템학회논문지
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• 제14권11호
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• pp.1189-1195
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• 2008

We introduce a MEMS-based pedestrian dead reckoning (PDR) system. A walking navigation algorithm for pedestrians is presented and map-matching algorithm for the navigation system based on dead reckoning (DR) is proposed. The PDR is equipped on the human body and provides the position information of pedestrians. And this is able to be used in ubiquitous sensor network (USN), U-hearth monitoring system, virtual reality (VR) and etc. The PDR detects a step using a novel technique and simultaneously estimates step length. Also an azimuth of the pedestrian is calculated using a fluxgate which is the one of magnetometers. Map-matching algorithm can be formulated to integrate the positioning data with the digital road network data. Map-matching algorithm not only enables the physical location to be identified from navigation system but also improves the positioning accuracy. However most of map-matching algorithms which are developed previously are for the car navigation system (CNS). Therefore they are not appropriate to implement to pedestrian navigation system based on DR system. In this paper, we propose walking navigation system and map-matching algorithm for PDR.