• Title/Summary/Keyword: Air plane

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Design of an Autonomous Air Combat Guidance Law using a Virtual Pursuit Point for UCAV (무인전투기를 위한 가상 추적점 기반 자율 공중 교전 유도 법칙 설계)

  • You, Dong-Il;Shim, Hyunchul
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.42 no.3
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    • pp.199-212
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    • 2014
  • This paper describes an autonomous air combat guidance law using a Virtual Pursuit Point (VPP) in one-on-one close engagement for Unmanned Combat Aerial Vehicle (UCAV). The VPPs that consist of virtual lag and lead points are introduced to carry out tactical combat maneuvers. The VPPs are generated based on fighter's aerodynamic performance and Basic Fighter Maneuver (BFM)'s turn circle, total energy and weapon characteristics. The UCAV determines a single VPP and executes pursuit maneuvers based on a smoothing function which evaluates probabilities of the pursuit types for switching maneuvers with given combat states. The proposed law is demonstrated by high-fidelity real-time combat simulation using commercial fighter model and X-Plane simulator.

Flashover Characteristics of The Vertical Disposition Electrode Caused by Combustion Flames (연소화염에 의한 수직배치 전극의 플레시오버 특성)

  • Lee, Sang-Woo;Kim, Chung-Nyun;Lee, Seung-Wook;Kim, In-Sik;Kim, Lee-Kook;Bak, Jai-Yong
    • Proceedings of the KIEE Conference
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    • 2001.11a
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    • pp.208-212
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    • 2001
  • In this paper, characteristics of the ac and do flashover voltages in the vertical air gap of a needle-plane, sphere-plane and rod-plane electrode system were investigated when the combustion flames were present near the high-voltage electrode. As the results of an experimental we found that the reduction of flashover voltages characteristics with the vertical distance caused, in comparison with the no-flame case were about 1/3 times when a short sap d=1[cm] and 2[cm] of the ac voltages were applied. Also, flashover voltages characteristics of the do negative polarity under sphere-plane and rod-plane electrode system with the combustion flame were increased about two times than those of the do positive polarity.

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Implementation of a X-Plane and MATLAB/Simulink based Simulation System for Multiple UAVs (X-Plane 및 MATLAB/Simulink 기반의 복수무인기 모의실험 시스템 개발)

  • Moon, Sangwoo;Oh, Eun-Mi;You, Dong-Il;Shim, David Hyunchul
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.5
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    • pp.442-449
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    • 2013
  • In this paper, a simulation system based on X-Plane and MATLAB/Simulink for multiple UAVs is presented. For the conceptual design of this proposed system, a hierarchical system architecture for multiple UAVs is presented. This architecture has object-oriented data structure which consists of three objects (UAV status, mission and task, and environment) and a hierarchy consisting of four layers (decision making layer, task assignment layer, path and motion planning layer, and collision avoidance layer) is also proposed. In addition, this paper shows a implementation of simulation system based on the proposed system architecture using X-Plane and MATLAB/Simulink. The result of simulation from the developed system in this paper validate capability of application for multiple UAVs in real environment.

Torque Density Improvement of Five-Phase PMSM Drive for Electric Vehicles Applications

  • Zhao, Pinzhi;Yang, Guijie
    • Journal of Power Electronics
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    • v.11 no.4
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    • pp.401-407
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    • 2011
  • In order to enhance torque density of five-phase permanent magnetic synchronous motor with third harmonic injection for electric vehicles (EVs) applications, optimum seeking method for injection ratio of third harmonic was proposed adopting theoretical derivation and finite element analysis method, under the constraint of same amplitude for current and air-gap flux. By five-dimension space vector decomposition, the mathematic model in two orthogonal space plane, $d_1-q_1$ and $d_3-q_3$, was deduced. And the corresponding dual-plane vector control method was accomplished to independently control fundamental and third harmonic currents in each vector plane. A five-phase PMSM prototype with quasi-trapezoidal flux pattern and its fivephase voltage source inverter were designed. Also, the dual-plane vector control was digitized in a single XC3S1200E FPGA. Simulation and experimental results prove that using the proposed optimum seeking method, the torque density of five-phase PMSM is enhanced by 20%, without any increase of power converter capacity, machine size and iron core saturation.

Breakdown Characteristics for Imitation Air and $SF_6$ with Pressure Variation under Uniform and Non-Uniform Field (평등/불평등 전계하에서 제조공기(I-Air)와 $SF_6$에 대한 압력별 절연파괴특성)

  • Lee, Chang-Uk;Lee, Chang-Hun;Choi, Eun-Hyuck;Jang, Seung-Ho;Lee, Kwang-Sik
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2007.11a
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    • pp.259-262
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    • 2007
  • In this paper approves AC high voltage by experimental GIS(Gas Insulated Switchgear) chamber and AC 300[kV] power source to study breakdown characteristics by pressure(P) change and change of electrode distance(d) at AC high voltage of Imitation Air(I-Air, $N_2$ : $O_2$ = 79(%) : 21[%]) to alternate $SF_6$ and achieved research. Gave P change of I-Air to study I-Air's breakdown characteristics using uniform(Sphere-Sphere electrode) and non-uniform fields(Needle-Plane electrode) and studied relations breakdown voltage($V_B$) by each P different d.

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Design of Trapezoidal Air Screw for Elevators (엘리베이터용 사다리꼴 에어 스크류의 설계)

  • Park, Sang-Shin;Kim, Jin-Ho
    • Tribology and Lubricants
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    • v.24 no.1
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    • pp.14-20
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    • 2008
  • In this paper, the characteristics of trapezoidal air screws is studied. These screws can e applied to the elevator having column driving shaft. The generalized coordinate transformation technique is used to solve incompressible Reynolds' equation because the air lubricated plane is twisted. The transformed equation is discretized by the base of Finite difference method. Using Visual C++ language, a GUI program which can calculate he load carrying capacity for this kind of air screw is developed, then the design variables for these air screws is studied.

Breakdown Characteristics of Imitation Air under Non-Uniform Fields (불평등 전계하의 제조공기(I-Air)에 대한 절연파괴 특성)

  • Lee, Chang-Uk;Lee, Chang-Hun;Choi, Eun-Hyuck;Yoon, Dae-Hee;Jang, Seung-Ho;Kim, Jung-Bae;Park, Won-Zoo;Lee, Kwang-Sik
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2007.05a
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    • pp.385-388
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    • 2007
  • In this paper approves AC high voltage by experimental GIS(Gas Insulated Switchgear) chamber and AC 300[kV] power source to study breakdown characteristics by pressure(P) change and change of electrode distance(d) at AC high voltage of Imitation Air(I-Air, $N_2$ : $O_2$ = 79[%] : 21[%]) to alternate $SF_6$ and achieved research. Gave P change of I-Air to study I-Air's breakdown characteristics using non-uniform fields(Needle--Plane electrode) and studied relations breakdown voltage ($V_B$) by each P different d.

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Breakdown Characteristics of Imitation Air under Uniform Fields and Non-Uniform (평등/불평등 전계 하에서의 제조공기(I-Air) 절연파괴특성)

  • Lee, Chang-Uk;Lee, Chang-Hun;Choi, Eun-Hyuck;Kim, Jung-Bae;Lee, Kwang-Sik
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1424-1425
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    • 2007
  • In this paper approves AC high voltage by experimental GIS(Gas Insulated Switchgear) chamber and AC 300[kV] power source to study breakdown characteristics by pressure(P) change and change of electrode distance(d) at AC high voltage of Imitation Air(I-Air, $N_2$ : $O_2$ = 79[%] : 21[%]) to alternate $SF_6$ and achieved research. Gave P change of I-Air to study I-Air's breakdown characteristics using niform fields(Sphere-Sphere electrode) and non-uniform fields(Needle-Plane electrode) and studied relations breakdown voltage ($V_B$) by each P different d.

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Drying of Crops with Solar Heated Air -Drying of Rough Rice - (태양열을 이용한 농산물건조에 관한 연구 (I)-벼의 건조에 대하여)

  • 이문남;금동혁;류능환
    • Journal of Biosystems Engineering
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    • v.3 no.2
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    • pp.100-113
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    • 1978
  • Drying grain with conventional artificial drying methods requires great quantities of petroleum fuels. Depletion of fossil fuel increases the need of the utilization of solar energy as an alternative to petroluem fuels for drying grain , an energy intensive agricultural operation. Many techniques for the utilization of solar energy in grain drying have been developed, however, there are many problems in adopting solar energy as an energy sources for drying grain. Futhermore, very little research has been done on solar grain drying in Korea. This study was conducted to evaluate the availability of solar energy for drying of rough rice in Chuncheon, Suweon, and Jinju areas based on 50year meteorological data, and to analyze experimentally the performance of a solar air collector for dying grain, and to find the effects of solar heated air compared to unheated air on the rate of drying and energy consumption required for drying of rough rice. The results of this study was may be summarized as follows ; 1. Monthly average daily total radiation on a horizontal surface in October was 260.6 ly/day for Chuncheon, 240.3 ly/day for Suweon , and 253.4 ly/day for Jinju area, respectively. 2. the ratio of monthly average daily diffuse radiation to daily total radiation on a horizontal surface was approximately 0.41 for Chuncheon, 0.45 for Suweon, and 0.44 for Jinju area, respectively. 3. Although the statistical distribution curves of daily total radiation for the three locations were not identical , the differences among them were not large and may be neglected for many practical purposes. 4. I was estimated that the optimum tilting angle of the collector in October was approximately 46 degrees for Chuncheon and Suweon and 45 degrees for Jinju. 5. The ratio of the total radiation on a optimum tilting plane to that on a horizontal plane was estimated to be 1.36 for Chuncheon, 1.31 for Suweon, and 1.27 for Jinju , respectively. 6. The collection efficiency of the solar air collector ranged from 47. 8 to 51. 5 percent at the air flow rates of 251. 1-372.96 $m^3$/hr. High efficiency remained nearly , constant during the best sunshine hours, 10 a.m. to 2 p.m. and decreased during other hours. More energy was collected as the air flow rate incresed. 7. The average temperature rise in the drying air from the solar collector for the test period varied from $6.5^\circC$ to $21.8^\circC$ above the ambient air temperature. 8. Solar-dried rough rice averaged 13.7 percent moisture (w.b.) after 130 hours of drying with the air flow rate of 1. 64 ccm/$m^3$, and rough rice dried with natural air averaged 15.1 percent moisture (w.b.) after 325 hours of drying with the same air flow rate. 9. Energy saving of 2.4 kwh per $m^3$ percentage point of moisture removed was obtained from solar heated air drYing. The solar bin used 53.3 percent less energy per percentage point of moisture removed than the natural air bin.

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Unequal Distance Sampling Technique to Design Velocity-Type Respiratory Air Flow Transducer (속도 계측형 호흡기류센서 설계를 위한 비균등 샘플링 기법)

  • 김경아;이태수;차은종
    • Journal of Biomedical Engineering Research
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    • v.25 no.5
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    • pp.351-359
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    • 2004
  • Velocity-type repisratory air flow transducer measures dynamic pressure converted from air velocity based on the we1l-known Bernoulli's principle. It requires multiple velocity sampling holes on the flow plane. Measurement error theoretica1ly estimated by computer simulation was demonstrated to significantly reduce by unequally locating the velocity sampling holes. The flow plane was divided into multiple equi-area rings and the sampling holes were located on the circles also equally dividing each ring's area, which decreased measurement error down to 1/5 of the simple equi-radius ring division method. Also, less than 1 % relative error was estimated with 4 or more sampling holes. The present technique was less sensitive by <1/2 to the velocity profile change compared to the euqi-radius sampling. Therefore, the present unequal distance velocity sampling technique should be of great use to design the structure of the velocity-type respiratory air flow transducer.