• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.11
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• pp.1104-1111
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• 2008

The supersonic advanced trainer based on digital flight-by-wire flight control system uses aircraft flight information such as altitude, calibrated airspeed and angle of attack to calculate flight control law, and this information is measured by IMFP(Integrated Multi-Function Probe) equipment. The information has triplex structure using three IMFP sensors. Final value of informations is selected by mid-value selection logic to have more flight data reliability. As the result of supersonic flight test, pitch oscillation is occurred due to IMFP noise when altitude hold autopilot mode is engaged. This tendency may affect stability and handling quality of an aircraft during autopilot mode. This paper addresses autopilot control law design to remove pitch oscillation and these control laws are verified by non-real time simulation and flight test. Also, pitch response characteristics of pitch attitude hold autopilot mode is improved by upgrading the control law structure and feedback gain tuning during bank turn.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.5
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• pp.57-64
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• 2005

Modern versions of supersonic jet fighter aircraft using digital flight-by-wire flight control system receive aircraft flight condition such as altitude, airspeed and AoA(angle of attack) from IMFP(Integrated Multi-Function Probe). IMFP sensors data have triplex structure using three IMFP sensors. An air data reconfiguration mode is applied to a T-50 flight control law to guarantee the aircraft flight stability when 2 or 3 IMFP sensors data are invalided. In this study, linear analysis and HQS(Handling Quality Simulator) pilot simulation are performed to analyze flight stability when the air data reconfiguration mode is applied to the control law. And we propose an example that the air data reconfiguration mode is applied to the control law due to second failure of IMFP during T-50 flight. It is found that the aircraft flight stability is not affected when the T-50 flight control law is changed to the air data reconfiguration mode.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.7
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• pp.85-91
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• 2005

Supersonic jet fighter aircraft must have been guaranteed appropriate for controllability and stability in HAoA(High Angle of Attack) region. Limit value of aircraft enter the deep stall at HAoA is related to problem of aircraft configuration design. But, In order to guarantee the aircraft safety in HAoA, control law is designed using digital Fly-By-Wire flight control system in modern versions of supersonic jet fighter aircraft. Also, In order to recovery if aircraft enter the deep stall or spin, anti-spin control law and MPO(Manual Pitch Override) mode is designed. AoA limiter and MPO is designed in longitudinal axis and HAoA departure prevention logic, roll command limiter, rudder fader and anti-spin logic is designed in lateral-directional axis. In this paper, we introduce the T-50 HAoA flight control law and propose that aircraft stability and adequate of these control law from HAoA flight test.

• ICROS
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• v.7 no.6
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• pp.10-17
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• 2001

본 논문에서는 훈련용과 연구용 시뮬레이터들에서 차량조종 및 자동조종(autopilot) 시스템들을 시뮬레이션하기 위하여 공통적으로 사용되는 기술들을 소개한다. 여기서 언급하는 차량 조종 시스템들은 고정익기와 회전익기의 비행제어시스템은 물론 지상차량의 조종 시스템들을 모두 포함한다. 본 논문은 다양한 유형의 비행 및 지상차량 조종 시스템들에 대한 검토로 시작된다. 다음으로 차량조종 및 자동조종 시스템들의 시뮬레이션과 모델링, 조정 부하(control loading)라 통상 일컫는 조종감(control feel)의 시뮬레이션, 조종계통 모델링툴 시스템 통함 및 시스템 성능 비준 등의 주요 주제들이 이어진다.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.4
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• pp.42-47
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• 2008

The power control system of Smart UAV is similar to the propeller pitch governing concept of turboprop aircraft. The pilot adjusts the engine power directly and the pitch governor controls the propeller pitch to maintain the propeller rotational speed. The electronic engine controller(EEC) of PW206C engine developed for helicopter is not fit for the power control concept of Smart UAV, and therefore the manual back-up system of PW206C engine is used for the engine power control of Smart UAV. Engine performance estimation program is used to predict the control range of power lever angle(PLA) according to the variation of engine output shaft speed, flight altitude and flight speed. These data provide a guide for the PLA control in manual mode operation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.7
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• pp.105-111
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• 2006

The aircraft engine is to generate thrust for the maneuver of aircraft and to provide the power to the related hydraulic system and electrical system. Since the power provided to the systems is extracted from the high pressure compressor of aircraft engine, the extracted power is called horsepower extraction (HPX). If the HPX provided from the engine is smaller than the HPX required from the related systems, there could be abnormal engine behavior, like engine rollback or stall. Analysis on comparing the required HPX and the engine HPX capability had been performed during the T/A-50 FSD (Full Scale Development) period. The analysis results make the engine schedule changed, and T/A-50 flight test has been performed with the changed engine schedule. The analysis results and changing the engine control schedule were verified to be valid with the flight test results.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.10
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• pp.60-67
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• 2005

Modern version of supersonic jet fighter aircraft must have guaranteed appropriate controllability and stability in HAoA(high angle of attack). Limit value of aircraft entering into the deep stall in HAoA is related to aircraft configuration design. But, In order to guarantee the aircraft's safety in HAoA, control law for HAoA region implemented in digital Fly-By-Wire flight control system of supersonic jet fighter. The AoA limiter is designed for positive HAoA in longitudinal control law. But, aircraft departure during aggressive negative pitch maneuver such as push over in departure resistance flight test. Therefore negative AoA limiter is needed in longitudinal control law. Result of T-50 flight test show that the AoA is exceed the limit value during aggressive positive pitch maneuver in pull up of power approach mode. In this paper, the AoA limit control law in positive and negative AoA was proposed in order to improve aircraft controllability and stability.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.12
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• pp.1095-1102
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• 2016

This paper presents the results of the design, fabrication and tether test for a gross weight 20 kg tilt-duct VTOL aerial robot. The tilt-duct vehicle, a tri-ducts air-vehicle, which composed of two main tilt ducts for thrust and an aft-fan for pitch attitude control, has been developed as an aerial platform. The research on the air vehicle has been focused on the hover characteristics and controllability to improve the thrust and stability. The tether test for measuring various performance of vehicle and evaluating controllability have been carried out to figure out effects of modified main-prop linkage, actuator, duct configuration and control surfaces.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.8
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• pp.50-55
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• 2005

An advanced method of Relaxed Static Stability (RSS) is utilized for improving the aerodynamic performance of modern version supersonic jet fighter aircraft. The laws of flight control system utilize RSS criteria in both longitudinal and lateral-directional axes to achieve performance enhancements. Particularly, the design of longitudinal control laws for utilizing RSS methods greatly affects the performance of the aircraft in Air-to-Air Tracking and Air-to-Ground modes, which improves weapon delivery. In the area of Air-to-Air Tracking, the development of longitudinal control laws aids in the fine tracking and gross acquisition of other aircraft. This paper proposes that new concept of longitudinal control law introduce in order to improve fine tracking performance in air-to-air tracking maneuver. Result of HQS pilot simulation and flight test, fine tracking performance improve without degradation of gross acquisition when new concept of control law is applied.

• Defense and Technology
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• no.5 s.267
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• pp.52-59
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• 2001

본딩은 전기/전자 시스템뿐만 아니라 연료, 엔진, 비행제어, 유/공압계통 등에서도 안전한 전기적인 운용을 하기 위해서 필요하다. 항공기 개발에서 본딩은 설계시부터 요구조건을 두어 엄격히 관리해야 하며, 제작시에도 제시된 요구조건에 맞게 본딩을 해야 한다. 항공기의 전기/전자계통 설계시 요구성능과 항공기 및 운용자의 안전성 확보를 본딩 계통의 설계목표로 설정하고, 세부적인 본딩 요구조건과 유사기종의 설계개념을 보완하여 현실적으로 적용가능한 적용분야별 본딩 설치 및 설계 요구조건을 정립하는 것이 매우 필수적이라고 판단된다. 이 글에서는 항공기 설계시 고려해야 되는 본딩 일반요구조건에 대하여 기술해 보고자 한다.