• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
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• pp.141-144
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• 2001

This paper proposes a decentralized control technique for 2-dimensional experimental helicopter systems. The decentralized control technique is especially suitable in large-scale control systems. We derive the stabilization condition for the interconnected Takagi-Sugeno (75) fuzzy system using the rigorous tool - Lyapunov stability criterion and formulate the controller design condition in terms of linear matrix inequality (LMI). To demonstrate the feasibility of the proposed method, we include the experiment result as well as a computer simulation one, which strongly convinces us the applicability to the industry.

• 한국군사과학기술학회지
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• 제12권6호
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• pp.750-759
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• 2009

FLIR(Forward Looking Infrared) geo-pointing is a function that helps pilots to see a target within the field of view under all coordinates and attitudes of helicopter. Geo-pointing controls FLIR LOS(line of sight) toward known target coordinates by using azimuth and elevation angles calculated from several information such as helicopter coordinates and attitudes, a FLIR position from a GPS antenna, and target coordinates. Geo-pointing performance has been tested and evaluated on the ground to save flight test costs and ensure flight safety. In this paper, design and implementation of a geo-pointing system is described with the results of performance test conducted on the ground test system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.763-766
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• 1996

A model helicopter is an unstable, multi-input multi-output nonlinear system exposed to strong disturbances and its system parameters change continually. In this paper, Time Delay Control(TDC) is adopted for these reasons. TDC uses past observation of the system's response and the control input to directly modify the control action rather than adjusting the controller gains leading to a model independent robust controller. TDC can force the plant to follow an appropriate reference model, but the reference model cannot be chosen arbitrarily. In this paper the procedure of choosing a reference model and the performance of the controller are presented.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.300-303
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• 2006

The rotor blade of a helicopter is the key structural units and provides three components such as vertical lifting force, horizontal propulsive force and control force. With advancements in aerospace technology, composite materials have been widely used in lightweight structures. In addition, composites show great potential on the design of rotor blades due to the advantages of strength, durability and weight of the materials. In the operational condition of a helicopter, it is required the vibration characteristics of the rotating blades for avoiding resonance and analysis of efficient performance prediction et al. In this study, the CAMRAD-II is used for analyzing the vibration characteristics of rotating composite blades. The effects of rotating speed and collective angles are investigated. Also, the numerical results are compared with experimental data.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.347-349
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• 2009

Unmanned helicopters are needed in various fields such as monitoring system, agriculture and forest fire. Swash plate is a essential part for exact driving of unmanned helicopter. And it is usually produced by machining. In this research, hot forging process of upper swash plate has been studied to improve proof stress against repeated loading of the product. In the forming analysis, design parameters such as effective stress, effective strain and distribution of damage have been considered in the hot forging.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.457-459
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• 1998

This paper presents a 3-DOF hovering flight controller for a model helicopter using the minimal order LQG/LTR technique. A model helicopter is an unstable multi-input multi-output nonlinear system strongly exposed to disturbances, so a robust multi-variable control theory should be applied to control it. The minimal order LQG/LTR technique which uses a reduced-order observer in the LTR procedure is used to design the controller. Performances for the 3-DOF hovering flight controller are evaluated through computer simulations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.1949-1951
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• 2001

This paper deals with the control of a nonlinear experimental helicopter system by using the fuzzy-model-based control approach. The fuzzy model of the experimental helicopter system is constructed from the original nonlinear dynamic equations in the form of an affine Takagi-Sugeno (TS) fuzzy system. In order to design a feasible switching-type fuzzy-model-based controller, the TS fuzzy system is converted to a set of uncertain linear systems, which is used as a basic framework to synthesize the fuzzy-model-based controller.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2001년도 추계학술발표대회 논문집
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• pp.206-209
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• 2001

본 논문에서는 헬리콥터용 힌지없는 로터 시스템의 축소 복합재료 블레이드의 개발 과정을 소개한다. 블레이드 설계에는 자체 보유의 CORDAS 프로그램을 이용하였으며 블레이드 동역학 해석에는 헬리콥터용 해석 프로그램인 Flightlab 상용 프로그램을 이용하였다. 힌지없는 허브에 설계된 복합재료 로터 블레이드를 연결하여 동적 특성을 분석하였으며 그 결과를 이용하여 설계 변경하는 과정을 수행함으로써 최적의 설계값을 구하는 과정을 기술하였다. 효과적인 성형 공법을 정립하여 설계된 축소 복합재료 블레이드를 제작하였다. 본 연구를 통해 복합재료 블레이드 개발 과정에 대한 경험을 축적하였으며 축적된 기술을 관련 분야에 적용할 예정이다.

• 제어로봇시스템학회논문지
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• 제11권3호
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• pp.207-213
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• 2005

This paper deals with an autonomous flight guidance and control algorithm design for TR301 tilt-rotor airplane under development by Korea Aerospace Research Institute for simulation purpose. The objective of this study is to design autonomous flight algorithm in which the tilt-rotor airplane should follow the given waypoints precisely. The approach to this objective in this study is that, first of all, model-based inversion is applied to the highly nonlinear tilt-rotor dynamics, where the tilt-rotor airplane is assumed to fly at helicopter flight mode(nacelle angle=0 deg), and then the control algorithm, based on classical control, is designed to satisfy overall system stabilization and precise waypoint following performance. Especially, model uncertainties due to the tiltrotor model itself and inversion process are adaptively compensated in a simple neural network(Sigma-Phi NN) for performance robustness. The designed algorithm is evaluated in the tilt-rotor nonlinear airplane in helicopter flight mode to analyze the following performance for given waypoints. The simulation results show that the waypoint following responses for this algorithm are satisfactory, and control input responses are within control limits without saturation.

• EDISON SW 활용 경진대회 논문집
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• 제5회(2016년)
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• pp.183-189
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• 2016

In this paper, an optimization study on a helicopter rotor blade cross-section was made. Generalization was made to the baseline cross-section to simplify the analysis. To have better performance in aeroelastic response, with the aerodynamic center being the origin of the baseline, the distance between aerodynamic center and shear center, and the distance between mass center and shear center of the blade were minimized. For efficient searching of optimum solutions over the design space, grid search method, which is a method of graphical search was used. Two design variables, radius of balancing weight at leading edge, and offset of the spar from leading edge were selected for the study. Cubic spline interpolation method was used to accommodate searching of the optimum solution. 2-Leveled searching system was devised in accordance with the interpolation method. Optimum solution was found to show 6% decrease in both distance between aerodynamic center and shear center, and mass center and shear center to the baseline.