• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.6
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• pp.726-732
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• 2013

It is required for UGV(Unmanned Ground Vehicle) to have a LPP(Local Path Plan) component which generate a local path via the center of road by analyzing binary map to travel autonomously unpaved road in rough environment. In this paper, we present the method of boundary estimation for unpaved road and a local path planning method based on RANGER algorithm using the estimated boundary. In specially, the paper presents an approach to estimate road boundary and the selection method of candidate path to minimize the problem of zigzag driving based on Bayesian probability reasoning. Field test is conducted with scenarios in rough environment in which bush, tree and unpaved road are included and the performance of proposed method is validated.

• Journal of Aerospace System Engineering
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• v.3 no.4
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• pp.35-40
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• 2009

The first purpose of this study is to develop a GCS(Ground Control System) by using RF(Radio Frequency) wireless communication equipments for UAV(Unmanned Aerial Vehicle). The second goal is to develop an antenna tracking system operating automatically. UAV receives flight data from a RF wireless system. So the role of antenna tracking system is very important to keep good communication state between UAV and GCS. GCS can check flight data and display a aviation state of UAV in real-time. The flight data displayed in real-time by GCS include the latitude, longitude, altitude, speed and so on. Experiments that measure a communication range and reliability are needed to develop a RF wireless communication system.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.1
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• pp.39-48
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• 2022

In this paper, we propose an anomaly detection system (ADS) to detect anomalies of the in-vehicle network for unmanned aerial vehicle (UAV). The proposed ADS detects the anomalies by measuring the similarity of status messages sequences periodically sent by the UAV to the ground control system. We defined three types of malicious message injection attacks that can be performed on the in-vehicle network of UAV and simulated those attack techniques in the Pixhawk4 quadcopter. The proposed ADS can detect abnormal sequences with accuracy of higher than 96%.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.4
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• pp.623-640
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• 2017

The full nonlinear equations of an unmanned aerial vehicle ground taxiing mathematical dynamic model are built based on a type of unmanned aerial vehicle data in LMS Virtual.Lab Motion. The flexible landing gear model is considered to make the aircraft ground motion more accurate. The electric braking control system is established in MATLAB/Simulink and the experiment of it verifies that the electric braking model with the pressure sensor is fitted well with the actual braking mechanism and it ensures the braking response speediness. The direction rectification control law combining the differential brake and the rudder with 30% anti-skid brake is built to improve the directional stability. Two other rectifying control laws are demonstrated to compare with the designed control law to verify that the designed control is of high directional stability and high braking efficiency. The lateral displacement increases by 445.45% with poor rectification performance under the only rudder rectifying control relative to the designed control law. The braking distance rises by 36m and the braking frequency increases by 85.71% under the control law without anti-skid brake. Different landing conditions are simulated to verify the good robustness of the designed rectifying control.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.6
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• pp.542-547
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• 2012

Until recently, most of GCS(Ground Control Software) has been required to visualize attitude, position, status of vehicle and to transmit control and mission commands for a single UAV(Unmanned Aerial Vehicle). However, the GCS needs to expand its functions to handle more complex situations. Simultaneous operation of multiple UAVs is emerging as a new practice. Hence, we set up requirements for operation of multiple UAVs and suggest the architecture of GCS that satisfy the requirements. In this study, we analyze the upper requirements and define the total structure of GCS at first. Then we design the inner structure for requirements in detail. Finally, we verify the functions of GCS on PILS(Processor In the Loop Simulation) System.

• Journal of the Korean Geotechnical Society
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• v.38 no.7
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• pp.39-47
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• 2022

This study aims at evaluating the stability of disaster risks, such as schools, apartments, and geotechnical structures located around slopes in urban areas. The research conducted an aerial photography analysis on where the slope of the retaining wall behind 𐩒𐩒 High School in Gwangju collapsed in August 2018 due to heavy rain. In general, the overflow of rainwater has been managed through drainage channels around slopes during the rainy season, and the surface flow of rainfall was limited due to the presence of dense forests in the area. However, when the slope collapsed, a lot of water flowed out of the ground, and the saturated surface layer ground was destroyed. To analyze the cause, the changed terrain of the upper slope area, which could not be directly identified, was photographed using unmanned aerial vehicles. Digital Elevation Model by unmanned aerial vehicle shooting was performed by analyzing the slope map, calculating the direction of rainfall and the length and width of water-logged areas. The change in the instability of the slope over time due to a 10-day rainfall was also analyzed through numerical analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.1
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• pp.205-213
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• 2017

This paper is a study on the method to derive the functional level required for autonomous unmanned ground vehicle, one of the defense robots. Conventional weapon systems are not significantly affected by the operating environment, while defense robots exhibit different performance depending on the operating environment, even if they are on the same platform. If the performance of defense robot is different depending on operational environment, results of mission performance will be vary significantly. Therefore, it is necessary to clarify the level of function required by the military in order to research and develop most optimal defense robots. In this thesis, we propose a method to derive the required function level of unmanned ground vehicles, focusing on autonomous driving, one of the most vital functions of defense robots. Our results showed that the autonomous driving function depending intervention levels and evaluated functional sensitivity for autonomous driving of the unmanned vehicle using climate and topography as variables.

• International Journal of Aeronautical and Space Sciences
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• v.8 no.2
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• pp.54-66
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• 2007

Traffic and emergency monitoring systems are essential constituents of Intelligent Transportation System (ITS) technologies, but the lack of traffic monitoring has become a primary weakness in providing prompt emergency services. Demonstrated in numerous military applications, unmanned aerial vehicles (UAVs) have great potentials as a part of ITS infrastructure for providing quick and real-time aerial video images of large surface area to the ground. Despite of obvious advantages of UAVs for traffic monitoring and many other civil applications, it is rare to encounter success stories of UAVs in civil application including transportation. The objective of this paper is to report the outcomes of research supported by the state agency in US to investigate the feasibility of integrating UAVs into urban highway traffic monitoring as a part of ITS infrastructure. These include current technical and regulatory issues, and possible suggestions for a future UAV system in civil applications.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_2
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• pp.1063-1071
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• 2023

Unmanned aerial vehicles (UAVs, drones) are becoming increasingly useful in a variety of fields. Advances in UAV and camera technology have made it possible to equip them with ultra-high resolution sensors and capture images at low altitudes, which has improved the reliability and classification accuracy of object identification on the ground. The distinctive contribution of this study is the derivation of sensor-specific performance metrics (GRD/GSD), which shows that as the GSD increases with altitude, the GRD value also increases. In this study, we identified the characteristics of various onboard sensors and analysed the image quality (discrimination resolution) of aerial photography results using UAVs, and calculated the shooting conditions to obtain the discrimination resolution required for reading ground objects.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.2
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• pp.227-233
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• 2015

In this study, an indoor test environment was developed for studying the vision stabilizer of an unmanned vehicle, using a virtual environment and a 6-axis motion simulator. The real driving environment was replaced by a virtual environment based on the Aberdeen Proving Ground bump test course for military tank testing. The vehicle motion was reproduced by a 6-axis motion simulator. Virtual reality driving courses were displayed in front of the vision stabilizer, which was located on the top of the motion simulator. The performance of the stabilizer was investigated by checking the image of the camera, and the pitch and roll angles of the stabilizer captured by the IMU sensor of the camera.