• Title, Summary, Keyword: 고정익

Search Result 176, Processing Time 0.032 seconds

How to Manage Aging Aircraft (노후 항공기 관리방안)

  • Choe, Se-Jong;Kim, Cheon-Yong
    • 한국항공운항학회:학술대회논문집
    • /
    • /
    • pp.202-208
    • /
    • 2016
  • 최근 5년간 발생한 국적 항공기 사고 23건 중 헬기사고가 16건으로 전체 항공사고의 70%를 차지한다. 현재 국내에서 고정익 항공기 549대, 회전익 항공기 186대가 각각 운영(군 경찰 보유헬기 제외)되고 있음을 감안하면 회전익 항공기 사고가 훨씬 높은 편이며, 고정익 항공기 가동시간에 비하여 가동률이 매우 낮은 회전익 항공기를 고려하면 비행시간당 항공기 사고 비율은 회전익 항공기가 월등하게 높은 편이다. 또한 고정익 항공기의 평균기령은 10.9년인데 비하여 산림항공본부를 비롯한 헬기운영업체에서 운영 중인 회전익 항공기의 평균기령은 18.9년으로 회전익 항공기가 전체적으로 노후화 되어 있으나, 국적항공사에 운영 중인 노후 항공기 관리프로그램을 회전익 항공기 운영사에서는 운영하지 않고 있다. 따라서 본 연구를 통하여 노후 항공기 운영현황을 검토하여 노후 회전익 항공기 운영기준을 수립하고 노후 회전익 항공기의 정비프로그램을 정립하여 회전익 항공기의 지속감항성을 확보할 수 있는 방안과 수명주기 설정을 마련하고자 한다.

  • PDF

Accuracy Assessment of Parcel Boundary Surveying with a Fixed-wing UAV versus Rotary-wing UAV (고정익 UAV와 회전익 UAV에 의한 농경지 필지경계 측량의 정확도 평가)

  • Sung, Sang Min;Lee, Jae One
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.35 no.6
    • /
    • pp.535-544
    • /
    • 2017
  • UAVs (Unmanned Aerial Vehicle) are generally classified into fixed-wing and rotary-wing type, and both have very different flight characteristics each other during photographing. These can greatly effect on the quality of images and their productions. In this paper, the change of the camera rotation angle at the moment of photographing was compared and analyzed by calculating orientation angles of each image taken by both types of payload. Study materials were acquired at an altitude of 130m and 260m with fixed-wing, and at an altitude of 130m with rotary-wing UAV over an agricultural land. In addition, an accuracy comparison of boundary surveying methods between UAV photogrammetry and terrestrial cadastral surveying was conducted in two parcels of the study area. The study results are summarized as follows. The differences at rotation angles of images acquired with between two types of UAVs at the same flight height of 130m were significantly very large. On the other hand, the distance errors of parcel boundary surveying were not significant between them, but almost the same, about within ${\pm}0.075m$ in RMSE (Root Mean Square Error). The accuracy of boundary surveying with a fixed-wing UAV at 260m altitude was quite variable, $0.099{\sim}0.136m$ in RMSE. In addition, the error of area extracted from UAV-orthoimages was less than 0.2% compared with the results of the cadastral survey in the same two parcels used for the boundary surveying, In conclusion, UAV photogrammetry can be highly utilized in the field of cadastral surveying.

Development of the Multi-Propeller based Attitude Control Method for VTOL type Compound Aircraft (VTOL 타입의 복합형 비행체에 적용가능한 다수 프로펠러 기반 자세제어기법의 개발)

  • Seung, Myeonghun;Han, Sanghyuck;Kim, Jongchul;Gong, Hyeon Cheol
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.45 no.6
    • /
    • pp.455-462
    • /
    • 2017
  • In recent decades, many researchers have been struggling to developing the compound aircraft that is capable high speed and VTOL flight. And in recent years, multi-copters are very popular because of having advantages of VTOL and easy handling, but they are lack of doing long-range mission. Therefore, we presents simple aircraft architecture which is equipped fixed wing, multi propellers and no control surfaces. In this paper, we designed the attitude control for the compound aircraft prototype and measured the attitude control performance with flight test for validating prototype's performance. We analysed the attitude control test result comparing with similar size of a fixed wing aircraft. The performance was almost same as fixed wing aircraft.

Availability Evaluation for Generation of Geospatial Information using Fixed Wing UAV (고정익 무인항공기를 이용한 공간정보 구축의 활용성 평가)

  • Park, Young Jin;Jung, Kap Yong
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.22 no.4
    • /
    • pp.159-164
    • /
    • 2014
  • These days, inexpensive and high efficiency UAV of disaster prevention and spatial information has been given more attention. But studies about test of accuracy of UAV were not enough despite high interest. This research produced DSM and ortho photo and estimated accuracy by comparing coordinates with GNSS survey to evaluate outcome of fixed wing UAV. The ortho photo was found to make use of it to update 1/1,000 map. This research investigated spatial information construction using existing terrestrial LiDAR to suggest effectiveness of fixed wing UAV.

Electric power Small fixed wing UAV Aerodynamic performance Analysis (전기 동력 소형 고정익 무인항공기 공력성능 연구)

  • Jeong, Seongrok
    • Journal of Aerospace System Engineering
    • /
    • v.13 no.1
    • /
    • pp.11-17
    • /
    • 2019
  • In this paper, the performance of a small fixed wing unmanned aerial vehicle is predicted theoretically with the minimum specifications and a low Reynolds number. Based on the results, it was compared with the results of an actual flight test and simple electric motor wind tunnel test. As a result of the validity of the analysis, a 3.5 kilograms class fixed wing small UAV can predict aerodynamic performance by general theory analysis. However, the required thrust was analyzed as a possible design error. Based on the results of this study, this paper proposed a method to minimize the design error when developing small fixed wing UAV flying in a low Reynolds number.

Model-Reference Adaptive Pitch Attitude Control of Fixed-Wing UAV (고정익 무인 항공기 피치 자세의 모델-참조 적응 제어)

  • Kim, Byung-Wook;Park, Sang-Hyuk
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.47 no.7
    • /
    • pp.499-507
    • /
    • 2019
  • Despite the well-known mathematical model of fixed-wing aircraft, there are various studies to meet desired performances by considering the modeling errors in the extended flight envelope. This paper proposes a new adaptation mechanism of model-reference adaptive control, which applies the Levenberg-Marquardt algorithm to the pitch attitude control of fixed-wing UAV. In addition, reference model in the adaptation law is set by referring to the dynamic properties of the plant model. The performance of the proposed adaptive control law is verified through simulations and flight tests.

CFD Analysis of Aerodynamic Characteristics of Regional Turboprop Aircraft Propeller (중형 터보프롭 항공기급 프로펠러 공력특성 전산해석)

  • Choi, W.;Choi, J.S.;Jung, I.M.;Kim, J.H.;Lee, I.W.;Han, S.H.;Won, Y.S.
    • 한국전산유체공학회:학술대회논문집
    • /
    • /
    • pp.447-452
    • /
    • 2011
  • Propeller shall have high efficiency and improved aerodynamic characteristics to get the thru5t to fly at high speed for the Regional turboprop aircraft. That is way Clark-Y airfoil which is used to conventional turboprop aircraft propeller is selected as a blade airfoil. Adkins method is used for aerodynamic design and performance analysis with respect to the propeller design point. Adkins method is based on the vortex-blade element theory which design the propeller to satisfy the condition for minimum energy loss. propeller geometry is generated by varying chord length and pitch angle at design point of Regional turboprop aircraft. The propeller design results indicate that is evaluated to be properly constructed, through analysis of propeller aerodynamic characteristics using the Meshless method and MRF, SM method.

  • PDF

Two-Dimensional Flow Behavior Through a Stage of an Axial Compressor (축류 압축기내의 2차원 유동 특성)

  • Hong, Seong-Hun;Baek, Je-Hyeon
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.20 no.8
    • /
    • pp.2561-2571
    • /
    • 1996
  • The flow in the turbomachinery is very unsteady due to the stator-rotor interaction. It has been indicated that the stator-rotor interaction has three distinct causes of unsteadiness: that is, the viscous vortex shedding, wake rotor interaction and potential stator-rotor interaction. In this paper, the mechanism of unsteady potential interaction and wake interaction in the stator-rotor stage flow is numerically investigated in two-dimensional view point. The numerical technique used is the upwind scheme of Van Leer's Flux Vector Splitting(FVS) and cubic spline interpolation is applied on zonal interface. Then, the flow field of a compressor stage composed of NACA 65410 is analyzed. Flow fields are found to be simulated reasonably by this method and the sensitivity due to back-pressure variation is more stronger than rotor-velocity variation.

On-site Demonstration of Topographic Surveying Techniques at Open-pit Mines using a Fixed-wing Unmanned Aerial Vehicle (Drone) (고정익 무인항공기(드론)를 이용한 노천광산 지형측량 기술의 현장실증)

  • Lee, Sungjae;Choi, Yosoon
    • Tunnel and Underground Space
    • /
    • v.25 no.6
    • /
    • pp.527-533
    • /
    • 2015
  • This study performed an on-site demonstration of the topographic surveying technique at a large-scale open-pit limestone mine in Korea using a fixed-wing unmanned aerial vehicle (UAV, Drone, SenseFly eBee). 288 sheets of aerial photos were taken by an automatic flight for 30 minutes under conditions of 300 m altitude and 12 m/s speed. Except for 37 aerial photos in which no keypoint was detected, 251 aerial photos were utilized for data processing including correction and matching, then an orthomosaic image and digital surface model with 7 cm grid spacing could be generated. A comparison of the X, Y, Z-coordinates of 4 ground control points measured by differential global positioning system and those determined by fixed-wing UAV photogrammetry revealed that the root mean squared errors were around 15 cm. Because the fixed-wing UAV has relatively longer flight time and larger coverage area than rotary-wing UAVs, it can be effectively utilized in large-scale open-pit mines as a topographic surveying tool.

Steady State Operational Characteristic Analysis of the Propulsion System for the Canard Rotor Wing UAV in three different Flight Modes (비행 모드에 따른 CRW UAV 추진시스템의 정상상태 운전특성 해석)

  • 공창덕;강명철;기자영;박종하;양수석;전용민
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • /
    • pp.215-218
    • /
    • 2003
  • In this study, a performance model of the Smart UAV propulsion system with ducts, tip jets and variable main nozzle, which has flight capability of the rotary wing mode for the take-off/landing and low speed forward flight as well as the fixed wing mode for high speed forward flight, has been newly developed. With the proposed model, steady-state performance analysis was performed at various flight modes and conditions, such as rotary wing mode, fixed wing mode, compound wing, mode altitude and flight speed.

  • PDF