• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.668-671
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• 1996

Two expressions for the inertial navigation system error equations are derived using a perturbation method; one in navigation frame, and the other in geographic frame. The equivalence between two expressions is shown by explicit equations and computer simulation.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.6
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• pp.755-760
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• 2011

This paper presents a method for improving the positioning accuracy of the laser navigation. As a wireless navigation system, the laser navigation which is more flexible than a wired guidance system is used for the localization and control of an AGV(automatic guided vehicle). However, the laser navigation causes the large positioning error while the AGV turns or moves fast. To solve the problem, we propose the method for improving the positioning accuracy of the laser navigation using particle filter which has robust and reliable performance in non-linear/non-gaussian systems. For the experiment, we use the actual fork-type AGV. The AGV has a gyro, two encoders and a laser navigation. To verify the performance, the proposed method is compared with the laser navigation which is a product. In the experimental result, we verified that the proposed method could improve the positioning accuracy by approximately 66.5%.

• Journal of Positioning, Navigation, and Timing
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• v.6 no.3
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• pp.117-123
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• 2017

In this paper, we propose a performance index that can compare the position estimation performance according to the time slot allocation order, which is superior in the position estimation performance in the operation of the Link-16 based relative navigation system. In order to verify the validity of the performance index, a software-based Link-16 relative navigation system performance analysis platform composed of a signal generator, a signal reception and navigation algorithm execution unit, and a performance analysis unit was designed. Using the designed software platform, we analyzed the relationship between proposed performance index and position estimation performance according to time slot allocation order in the same position reference (PR) arrangement. The performance index of the proposed time slot allocation is expected to be utilized not only for the Link-16 system, but also for the Time Division Multiple Access (TDMA)-based navigation system.

• Journal of Positioning, Navigation, and Timing
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• v.5 no.2
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• pp.97-107
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• 2016

Military Autonomous Underwater Vehicle (AUV) is utilized to search a mine under the sea. This paper presents design and performance verification of real-time hybrid navigation system for AUV. The navigation system uses Doppler Velocity Log (DVL) integration method to correct INS error in underwater. When the AUV is floated on the water, the accumulated error of navigation algorithm is corrected using position/velocity of GPS. The navigation algorithm is verified using 6 Degree Of Freedom (DOF) simulation, Program In the Loop Simulation (PILS). Finally, the experiments are performed in real sea environment to prove the reliability of real-time hybrid navigation algorithm.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.3
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• pp.479-484
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• 2012

Geometric effect of landmarks to the navigation error is investigated in the two-dimensional line-of-sight measurement based vision navigation system. DOP is derived between line-of-sight measurement error and navigation solution error. For cases of three landmarks in an area, variations of the DOP were observed through computer simulations. Vision navigation system experiments were performed for the cases. Simulation and experimental results show that navigation solution errors have similar trend to DOP values of the simulation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.11a
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• pp.346-347
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• 2018

This study is a case study on ship zone identification for the generalization of fire safety module in Korean e-Navigation system and assessed the method of dividing the area of the ship based on the location of the fire detector of the target ship.

• Journal of Positioning, Navigation, and Timing
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• v.11 no.2
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• pp.59-70
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• 2022

In this paper, a GPS/GF-INS integrated navigation system is proposed, in which the high rate attitude aiding signal, the high rate position and velocity aiding of GPS receiver is used for the cube structure of the GF-IMU, effectiveness of the proposed GPS/GF-INS integrated navigation system was shown when the vehicle follows two trajectories, circling and spiraling. Performance evaluation results show that the proposed GPS/GF-INS integrated navigation method gives better navigation outputs when the attitude output of GPS is used and more better navigation outputs are obtained when the rate of GPS aiding signal is higher.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.4
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• pp.409-421
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• 2023

In order to develop navigation systems, simulators that provide navigation sensors data are required. A trajectory generator that simulates vehicle motion is needed to generate navigation sensors data in the simulator. In this paper, a trajectory generator for evaluating navigation system performance is proposed. The proposed trajectory generator consists of two parts. The first part obtains parameters from the motion scenario file whereas the second part generates position, velocity, and attitude from the parameters. In the proposed trajectory generator six degrees of freedom, halt, climb, turn, accel turn, spiral, combined, and waypoint motions are given as basic motions with parameters. These motions can be combined to generate complex trajectories of the vehicle. Maximum acceleration and jerk for linear motion and maximum angular acceleration and velocity for rotational motion are considered to generate trajectories. In order to show the usefulness of the proposed trajectory generator, trajectories were generated from motion scenario files and the results were observed. The results show that the proposed trajectory generator can accurately simulate complex vehicle motions that can be used to evaluate navigation system performance.

• Current Industrial and Technological Trends in Aerospace
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• v.5 no.1
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• pp.65-74
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• 2007

현재 운용중인 전 세계적인 위성항법시스템(GNSS : Global Navigation Satellite System)은 미국의 GPS(Global Positioning System)와 러시아의 GLONASS(Global Navigation Satellite System)가 있다. 전 세계적으로 주로 사용되는 시스템은 GPS이며, GLONASS는 러시아의 경제사정 악화로 인하여 지속적인 위성발사가 이루어지지 못하고 있다. 추가적으로 추진되고 있는 위성항법시스템은 유럽의 갈릴레오(Galileo), 중국의 북두(Beidou), 일본의 JRANS(Japanese Regional Advanced Navigation System) 그리고 2006년 5월에 구축 프로젝트가 승인된 인도의 IRNSS(Indian Regional Navigation Satellite System)가 있다. 보강시스템의 경우, 미국 FAA(Federal Aviation Administration)는 광역오차보정시스템(WAAS)을 Raytheon사와 개발하였으며, 현재 착륙용 근거리오차보정시스템(LAAS)을 Raytheon사 및 Honeywell사와 함께 정부/산업체 공동개발 사업(GIP; Government Industry Partnership)으로 진행 중에 있다. 유럽은 EGNOS(European Geostationary Navigation Overlay Service)를 사용하고 있으며, 일본의 MSAT(MTSAT Satellite Based Augmentation System)와 인도의 GAGAN(GPS and GEO Augmented Navigation)은 추진 중이다. 이 글에서는 위성항법시스템과 위성항법 보강시스템의 현황을 살펴본다.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.1
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• pp.1-10
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• 2015

In urban area, since multipath and signal attenuations frequently occur due to street trees, street lights and buildings, it is difficult to obtain accurate navigation solution using GPS. As these problems also impact negatively on the INS/GPS coupled system, implementing advanced transportation systems such as autonomous navigation system and Intelligent Transportation System (ITS) become quite hard. For this reason, to alleviate deterioration of navigation system performance in urban area, direction information extraction algorithm using vision system is proposed in this paper. 2D Finite Rate of Innovation (FRI) technique is applied to extract lane edges. The proposed technique is simulated using road images and feasibility of proposed technique is analyzed through the simulation results.