• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.4
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• pp.418-424
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• 2005

For the safety and cost reduction of the navigation in the sea, we need automatic and intelligent system for the ship. For the ship automation, we need a route planning based on GPS and the nautical chart. In this paper, we propose a route planning technique using point of contact of the obstacle and treecreation technique. The efficiency of the proposed technique is proved by comparing with A* search technique that is the most famous search technique for route planning from the optimal point of view.

• ETRI Journal
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• v.28 no.2
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• pp.131-144
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• 2006

This work demonstrates a dead-reckoning (DR) scheme for a low-cost land navigation system and a DR/GPS system design using the sigma point Kalman filter (SPKF). T hrough an observability analysis and some simulations, it is shown that the performances of a stand-alone DR system and DR/GPS system can be improved by employing the proposed DR scheme and SPKF. By using the designed DR scheme and filter, the stand-alone DR system does not have any undetectable errors occurring on the curve trajectory. And the DR/GPS system can provide a stable and seamless navigational solution even in the case where the initial heading estimation error is large, such as 160 degrees, or when the GPS signal is unavailable due to tunnels, buildings, and so on. Simulation results indicate a satisfactory performance of the proposed system.

• Journal of Positioning, Navigation, and Timing
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• v.11 no.4
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• pp.269-277
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• 2022

In this paper, we overview the system development status of the national maritime precise point positioning-real-time kinematic (PPP-RTK) service in Korea, also known as the Precise POsitioning and INTegrity monitoring (POINT) system. The development of the POINT service began in 2020, and the open service is scheduled to start in 2025. The architecture of the POINT system is composed of three provider-side facilities-a reference station, monitoring station, and central control station-and one user-side receiver platform. Here, we propose the detailed functionality of each component considering unidirectional broadcasting of augmentation data. To meet the centimeter-level user positioning accuracy in maritime coverage, new reference stations were installed. Each reference station operates with a dual receiver and dual antenna to reduce the risk of malfunctioning, which can deteriorate the availability of the POINT service. The initial experimental results of a testbed from corrections generated from the testbed network, including newly installed reference stations, are presented. The results show that the horizontal and vertical accuracies satisfy 2.63 cm and 5.77 cm, respectively. For the purpose of (near) real-time broadcasting of POINT correction data, we designed a correction message format including satellite orbit, satellite clock, satellite signal bias, ionospheric delay, tropospheric delay, and coordinate transformation parameters. The (near) real-time experimental setup utilizing (near) real-time processing of testbed network data and the designed message format are proposed for future testing and verification of the system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.31-36
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• 2006

The evaluation of safety of simulated maneuvers is frequently analysed by so called goal line or point of interest. This paper is to suggest that regarding the results of simulation the goal analysis and in length analysis are investigated respectively and the availability of which is effective and is also to suggest closest distance to channel boundary at each ship's position, not centerline, as one of proximity measures.

• ETRI Journal
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• v.45 no.5
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• pp.836-846
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• 2023

Mobile robots are used in modern life; however, object recognition is still insufficient to realize robot navigation in crowded environments. Mobile robots must rapidly and accurately recognize the movements and shapes of pedestrians to navigate safely in pedestrian-rich spaces. This study proposes real-time, accurate, three-dimensional (3D) multi-pedestrian detection and tracking using a 3D light detection and ranging (LiDAR) point cloud in crowded environments. The pedestrian detection quickly segments a sparse 3D point cloud into individual pedestrians using a lightweight convolutional autoencoder and connected-component algorithm. The multi-pedestrian tracking identifies the same pedestrians considering motion and appearance cues in continuing frames. In addition, it estimates pedestrians' dynamic movements with various patterns by adaptively mixing heterogeneous motion models. We evaluate the computational speed and accuracy of each module using the KITTI dataset. We demonstrate that our integrated system, which rapidly and accurately recognizes pedestrian movement and appearance using a sparse 3D LiDAR, is applicable for robot navigation in crowded spaces.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.31-36
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• 2006

In this paper data of index is acquired by some experts. Then the ambipolar models of Fussy Synthesis Evaluation theory is adopted in this paper which helps to the synthesis analysis of the Aids to Navigation in DaLian port area. At the same time, in accordance with the suggestion of the experts and the real condition, the idiographic implement way is mentioned in the point of view of Quality. The two points of view make the scheme more scientific and feasible. After achieving the status, the project scheme of synthetical alteration to Aids to Navigation in DaLian port area is put forward. It arranges the improved ideas from the different point of view of content, efficiency expectation of Aids to Navigation which gives the reference of the alteration and development of the Aid to Navigation which gives the reference of the alteration and development of the Aids to Navigation in DaLian port area for the future.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.3
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• pp.302-308
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• 2014

In this paper, a detailed investigation of the random vibration test is presented for strapdown inertial navigation systems (INS). The effect of the random vibration test has been studied from the point of view of navigation performance. The role of distribution functions and RMS value is represented to determine a feasible method to reject or reduce vibration related error in position and velocity estimation in inertial navigation. According to a survey conducted by the authors, this is the first time that the effect of the distribution function in vibration related error has been investigated in random vibration testing of INS. Recorded data of navigation grade INS is used in offline static navigation to examine the effect of different characteristics of random vibration tests on navigation error.

• International Journal of Internet, Broadcasting and Communication
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• v.8 no.1
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• pp.27-32
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• 2016

The global positioning system (GPS)-enabled mobile phones provide location-based applications such as car and pedestrian navigation services. The pedestrian navigation services provide safe and comfortable route and path guidance for pedestrians and handicapped or elderly people. One of the essential components for a navigation system is a spatial database used to perform navigation and routing functions. In this paper, we develop modeling and categorization of pedestrian path components for smart tour guide services using the mobile pedestrian navigation application. We create pedestrian networks using 2D base map and sky view map in urban area. We also construct pedestrian networks and attributes of node, link, and POI using on-site GPS data and photos for smart pedestrian tour guide in the major walking tourist spots in Jeju.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.6
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• pp.596-601
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• 2011

Autonomous navigating algorithms for mobile robots have been proved to be a difficult task. Based on the excellent homing performance shown by many insects, bio-inspired navigation algorithms for robotic experiments have been widely researched and applied to the design of navigational strategies for mobile robots. In this paper, among them, we analyze two simple landmark navigation methods their strengths and limits. We investigate the effect of the occlusion problem mainly, which is an important yet tough problem in many landmark navigation algorithms. In the point of view of the error of homing vector and the performance of the homing paths in the environment with artificial occlusions, we investigate the effect of occlusion problem in both methods in order to further study on solutions.

• Journal of Positioning, Navigation, and Timing
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• v.5 no.1
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• pp.37-45
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• 2016

In this paper, design and implementation issues for a network-oriented RF emitter localization system with array antenna are discussed. For hardware, the problem of array mismatch and RF/IF channel mismatch are introduced and the calibration schemes for solving those problems are also provided. For software, it is explained how to overcome the drawback of conventional MUltiple Signal Identification and Classification (MUSIC) algorithm in a point of identifying the number of received signals and problems such as Data Association Problem and Ghost Node Problem in regard to multiple emitter localization are presented with some approaches for getting around those problems. Finally, for implementation, a criterion for arranging each of sensors and a requirement for alignment of array antenna' orientation are also given.