• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.3
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• pp.293-300
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• 2009

The rotorcraft-based unmanned aerial vehicle(UAV) capable of performing close-range surveillance and reconnaissance has been developed. Trade studies on mission feasibility led to the adoption of a coaxial rotorcraft with twin rotors counter-rotating in one axis and driven by electric motors. A commercial off-the-shelf flight control computer(FCC) and a radio frequency modem were adopted for autonomous navigation. In order to achieve an aerial view, commercial charge-coupled device camera was also integrated into the vehicle. The performance of the completed vehicle was proved with manual flight test, and mission capability was verified through waypoint navigation flight after being equipped with FCC. This paper treats the whole process of design and system integration for development of the coaxial rotorcraft UAV.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.12
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• pp.1388-1396
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• 2011

This paper is focused on the procedure of the development of a micro air vehicle which has vertical take-off and landing capability for indoor reconnaissance mission. Trade studies on mission feasibility led to the proposal of a coaxial rotorcraft configuration as the platform. The survey to provide a guide for preliminary design were conducted based on commercial off-the-shelf platform, and the rotor performance was estimated by the simple momentum theory. To determine the initial size of the micro air vehicle, the modified conventional fuel balance method was applied to adopt for electric powered vehicle, and the sizing problem was optimized with the sequential quadratic programming method using MATLAB. The designed rotor blades were fabricated with high strength carbon composite material and integrated with the platform. The developed coaxial rotorcraft micro air vehicle shows stable handling quality with manual flight test in indoor situation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.12
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• pp.997-1004
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• 2020

A synchropter is a type of rotorcraft in which a pair of blades inclined with each other rotates in synchronization. Removing the tail rotor enables an efficient and compact configuration similar to a coaxial-rotor helicopter. This paper describes the design and flight test results of a small synchropter to examine the suitability of a drone system for the army. The synchropter in this paper is a small vehicle with a rotor diameter of 1.4m and a weight of 7kg and was assembled based on commercial parts to examine flight characteristics effectively. The flight control system adopted Pixhawk, which is designed based on an open-architecture. The model-based design technique is applied to develop the control law of the synchropter and a new firmware embedded on the Pixhawk. Through qualitative flight tests, we analyzed the flight characteristics. As a result of the analysis, we confirmed the possibility of application as a drone system of the synchropter.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.1
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• pp.75-84
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• 2021

The authors had presented two previous papers[1,2] on Helicopter/Rotorcraft develoment in Europe and US. Meanwhile, the next generation rotorcrafts, currently under development in US and Europe, have new configurations (tilt-rotor, coaxial, compound) of rotor-type vertical takeoff/landing rotorcrafts to overcome the disadvantages of traditional helicopters. For developing these new types of rotorcrafts, the upgraded conceptual design/comprehensive programs are required. In US and Europe, they are already developing new program tools with their technologies and database obtained during more than last half centuries. For us, many academia, research institutes and industrial engineers have experienced and developed core technologies on rotorcrafts (aerodynamics, structural analysis, flight dynamics, and noise analysis etc.) comparable to US and Europe during last couple of decades of developing helicopters and various configurations of rotorcrafts. In this paper, the pros and cons of conceptual design/comprehensive tools currently used in US and Europe have been summarized. Furthermore, the possibilities and problems to develope our own design and analysis tools have been studied.