• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.8
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• pp.56-64
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• 2005

It is prerequisite that we have to fomulate the nonlinear mathematical modeling to design the guidance and control system of rotorcraft-based unmanned aerial vehicle using a small-scaled commercial helicopter. The small-scaled helicopters are very different from the full-scale helicopters in dynamic behavior such as high rotation speed and high frequency dynamic characteristics. In this paper, the formulation of the mathematical model of the small-scaled helicopter to minimize the complexity is presented by component and source build-up approach. It is linearized at the trim condition of hovering and forward flight and analyzed the flight modes. The results of this approach have general trends but a little difference. To verify this approach, it is necessary to compare this theoretical model with experimental results by system identification using flight test as a next research topic.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.04a
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• pp.168-171
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• 2004

본 논문에서는 대표적인 비선형 동특성을 가지는 실제 헬리콥터의 회전 및 자세 운동을 근사화한 모형 헬리콥터의 시스템을 소개하고 이 시스템의 정지 자세 제어를 위하여 WAVENET 제어기와 PID 제어기를 설계하였으며, WAVENET의 신경망 연결 가중치(weight) 및 웨이브렛의 신축 및 이동변수와 PID 제어기의 최적 이득 계수를 GA를 사용하여 조정되도록 하였다. 그리고 과도 응답 특성이 우수한 WAVENET 제어기와 정상 상태 특성이 우수한 GA-PID 제어기를 Hybrid 형태로 구성한 Hybrid GA-PID WAVENET 제어기를 비선형 시스템인 모형 헬리콥터 시스템에 적용하여 제안한 제어기 설계 알고리즘의 유효성과 우수성을 입증하고자 한다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.05a
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• pp.307-310
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• 2003

본 논문에서는 대표적인 비선형 동특성을 가지는 실제 헬리콥터의 회전 띤 자세 운동을 근사화한 모형 헬리콥터의 시스템을 소개하고 이 시스템의 정지 자세 제어를 목표로 직접 적응 웨이브렛 신경회로망 제어기를 다음의 과정에 의해 만든다. 우선 상태 공간에 적용할 웨이브렛 기준 함수를 정의하고 나서 제어기로 들어오는 입력 값의 대략적인 범위와 특성을 파악해서 웨이브렛 이론에 근거해 신축(dilation)과 이동(traslation) 변수 값을 선택하여 초기 적응 웨이브렛 신경회로망 제어기를 건설한다. 마지막으로 시스템의 안정화 제어를 위하여 선택, 교배, 돌연변이의 진화연산자에 의해 일시에 최적의 구조와 결합가중치로 진화시켜 가는 새로운 형태의 ENNC를 제안하여 연결 가중치(weight)를 조정한다. 이 직접 적응 웨이브렛 신경회로망 제어기를 비선형 시스템인 모형 헬리콥터 시뮬레이터에 적용하여 제안한 제어기의 견실성 및 그 우수성을 입증하고자 한다.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.6
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• pp.563-568
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• 1997

본 논문에서는 약간의 가정하에 리모트 제어용 모형 헬리콥터의 동역학방정식을 유도하였으며, 이를 토대로하여 헬리콥터의 자세안정을 위한 제어 알고리듬을 제안하였다. 제어이론으로서는 파라메타의 변화및 외란에 강인한 가변구조 제어이론을 활용하였다. 본 제어 알고리듬에서는 헬리콥터의 위치이동 제어에 대하여서는 다루지를 못하였으며, 단지 헬리콥터의 hovering 상태에서의 자세 안정화에만 촛점을 두어 제어 알고리듬을 제안하였다. 컴퓨터 모사를 통하여, 제안된 제어 제어 알고리듬의 타당성을 보였으며, 약 2-3초의 시간이 경과된 이후 자세가 안정화 됨을 볼 수 있었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.2
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• pp.397-402
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• 1999

In this paper, we derive dynamic equation of a simulated helicopter and propose the control method base on a neural network to control its attitude. The coupling coefficients are adjusted to minimize the error between the output of a control system and the reference value. The gain of the proposed controller are automatically adjusted by the back propagation of a neural network. Simulation results using MATLAB are given in this paper.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.2
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• pp.111-116
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• 2008

The study installed non metric camera which was a 10 Mega Pixel camera in RC Helicopter. And the study controlled images hotographed in air on land, considering their overlap. The study could express DEM by abstracting TIN from the acquired images through image registration. Also, the study compared and examined accuracy between reference point and check point observed by Total Station which was a conventional type of survey. As the results, the study could get errors of $-0.194{\sim}0.224\;m$ on X axis, $-0.088{\sim}0.180\;m$ on Y axis and $-0.286{\sim}0.285\;m$ on Z axis. Expressing an error's RMSE in the checkpoint, the study could get of 0.021388 m on X axis, 0.015285 m on Y axis and 0.041872 m on Z axis. It is judged that the above photographing and analyzing technique are better than the existing Total Station to acquire more terrain elevation data.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.185-188
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• 1993

The goal of this paper is to develop an on-board controller for a model helicopter's hovering attitude control, using i8096 one-chip microcontroller. Required controller algorithm is programmed in ASM-96 assembly language and downloaded into an i8096 microcontroller. The performance of hovering flight using this system is verified by experiments with the model helicopter mounted on an instrumented flight stand where 3 potentiometers and an optical proximity sensor measure te attitude and main rotor speed of the helicopter.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2317-2319
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• 2001

This paper presents a sensor fusion algorithm for the RC helicopter which uses a complementary filter. To measure the attitude angle of the helicopter, 3rate gyroscopes and a 3-axis accelerometer are mounted on the helicopter. The signals from them are passed though a complementary filter to produce estimation outputs. Experiments show that designed system is effective for the attitude estimation.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.6
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• pp.1399-1411
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• 1994

A model helicopter has more versatile flight capability than the fixed-wing aircraft and it can be used as an unmaned vehicle in hazardous area. A helicopter, similar to other aircrafts, is an unstable, multi-input multi-output nonlinear system exposed to strong disturbance. So it should be controlled by robust control theories that can be applied to multivariable systems. In this study, motion equations of hovering are established, linearized and transformed into a state equation form. Various parameters are measured and calculated in other to obtain the stability derivatives in the state equation. Hovering flight controller is designed using the digital LQG/LTR(Linear Quadratic Gaussian/Loop Transfer Recovery) control theory. The designed controller is tested by the nonlinear simulations and implemented on an IBM-PC/386. Experiments were carried out on a model helicopter attached to the 3-DOF gimbal. The designed controller showed satisfactory hovering capability to maintain the hovering for more than 40 seconds.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.4
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• pp.675-684
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• 2004

The Helicopter system has a non-linearity and complexity. Futhermore, because of absence of its correct mathematical model. it is difficult to control accurately its attitudes for elevation angle and azimuth one. Therefore, we proposed a GA-PID control technique to control these angles efficiently. The proposed GA-PID controller can systematically generate optimal PID parameters by applying GA theory to a helicopter attitude control system. Through the computer simulation, the GA-PID technique shows better attitude control characteristic than traditional PID control technique.