• Journal of Aerospace System Engineering
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• v.10 no.2
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• pp.7-13
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• 2016

Multi disciplinary approach for aerodynamics, structure, propulsion, and flight control system is necessary to develop High Altitude Long Endurance Unmanned Aerial Vehicles (HALE UAV). Various HALE UAV development trends are surveyed to understand their operational requirements. Separating the UAV Take Off Weight by 150kg, Airworthiness implementation direction for HALE UAV is studied under the current Airworthiness regulations. NATO STANAG 4671 and STANAG 4703 Airworthiness certification criteria are analyzed, and their applicability was proposed for future HALE UAV development. In addition, minimization of the risk for UAV is studied by considering probability of cumulative catastrophic failure for HALE UAV. This Hazard Risk Index can support the future UAV Airworthiness Certification Criteria.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.21 no.1
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• pp.23-29
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• 2013

This paper presents a tracking filter of radar beacon system (RBS) for automatic takeoff and landing of an unmanned aerial vehicle. The proposed tracking filter is designed as the decoupled tracking filter to reduce the computational burden. Also, an adaptive estimation method of the measurement error covariance is proposed to provide an improved tracking performance compared to the conventional decoupled tracking filter whenever the accuracy of RBS observations is degraded. 100 times Monte Carlo runs performed to analyze the performance of the proposed tracking filter in case of normal operation and degraded operations, respectively. The simulation results show that the proposed tracking filter provides the improved tracking accuracy in comparison with the conventional decoupled tracking filter.

• Journal of Biosystems Engineering
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• v.31 no.2 s.115
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• pp.95-101
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• 2006

Present chemical application system using a power sprayer has been a labor intensive, ineffective and shirking task in farming. Therefore, a small RF controlled (unmanned) helicopter was suggested to replace the conventional spray system. The aerial application using the unmanned helicopter has been already utilized in Japan, where total area applied up to 704,000 ha in 2005. In this article, the status and cost analysis on the unmanned agricultural helicopter were studied. The aerial application using the agricultural helicopter helps precise and timely spraying and reduces labor intensity and pollution. The field capacity of the helicopter was found to be 60-70 ha a day. The break even point was estimated near the operating area of 750 ha annum. The development of an agricultural helicopter was necessary for taking advantages of both technique and economy.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.2
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• pp.57-67
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• 2017

This study examines methods for creating terrain models of reservoirs and techniques for verifying the accuracy. Such methods and techniques use unmanned aerial vehicles which are capable of capturing high-resolution images repetitively, are highly economic, and capable of surveying wide areas. In addition, this study suggests methods of acquiring data for reservoir safety management, the methods which also employ the unmanned aerial vehicles. Therefore, this study helps solving problems that can arise when National Disaster Management System rebuilds a reservoir management database, such as a shortage of local government manpower. This study also contributes to providing element technology necessary for advancing the database.

• Journal of Aerospace System Engineering
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• v.13 no.3
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• pp.48-55
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• 2019

This paper presents a study on Fault History Management Equipment (FHME) of Unmanned Aerial Systems (UAS). UAS comprise of various types of electronic equipment for high reliability design for flight safety. Consequently, it is mandatory for each on-board equipment to have its own Built-In-Test (BIT) function, because rapid fault-detections for UAS are necessary. FHME is developed for the purposes of display, storage and management of such BIT results on ground. This paper describes the outline, development requirements, design and verification process of FHME.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.3
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• pp.302-312
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• 2023

This paper describes the analysis of lightning strike zoning, the indirect lightning data simulation and the protection design for lightning indirect effects of equipment by lightning strike for unmanned aircraft consisting of composite wings. Through the analysis of lightning strike zoning according to the external shape of unmanned aerial vehicles, the structure areas that should be protected during lightning strike is derived, and the protection requirements of lightning indirect effects for flight critical equipments and equipment that must be operated upon lightning strike was derived. Lightning protection levels according to the location of mounting equipment and surrounding structure materials for each equipment was derived, and the protection design of the unmanned aerial vehicle with composite structures was also proposed from direct effect of lightning. Later, the lightning protection technology will be verified by the ground test of lightning direct and indirect effects.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.30 no.4
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• pp.57-64
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• 2022

A study on propllers for unmaned aerial vehicles is conducted using the open softwares. Since the shape of the propeller is closely related to the thurst characteristics of the propulsion system, adopting an appropriate propeller will significantly reflect stable aerodynamic performances. In this study, propellers for unmanned aerial vehicles were modeled by using OpenVSP and Propel for comparison, the thrust characteristics according to the number of blades and the diameter of the propeller were analyzed. In addition, the tendency of thrust characteristics according to various propeller pitch angles was confirmed. Based on the analysis results of this study, the applicability of the propeller shape to the design of the unmanned aerial vehicle was confirmed. It is shownthat the analysis results of this study can be utilized when modeling the propeller shape in research such as a conceptual design of unmanned aerial vehicle. In this case, it should be noted that OpenVSP does not involve the viscous effect of air.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.141.3-141
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• 2001

Since 1990´s, there has been many researches for the development of the Unmanned Aerial Vehicle (UAV). Especially, for the development of digital electronics, the technologies of UAV toward to the miniaturization low-cost, and high reliability. Therefore, recent trends for the development of UAV are focused on the development modern Flight Control System (FCS). In this paper, focusing on the FCS, the development process for Sejong Unmanned Research Vehicle -1 (SURV-1) from design to flight test is presented.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.11a
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• pp.105-110
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• 2008

Unmanned helicopter has several abilities such as vertical take off, hovering, low speed flight at a specific altitude. Such vehicles are becoming popular in actual applications such as search and rescue, aerial reconnaissance and surveillance in the case of a large size disaster and forest fire. In this paper, a flight control system was designed for an unmanned helicopter. This paper was concentrated on describing the systematic design, electronic equipments and their interconnections for realizing the autonomous flight and aerial monitoring. A study on the autonomous waypoint navigation and altitude control performance were performed and tested on a test unmanned helicopter and the performance and the feasibility were represented.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1375-1379
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• 2004

Unmanned Helicopter has several abilities such as vertical Take off, hovering, low speed flight at low altitude. Such vehicles are becoming popular in actual applications such as search and rescue, aerial reconnaissance and surveillance. These vehicles also used under risky environments without threatening the life of a pilot. Since a small aerial vehicle is very sensitive to environmental conditions, it is generally known that the flight control is very difficult problems. In this paper, a flight control system was designed for an unmanned helicopter. This paper was concentrated on describing the mechanical design, electronic equipments and their interconnections for acquiring autonomous flight. The design methodologies and performance of the helicopter were illustrated and verified with a linearized equation of motion. The LQG based estimator and controller was designed and tested for this unmanned helicopter.