• 한국항공우주학회지
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• 제42권2호
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• pp.173-180
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• 2014

본 논문에서는 한국형 기동헬기의 계기비행 인증절차 및 주요 비행시험 결과를 제시하였다. 한국형 기동헬기의 계기비행 인증을 위해 장착된 계기 및 장비의 적합성을 검토하였으며, 지상 및 비행시험을 통해 검증하였다. 아울러 항공기가 충분한 종축, 횡축 및 방향축에 대한 정안정성 및 동안정성을 보유하고 있는지를 확인하기 위해 FAR-29 Appendix B에 따라 시험을 실시하였다. 정안정성은 주로 조종입력에 대한 항공기의 속도 및 자세 변화를 통해 판단하였으며, 동안정성은 장주기 및 단주기 입력 후 항공기 거동이 얼마나 빨리 수렴하는지를 통해 평가하였다. 조종사의 임무부하 평가는 IMC 모사 비행시험을 통해 이뤄졌다. 본 논문에서는 항공기가 정상적인 상황뿐만 아니라 비행조종, 엔진 및 계기 등에 고장이 발생한 상황에 대한 임무부하 평가결과도 함께 제시하였다. IMC 모사 비행시험이 완료된 이후에는 실제 IMC 환경에서 항공관제에 맞춰 실제 계기비행시험을 실시하였다.

• 한국항공운항학회지
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• 제15권4호
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• pp.9-16
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• 2007

Tilt rotor aircraft can take off and land vertically and cruise faster than any other helicopter. A scaled flight demonstration model of a tilt rotor aircraft has been developed by KARI. Because the flight characteristics of tilt rotor are not well known, the developed scaled model would be helpful to evaluate flight control algorithm of a full scale aircraft. The tethered hover test has been performed in order to improve hover flight characteristics of tilt rotor aircraft prior to flight test of the small scaled model. During the tethered hover test, the performance of rotor speed governor, rate SAS (Stability Augmentation System) and control surface mixers have been evaluated. We expect that the results of real flight hover test would be quite same as tethered hover test. Therefore the tethered hover test results will reduce the risk of flight test properly by fixing some of hidden problems which might occur during the flight test. This paper presents the results of tethered hover test in detail and shows how it could be final ground test before flight test. The control mixer gain and rate SAS feedback gains were modified in order to get higher controllability and stability during the tethered hover flight. The rotor governor showed that it could keep rotor RPM constant with very small deviation even during severe pilot collective input change. The tethered hover test results gave pilot and engineers confirmation and experience about the scheduled flight test.

• 제어로봇시스템학회논문지
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• 제18권9호
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• pp.878-886
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• 2012

This paper investigates the implementation and flight test of realtime vision guided autopilot system based on virtual instrumentation platform. A graphical design process via virtual instrumentation platform is fully used for the image processing, communication between systems, vehicle dynamics control, and vision coupled guidance algorithms. A significatnt ojective of the algorithm is to achieve an environment robust autopilot despite wind and an irregular image acquisition condition. For a robust vision guided path tracking and hovering performance, the flight path guidance logic is combined in a multi conditional basis with the position estimation algorithm coupled with the vehicle attitude dynamics. An onboard flight test equipped with the developed realtime vision guided autopilot system is done using the rotary UAV system with full attitude control capability. Outdoor flight test demonstrated that the designed vision guided autopilot system succeeded in UAV's hovering on top of ground target within about several meters under geenral windy environment.

• 한국항공우주학회지
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• 제36권7호
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• pp.712-718
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• 2008

본 논문은 비행 중 비행제어법칙을 전환함으로써 실험 대상 비행제어법칙을 검증할 수 있는 비행제어법칙 전환시스템 개발에 관한 논문이다. 본 연구를 통하여 제어법칙 간 전환에 따른 천이응답을 최소화하기 위한 페이더 설계 및 대기 모드 상태에 있는 비행제어법칙의 적분기 안정화 설계가 도입되었다. 두 개의 제어법칙 간 데이터 통신은 1553 통신 방식을 채택하였다. 본 논문은 개발된 비행제어법칙 전환시스템의 구조 및 주요 개념 설계 연구 및 고등훈련기급의 비행성 평가 시뮬레이터를 이용한 시스템 검증 결과를 포함한다.

• 한국항공우주학회지
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• 제50권12호
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• pp.857-866
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• 2022

고정익 UAV는 다른 항공기 플랫폼보다 항속거리와 항속시간에서 큰 이점을 가진다. 이러한 이유로 군에서 정찰용으로 많이 사용된다. 본 연구에서는 랜딩기어를 포함한 고정익 UAV의 모델링을 실시하고, 비행조종컴퓨터에 사용될 유도 및 제어기 설계 및 HILS 환경 구축을 실시하였다. 또한 이륙, 순항, 착륙의 모든 과정을 자동으로 수행하는 오토파일럿 시스템을 제작하였다. 연구에 사용한 고정익 UAV를 Datcom 및 AVL 공력해석 소프트웨어를 사용하여 공력계수를 추출하고 6자유도 모델링을 실시하였다. 비행조종컴퓨터는 항공기의 16개의 비행모드를 분별하여 Carrot Chasing 기반 유도 명령을 생성하는 유도기와 Nonlinear Dynamic Inversion 기법을 사용한 제어기로 구성되어있다. SIMULINK를 사용하여 구현된 모델링과 비행조종컴퓨터는 RTNgine을 사용하여 HILS 환경을 제작하여 고정익 UAV의 통합 시뮬레이션 환경을 제작하였다.

• International Journal of Aeronautical and Space Sciences
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• 제18권4호
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• pp.740-756
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• 2017

This paper proposes a feedback-linearization-based control algorithm for multirotor unmanned aerial vehicles (UAVs). The feedback linearization scheme is highly efficient for considering nonlinearity between the rotational and translational motion of multirotor UAVs. We also propose a dynamic equation that reflects the aerodynamic effects of the vehicles; the equation's parameters can be determined through curve fitting using actual flight data. We derive the feedback linearization controller from the proposed dynamic equation, and propose a Luenberger observer to attenuate measurement noises. The proposed algorithm is implemented using our in-house flight control computer, and we describe its implementation in detail. To investigate the performance of the proposed algorithm, we carry out two flight scenarios: the first scenario, an autonomous landing on a moving platform, is a test of maneuverability; the second, picking up and replacing an object, test the algorithm's accuracy. In these scenarios, the proposed algorithm precisely controls multirotor UAVs, and we confirm that it can be successfully applied to real flight environments.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2012년도 추계학술대회
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• pp.259-260
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• 2012

본 논문은 저탄소사회 구현을 위해, 신재생에너지원에 관심을 갖고 있는 요즘에, 고공풍력을 이용하여 발전을 할 수 있는 Kite 자동비행에 대한 연구내용이다. 기존의 Kite Sport와 비행기술의 원리를 응용하여, 우선적으로 시제품을 설계/제작하여 시험비행 중이다. 첫 단계로는 RC 조종을 기반으로 한 수동비행제어에서도 Kite의 비행제어가 가능한지의 여부판단이 목적이고, 이를 통한 향 후, 자동비행제어 조건의 설계를 위해 필요로 하는 시험데이터 확보에 초점을 두었다. 현 시제품의 Kite 비행체 내부 구성과 시험내용을 보여주고 있으며, 향 후, 진행방향과 Kite를 통한 에너지활용 측면에서, 해양산업 및 생태문화 보존을 위한 도서지역의 전원공급에 대한 언급을 서술하였다.

• International Journal of Aeronautical and Space Sciences
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• 제11권4호
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• pp.285-302
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• 2010

Active aeroelastic control is an emerging technology aimed at providing solutions to structural systems that under the action of aerodynamic loads are prone to instability and catastrophic failures, and to oscillations that can yield structural failure by fatigue. The purpose of the aeroelastic control among others is to alleviate and even suppress the vibrations appearing in the flight vehicle subcritical flight regimes, to expand its flight envelope by increasing the flutter speed, and to enhance the post-flutter behavior usually characterized by the presence of limit cycle oscillations. Recently adaptive and robust control strategies have demonstrated their superiority to classical feedback strategies. This review paper discusses the latest development on the topic by the authors. First, the available control techniques with focus on adaptive control schemes are reviewed, then the attention is focused on the advanced single-input and multi-input multi-output adaptive feedback control strategies developed for lifting surfaces operating at subsonic and supersonic flight speeds. A number of concepts involving various adaptive control methodologies, as well as results obtained with such controls are presented. Emphasis is placed on theoretical and numerical results obtained with the various control strategies.

• 대한기계학회논문집A
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• 제31권10호
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• pp.1031-1038
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• 2007

A study on the development of control loading system for a pilot command in the helicopter flight training device is performed. The key issue of the device is how to provide closely the real feeling of the stick forces to the trainer during the flight training. Focusing on this proviso and considering the suitable approach than the complexity of the hydraulic system, we adopt the AC servo motor system although its inherent disadvantages such as the torque ripple and the stick-slip friction effect at a low control force. However, we overcome these detrimental effects by introducing the appropriate control device and the robust structural design of the actuating system, thereby the feasibility and applicability to the system can be obtained by showing good performance, meeting the required specification.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.148.3-148
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• 2001

This paper deals with a problem of decreasing the airspeed and the altitude of a transport aircraft using thrust only. Such a situation can occur, if the aircraft loses all hydraulic power that drives the control surfaces. A controller for flight path angle control is designed using the model following servo control method, which is a PI-type optimal regulator. For computer simulation, a simulation model that covers a range of flight envelope is made using given linear models and trim points at some flight conditions. Nondimensional aerodynamic coefficients, derivatives and trim points that are not at the given trim points are computed by linear interpolation. The model is effective in simulation where the trim point varies. Simulation using ...