• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.9
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• pp.639-646
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• 2022

Landing site searching algorithms are developed for a quadrotor using a depth map in unknown environment. Guidance and control system of Unmanned Aerial Vehicle (UAV) consists of a trajectory planner, a position and an attitude controller. Landing site is selected based on the information of the depth map which is acquired by a stereo vision sensor attached on the gimbal system pointing downwards. Flatness information is obtained by the maximum depth difference of a predefined depth map region, and the distance from the UAV is also considered. This study proposes three landing methods and compares their performance using various indices such as UAV travel distance, map accuracy, obstacle response time etc.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.502-509
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• 2019

Studies have been made on performance evaluation of expansion joint systems for an ordinary highway or road bridge. However little study has been made for runway connection bridges at airports. A study on performance evaluated from computer code analysis and shrinkage, extension, and compression repetition tests based on KS F 4425 is conducted to a newly developed expansion joint system which has been installed in a runway connection bridge at Incheon Airport Extension 2 Construction Site. The MIDAS computer code is used to analyze the performance before the manufacture of the mock-up of expansion joint system on the basis of design requirements. Tests based on the KS F 4425 of 2001 year-version are conducted for the mock-up. Domestic codes and standards to validate the performance of the expansion joint system in a connection bridge have been developed for a vehicle. However the expansion joint system tested in this study is installed in a runway connection bridge for an aircraft. Conservatively the heaviest one among airplanes departing and landing at Incheon Airport is assumed level-F $468.4kN/m^2$ and adopted for the tests and analyses in this study. KS F 4425 method is selected for the shrinkage, extension, and compression repetition tests. No remarkable problem was observed for the 2,500-cycle shrinkage and extension and two million-cycle repeatition load tests. The results of this study are expected to contribute to establishment of code and standard for the performance validation of an expansion joint system installed in a runway connection bridge for an aircraft by providing performance test results and computer analysis results based on finite element methods.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.2
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• pp.105-114
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• 2008

In this study, the sizing and performance analysis program is developed for the canard rotor wing(CRW) aircraft which operates in dual modes (fixed wing mode and rotary wing mode). The developed program is verified for both fixed wing and rotary wing modes using the existing aircraft data and the design optimization formulation is made to perform the reconnaissance mission. For the canard rotor wing aircraft optimization , multi-objective function is constructed to consider both the fixed wing mode and rotary wing mode the weighting factor. For six design cases with different weighting factors and different design constraints, the optimization is performed and improved rotor design results are derived.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.4
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• pp.336-346
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• 2017

Applications of Sigma-Delta STAP, and a method of GMTI processing are presented for GMTI(Ground Moving Target Indication) mode of airborne radar with sigma, delta, and guard channels. We showed results of performance analyses of presented methods by clutter simulation with ICM(Internal Clutter Motion), signal processing simulation and MDV(Minimum Detectable Velocity). Presented methods for Sigma-Delta STAP and GMTI processing are easy to apply practically in GMTI mode of airborne radar without restriction by specific airborne radar system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.1
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• pp.20-27
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• 2002

Aircraft design requires the intergration of several disciplines, inculding aerodynamics, structures, controls. To achieves advances in performance, each technology, or discipline must be more accurate in analysis and must be more highly intergrated. One of the important interdisciplinary interactions in mordern aircraft design is that of aerodynamics and structures. In this study, for increasing accuracy in each discipline's analysis, CFD for aerodynamic analysis and FEM for structurral analysis was used and, for considering important interdisciplinary interactions, aeroelastic effect was considered. As optimization algorithm, PBIL algorithm was used for global optima and was parallelized to alleviate the computational burden. The efficiency and accuracy of the present method was assesed by range maximiziation of reference of reference wing.

• Information and Communications Magazine
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• v.25 no.6
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• pp.18-24
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• 2008

항공분야 산업은 기계/전자/소재/정보통신 등 첨단과학기술이 유기적으로 융합되어 운영되는 대표적인 IT융합산업이다. 특히, 항공기에서 IT기반 기술이 융합되어 적용되는 곳은 조종사의 성공적인 임무수행을 위한 항공기에 탑재된 응용 소프트웨어와 항공전자장비들로 구성된 항공 임베디드 시스템이다. 항공 임베디드 시스템은 항공기의 성능과 직결되고 신규 개발 및 성능 개량 시 필수적으로 개발해야하는 시스템 종속적인 1차 시스템과 시스템 독립적이며 국내외 부품시장에서 구매 가능한 서브시스템인 2차 시스템으로 나눌 수 있다. 최근 기간산업에 IT 활용 비중이 점차 높아짐에 따라 IT가 기간산업의 경쟁력을 좌우하는 핵심 요소로 부상하고 있으나, IT산업은 성장이 점차 둔화되고 있는 실정이다. 지식경제부는 이에 따라 기간산업의 경쟁력을 높이고 IT기반 융합신산업을 창출하기 위해 5대 IT융합 신 산업 창출과제를 발표했다. 5대 과제중의 하나인 국방전력 극대화 사업으로 우리 기술로 개발한 초음속 고등훈련기인 T-50에 탑재되는 임베디드 소프트웨어 및 컴퓨터를 국산화하고 있다. 본 사업으로 비행운용프로그램, 실시간 운영체제, 미들웨어, 임무컴퓨터 및 무장관리컴퓨터 등이 순조롭게 개발될 경우 전량수입에 의존하고 있는 T-50의 1차 시스템을 100% 국산화할 수 있을 것으로 기대되며 수입대체 효과와 유지보수비용 절감으로 약 2조원의 부가가치 창출이 예상된다. 본 논문에서는 현재 개발을 진행하고 있는 항공 임베디드 시스템에 대하여 알아본다.

• Proceedings of the ESK Conference
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• 1993.10a
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• pp.145-162
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• 1993

조종실은 항공기-조종사 시스템에서 항공기와 조종사간의 긴밀한 상호작용이 이루어지는 유일한 공유영역으로서, 조종사의 인간성능 특성과 조종업무 특성의 체 계적 반영이 요구되어 진다. 인간공학적으로 설계된 조종실은 조종 편이성, 운용성 및 비행 안정성의 향상을 가져올 수 있다. 항공산업 육성의 초기 단계에 있는 국내 에서는 항공기 장비성능 개발 연구가 활발히 진행되고 있으나, 조종실에 대한 인간 공학적 분석 연구는 미흡한 실정이다. 조종사의 인간요소특성에 적합한 조종실 공 간을 체계적으로 설계하기 위하여, -조종실 공간 설계요소의 체계적 추출 및 계층적 구조 설정 -공간 설계에 적용될 인체측정요소의 정의 및 계층적 구조 설정, -설계요 소의 특성 파악을 위한 설계요소간 연관관계 분석, -설계요소와 인간요소간의 연관 관계 분석, -기존 전투기, 훈련기의 설계 제원 현황 및 설계지침 파악, -한국인 인체 측정자료의 Data Base화, -인간공학적인 조종실 공간 설계제원 분석을 수행하였다. 조종실 공간 설계요소로는 143 항목이 정의 되었으며, 설계요소들 간의 연관관계 Matrix 분석을 통하여 선행/병행/후행 설계요소 및 설계요소의 중요도가 파악되었다. 조종실 공간 설계에 적용될 인간 측정요소로는 133개 항목이 정의 되었으며, 설계요소 와 인간요소간의 연관관계 분석을 통하여 설계요소별로 고려되어질 인간요소를 분석 하였다. 또한 설계요소와 관련된 다른 설계요소, 인간요소 및 인체측정치, 설계지침을 종합적으로 적용함으로써 인간공학적인 조종실 공간 설계제원을 제시하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.4
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• pp.287-294
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• 2008

This paper describes an implementation of a wide-range dimming controller of a LED backlight for Avionics applications such as a control display unit(CDU) and multi-function display(MFD). The digital dimming controller employing a current controlled buck converter and light sensor feedback is proposed. The proposed system provides a wide dimming control range of from 150fL to 0.05fL(3000:1) required for avionic displays. The experimental results are provided to show the control performance.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.3
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• pp.311-320
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• 2022

In this paper, we studied the optimal method of improving performance for aircraft having various variants within the same type. The study defined configuration of an entire fleet of aircraft being subject to a performance improvement program. And selected the most complicated aircraft configuration among them as a Standard Aircraft for modification by according to the proposed Aircraft Selection Process for developing an optimal Aircraft Performance Improvement Process. Based on the selected the Standard Aircraft, drew a system integration design result and carried out Evaluation Test and obtained Airworthiness Certification. Created the database with the design data of the Standard Aircraft, Evaluation Test, and Airworthiness Certification results, and applied it to variants of aircraft to complete the performance improvement program with optimized schedules and costs. By applying the proposed method to IFF performance improvement program, drew optimal system integration design and completed the program with minimized schedule.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.30 no.1
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• pp.38-43
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• 2022

As the use of unmanned aerial vehicles increases, in order to expand the operability of the unmanned aerial vehicle, it is essential to develop an unmanned aerial vehicle traffic management system, and to establish the system, it is necessary to analyze the integrated navigation performance of the unmanned aerial vehicle to be operated. Integrated navigation performance is affected by various factors such as the type of unmanned aerial vehicle, flight environment, and guidance law algorithm. In addition, since a large amount of flight data is required to obtain high-reliability analysis results, efficient and consistent flight scenarios are required. In this paper, a flight scenario that satisfies the requirements for integrated navigation performance analysis of rotary and fixed-wing unmanned aerial vehicles was designed and verified through flight experiments.