• Journal of the Korean Society of Propulsion Engineers
• /
• v.14 no.4
• /
• pp.65-70
• /
• 2010

A small unmanned aerial vehicle(UAV), which uses a propulsion system consisting of electric motor and battery, weighs less than 8 kg, capable of hand launch. Because it is easy to operate and able to transmit image information in real time, the use of small UAV has been increasing. However, very few analysis methods or analysis results on flight performance of the small UAV have been known so far. In this paper, the performance analysis methods of a small UAV, which is manufactured to study an electric powered UAV, are suggested and their results are achieved. Aerodynamic data of the vehicle are obtained by making use of gliding performance from actual flight test, and required thrust and required power by flight speed are predicted. In addition, the methods to predict range and endurance in case of using battery as power source are suggested and their results are achieved.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2012.07a
• /
• pp.251-252
• /
• 2012

본 논문에서는 UAV(Unmanned Aerial Vehicle)을 이용하여 목표물을 찾고 목표물의 위치가 멀거나 목표물이 이동 시에도 기지국까지 지속적인 통신 연결을 제공하기 위해 UAV 집단을 제어하는 방안을 제안한다. 기존의 통신 시설을 이용할 수 없으며, UAV들 간에만 무선 랜 통신이 가능한 전시상황이나 특수 재난 상황에서 사용되는 것을 가정하였다. 제안 방안은 UAV들이 탐색지역 내에 목표물을 찾은 후에 목표물에 대한 정보를 기지국까지 전달하기 위하여 UAV들을 이동시킨다. 목표물이 먼 곳에 위치할 시에는 UAV들이 기지국까지의 통신 연결을 주기적이라도 유지하기 위해 UAV가 다른 UAV의 통신 범위까지 이동하여 정보를 전달하고 원래 위치로 복귀하는 방안과, 목표물이 이동할 때 목표물을 추적하며 기지국과의 연결성을 유지하는 방안을 제안한다. 이와 같은 과정들은 NS-2를 사용한 모의실험을 통하여 제안되는 기법을 검증하고 성능을 평가한다.

• Aerospace Engineering and Technology
• /
• v.8 no.1
• /
• pp.1-9
• /
• 2009

The ground integration test of Smart UAV has been performed according to the flight test plan. The flight test of full scaled model will be performed followed by 4 DOF ground rig test and a tethered hover test. Smart UAV is the first indigenous tiltrotor aircraft which can fly with fast cruise speed and take off or land vertically. In order to prove the flight control law of Smart UAV, the 40% scaled airplane was developed and have been tested. During flight test of small scaled model, many unique and unexpected problems occurred. After clearing these problems, fully automatic flight test was performed successfully. The experiences about many trouble shooting and resolving the problems would be basic material to avoid the unexpected but similar flight test problems hidden behind of the full scaled Smart UAV. This paper presents the detailed procedures of trouble shootings to solve the unique problems which occurred during the flight test of small scaled tiltrotor UAV.

• Journal of Platform Technology
• /
• v.8 no.2
• /
• pp.32-43
• /
• 2020

The Unmanned Aerial Vehicle(UAV) system has been mainly used for military domains, but it also widely applied to used in the civilian domains. In civilian domains, low-cost and small-sized UAV systems are mainly applied in various industries. The software that operates UAV systems has a lot of common functions. However, even though there are many common functionalities of the software, changing the devices may cause a problem requiring software modification. These problems degrade interoperability, modularity and portability in UAV systems. In order to solve the problems, an Open System Architecture(OSA) has been proposed. In this paper, we propose a UAV system software architecture based on Future Airborne Capability Environment(FACE) standard. Our system can support UAV systems of various platforms in the civilian domains, which is supplied in small quantity batch production. And it has the advantages of software consolidation and portability. Finally, We describe the development and conformant methodology of the software based on the FACE standard using open development tools.

• Journal of Aerospace System Engineering
• /
• v.17 no.6
• /
• pp.16-26
• /
• 2023

With the growing demand for unmanned aerial vehicles (UAVs), various collision avoidance methods have been proposed, mainly using LiDAR and stereo cameras. However, it is difficult to apply these sensors to small UAVs due to heavy weight or lack of space. The recently proposed methods use a combination of object recognition models and distance sensors, but they lack information on the obstacle size. This disadvantage makes distance determination and obstacle coordination complicated in an early-stage collision avoidance. We propose a method for estimating obstacle sizes using a monocular camera-YOLO and infrared sensor. Our experimental results confirmed that the accuracy was 86.39% within the distance of 40 cm. In addition, the proposed method was applied to a small UAV to confirm whether it was possible to avoid obstacle collisions.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.10
• /
• pp.1031-1037
• /
• 2010

This paper proposed lightweight aluminum bipolar plates as an alternative for conventional graphite bipolar plates in fuel cell systems used as a power source for small reconnaissance UAVs. Since bipolar plates occupy more than 80% of the total weight of the fuel cell system, lightweight aluminum bipolar plates can improve the overall payload and flight time of the fuel cell UAV. The aluminum and graphite bipolar plates were fabricated to compare the performance of each of them. A 15% higher performance per weight was obtained from aluminum bipolar plates than the graphite bipolar plates. Also, the performance of a single cell using aluminum bipolar plates was evaluated under various operating conditions.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.34 no.3
• /
• pp.283-290
• /
• 2016

Even though existing methods for orthophoto production in traditional photogrammetry are effective in large areas, they are inefficient when dealing with change detection of geometric features and image production for short time periods in small areas. In recent years, the UAV (Unmanned Aerial Vehicle), equipped with various sensors, is rapidly developing and has been implemented in various ways throughout the geospatial information field. The data and imagery of specific areas can be quickly acquired by UAVs at low costs and with frequent updates. Furthermore, the redundancy of geospatial information data can be minimized in the UAV-based orthophoto generation. In this paper, the orthophoto and DEM (Digital Elevation Model) are generated using a standard low-end UAV in small sloped areas which have a rather low accuracy compared to flat areas. The RMSE of the check points is σ_H = ±0.12 m on a horizontal plane and σ_V = ±0.09 m on a vertical plane. As a result, the maximum and mean RMSE are in accordance with the working rule agreement for the airborne laser scanning surveying of the NGII (National Geographic Information Institute) on a 1/500 scale digital map. Through this study, we verify the possibilities of the orthophoto generation in small slope areas using general-purpose low specification UAV rather than a high cost surveying UAV.

• Journal of Aerospace System Engineering
• /
• v.14 no.5
• /
• pp.83-90
• /
• 2020

Disasters are causing significant damage to the lives and property of our society and are recognized as social problems that need to be solved nationally and globally. The 4th industrial revolution technologies affecting society as a whole such as the Internet of Things(IoT), Artificial Intelligence(AI), Drones(Unmanned Aerial Vehicles), and Big Data are continuously absorbed into the disaster and safety industries as scientific and technological tools for solving social problems. Very soon, twenty-nine domestic UAV-related organizations/companies will complete the construction of a multicopter type small UAV integrated system ('17~'20) that can be operated at disaster and security sites. The current work considers and proposes the mid-to-long term R&D direction of disaster UAV as a strategic asset of the national disaster response system. First, the trends of disaster and safety industry and policy are analyzed. Subsequently, the development status and future plans of small UAV, securing shortage technology, and strengthening competitiveness are analyzed. Finally, step-by-step R&D direction of disaster UAV in terms of development strategy, specialized mission, platform, communication, and control and operation is proposed.

• Journal of Institute of Control, Robotics and Systems
• /
• v.18 no.5
• /
• pp.433-438
• /
• 2012

In this paper, a operation network system equipped with onboard wireless communication systems and ground-based mission control systems is proposed for swarm flight of small UAVs. This operating system can be divided into two networks, UAV communication network and ground control system. The UAV communication network is intend to exchange the informations of navigation, mission and flight status with minimum time delay. The ground control system consisted of mission control systems and UDP network. Proposed operation network system can make a swarm flight of various UAVs, execute complex missions decentralizing mission to several UAVs and cooperte several missions. Finally, PILS environments are developed based on the total operating system.

• International Journal of Aeronautical and Space Sciences
• /
• v.13 no.1
• /
• pp.34-42
• /
• 2012

This paper discusses the mathematical modeling of a small scale ducted-fan UAV and examines its results in comparison to the wind tunnel test. A wind tunnel test is first performed, producing a substantial amount of test data. The acquired set of wind tunnel test data is then categorized and approximated as mathematical functions. Finally, the mathematically modeled forces and moments acting on the UAV are compared with the acquired wind tunnel data. The analysis involves a gradient-based algorithm and is applied to extract trim states with respect to various flight conditions. Consequently, a numerical analysis demonstrates that there exists a reasonable flight status with respect to airspeed.