• International Journal of Aeronautical and Space Sciences
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• v.13 no.1
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• pp.74-89
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• 2012

An adaptive backstepping controller is designed for the automatic landing of a fixed-wing aircraft. The backstepping control scheme is adopted by using the nonlinear six degree-of-freedom dynamics of the aircraft during the landing phase. The adaptive law is integrated along with the backstepping controller in order to estimate the aircraft modeling errors as well as the external disturbance. The dynamic constraints of the states and the actuator inputs are taken into account in the parameter adaptation. This is done to prevent an aggressive adaptation and to provide reliable control commands. Numerical simulations were performed to verify the performance of the proposed control law for the landing of the aircraft with the presence of gust and actuator stuck.

• Journal of Aerospace System Engineering
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• v.6 no.4
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• pp.18-23
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• 2012

The fuel boost pump for the aircraft was first indigenously developed in Korea. It is one of the core component for fuel subsystem and composed of motor assembly, impeller assembly, and body assembly with BLDC motor. It shall provide some amount of fuel to engine system continuously for any flight condition considering sudden altitude change and any attitude. This paper describes the procedures and the results for the design, the integration, and the performance analysis of the fuel boost pump.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.2
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• pp.344-351
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• 2017

This paper presents a method to estimate steady wind and airspeed bias error using an aircraft with GPS and airspeed sensor. The estimation uses the vector relation between the inertial, air, and wind velocities through a novel design of an extended Kalman filter. The observability analysis is also presented to show that the aircraft is required to keep changing its flight direction for the desired observability. The feasibility and performance of the proposed algorithm is demonstrated through simulations and flight experiments.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.423-427
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• 2003

In this paper, it is to development of brake system with ABS function for aircraft. The test of brake system is required before applying on aircraft. The real-time dynamic simulator with 5-D.O.F. aircraft dynamic model is developed for braking performance test of ABS (Anti-skid Brake System) control h/w with anti-skid brake functions. The dynamic simulator is real-time interface system that is composed of dynamic simulation parts, master control parts, digital and analog in/out interface parts, and user interface parts. The 5-D.O.F. aircraft dynamic model is composed of a big contour and a little contour by simulation s/w. The big contour represents the interactions of forces in airframe, nose and main landing gear, and engines on the center of gravity. The little contour represents interactions of wheel, braking units, hydraulic units and a control unit. ABS control h/w unit with ABS control algorithm is also developed and is tested with simulator under the some conditions of gripping coefficient. We have known that ABS control h/w unit on wet or snowy runway as well as dry runway very well protects wheel skid.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.6
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• pp.764-772
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• 2014

The stealth performance of supersonic aircraft in recent air battlefield is one of the most significant feature for latest fighters. Especially, as the technology is advancing, the IR stealth capability becomes more important because of its passive characteristic. To design an aircraft with stealth capability, we must know how much the IR signature is generated from the aircraft. Also, predicting the IR signature of enemy's aircraft is tactically crucial. In this study, we calculated MWIR and LWIR infrared signature of $5^{th}$ generation supersonic aircraft against air-to-air and surface-to-air threat using IR simulation code and CFD coupled procedure.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.8
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• pp.649-656
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• 2013

High-lift devices have a major influence on takeoff, landing and stall performance of an aircraft. Therefore, a slotted flap design optimization process is proposed in this paper to obtain the most effective flap configuration from supported 2D flap configuration. Flap deflection, Gap and Overlap are considered as main contributors to flap lift increment. ANSYS Fluent 13.0.0$^{(R)}$ is used as aerodynamic analysis software that provides accurate solution at given flight conditions. Optimum configuration is obtained by Sequential Quadratic Programing (SQP) algorithm. Performance of the aircraft with optimized flap is estimated using Aircraft Design Synthesis Program (ADSP), the in-house performance analysis code. Obtained parameters such as takeoff, landing distance and stall speed met KAS-VLA airworthiness requirements.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.2
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• pp.114-121
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• 2019

Tailless aircraft have advantages of low visibility compared to conventional aircraft, but drawback of poor stability as well which makes designing controller difficult. The controller design is more difficult, especially when the center of gravity moves due to store release or fuel consumption during flight. In this paper, an L1 adaptive controller is proposed as a way to overcome these problems. The reliability and performance of the controllers were verified by non-linear simulations. RPV Flying Quality Design criteria were used for design criteria. Using the simulation, it is shown that the adaptive controller maintains stability of the unmanned aircraft for sudden large change in the inertial properties. It is also shown that the calculation burden can be reduced when it is used with the gain scheduling method.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.4
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• pp.59-69
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• 2018

This study deals with the case study on the pallet quantity determination problem for the flexible manufacturing system producing 32 different types of aircraft wing ribs which are major structures of an aircraft wings. A Korean company has constructed the WFMS (wing rib flexible manufacturing system) that is composed of several automated equipments such as the 5-axis machining centers, the RGV (rail guided vehicles)s, the AS/RS (automated storage and retrieval system), the loading/unloading stations, and so on. Pallets play a critical role in the WFMS to maintain high system utilization and continuous work flow between 5-axis machining machines and automated material handling devices. The discrete event simulation method is used to evaluate the performance of the WFMS under various pallet mix alternatives for wing rib manufacturing processes. Four performance measures including system utilization, throughput, lead-time and work in process inventory level are investigated to determine the best pallet mix alternative. The best pallet mix identified by the simulation study is adopted in setting up and operating a real Korean aircraft parts manufacturing shop. By comparing the real WFMS's performances with those of the simulation study, we discussed the cause of performance difference observed and the necessity of developing the CPS (cyber physical system).

• Journal of Advanced Navigation Technology
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• v.26 no.5
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• pp.325-330
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• 2022

The sensors of aircraft are necessity for mission performance and fusion process of data from them is applied for increase of mission efficiency and decrease of aircraft pilot workload. Data fusion is applied and developed to provide pilot a series of more processed data format about a specific target from sensors in aircraft. Military aircraft currently in operation are linked with a tactical data link such as Link-16 to display improved tactical situation to pilots to increase mission efficiency. By fusing the sensor data with improved accuracy obtained as the sensors' performance mounted on the aircraft become higher and the tactical situation information received through the tactical data link, it provides the pilot with a highly reliable tactical situation and mission environment, and expects efficient mission performance and high survivability. In this paper, a fusion architecture to produce fused data with realtime information from the sensors and data through a tactical data link is shown.

• Journal of Advanced Navigation Technology
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• v.28 no.3
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• pp.300-308
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• 2024

Urban air mobility (UAM) is emerging as a revolutionary transportation solution to urban congestion and environmental issues. Especially, electric vertical take-off and landing (eVTOL) aircraft are expected to enhance urban mobility, reduce traffic congestion, and decrease environmental pollution. However, the successful implementation and operation of UAM systems heavily rely on advanced technological infrastructure, particularly in sensor technology. Among these, 3D light detection and ranging (LiDAR) systems are essential for detecting obstacles and generating pathways in complex urban environments. This paper focuses on the challenges of developing LiDAR-based perception solutions, emphasizing the importance and performance of object detection capabilities using 3D LiDAR. It integrates LiDAR data processing algorithms and object detection methodologies to experimentally validate the effectiveness of perception solutions that contribute to the safe navigation of aircraft. This research significantly enhances the ability of aircraft to recognize and avoid obstacles effectively within urban settings.