• 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 Korean Society of Computer Information Conference
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• 2018.07a
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• pp.279-280
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• 2018

본 과제는 비행체에 자동제어 시스템인 자동항법비행기능을 탑재한 무인기를 제작한다. 자동항법비행이 가능한 무인기는 사람이 직접 조종하는 기존의 비행체들 보다 정밀하고 섬세한 제어가 가능하며 조종자의 시야가 닿지 않는 곳에서의 비행이 가능하다는 장점을 가진다. 또한 상공에서 영상을 촬영하며 5.8GHz대역의 영상 송 수신기를 통한 실시간 영상 확인이 가능하다. 본 과제는 GPS를 이용한 프로그래밍을 통해 미리 지정한 좌표를 따라 비행이 가능하며 실시간 영상 수신이 가능하기 때문에 사람이 직접 갈 수 없는 오염된 지역 등의 정찰이 가능하고, 비행체에 장착되는 장비에 따라 군용, 소방용 등의 다양한 범위에서의 활용이 가능할 것으로 예상된다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.215-217
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• 2017

기술의 발달에 따라 무인표지에도 기존의 등명기 이외에도 Racon, Fog Detector, 전기폰, 기상 및 해양 관측장비, 휴대폰 중계기 등 전력을 필요로하는 다양한 장비가 설치되고 잇는 실정인데 반해, 현재의 무인표지 전력제어시스템은 기존의 관습대로 등대 내 협소한 구내에 축전지, 충방전 조절기, 전력선 등이 널 부러져 있는 상태로서 효과적인 전력관리와 능률적이고도 안전한 전력 관리를 위하여는 종합적 전력제어시스템 설치가 필요한 실정이다.. 이 연구에서는 현재 무인표지의 전력 시스템을 체계적이고도 안전한 방법으로 관리 할 수 있으며, 축전지 잔량표시, 저전압 충전시스템, 낙뢰피해 방지 및 원격 감시기능 등 기능적인 측면에서도 뛰어난 성능을 가질 수 있도록 무인등대용 표준전력제어장치를 연구 개발하였다.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1944-1945
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• 2011

본 논문은 심도각 범위를 고려한 무인 잠수정(autonomous underwater vehicles: AUVs)의 타카키-수게노 (Takagi-Sugeno: T-S) 퍼지 모델 기반 강인 심도 제어기의 설계 기법을 제안한다. 무인 잠수정의 비선형 시스템은 Sector nonlinearity 기법을 이용하여 T-S 퍼지 시스템으로 모델링된다. 리아푸노프(Lyapunov) 함수를 이용하여 무인 잠수정의 성능을 보장하는 선형 행렬 부등식(Linear matrix inequality: LMI) 형태의 강인 제어기 설계 조건은 유도된다. 또한 무인 잠수정의 심도각 범위를 고려하여 입력 및 출력에 제한 조건을 포함한다. 모의 실험을 통해 제안된 기법의 심도 제어 성능을 검증한다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.12
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• pp.1170-1176
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• 2010

This study addresses adaptive control of UAVs(Unmanned Aerial Vehicles) pitch-axis maneuver. The MRAC(Model Referenced Adaptive Control) approach is employed to accommodate uncertainties which are introduced by feedback linearization of pitch attitude control by elevator input. The model uncertainty is handled by adaptation laws which update model parameters while the UAV is under control by the feedback control law. Steady-state pitch attitude achieved by the stabilizing control law is derived to provide insight on the closed-loop behavior of the controlled system. The proposed idea is free of linearization, gain-scheduling procedures, so that one can design high maneuverability of UAVs for pitching motion in the presence of significant model uncertainty.

• Journal of Advanced Navigation Technology
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• v.25 no.3
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• pp.211-216
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• 2021

Multiple UAV System has been used for various purposes such as reconnaissance, networking and aerial photography. In such systems, it is essential to form and maintain the formation of multiple UAVs. This paper proposes the algorithm that produces an autonomous distributed control for each vehicle for a flexible formation. This command is a repulsive force in the form of the second-order system by the nearest UAV or mission area. The algorithm uses the relative position/speed through sensing and communication for calculating the command without external intervention. The command allows each UAV to follow the reference distance and fill the mission area as densely as possible without overlapping. We determine the reference distance via optimization technique solving the packing problem. The mission area comprises the desired formation outline and can be set flexibly depending on the mission. Numerical simulation is carried out to verify the performance of the proposed algorithm under a complex and flexible environment. The formation is formed in 26.94 seconds and has a packing density of 71.91%.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.2
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• pp.107-114
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• 2007

This paper focuses on the performance evaluation of various control allocation methods applied on DURUMI-II UAV system. In order to implement control allocation scheme to aircraft control system, control system can be designed through two step design procedure. The first step is to design a baseline control system for an aircraft without consideration of control surface failure. The second step is to design a control allocator that maps the total control command on the individual control surfaces. In this paper, several control allocation methods such as Psuedo-Inverse CA method, Direct CA method, and Optimization CA method are implemented and integrated to the baseline flight control system of DURUMI-II UAV. The performance of these control allocation methods is evaluated by nonlinear simulation under the flight scenario of control surface failure.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.4
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• pp.352-362
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• 2010

The simultaneous operation of multiple UAV's makes it possible to enhance the mission accomplishment efficiency. In order to achieve this, easily scalable control algorithms are required, and swarm intelligence having such characteristics as flexibility, robustness, decentralized control, and self-organization based on behavioral model comes into the spotlight as a practical substitute. Recently, evolutionary robotics is applied to the control of UAV's to overcome the weakness of difficulties in the logical design of behavioral rules. In this paper, a neural network controller evolved by evolutionary robotics is applied to the control of multiple UAV's which have the mission of searching limited area. Several numerical demonstrations show the proposed algorithm has superior results to those of behavior based neural network controller which is designed by intuition.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.2
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• pp.225-231
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• 2012

In this paper, we propose a method for designing the path tracking controller using an approach angle concept for an underactuated autonomous underwater vehicle (AUV). The AUV is controlled by the surge speed and yaw rate: there is no side thruster. To solve this underactuated AUV problem in the path tracking, we introduce an approach angle concept which makes the AUV converge to the reference path. And we design the path tracking controller using the proposed approach angle. To design the path tracking controller, we obtain the new vehicle's error dynamics in the body-fixed frame, and then design the path tracking controller based on Lypunov direct method. Finally, some simulation results demonstrate the effectiveness of the proposed controller.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.3
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• pp.302-306
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• 2011

This paper presents Takagi-Sugeno (T-S) fuzzy-model-based controller for depth control of autonomous underwater vehicles(AUVs). Through sector nonlinearity methodology, The nonlinear AUV is represented by T-S fuzzy model. By using the Lyapunov function, the design condition of controller is derived to guarantee the performance of depth control in the format of linear matrix inequality (LMI). An example is provided to illustrate the effectiveness of the proposed methodology.