• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.6
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• pp.492-501
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• 2016

Three-Loop autopilot is generally used for the acceleration control of guided missiles. Because the acceleration command to the three-loop autopilot is given as values at the center of gravity, feedback information of IMU should be obtained at the same position. However, the position of IMU might not be located at the center of gravity due to the sub-system assignment. This paper presents the stability analysis of three-loop autopilot with respect to the arbitrary position of IMU and variation rate of center of gravity. Gain and phase margins are calculated for several trim points for general anti-tank missiles.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.2
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• pp.163-171
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• 2014

Based on the GPS/IMU integration, the car navigation has unstable conditions as well as drastically reduces accuracies in urban region. Nowadays, many cars mounted the camera to record driving states. If the ground coordinates of street furniture are known, the position and attitude of camera can be determined through SPR(Single Photo Resection). Therefore, an estimated position and attitude from SPR can be applied measurements in Kalman filter for updating errors of navigation solutions from GPS/IMU integration. In this study, the GPS/IMU/SPR integration algorithm was developed in loosely coupled modes through extended Kalman filters. Also, in order to analyze performances of GPS/IMU/SPR, simulation tests were conducted in GPS signal reception environments and the GCPs (Ground Control Points) distributions. In fact, the position and attitude gathered from GPS/IMU/SPR integration are more precise than the position and attitude from GPS/IMU integration. When IPs (image points), corresponded to GCPs, were concentrated in the center of image, the position error in the optical axis respectively increased. To understand effects from SPR, we plan to carry additional test on the magnitude of GCP, IP and initial exterior orientation errors.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.18-20
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• 2021

In order to prevent collision accidents of ships, which has been increasing recently, research on artificial intelligence-based autonomously operated ships (Maritime Autonomous Surface Ship, MASS) is underway. However, most of the studies related to autonomous ships mainly target medium-to-large ships due to the size and cost of the autonomous navigation system, and the sensors used here have a problem in that it is difficult to mount them on small ships. Therefore, this paper provides a path tracking system equipped with GPS and IMU sensors for autonomous operation of small ships. GPS and IMU sensors are utilized to determine the exact position of the vessel, which allows the proposed system to manually control the small vessel model to create a path and then when the small vessel travels the same path. Use the Pure Pursuit algorithm to follow the path. As a result, In this research, it is expected that a lightweight and low-cost sensor can be used to develop an autonomous operation system for small ships at low cost.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.3 s.21
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• pp.89-97
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• 2002

We have developed the 45-Van system in order to maximize the interoperability of spatial data in 45(GNSS, SIIS, GIS, ITS) by sharing and providing spatial data of remote site. The 4S-Van system enables to acquisition and production of information for GIS database and the accurate position information by combining and connecting GPS/IMU, laser, CCD(charged-coupled device) image, and wireless telecommunication technology. That is, 4S-Van system measures its position and attitude using integrated GPS/IMU and takes two photographs of the front scene by two CCD cameras, analyzes position of objects by space intersection method, and constructs database that has compatibility with existing vector database system. Furthermore, infrared camera and wireless communication technique can be applied to the 4S-Van for a variety of applications. In this paper, we discuss the design and functions of 4S-Van that is equipped with GPS, CCD camera, and IMU.

• Journal of Digital Convergence
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• v.11 no.4
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• pp.243-249
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• 2013

In this paper, GPS(Global Positioning System) that can be used outdoors and GPS(Global Positioning System) is not available for indoor Wi-Fi(Wireless Fidelity) using the Android-based location information system has been designed and implemented. Pedestrians in a room in order to estimate the location of the pedestrian's position, regardless of need to obtain the absolute position and relative position, depending on the movement of pedestrians in a row it is necessary to estimate. In order to estimate the initial position of the pedestrian Wi-Fi Fingerprinting was used. Most existing Wi-Fi Fingerprinting position error small WKNN(Weighted K Nearest Neighbor) algorithm shortcoming EWKNN (Enhanced Weighted K Nearest Neighbor) using the algorithm raised the accuracy of the position. And in order to estimate the relative position of the pedestrian, the smart phone is mounted on the IMUInertial Measurement Unit) because the use did not require additional equipment.

• Journal of Korea Spatial Information System Society
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• v.6 no.1 s.11
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• pp.51-58
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• 2004

Mobile Mapping System is an effective wav to obtain position and image using vehicle equipped with GPS(Global Positioning System), IMU(Inertial Measurement Unit), and CCD camera. It have been used various fields of load facility management, map upgrade and etc. It is difficult to upgrade Mobile Mopping System which is developed from abroad and add other sensors because we don't know the way to integrate and synchronize multi-sensors. In this paper, we present the effective way of the integration and synchronization method for multi sensors we designed and manufactured Synchronization equipment by considering sensors of laser, odometer and etc.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.5
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• pp.385-392
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• 2018

This paper suggests a new method to estimate the roll and pitch damping moment coefficients of a flying disc through sensor data from the onboard IMU module. This method can be easily performed than wind tunnel or computational fluid dynamics methods because it estimates aerodynamic coefficients simply after accumulating the inertial data through several repeated flight experiments. Estimated coefficients are applied to a simulator which is based on the flight dynamics of a flying disc. Finally, the predicted flight trajectory is compared with the true position provided by GPS, which demonstrated the validity of the proposed estimation method.

• Journal of IKEEE
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• v.23 no.3
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• pp.844-851
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• 2019

As wearable technology is becoming more common and a part of our lives, there have been many efforts to offer various smart services with wearable devices, such as motion recognition, safety of driving, and so on. In this paper, we present a method that exploits the 9-axis inertial sensors embedded in a smartwatch to identify whether the user is a vehicle driver or not and to estimate the steering wheel turning direction in the vehicle. The system consists of three components: (i) position recognition, (ii) driver recognition, and (iii) steering-wheel turning detection components. We have developed a prototype system for detecting user's motion with Arduino boards and IMU sensors. Our experiments show high accuracy in recognizing the driver and in estimating the wheel rotation angle. The average experimental error was $11.77^{\circ}$ which is small enough to perceiver the turning direction of steering-wheel.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.18 no.4
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• pp.405-414
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• 2000

A new generation of commercial satellites like IKONOS, SPOT-5 and OrbView-3,4 will have improved features, especially an higher geometric resolution with a better dynamic radiometric range. In addition high precision orbital position and attitude data will be provided by the on-board GPS receivers, IMU(Inertial Measurement Units) and star trackers. This additional information allows for reducing the number of ground control points. Furthermore this information enables direct georeferencing of imagery without ground control points. In our work mathematical models for calculating the satellite orbital parameters of SPOT-3 and KOMPSAT-1 were developed and can be easily extended to process images from other high resolution imaging systems as they become available.

• 한국공간정보시스템학회:학술대회논문집
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• 2007.06a
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• pp.318-323
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• 2007

모바일매핑시스템은 차량에 CCD카메라, GPS IMU등의 장비를 탑재하고 도로 및 주변지역의 영상을 획득하여 지도제작 및 도로 도로시설물의 유지관리를 위한 시스템이다. 그러나 모바일매핑시스템의 자료는 자료의 양이 방대하여 지도제작 및 시설물 관리에 사용되기 위해서는 일차적인 가공이나 편집이 필요하다. 모바일매핑시스템은 대상물의 위치 및 영상정보를 획득할 수 있는 효율적인 시스템으로 도로 시설물의 유지 관리, 수치지도의 갱신 등 여러 분야에서 활용되고 있다. 이러한 모바일매핑시스템은 CCD 카메라 영상과 차량의 위치 및 자세정보를 제공하게 되고 이는 영상안의 객체에 대한 위치정보를 제공하는데 중요한 역할을 한다. 그러므로 본 연구에서는 모바일매핑시스템을 이용하여 영상내부에 나타난 거리표의 3차원 위치를 결정하고자 한다. 또 도로관리통합시스템의 핵심 키가 되는 거리표의 3차원 정보를 자동으로 추출함으로써 모바일매핑시스템의 방대한 정보를 효율적으로 처리하기 위한 방법을 알아볼 것이다.