• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.158-163
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• 2012

Spherical Flying Machine, unlike conventional aircraft structure, is protected by circular frame. This battery-operated propeller machine, which can do vertical take-off and hovering, is under development for indoor and outdoor operation and dubbed as Flying Ball in KARI. In the future, autonomous air vehicle will be constructed for reconnaissance and surveillance application.

• 한국항공운항학회:학술대회논문집
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• 2015.11a
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• pp.50-54
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• 2015

구형무인비행체는 다중 모터를 이용한 무인항공기에 비행 소형화, 경량화, 경제화 등의 장점을 가지고 있다. 본 논문에서는 구형무인비행체의 경로 추종을 위한 제어기 설계 및 성능에 대한 내용을 다루고 있다. 먼저 구형무인비행체의 운동방정식이 제어기 설계를 위해 유도되었고, 유도된 운동방정식을 이용해 경로 추종 제어기를 설계하였다. 구형무인비행체의 자세제어는 무게중심을 변화하는 방법을 사용하였다. 요구 경로를 설정하여 설계된 제어기의 경로 추종 성능을 MATLAB 시뮬레이션을 통해 확인하였다. 시뮬레이션 결과, 제시된 제어기가 설정된 경로를 추종하고 있음을 확인하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.11
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• pp.902-910
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• 2018

This paper deals with spacecraft intercept problem on non-coplanar elliptical obit considering J2 perturbation. This disturbance addressed in this work is a major factor changing the trajectory of a spacecraft orbiting the Earth. To resolve this issue, a real-time intercept method is proposed. This method is based on the optimization problem which consist of the equation of motion considering spherical earth and impulse, and the optimal solution numerically obtained is set as the direction of the thrust of the interceptor. The position error is resolved by iteratively solving the optimization problem and modifying the direction of thrust of interceptor. The proposed method in this paper is verified by using various numerical examples.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.5
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• pp.458-465
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• 2011

UAV-UGV teaming concept has been proposed that can compensate for weak points of each platform by providing carrying, launching, recovery and recharging capability for the VTOL-UAV through the host UGV. The teaming concept can expand the observation envelop of the UGV and extend the operational capability of the UAV through mechanical combination of each system. The spherical-shaped coaxial rotorcraft UAV is suggested to provide flexible and precise interface between two systems. Hybrid navigation solution that included vision-based target tracking method for precision landing is investigated and its experimental study is performed. Feasibility study on length-variable rotor to provide the compact configuration of the loaded rotorcraft platform is also described.