• Journal of Institute of Control, Robotics and Systems
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• v.20 no.11
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• pp.1136-1141
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• 2014

This paper proposes a new contact type ball tracking sensor to improve the control performance of a low cost ball-and-beam system. It is well-known that the impulsive measurement noise contained in ball position measurement is one of the factors which severely degrades the ball-and-beam control performance. The impulsive ball position measurement noises often appear under the sporadical ball floating on the beam. This fact motivates us to devise a simple analog preprocessing circuit to determine whether the ball loses the contact or not. Once the abnormal ball position measurement is detected, the design problem of the ball tracking sensor can be cast into the typical state estimation problem with missing data. In order to tackle the real-time implementation issue, a steady-state Kalman filter is applied to the problem. Through the experimental results, the usefulness of the proposed scheme is demonstrated.

• Information and Communications Magazine
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• v.10 no.11
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• pp.74-84
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• 1993

Hyundai Electronics Industries Corp has developed a navigation system which automatically computes the current position and displays it on the map using GPS(Global Positioning System). This system has such features as follow : searching of destination by means of digital mapping, locating of the present position on the map and detecting of guidance timing through signals from the artificial satellites and vehicle's sensors, and having a few of functions as TV & VTR monitoring, tracing the route, displaying service information which include hotels, restaurants, entertainments, et al. This paper describes the operations and construction of this navigation system.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.1
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• pp.51-58
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• 2023

Geofencing supports unmanned aerial vehicle (UAV) operation by defining stay-in and stay-out regions. National Aeronautics and Space Administration (NASA) has developed a prototype of the geofencing function, SAFEGUARD, which prevents stayout region violation by utilizing position estimates. Thus, SAFEGUARD depends on navigation system performance, and the safety risk associated with the navigation system uncertainty should be considered. This study presents a methodology to compute the safety risk assessment-based along-track position error bound under nominal and Global Navigation Satellite Systems (GNSS) failure conditions. A Kalman filter system using pseudorange measurements as well as pseudorange rate measurements is considered for determining the position uncertainty induced by velocity uncertainty. The worst case pseudorange and pseudorange rate fault-based position error bound under the GNSS failure condition are derived by applying a Receiver Autonomous Integrity Monitor (RAIM). Position error bound simulations are also conducted for different GNSS fault hypotheses and constellation conditions with a GNSS/INS integrated navigation system. The results show that the proposed along-track position error bounds depend on satellite geometries caused by UAV attitude change and are reduced to about 40% of those of the single constellation case when using the dual constellation.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.1
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• pp.16-25
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• 1997

This paper shows the development of the high accuracy vehicle positioning algorithm using the differential technique in vehicle tracking systems form the existing vehicle position which is acquired from the global positioning system (GPS). The control center receives the satellite ephemerise data and pseudorange correction from the reference station, and vehicle position from the moving vehicle. The pseudorange is calculated with the satellite position and the vehicle position, and corrected by pseudorange correction. Using this corrected pseudorange and kalman filter, more improved vehicle positioning data were obtained.

• Journal of Advanced Navigation Technology
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• v.21 no.4
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• pp.325-331
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• 2017

As a GPS stability problem arises, MLAT system is spotlighted as an alternative technology of ADS-B. MLAT system has a high position accuracy as much as ADS-B. Also, MLAT receives the mode A,C,S, and 1090ES(ADS-B) signals from the mounted aircraft transponder. MLAT receives signals from several receiver units and calculates aircraft positions. MLAT has ADS-B level positioning accurarcy using GPS and can calculate the position information with objects independently. According to global environment changes, Local area multiltilateration(LAM) surveillance system is under development for moving vehicles and aircraft detection in airport. These are still under testing in Tae-an Airfield. In the paper, we analyzed the performance by comparing the calculated position data from MLAT to RTK. In order to confirm the position accuracy of MLAT and the deviation of position data between fixed target and moving target on the ground during the field test in Tae-an Airfield.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.2
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• pp.178-182
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• 2005

The proposed system in this paper is designed to provide users with a means of global location information using Orbcomm satellite communication and X.400 protocol. The system's two-way data transmission capabilities allow users to track mobile or fixed objects anywhere in the world via Internet. This study utilizes the X.400 protocol, and the SIP(Serial Interface Protocol) and self defined control protocol to implement data communication link in this paper. Data processor board connected to SC(Subscriber Communicator) is also designed and implemented to interface with GPS receiver. The experimental results of the proposed global position location system is evaluated through real-time experiments, and we have confirmed it works well according to the protocol designed in this paper.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.443-447
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• 1996

The meeds of vehicle navigation system are increassing and the accurate determination of position is still of promary improtance. GPS (Global Positioning System)receiver and low cost dead reckoning sensors have been used for vehicle position location. The integartion of these can improve the system performance to cope with accumulating errors and multipath problem in urban area. However, the implementation of integrated system of two sensors is net easy, for their real data ave noises that are not apt to be modeled. This paper discusses how to combine a GPS receiver and dead reckoning sensors. The characteriatics of sensors and their data are investigated, and the system for field test is manufactured. The test results of a selected typical route are presented.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.123-127
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• 2004

Nowadays it is necessary to manage the road system effectively because of the explosive increment of vehicles and goods. To resolve this problems through the fast upgrade of information about position and time of moving vehicles, the combined navigation system using GPS(Global Positioning System) and complementary navigation system, i.e. INS(Inertial Navigation System), DR(Dead Rocking), etc. has been used. Although GPS is popular for the vehicles in the urban canyon because of its few satellites. In this paper, position tracking algorithm is presented, which reduces vehicle position error dramatically by fusing GPS and INS sensors. And the validity of our algorithm is demonstrated by the experimental results with the real car.

• Journal of the Korean Institute of Navigation
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• v.24 no.4
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• pp.219-226
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• 2000

Ship's position data obtaining method is one of the very important factor in navigation. Nowadays, GPS(Global Positioning System) using the earth orbiting satellites are equipped and operated for the position finding. Because it provides more precise position information than other equipments and is very convenient for navigator. In this study, it is designed to develop the GPS simulator for everybody being able to practise the GPS operating skill like as navigation planning, navigation calculating etc. And also, it can be operated with personal computer without real GPS receiver. This simulation system is based on the real GPS receiver and built by the visual basic 5.0 program. And it displays the ship's position and navigating information and plots the ship's moving track on the screen in real time according as initial setup data-main engine's rpm, rudder angle, departure position and waypoint.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.45-49
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• 2004

The Navstar Global Positioning System(GPS) is an advanced navigation satelite system for determination of position, velocity and time. It can provide three-dimensional positioning on a global basis, independent of weather, 24 hours per day. Test results show that the carrier phase and pseudorange corrections are suitable for a kinematic GPS system. Using these corrections are more effective than using raw GPS data, since fewer bits are required for transmission Additionally, the number of computation required at the rover is reduced when corrections, rather than raw measurement are transmitted