• 제목/요약/키워드: Scaled Vehicle

검색결과 98건 처리시간 0.023초

스마트 무인기 TR-S2 형상의 정적 풍동시험 (Static Wind Tunnel Test of Smart Un-manned Aerial Vehicle(SUAV) for TR-S2 Configuration)

  • 최성욱;조태환;정진덕
    • 대한기계학회논문집B
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    • 제29권6호
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    • pp.755-762
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    • 2005
  • To evaluate the aerodynamic efficiency of TR-S2 configuration designed by SUDC, wind tunnel tests of $40\%$ scaled model were done in KARI LSWT. The aerodynamic characteristics of plain and Semi-Slotted Flaperon were compared, and vortex generators were installed to improve flow pattern along the wing surface. Effects of the control surface such as elevator, rudder, aileron, and incidence angle of horizontal tail are measured for various testing conditions. Test results showed that Semi-Slotted Flaperon produced more favorable lift, lift/drag, and stall margins and application of vortex generator would be best choice to enhance wing performance. Longitudinal, lateral and directional characteristics of TR-S2 were found to be stable for the pitch and yaw motions.

스마트 무인기 TR-S4 형상의 정적 풍동시험 (Static Wind Tunnel Test of Smart Un-manned Aerial Vehicle(SUAV) for TR-S4 Configuration)

  • 최성욱;김철완;이장연;정진덕
    • 대한기계학회논문집B
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    • 제30권10호
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    • pp.1012-1018
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    • 2006
  • To evaluate the aerodynamic efficiency of TR-S4 configuration, wind tunnel tests of 40% scaled model were done in KARI LSWT. TR-S4 configuration has different nacelle shape, larger EO/IR camera and aftward wing location compared with TR-S2. Component build-up test after adding each element of model is performed. Also effects of horizontal tail incidences, Flaperon and Aileron deflection. on aerodynamic characteristics are measured. Test results showed that TR-S4 configuration has favorable stability characteristics in longitudinal, lateral and directional for the pitch and yaw motions.

스마트 무인기 TR-E2 형상 풍동시험 결과 (Wind Tunnel Test of Smart Un-manned Aerial Vehicle(SUAV) for TR-E2 Configuration)

  • 윤성준;조태환;정진덕
    • 대한기계학회논문집B
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    • 제29권1호
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    • pp.35-45
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    • 2005
  • TR-E2 configuration designed by Bell Textron was tested in KARI 1-m wind tunnel. To explore aerodynamic characteristics for the given configuration, a $12\%$ scaled model was fabricated and tested. Wind tunnel test for TR-E2 had been performed by changing the incidence angles of wing and deflection angles of control surfaces. Test result showed that the lower wing incidence angle has more favorable lift to drag ratio compared with original design. Longitudinal and directional characteristics of TR-E2 were found to be stable for the pitch and yaw motions. However, the lateral stability of TR-E2 is not stable for certain control surface deflection.

온도에 따른 고분자 전해질형 연료전지시스템의 출력 특성 연구 (A Study on Performance Characteristics of PEMFC with Thermal Variation)

  • 박세준;신영식;정성찬;최정식;차인수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 춘계학술대회 논문집 에너지변화시스템부문
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    • pp.212-214
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    • 2009
  • The polymer electrolyte membrane fuel cell(PEMFC) with the advantages of low-operating temperature, high current density, low cost and volume, fast start-up ability, and suitability for discontinuous operation becomes the most reasonable and attractive power system for transportation vehicle and micro-grid power plant in a household. 200W PEMFC(Polymer electrolyte membrane fuel cell) system applied to middle and small-scaled micro-grid power system was constructed by this study, then the electrical characteristics and diagnosis of the fuel cell were analyzed with thermal variation.

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PMF 모델을 이용한 대기 중 PM-10 오염원의 확인 (Source Identification of Ambient PM-10 Using the PMF Model)

  • 황인조;김동술
    • 한국대기환경학회지
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    • 제19권6호
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    • pp.701-717
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    • 2003
  • The objective of this study was to extensively estimate the air quality trends of the study area by surveying con-centration trends in months or seasons, after analyzing the mass concentration of PM-10 samples and the inorganic lements, ion, and total carbon in PM-10. Also, the study introduced to apply the PMF (Positive Matrix Factoriza-tion) model that is useful when absence of the source profile. Thus the model was thought to be suitable in Korea that often has few information about pollution sources. After obtaining results from the PMF modeling, the existing sources at the study area were qualitatively identified The PM-10 particles collected on quartz fiber filters by a PM-10 high-vol air sampler for 3 years (Mar. 1999∼Dec.2001) in Kyung Hee University. The 25 chemical species (Al, Mn, Ti, V, Cr, Fe, Ni, Cu, Zn, As, Se, Cd, Ba, Ce, Pb, Si, N $a^{#}$, N $H_4$$^{+}$, $K^{+}$, $Mg^{2+}$, $Ca^{2+}$, C $l^{[-10]}$ , N $O_3$$^{[-10]}$ , S $O_4$$^{2-}$, TC) were analyzed by ICP-AES, IC, and EA after executing proper pre - treatments of each sample filter. The PMF model was intensively applied to estimate the quantitative contribution of air pollution sources based on the chemical information (128 samples and 25 chemical species). Through a case study of the PMF modeling for the PM-10 aerosols. the total of 11 factors were determined. The multiple linear regression analysis between the observed PM-10 mass concentration and the estimated G matrix had been performed following the FPEAK test. Finally the regression analysis provided source profiles (scaled F matrix). So, 11 sources were qualitatively identified, such as secondary aerosol related source, soil related source, waste incineration source, field burning source, fossil fuel combustion source, industry related source, motor vehicle source, oil/coal combustion source, non-ferrous metal source, and aged sea- salt source, respectively.ively.y.

실험적 방법에 의한 콘크리트 사장교의 보행자 중심 진동사용성 평가 (Vibration Serviceability Evaluation for Pedestrian of Concrete Cable-stayed Bridge by Experimental Method)

  • 강성후;최봉현;박선준
    • 한국방재학회 논문집
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    • 제11권2호
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    • pp.59-66
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    • 2011
  • 본 연구에서는 콘크리트 사장교를 대상으로 차량주행속도와 교면아스팔트의 포장 상태, 차량중량 등을 실험변수로 하여 차량이 교량을 주행할 때 교면(보도)진동이 보행자에게 미치는 진동사용성 평가 방법에 대해 연구하고 그 결과로부터 진동사용성 여부를 평가하였다. 특히, 실험변수 가운데 교면포장 상태를 BMS기준에 의해 A와 C등급으로 구분하였다. 여기에는 진동을 발생시키는 에너지원을 "환산중량"으로 정의하고 차량주행 속도와 차량중량의 자승근을 곱한 형태로 사용하였다. 환산중량 228.0~1161.9 km/h kN 범위 내의 동일한 실험 조건에서 얻어진 교면포장 상태 A등급의 경우에 대한 C등급 경우의 진동가속도 응답 비율은 1.23~1.43으로 분석되어 교면포장 상태가 진동가속도 응답을 결정짓는데 큰 영향을 미치고 있음을 확인 할 수 있었다. 연구대상 교량의 교면 진동가속도 응답을 추정할 수 있는 진동추정식을 신뢰도 50%, 90%, 95%로 구분하여 제시하였으며, 실험 교량에서 교면 포장 A등급과 C등급의 경우 각각 전체응답의 30%, 40%가 레벨 C(강하게 감지)범위, 70%, 60%가 레벨 D(명확하게 감지) 범위에 있는 것으로 나타났다.

지상시험장비를 통한 우주발사체 고공환경모사 기법 연구 (High-Altitude Environment Simulation of Space Launch Vehicle in a Ground-Test Facility)

  • 이성민;오범석;김영준;박기수
    • 한국항공우주학회지
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    • 제45권11호
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    • pp.914-921
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    • 2017
  • 우주발사체 고공환경모사의 실험적 연구는 우주발사체 발사 및 임무완수에 대한 독자적 기술력 확보를 위해 중요하다. 본 연구는 한국형발사체(Korean Space Launch Vehicle; KSLV-II)의 발사 후 마하수 6을 돌파하는 고도 65 km 조건을 선정하였다. 지상시험장비중 하나인 충격파 터널을 이용하여 고공환경모사를 수행하였다. 유동발달 이후 공기열역학적 특성과 수직 및 경사충격파 확인을 위해 선두부 모델의 정체 압력과 정체 열 유량, 그리고 반구형상 모델의 충격파 이탈거리 측정을 통해 유동검증을 수행하였다. 추가적으로 발사체 측면과 저부면 현상연구에 사용되는 시험모델의 자유류 회복을 위한 충격파 상쇄 기법을 개발 및 검증하였다. 세 가지 유동검증 결과를 통해 이론값과 약 ${\pm}3%$ 이내의 오차를 갖는 정확한 유동이 발달되었음을 확인하였다. 그리고 충격파 상쇄기법을 갖는 천이구간 축소 모델의 경사충격파 경사각과 수평 평판모델의 경사각, 그리고 모델 측면 정압력의 실험값과 이론값의 오차가 각각 2%, 그리고 1% 으로 확인되었으며, 이를 통해 해당 충격파 상쇄 기법의 합리적인 효과가 검증되었다.

자기상보 원리를 이용한 UAV 탑재용 초광대역 반파장 루프 안테나 (A Ultra-wide Band Half-wavelength Loop Antenna using Self-complementary Principle for UAV Applications)

  • 윤명한;김준원;우종명
    • 한국인터넷방송통신학회논문지
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    • 제15권2호
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    • pp.213-219
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    • 2015
  • 본 논문에서는 무인 항공기에 장착 가능한 초광대역 반파장 루프 안테나를 설계하였다. 설계된 안테나는 야구공 모양에 자기상보 원리(self-complementary principle)를 적용하여 광대역 특성을 얻었다. 또한 저자세로 변형하기 위해 방사체 사이에 접지면을 두어 image theory를 적용하였다. 이렇게 설계된 초광대역 반파장 루프 안테나의 크기는 $0.20{\lambda}_L{\times}0.14{\lambda}_L{\times}0.16{\lambda}_L$ (${\lambda}_L$은 최저주파수의 공기 중 한 파장)이며, -10 dB 대역폭은 50 : 1(0.3 GHz ~15 GHz) 이상으로 측정되었다. 방사패턴은 모든 주파수에서 모노폴 안테나와 유사한 패턴을 가진다. 또한 설계된 안테나를 축소된 UAV(Unmannded Aerial Vehicle)의 동체 배면에 장착하여 그 특성 확인결과 초광대역 특성을 유지하면서, 모든 주파수 대역에서 모노폴 안테나와 유사한 방사패턴을 나타내었다.

상대속도를 고려한 포텐셜 필드 기반 군집 무인수상선의 대형 제어 (A Formation Control of Swarm Unmanned Surface Vehicles Using Potential Field Considering Relative Velocity)

  • 백승대;김민승;우주현
    • 대한조선학회논문집
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    • 제61권3호
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    • pp.170-184
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    • 2024
  • With the advancement of autonomous navigation technology in maritime domain, there is an active research on swarming Unmanned Surface Vehicles (USVs) that can fulfill missions with low cost and high efficiency. In this study, we propose a formation control algorithm that maintains a certain shape when multiple unmanned surface vehicles operate in a swarm. In the case of swarming, individual USVs need to be able to accurately follow the target state and avoid collisions with obstacles or other vessels in the swarm. In order to generate guidance commands for swarm formation control, the potential field method has been a major focus of swarm control research, but the method using the potential field only uses the position information of obstacles or other ships, so it cannot effectively respond to moving targets and obstacles. In situations such as the formation change of a swarm of ships, the formation control is performed in a dense environment, so the position and velocity information of the target and nearby obstacles must be considered to effectively change the formation. In order to overcome these limitations, this paper applies a method that considers relative velocity to the potential field-based guidance law to improve target following and collision avoidance performance. Considering the relative velocity of the moving target, the potential field for nearby obstacles is newly defined by utilizing the concept of Velocity Obstacle (VO), and the effectiveness and efficiency of the proposed method is verified through swarm control simulation, and swarm control experiments using a small scaled unmanned surface vehicle platform.

DYNAMIC CHARACTERISTICS OF SCALED-DOWN W-BEAMS UNDER IMPACT

  • Hui, T.-Y.-J.;Ruan, H.-H.;Yu, T.-X.
    • International Journal of Automotive Technology
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    • 제4권1호
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    • pp.31-40
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    • 2003
  • W-beam guardrail system has been the most popular roadside safety device around the world. Through large plastic deformation and corresponding energy dissipation, a W-beam guardrail system contains and re-directs out-of-control vehicles so as to reduce the impact damage on the vehicle occupants and the vehicles themselves. In this paper, our recent experiments on 1 : 3.75 downscaled W-beam and the beam-post system are reported. The static and impact test results on the load characteristics, the global response and the local cross-sectional distortion are reveled. The effects of three different end-boundary conditions for the beam-only testing are examined. It is found that the load characteristics are much dependent on the combined contribution of the local cross-sectional distortion and the end-supporting conditions. The energy Partitioning between the beam and the supporting Posts in the beam-Post-system testing were also examined. The results showed that the energy dissipation partitioning changed with the input impact energy. Finally, a simple mass-spring model is developed to assess the dynamic response of a W-beam guardrail system in response to an impact loading. The model's prediction agrees well with the experimental results.