• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.34 no.8
• /
• pp.63-70
• /
• 2006

Due to the small size and weight of micro aerial vehicle (MAV), only miniaturized MEMS type sensors are applicable for MAV autonomous flight system. In this paper, we propose a accelerometer and gyro mixing algorithm to improve an attitude performance of MEMS type sensors. The performance of the proposed mixing algorithm is compared with the performance of fuzzy-based mixing algorithm through simulation. The simulation results show that the attitude compensation method through the attitude compensation has better performance than the fuzzy-based mixing method for MAV attitude estimation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.16 no.2
• /
• pp.235-242
• /
• 1998

This study aims to detect and to reduce the multipath errors which are main errors source in high precious surveying such as GPS-aided aerial triangulation and Car Navigation. which reference receivers being fixed, when kinematic receivers move continuously, multipath is performed using smoothed code measurement and pure code measurement in the network. Through this methods, 3D RMS errors are reduced into about 30% in the single differential code solution to the kinematic receiver. This is based on the fact that the network adjustment are performed at multiple reference receivers, but positioning is carried out by the single differential methods between a reference receiver and a kinematic receiver. So it was supposed that this methods reduced the correlation errors including the atmospheric errors using the nearest receivers and can be mixed with another methods.

• Journal of Korean Society for Geospatial Information Science
• /
• v.18 no.4
• /
• pp.101-107
• /
• 2010

The aim of this paper is to come up with a methodology of constructing an efficient model for multiple representations which can manage and reconcile real-time data about large-scale roads in Vector Domain. In other words, we suggested framework based on a bottom-up approach, which is allowed to integrate data from the network of the lowest level sequentially and perform automated matching in order to produce variable-scale map. Finally, we applied designed multi-LoD model to in-vehicle application.

• Current Industrial and Technological Trends in Aerospace
• /
• v.8 no.1
• /
• pp.131-139
• /
• 2010

Avionics technologies have been developed with a development of an airplane since 1903. Historically, radio communication was started in 1910's, radio navigations in 1920's and autopilot was applied first in 1930's. Glass cockpit was initiate on MD-80 in 1979 first and now spreaded widely and similar with GPS navigation. Avionics in modern aircraft has a great deal of importance in view of flight safety and maintaining comfortableness. As avionics develops, so do the certification technologies. This paper introduces update avionics certification technologies developed recently.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2009.11a
• /
• pp.21-22
• /
• 2009

유비쿼터스 사회(Ubiquitous Society)로의 진입에 발맞추어 USN(Ubiquitous Sensor Network) 기반의 인간 중심적 편의 시스템에 관한 연구가 활발하게 진행되고 있다. 그 중 대형 시장을 갖는 차량 편의시설에 관한 연구는 지능형 차량 시스템(Intelligent Car System)을 중심으로 활발히 이루어지고 있다. 지능형 차량 시스템의 주요 연구는 자동 항법 장치, 사고 예방 장치, 자가 진단 시스템 등 탑승자의 편의성과 안전성을 중심으로 진행되었다. 그러나 탑승자의 사고 발생 시 응급 상황 처리를 위한 지원 시스템은 미미하다. 탑승자 부상으로 사고 신고를 하지 못할 경우, 사고지점 확인, 탑승자의 위급(현재) 상황, 부상 정보와 같은 정보를 얻을 수 없어 응급 상황 대처에 신속하지 못할 수 있다. 따라서 본 논문은 다양한 센서를 이용하여 차량의 정보를 수집하고, 사고 판단 시 차량 위치 정보, 탑승자 상황 정보를 응급 기관에 전달할 수 있는 차량용 스마트 안전장치를 설계 및 구현하였다. 테스트를 위해 Intel PXA255 MCU와 AM-3AXIS(3축 가속 센서), MDSM-1000A(지자기 센서), RX-M800S CDMA, GPS520, Alpha cam, Flex Sensor로 시스템을 제작하였으며 모의 도로 모형에서 테스트 하였다.

• Journal of Korea Game Society
• /
• v.10 no.6
• /
• pp.157-168
• /
• 2010

A terrain is an essential element for constructing a virtual world in which game characters and objects make various interactions with one another. Creating a terrain requires a great deal of time and repetitive editing processes. This paper presents a 3D terrain reconstruction system to create 3D terrain in virtual space based on real terrain data. In this system, it converts the coordinate system of the height maps which are generated from a stereo camera and a laser scanner from global GPS into 3D world using the x and z axis vectors of the global GPS coordinate system. It calculates the movement vectors and the rotation matrices frame by frame. Terrain meshes are dynamically generated and rendered in the virtual areas which are represented in an undirected graph. The rendering meshes are exactly created and updated by correcting terrain data errors. In our experiments, the FPS of the system was regularly checked until the terrain was reconstructed by our system, and the visualization quality of the terrain was reviewed. As a result, our system shows that it has 3 times higher FPS than other terrain management systems with Quadtree for small area, improves 40% than others for large area. The visualization of terrain data maintains the same shape as the contour of real terrain. This system could be used for the terrain system of realtime 3D games to generate terrain on real time, and for the terrain design work of CG Movies.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.26 no.3
• /
• pp.263-273
• /
• 2008

The precision of sensors' position is particularly important in the application of road extraction or digital map generation. In general, the various ranging solution systems such as GPS, Total Station, and Laser Ranger have been employed for the position of the sensor. Basically, the ranging solution system has problems that the signal may be blocked or degraded by various environmental circumstances and has low temporal resolution. To overcome those limitations a IMU/range integrated system could be introduced. In this paper, after pointing out the limitation of extended Kalman filter which has been used for workhorse in navigation and geodetic community, the two sampling based nonlinear filters which are sigma point Kalman filter using nonlinear transformation and carefully chosen sigma points and particle filter using the non-gaussian assumption are implemented and compared with extended Kalman filter in a simulation test. For the ranging solution system, the GPS and Total station was selected and the three levels of IMUs(IMU400C, HG1700, LN100) are chosen for the simulation. For all ranging solution system and IMUs the sampling based nonlinear filter yield improved position result and it is more noticeable that the superiority of nonlinear filter in low temporal resolution such as 5 sec. Therefore, it is recommended to apply non-linear filter to determine the sensor's position with low degree position sensors.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.11
• /
• pp.139-147
• /
• 2016

This study described the design scheme for each step of the production test for the Fire Control System(FCS) of the K-55A1 PIP business of Hanwha Thales since 2011. From the time of receipt of the product It is necessary to improve the FCS's reliability by using the Unit Test, burn-In test, System Test. FCS of K-55A1 acts as a 'head' that control the self-propelled howitzer, and connected with the electrical and physical connection of self-propelled howitzer's multiple unit (Inertial navigation systems(IN), Muzzle Velocity Radar (MVR)) for the normal operation without an inch of error in operating. We designed the production testing equipment automatically as much as possible and designed with the environment similar to the self-propelled howitzer. by using this production testing equipment, It should help for the strengthen national defense of the Republic of Korea.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.45 no.6
• /
• pp.149-156
• /
• 2008

SLAM(Simultaneous Localization and Mapping) system is to find a global position and build a map with sensing data when an unmanned-robot navigates an unknown environment. Two kinds of system were developed. One is used distance measurement sensors such as an ultra sonic and a laser sensor. The other is used stereo vision system. The distance measurement SLAM with sensors has low computing time and low cost, but precision of system can be somewhat worse by measurement error or non-linearity of the sensor In contrast, stereo vision system can accurately measure the 3D space area, but it needs high-end system for complex calculation and it is an expensive tool. In this paper, we implement the SLAM system using a single camera image and a PSD sensors. It detects obstacles from the front PSD sensor and then perceive size and feature of the obstacles by image processing. The probability SLAM was implemented using the data of sensor and image and we verify the performance of the system by real experiment.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.36 no.1
• /
• pp.39-47
• /
• 2008

Automatic landing performance of UAV can be enhanced by adding Pseudolite(PL) to GPS. However, it is very hard to install and operate PL with confidence because GPS satellites are moving and the landing zone are usually changeable. The coverage and accuracy of combined GPS and PL can be estimated by using simulator and the correct information is very crucial to UAV operation. In this paper, design, implementation and evaluation of GPS/PL simulator for UAV landing are given. A very realistic coverage estimation is obtained using GIS data and ray launching method with considerations of the transmitter power level, altitude of UAV, number and location of PL. The expected accuracy is estimated using DOP and NSP computed using both GPS and PL. The performance of simulator is evaluated by comparing with the results of a real GPS receiver, and the certified simulator shows the required accuracy for UAV landing can be easily met by proper installation of at least 2 PLs.