• Title/Summary/Keyword: space flight

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Three-dimensional Guidance Law for Formation Flight of UAV

  • Min, Byoung-Mun;Tahk, Min-Jea
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.463-467
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    • 2005
  • In this paper, the guidance law applicable to formation flight of UAV in three-dimensional space is proposed. The concept of miss distance, which is commonly used in the missile guidance laws, and Lyapunov stability theorem are effectively combined to obtain the guidance commands of the wingmen. The propose guidance law is easily integrated into the existing flight control system because the guidance commands are given in terms of velocity, flight path angle and heading angle to form the prescribed formation. In this guidance law, communication is required between the leader and the wingmen to achieve autonomous formation. The wingmen are only required the current position and velocity information of the leader vehicle. The performance of the proposed guidance law is evaluated using the complete nonlinear 6-DOF aircraft system. This system is integrated with nonlinear aerodynamic and engine characteristics, actuator servo limitations for control surfaces, various stability and control augmentation system, and autopilots. From the nonlinear simulation results, the new guidance law for formation flight shows that the vehicles involved in formation flight are perfectly formed the prescribed formation satisfying the several constraints such as final velocity, flight path angle, and heading angle.

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The Flight Test of the KSLV-I Electronic Systems Using a Light Airplane (경항공기를 이용한 KSLV-I 전자탑재장비 비행시험)

  • Ji, Ki-Man;Lee, Soo-Jin;Chung, Eui-Seung
    • Aerospace Engineering and Technology
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    • v.7 no.1
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    • pp.142-150
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    • 2008
  • In order to ensure the individual and mutual performances among the telemetry system, tracking system, flight termination system, GPS, and inertial navigation & guidance system which are installed in the KSLV-I 2nd stage and ground equipment of the Naro space center, flight test using a light airplane is required. Since the high degree of test efficiency is fulfilled through the minute plan and analysis about selection of the equipment which are applicable to the test, harness, operation strategy, and antenna installation. KSLV-I communication environment and flight profile should be precisely taken into account during the flight test. In this document, overall aspect of the KSLV-I 2nd stage equipment specification, a rack for the installation, harness, the airplane specification, and flight route which are required for the effective flight test are presented.

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Aerodynamic Design of the Solar-Powered High Altitude Long Endurance (HALE) Unmanned Aerial Vehicle (UAV)

  • Hwang, Seung-Jae;Kim, Sang-Gon;Kim, Cheol-Won;Lee, Yung-Gyo
    • International Journal of Aeronautical and Space Sciences
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    • v.17 no.1
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    • pp.132-138
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    • 2016
  • Korea Aerospace Research Institute (KARI) is developing an electric-driven HALE UAV in order to secure system and operational technologies since 2010. Based on the flight tests and design experiences of the previously developed electric-driven UAVs, KARI has designed EAV-3, a solar-powered HALE UAV. EAV-3 weighs 53kg, the structure weight is 22kg, and features a flexible wing of 19.5m in span with the aspect ratio of 17.4. Designing the main wing and empennage of the EAV-3 the amount of the bending due to the flexible wing, 404mm at 1-G flight condition based on T-800 composite material, and side wind effects due to low cruise speed, $V_{cr}=6m/sec$, are carefully considered. Also, unlike the general aircraft there is no center of gravity shift during the flight because of the EAV-3 is the solar-electric driven UAV. Thus, static margin cuts down to 28.4% and center of gravity moves back to 31% of the Mean Aerodynamic Chord (MAC) comparing with the previously designed the EAV-2 and EAV-2H/2H+ to upgrade the flight performance of the EAV-3.

Numerical Investigation of Aerodynamic Interference in Complete Helicopter Configurations

  • Lee, Hee-Dong;Yu, Dong-Ok;Kwon, Oh-Joon;Kang, Hee-Jung
    • International Journal of Aeronautical and Space Sciences
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    • v.12 no.2
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    • pp.190-199
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    • 2011
  • Unsteady flow simulations of complete helicopter configurations were conducted, and the flow fields and the aerodynamic interferences between the main rotor, fuselage, and tail rotor were investigated. For these simulations, a three-dimensional flow solver based on unstructured meshes was used, coupled with an overset mesh technique to handle relative motion among those components. To validate the flow solver, calculations were made for a UH-60A complete helicopter configuration at high-speed and low-speed forward flight conditions, and the unsteady airloads on the main rotor blade were compared to available flight test data and other calculated results. The results showed that the fuselage changed the rotor inflow distribution in the main rotor blade airloads. Such unsteady vibratory airloads were produced on the fuselage, which were nearly in-phase with the blade passage over the fuselage. The flow solver was then applied to the simulation of a generic complete helicopter configuration at various flight conditions, and the results were compared with those of the CAMRAD-II comprehensive analysis code. It was found that the main rotor blades strongly interact with a pair of disk-vortices at the outer edge of the rotor disk plane, which leads to high pulse airloads on the blade, and these airloads behave differently depending on the specific flight condition.

Research on the Method of a Composite Navigation Algorithm Using Aircraft Recorder Data (비행기록자료를 이용한 복합항법 알고리즘 구성)

  • Kim, Jae-Hyung;Lyou, Joon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.5
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    • pp.462-471
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    • 2008
  • Flight recoder is used to analyze the accident factors and prevent the accident. In the analysis of the flight recorder, the most important factor is how to estimate the precise location of the flight. Traditional aviation navigation is based on stable sensors such as DME and VOR. In order to enhance the precision of the location estimation, the integrated navigation algorithm is designed to incorporate DME, Air data sensors and INS(Inertial Navigation System). The results demonstrate that the proposed algorithm can achieve better accuracy, comparing with the traditional navigation schemes, in flight location estimation.

A Study for the Airworthiness Certification Criteria and Compliance Related to the Flight Control Law (비행제어법칙 감항인증 기준 설정 및 입증 연구)

  • Koh, Gi Ok;Ko, Joon Soo;An, Young Gab
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.7
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    • pp.569-576
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    • 2013
  • The Airworthiness Certification from the government has an increasingly important role due to the dramatic growth of military aircraft development industry. It is a mandatory process of qualifying the flight safety within the aircraft's operational boundaries throughout its life cycle. The introduction of airworthiness certification has resulted in development paradigm shift from one requirement for one consumer need to the common requirement for many needs. This research paper provide the refinement of airworthiness certification criteria related to the flight control law and the verification methods which comply with its criteria.