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

• International Journal of Aeronautical and Space Sciences
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• v.16 no.4
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• pp.581-589
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• 2015

This paper describes a monocular vision-based formation flight technology using two fixed wing unmanned aerial vehicles. To measuring relative position and attitude of a leader aircraft, a monocular camera installed in the front of the follower aircraft captures an image of the leader, and position and attitude are measured from the image using the KLT feature point tracker and POSIT algorithm. To verify the feasibility of this vision processing algorithm, a field test was performed using two light sports aircraft, and our experimental results show that the proposed monocular vision-based measurement algorithm is feasible. Performance verification for the proposed formation flight technology was carried out using the X-Plane flight simulator. The formation flight simulation system consists of two PCs playing the role of leader and follower. When the leader flies by the command of user, the follower aircraft tracks the leader by designed guidance and a PI control law, and all the information about leader was measured using monocular vision. This simulation shows that guidance using relative attitude information tracks the leader aircraft better than not using attitude information. This simulation shows absolute average errors for the relative position as follows: X-axis: 2.88 m, Y-axis: 2.09 m, and Z-axis: 0.44 m.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.3
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• pp.173-180
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• 2022

The operation and transportation environment for an unmanned aerial vehicle will be completely different from those for the conventional air and ground transportation. The requirement for a traffic management system for its safe operation has been emerging. Accordingly, investigation is being conducted to analyze the danger that unmanned aerial vehicle may encounter during the flight and to provide the countermeasure by the simulation. When the drones operate in an urban environment, they may be affected by the wind around the building. Thus it is essential to predict the influence of the gust and analyze the resulting risk. In this paper, a method for evaluating the safety for a flight mission under the gust is suggested. By using the precise 6-degree-of-freedom flight simulation that is capable of simulating the gust condition, possible deviation from the pre-planned flight path in terms of the attitude orientation will be predicted. A method of quantifying the probability of the flight mission failure will also be presented.

• Journal of Aerospace System Engineering
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• v.1 no.3
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• pp.37-42
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• 2007

The flight safety system for the satellite launch vehicles is required in order to minimize the risk due to launch vehicle failure. For prompt and reliable decision of flight termination, the flight safety system usually uses multiple sensors to estimate launch vehicle's flight trajectory. In that case, multiple types of observed tracking data makes it difficult to identify the flight termination condition. Therefore, a fusion tracking filter handling the multiple tracking data is necessary for the flight safety system. This research developed a simulation software for generating multiple types of launch vehicle tracking data, and then processed the data with fusion filters.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.10
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• pp.927-932
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• 2007

The sophisticated mathematical model is required for the design and the database construction of the advanced flight control system of UAV. In this paper, flight test of KARI's research UAV, often called DURUMI-II, is implemented for the data acquisition from the maneuver flight. The flight path reconstruction is implemented to ensure that the measured data is consistent and error free. The nonlinear system identification for the refined mathematical modeling is implemented with the verified measurements from the flight path reconstruction. The simulation with the identified results have a good validation when the simulated responses were compared to the flight tested data.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.4
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• pp.21-29
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• 2010

The main purpose of this study is to obtain linear models for the design of automatic flight controller in order to operate the Light Sport Aircraft as unmanned air vehicle. Flight test equipments installed on the aircraft to acquire flight test data are described and maneuvers for practical speed calibration are introduced. Parameters for the linear models of lateral and longitudinal motion are estimated by the Output error method as well as trim data analysis using the flight test data. Simulated data using the estimated parameters is shown to agree well with the measurement data. Estimated parameters obtained for several flight conditions can be used to improve the aerodynamic database of the simulation program.

• Journal of the Korea Safety Management & Science
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• v.10 no.3
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• pp.63-71
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• 2008

This study was conducted with respect to the causal factors revealed through the investigation of the recent airlines aircraft crash accident which occurred while aircraft was on the climb-out or on the final approach. This study also highlighted the importance of flight deviation and exceedance occurrences in consideration of Flight Operational Quality Assurance Program(FOQA). Twenty airline pilots participated in the flight experiment to perform ten(10) sets of simulated approaches and landings. As a result, Twelve(12) kinds of deviation events were discovered. In this respect, The FOQA program must be fully implemented to prevent any flight safety incident under the auspices of the Korea domestic aviation community as well.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.11
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• pp.913-919
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• 2005

An advanced method of Relaxed Static Stability (RSS) is utilized for improving the aerodynamic performance of modem version supersonic jet fighter aircraft. The flight control system utilizes RSS criteria in both longitudinal and lateral-directional axes to achieve performance enhancements and improve stability. Standard CLDA (Control Law Design and Analysis) process is provided that reduce the development period of the flight control system. In addition, if this process is employed in developing flight control laws, it reduces the trial and error development and verification of control laws. This paper details the design process of developing a flight control law for the RSS aircraft, utilizing military specifications, linear and nonlinea, analysis using XMATH and ATLAS(Aircraft, Tim Linear and Simulation), handling quality tests using the HQS (Handling Quality Simulator), and real flight test results to verify aircraft dynamic flight responses.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.5
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• pp.422-428
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• 2007

This paper presents a neural network based adaptive control approach to a reconfigurable flight control law that keeps handling qualities in the presence of faults or failures to the control surfaces of an aircraft. This approach removes the need for system identification for control reallocation after a failure and the need for an accurate aerodynamic database for flight control design, thereby reducing the cost and time required to develope a reconfigurable flight controller. Neural networks address the problem caused by uncertainties in modeling an aircraft and pseudo control hedging deals with the nonlinearity in actuators and the reconfiguration of a flight controller. The effect of the reconfigurable flight control law is illustrated in results of a nonlinear simulation of an unmanned aerial vehicle Durumi-II.

• Journal of the Korea Society of Computer and Information
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• v.15 no.10
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• pp.79-86
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• 2010

This paper presents implementation of a system for effective visualizing flight information of aircraft using Google Earth. This system in order to use a detailed satellite image which provide from Google Earth used COM API. This system appeared the various flight information of the aircraft in the instrument panel using OpenGL and the aircraft flight condition is visible in the Google Earth Map. This research result used to flight evaluation and improvement. In future will be able to apply to flight software development.