• International Journal of Aerospace System Engineering
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• 제5권1호
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• pp.9-18
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• 2018

The longitudinal flight parameters of a light airplane are estimated from flight test data by use of the output error method. The reliability of the flight test measurement is examined in engineering judgment, scatter and Cramer-Rao bound, which turns out to be satisfactory with minor defects. Estimated parameter values are validated by comparing the simulated responses with the ones from actual flight tests. The FTD(Flight Training Device) of a light airplane turns out to satisfy the qualification of FAA Level 5 FTD in longitudinal motion. All the necessary practices for generation of high-fidelity data in longitudinal motion of a light aircraft are successfully performed in this study.

• 항공우주기술
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• 제11권1호
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• pp.178-184
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• 2012

본 논문에서는 초경량항공기의 사고 예방을 위한 실시간 안전진단 시스템(Health and Usage Monitoring System; HUMS)을 개발함에 있어 Test-bed 항공기에 HUMS를 적용한 주익 제작 과정을 살펴보고자 한다. 대상 항공기는 Jabiru-UL 모델이며, 주익 내부에 설치한 센서는 광섬유센서, 압전센서 및 스트레인 게이지이다. 센서 설치 후 조립을 완료한 주익에 대한 각 센서의 동작 여부에 대한 계측시험을 수행하였다. 조립 완료한 주익은 항공기에 장착되어 HUMS의 운영 성능 향상을 위한 데이터 획득 및 고장검출 알고리즘의 검증을 위한 Test-bed로 활용하고자 한다.

• 항공우주기술
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• 제7권1호
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• pp.142-150
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• 2008

KSLV-I 발사체에 탑재되는 원격측정시스템, 추적시스템, 비행종단시템, GPS, 관성항법유도시스템의 개별적인 성능과 고홍우주센터 및 제주추적 소에 설치된 지상장비와의 연계성능을 확인하기 위하여 항공기를 이용한 비행시험이 요구된다. 시험에 적용할 탑재장비의 선정, 하니스, 운용방법, 안테나 부착방법 등의 면밀한 계획과 분석을 통해 시험의 효율성이 향상되기 때문에 KSLV-I의 통신환경과 비행프로파일 둥이 비행시험에 최대한 정확하게 고려되어야 한다. 본 논문에서는 KSLV-I 전자탑재장비의 목록과 규격, 비행시험용 랙과 하니스, 항공기 제원, 비행궤적 둥 효과적인 비행시험을 위해 준비 및 분석되어야 하는 전반적인 사항이 제시된다.

• 한국소음진동공학회논문집
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• 제25권8호
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• pp.568-574
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• 2015

The present study was conducted by using stereo pattern recognition method(SPR method) to measure the displacement and vibration of an airplane wing in flight condition. A SPR based measurement system was developed using two visible light stereo cameras. The visible light stereo images were processed to obtain marker points by adaptive threshold method and marker filtering technique. The marker points were used to reconstruct 3D point, displacement, and vibration data. The SPR system was installed on F-16 fighter. The wing displacement and vibration were measured in flight condition. Therefore, this paper presents a possibility that SPR based measurement system using visible light stereo camera can be very useful for measuring displacement and vibration of an airplane in flight condition.

• International Journal of Aeronautical and Space Sciences
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• 제15권4호
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• pp.345-355
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• 2014

This paper focuses on aerodynamic and inertial modeling of the propeller for its applications in flight dynamics analyses of a propeller-driven airplane. Unsteady aerodynamic and inertial loads generated by the propeller are formulated using the blade element method, where the local velocity and acceleration vectors for each blade element are obtained from exact kinematic relations for general maneuvering conditions. Vortex theory is applied to obtain the flow velocities induced by the propeller wake, which are used in the computation of the aerodynamic forces and moments generated by the propeller and other aerodynamic surfaces. The vortex lattice method is adopted to obtain the induced velocity over the wing and empennage components and the related influence coefficients are computed, taking into account the propeller induced velocities by tracing the wake trajectory trailing from each of the propeller blades. Aerodynamic forces and moments of the fuselage and other aerodynamic surfaces are computed by using the wind tunnel database and applying strip theory to incorporate viscous flow effects. The propeller models proposed in this paper are applied to predict isolated propeller performances under steady flight conditions. Trimmed level forward and turn flights are analyzed to investigate the effects of the propeller on the flight characteristics of a propeller-driven light-sports airplane. Flight test results for a series of maneuvering flights using a scaled model are employed to run the flight dynamic analysis program for the proposed propeller models. The simulations are compared with the flight test results to validate the usefulness of the approach. The resultant good correlations between the two data sets shows the propeller models proposed in this paper can predict flight characteristics with good accuracy.

• 항공우주시스템공학회지
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• 제16권3호
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• pp.1-9
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• 2022

본 연구에서는 MDO 프레임워크 개발을 위하여 다양한 준경험적 방법에 근거한 해석적 방법으로 경비행기인 창공-91의 비행운동 특성 파라미터를 추출하고 비행시험 방법을 기준으로 비교하여 평가하였다. 비교 대상의 준경험적 분석 방법은 Perkins 방법, McCormick 방법, 그리고 Smetana 방법이며, 각각의 방법을 통하여 주요 안정성/조종성 미계수와 동안정 계수를 산출하였다. 이에 대한 비교 기준은 비행시험을 수행하여 취득한 데이터로부터 출력오차방법을 활용하여 비행운동 미계수와 동안정 계수를 추출하였다. 아울러 경비행기의 비행특성을 우리나라 국토교통부의 항공기기술기준(KAS, Korean Airworthiness Standard)의 항목과 미 군용의 MIL-F-8785C의 기준으로 분석하여 평가하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1300-1303
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• 1996

In this paper a typical problem is examined that a light, general aviation airplane, such as Cessna or Navion, in gliding turn flight shows helical-dive phenomenon when pilots try to stop the descent by using elevator only. It is known from pilot's experience that in a certain flight trim it is impossible to recover from helical-dive by using elevator only. From this study it is shown that helical-dive phenomenon is involved with longitudinal/lateral dynamics coupling to airplane's aerodynamics. Also this phenomenon consists of three parts of flight dynamics; first of all, fast longitudinal motion occurs, then is followed by a little slow lateral motion, and finally logitudinal/lateral coupled motion is fully developed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2965-2972
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• 2011

The 21th century is carried out a rearing activity of green industries as a part of friendly echo policy for preservation of earth environment. Korean government is spreaded on a whole country to setting up a goal to a sustainable growth power of national for low carbon green growth. The recently rolling stock is received the footlights as a best friendly echo transportation of transport system of automobile, airplane, ship etc., also that is playing a big role to reduction of $CO_2$ greenhouse gas and a discharge of air pollution. This study was carried out the investigation and analysis for technology trend of the system light-weighting of a recently urban railway vehicle on commercial operating in domestic and foreign countries. As the results are proposed a short-term development technology and a long-term development technology of the system light-weighting to be developed for reduction weight of urban railway vehicle.

• 천문학회보
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• 제40권1호
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• pp.81.3-81.3
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• 2015

Carbon Fiber Re-enforced Polymer (CFRP) has replaced steel, especially for mobile devices. As CFRP is stiff and light-weight, it has been applied to airplane, sport car, golf clubs, semiconductor transporter, satellites, etc. In the telescope, the plastic material was introduced to the supporting tubes or rods connecting the primary mirror assembly and the secondary mirror structure. Nowadays, even the mirror itself is produced by CFRP. In this poster, material properties and production of CFRP telescopes are presented, and pros and cons are discussed.

• 새물리
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• 제68권11호
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• pp.1268-1274
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• 2018

항공장애등이란 비행 중인 조종사에게 건축물이나 위험물의 존재를 알리기 위해 사용되는 등화를 말한다. 현재 대부분의 항공장애등의 광원은 발광다이오드(light-emitting diode, LED)로 대체되었고, 급격하게 확장 및 보급되었으나, 설치된 항공장애등이 광학적 성능 기준을 충족하지 못하여 항공 수송기기의 충돌 사고를 유발하고 있으며, 이러한 이유로 항공 안전상의 위험에 노출되어 있는 실정이다. 이러한 문제를 해결하기 위하여 본 연구에서는 $360^{\circ}$ 방향에서 동일한 광도 분포를 가지고, LED 광원에서 나오는 광선을 좁은 빔(beam) 발산각으로 시준할 수 있는 프레넬 렌즈(fresnel lens)를 각각의 비구면 조각의 집합 (array) 형태로 설계를 하였다. 그 후에, 렌즈 기울기(tilt), LED와 프레넬 렌즈 사이의 거리를 최적화하여 중심 광도 20,000 cd, $3^{\circ}$ 이상의 수직 빔 발산각을 구현하는 항공장애등 광학계 설계와 시뮬레이션을 진행하였다.