• 한국공간정보시스템학회:학술대회논문집
• /
• 2005.05a
• /
• pp.355-361
• /
• 2005

3차원 자료의 필요에 발맞추어 3차원 좌표를 직접적으로 획득할 수 있는 LIDAR 시스템이 등장하게 되었다 항공 LIDAR 시스템은 항공기, GPS, INS, Laser Scanner가 통합된 시스템으로 항공기에서 발사된 Laser의 반사파를 이용하여 거리와 그 때의 항공기의 자세, 위치를 통합하여 직접적인 3차원 포인트 자료를 획득할 수 있다. LiDAR 데이터는 지형, 건물, 식생 등의 지면위에 있는 모든 객체에 대한 3차원 자료와 영상자료를 함께 제공하고 있다. 이러한 LIDAR 자료로부터 DEM, DTM 등의 지형 정보와 식목, 건물 등 지물정보를 추출하는 연구가 활발하게 이루어지고 있다. 본 연구에서는 지형을 추출하는데 사용할 수 있는 몇 가지 필터링기법을 선정하여 국내의 다양한 지모, 지물에 적용하고 그 정확도를 평가해 보았다.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.24 no.2
• /
• pp.19-24
• /
• 2016

Positional stability analysis based on aerodynamic forces and induced moments of formation flight using two small aircraft models is presented. The aerodynamic force and moments of the trailing aircraft are analyzed in the aspect of flight stability. The induced moments with the change of local flow direction by wing-tip vortex from the leading aircraft can affect the flight positional stability of aircraft in closed formation flight. Aerodynamic forces and moments of trailing aircraft model are measured by 6-component internal balance at the 49 locations with vertical and lateral space between two aircraft models. Results are shown that the positional stability of trailing aircraft in formation flight can be analyzed by positional stability derivatives with vertical and lateral space. It is concluded that flying positions can be important factors for aircraft position stability due to induced aerodynamic force and moments with vertical and lateral spacing by the variation of flow pattern from the leading aircraft in formation flight.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.39 no.3
• /
• pp.242-253
• /
• 2011

The typical missions for the current stand-off UAVs are surveillance and reconnaissance. On the other hand, the primary mission for the future UCAS will be combat mission such as SEAD under the man-made ultimately hostile environment including SAM, antiaircraft artillery, threat radar, etc. Therefore, one of the most important challenges in UCAS design is improvement of survivability. The current studies for aircraft combat survivability are focused on the improvement of susceptibility and vulnerability of manned aircraft system. Although the survivability design methodology for UCAS might be very similar to the manned combat system but there are some differences in mission environment, system configuration, performance between manned and unmanned systems. So the parameters and their sensitivities which affect aircraft combat survivability are different in qualitatively and quantitatively. The susceptibility related parameters for F-16 C/D and X-45A as an example of manned and unmanned system are identified and the susceptibility parameter sensitivities are analyzed by using Monte-Carlo Simulation in this study.

• Journal of Advanced Navigation Technology
• /
• v.19 no.6
• /
• pp.492-498
• /
• 2015

With the rapid growth of technologies and demand of remotely piloted aircraft systems (RPASs), integration of such systems into the existing airspace is becoming an issue in many countries. To assess the impact of integrated operations of manned and remotely piloted aircraft (RPA), it is necessary to perform Human-in-The-Loop (HiTL) simulations of likely situations with an integrated simulation system. This paper defines several operational concepts for the integrated simulation. Several probable scenarios were developed including a traffic pattern at a small airport and an altitude maneuver at a route crossing. HiTL simulations were performed according to the developed scenarios. The simulation results are analyzed focusing on the impacts of different communication, safety, performance, and human machine interface (HMI) characteristics of RPA.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.44 no.4
• /
• pp.316-323
• /
• 2016

A UAV(Unmanned Aerial Vehicle) flies along pre-programed navigation points(in-flight, take-off, or landing) automatically without pilot input. Even though UAVs fly differently from general piloted aircraft as the pilot controls the aircraft from a ground station through means of a data-link system. Occasionally, the data-link connection can be lost for any number of reasons, in which case, the FLCC(Flight control Computer) must automatically switch to autopilot to continue flying. Hence, the FLCC is a flight-critical component that must be throughly tested and validated. This paper discusses the development of a HILS(Hardware in the Loop Simulation) test environment designed to simulate real flight conditions to verify the FLCC satisfies flying quality requirements and maintains robustness despite any potential malfunctions or emergency situations.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1993.04a
• /
• pp.112-117
• /
• 1993

최근의 급속한 산업발전에 의해 각종 기계나 내연기관의 운전조건이 가혹해 짐에 따라 윤활유의 물성도 점차 고성능화 되는 추세로 광유계윤활유에서 볼수 없는 높은 점도지수, 낮은 저온유동성, 우수한 화학적안정성등의 특성을 얻기 위해 유기합성방법에 의해 인위적으로 합성한 원료를 기유로 사용한 윤활유를 합성윤활유라 하며 합성기유는 작용기 종류, 합성방법에 다라 다양하게 분류된다. 합성윤활유의 종류에는 일반적으로 합성방법에 따라 폴리머형(P형)과 비폴리머형(N형)으로 대별되는데 폴리며형 합성에는 polybutene, polyalkyleneglycole, poly $\alpha$-olefin (PAO)와 diester가 주로 사용되고 있다. 본 연구에서는 그간 연구해온 광유계윤활유의 첨가제 합성, 혼련기술 및 PAO와 diester합성기술을 기초로 내연기관용 고성능 합성윤활유 혼련기술 개발과 더 나아가 항공기작동유나 Jet-engine유등 특수 윤활유 개발에 연구목적이 있다.

• Defense and Technology
• /
• no.8 s.138
• /
• pp.68-75
• /
• 1990

휴즈 항공사는 1050년대에 최초로 공대공 유도 미사일인 팰콘(Falcon)을 개발한이래 30여년 이상 첨단 전자기술분야에 참여하고 있다. 오늘날 휴즈사는 전자분야에서 미국내 가장 큰 방산업체이다. 휴즈사는 현재 유도 미사일, 항공전자, 통신위성, 전자광학, 항공기 레이다, 항공방위 지휘통제 시스템, 산업전자, 모의장비 및 훈련등 광범위한 기술분야에 참여하고 있다. 원래 세계군사장비에 탑재되는 항공전자장비 개발업체로 알려진 휴즈사는 신기술을 민수분야와 산업분야에 적용하였으며, 이에따라 우주시스템, 통신 서비스, 모의장비, 기타 첨단 전자 장비 및 민수용 장비 개발업체로 발전하였다. 지난 몇년동안 휴즈사는 미 국방부 매출액 10위권의 업체로 성장하였다.

• Current Industrial and Technological Trends in Aerospace
• /
• v.5 no.2
• /
• pp.87-97
• /
• 2007

오늘날 항공기 설계와 제작은 다국적인 산업의 형태로 이루어지고 있다. 즉 항공기 서브시스템은 세계 각국에서 독립적으로 설계, 제작 및 시험한 후 한 곳으로 납품되어 조립 제작되는 데 이 때 중요한 것이 표준화이다. 항공전자장비의 낙뢰 간접영향에 대한 인증의 경우 RTCA DO-160E, Section 22 Lightning Induced Transient Susceptibility(낙뢰 유도 과도현상 적응성)로 표준화 되어 있다. 이 Section 22는 낙뢰 간접영향에 대한 항공전자장비 단위 즉, LRU (Line Replaceable Units)와 같은 부품단위의 시험 요건을 규정하고 있으며 이 규격은 현재 전 세계적으로 통용이 되고 있다. 1980년대 초 상용 수송기에 디지털 "Fly by Wire" 비행 시스템과 엔진제어시스템(EEC, Electronic Engine Control)의 도입 이후, 항공기 시스템이 낙뢰 환경에서 운용시 신뢰성을 보증할 필요성이 대두되었다. 데이터 처리를 통하여 제어되는 각종 항공전자장비에는 다중타격(MS)과 다중파열(MB) 기법에 의한 시험 사항이 최근 추가 되었다. 실제 낙뢰 환경과 유사한 시험실 모사를 위해 계속적인 연구가 진행 중이며 신규 시험 규격서가 새로이 출간되고 있다.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.34 no.7
• /
• pp.55-62
• /
• 2006

This thesis describes collision avoidance using fuzzy logic based on "Right of way" rules of ICAO and FAA and pilot's experiences for Unmanned Aerial Vehicle(UAV). To apply the rules, we designed fuzzy logic based collision avoidance system. And we also designed decision logic for enable condition of collision avoidance system. Decision logic have three kinds of core key, i.e. Relative Range, Time of CPA(Closest Point of Approach) and Distance at CPA. Application of decision logic made a possible to avoid NMAC(Near Mid-Air Collision) and it has been verified through several simulations. To conclude, we proposed the method to carry out "See and Avoid" ability on UAVs, which is capability to mingle with manned aircraft in civil airspace.

• Journal of Advanced Navigation Technology
• /
• v.4 no.2
• /
• pp.114-131
• /
• 2000

An airline should consider the number of seats or size of aircraft, when it composes fleet or selects a type of aircraft for some routes. There are two major factors considered for this choice problem under the assumption that the objectives of an airline is a profit maximization: the operating cost and revenue from the aircraft operated. This research tries to solve the problem of aircraft size selection by airline. The study applies four steps to get optimal choice of aircraft size: (1) cost analysis for the relationship between airline operation cost and aircraft size: (2) market share and revenue analysis: (3) flight segment-level analysis, based on the derived cost, demand and revenue functions: and (4) network-level analysis to see how airlines make choice of aircraft size systematically at a network level. An airline can accommodate the increasing air travel demand by either increasing operation frequency, or increasing aircraft size that is represented by seat capacity, or both. Airport runway capacity and productivity depend on the size of aircraft used at airport. This paper presents the understanding of how airlines make decisions on the size of aircraft to operate, how they will adjust their choices when airport capacity is constrained, and how public regulation such as policy for landing fees could influence airlines' aircraft choice.