• Transactions of the KSME C: Technology and Education
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• v.3 no.1
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• pp.71-78
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• 2015

Although there are differences in the classification of category adopted by each country, small UAS is usually classified as the one less than 25 kg. UAS has been mainly used for military and public purposes, but in recent years, it has spread to the private sector for hobby, media, and so on. Especially, considering the nature of the operating region and applications, it is necessary to improve operating time, noise and vibration in small UAS to ensure the same level of safety with a manned aircraft. This is because the drone can pose health and safety hazard through collision with manned aircraft or crashing into the ground. In this paper, we investigated operational regulations in the United States and European countries. Based on the investigation, a domestic system development plan for small UAS operation is under development.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.1-2
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• 2011

최근 많은 분야에 무인시스템이 도입되고 있다. 초기에는 산업분야에서 인간이 하기 힘들거나 위험한 작업을 대신하는 단순 반복적인 자동화기술이 대부분이었으나, 최근에는 전자통신 기술발달에 힘입어 무인자동차, 무인항공기, 무인잠수정, 무인선박 등이 연구 개발되고 있다. 본연구에서는 자율형 소형무인선을 개발하고자 하였으며, 이와 관련하여 인터넷기반의 무선통신제어, 동력 추진 조타 냉각시스템, GPS 영상 헤딩센서 등 센싱시스템, 자율운항을 위한 제어기설계, GUI 등을 연구하였다. 아울러, 해상실험을 통해 유효성을 검증하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.1179-1180
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• 2023

국방 분야의 데이터링크 기술은 다양한 군사 응용 분야에서 무인 항공기 및 다른 무인시스템과의 효율적인 통신을 위한 것으로 국내 국방 공용 데이터링크 기술 내용 및 대형/소형 무인이동체 장비 형상을 확인하였다. 소형 무인이동체 데이터링크를 지원하기 위하여 사용되는 기술 현황을 확인하고 문제점을 식별하였다. 마지막으로 향후 군 요구 사항을 충족하기 필요성 및 관련 세부 기술 개발 내용을 제시하였다.

• Journal of the Korea Convergence Society
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• v.8 no.4
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• pp.183-188
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• 2017

As the price of small UAVs is getting cheaper and its controllability is getting greatly increased, many aerial applications using both fixed-wing and hoverable UAVs have appeared in recent years. In this paper, a new aerial advertising method is proposed using four hoverable UAVs. Using the UAV swarm control method, four UAVs are maneuvered to carry a $7.07{\times}7.07m^2$ square banner along collision-free and predefined waypoints for aerial advertising. According to simulation results, it takes about 270 s for UAVs to perform aerial advertising in $669{\times}669m^2$ size area and the minimum distance among UAVs turns out to be 0.45 m which proves there is no any collision. Due to abrupt direction changes of UAVs along the predefined waypoints, UAVs cannot always maintain exact square formation and it results the maximum and minimum side lengths of square formation to be 10.35 m and 1.96 m, respectively. Also, the maximum and minimum diagonal lengths of square formation turn out to be 14.75 m and 2.78 m, respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.7
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• pp.605-611
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• 2011

Shimmy is a self-excited vibration in lateral and torsional directions of a landing gear during either the take-off or landing. It is caused by a couple of conditions such as a low torsional stiffness of the strut, a free-play in the landing gear, a wheel imbalance, or worn parts, and it may make the aircraft unstable. This study was performed for an analysis of the shimmy stability on a small aircraft. A nose landing gear was modeled as a linear system and characterized by state-equations which were used to analyze the stability both in the frequency and time-domain for predicting whether the shimmy occurs and investigating a good design range of the important parameters. The root-locus method and the 4th Runge-Kutta method were used for each analysis. Because the present system has a simple mechanism using a friction to reinforce the stability, the friction, a non-linear factor, was linearized by a describing function and considered in the analysis and observed the result of the instability reduction.

• Journal of Advanced Navigation Technology
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• v.26 no.5
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• pp.249-260
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• 2022

Student pilots receiving flight education are inexperienced in piloting and situation judgment skills and are greatly affected by various factors such as psychological, physical, and environmental factors. In particular, one of the most influential factors in the flight education of student pilots is the weather conditions. Unlike large aircraft used in the air transportation business, small aircraft used for flight education have a great impact on education, such as flight restrictions depending on weather conditions, psychological pressure in severe weather, and deterioration of student skills. Therefore, in this study, the meteorological characteristics of meteorological factors that have a great influence on small aircraft were analyzed. As a result of the analysis, an efficient and safe training operation method was suggested to a professional pilot aviation training organization through the adjustment of the training period for the season, the increase in aircraft operation rate, and a safe solo flight plan considering the weather.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.451-456
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• 2020

In this paper, we studied the method of designing a embedded antenna for mounting on the JTDLS complete aircraft. The proposed antenna satisfies the MIDS-LVT operation frequency band and is designed as a broadband in consideration of expandability. As a result of the design, it was confirmed that the proposed antenna has similar electrical performance to the existing blade antenna and has broadband characteristics. As a result of EM analysis, the antenna was mounted on the top and bottom parts of the aircraft to check the mount of the aircraft, and it was confirmed that both the top and bottom parts had good radiation characteristics. The technology acquired through this study is judged to be applicable to the JTDLS completed aircraft.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.3
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• pp.233-239
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• 2013

A 100 W fuel cell system using chemical storage method has been applied for a propulsion system of the SUAV(Small Unmanned Aerial Vehicle). A fuel cell and battery have been combined for both the small/light hydrogen generation control system and the hybrid power supply system. A small hydrogen generation device was implemented to utilize NaBH4 aqueous solution and dead-end type PEMFC system, which were evaluated on the ground and by the flight tests. The system pressurized at a 45kpa stably operates and get higher fuel efficiency. The pressure inside of the hydrogen generation control system was maintained at between 45 kPa and 55 kPa. The 100W fuel cell system satisfies the required weight and power consumption rate as well as the propulsion system, and the fuel cell system performance was demonstrated through flight test.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.521-522
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• 2011

본 논문에서는 특정 위치를 비행하는 무인항공기를 이용하여 현재 위치의 수집된 센서 정보, GPS 수신정보, 영상정보를 무선통신을 이용하여 전송하는 정보 전송시스템을 구현한다. 무인항공기에 부착된 센서, GPS수신기, 소형카메라를 통해 산불 및 자연재해를 감지하고, 무선통신을 이용하여 감지된 위치의 정보들을 사용자에게 전송한다. 제안된 시스템은 위험 지역에 사람이 직접 가지 않고도 실시간 위험 상황을 파악 및 신속한 대처가 가능하다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.8 no.6
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• pp.33-41
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• 1971

This paper presents a theoretical calculation and measurements for the RCS(Radar Cross Scetion) value of a moving complex target, a small metal aircraft. The front view of aircraft on the drawing is divided in to several simple models to calculate its RCS value by the relative phase nlethod and the random phase method at the given frequency. The aircraft, cessna 305, inbounded from 170$^{\circ}$ to X international airport, is searched by radar with the wave length of 11cm to measure its miximum range which is necessary to determine the RCS value. The measured data are found to be similar to the theoretical values.