• Journal of Aerospace System Engineering
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• v.14 no.spc
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• pp.39-48
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• 2020

This paper deals with the process of estimating the environmental noise generated from the actual flying aircraft using the noise measurement results obtained through the wind tunnel test and verifying it through flight tests. In order to evaluate the environmental noise of an aircraft, noise tests and evaluations are generally conducted according to the procedures prescribed by the International Civil Aviation Organization (ICAO). In this paper, we introduced environmental noise evaluation method that can be applied to composite both fixed-wing aircraft and multi-copter, and introduced the evaluation method by experiment. This paper introduces the process of simulating the noise test results measured in the wind tunnel test using real flight test results. In addition, in consideration of flight operating conditions and noise measurement methods proposed by the ICAO, the effective perceived noise level (EPNL) was predicted by performing both the wind tunnel test and the aircraft flight test.

• Journal of Aerospace System Engineering
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• v.18 no.3
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• pp.76-85
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• 2024

Recently, from a global perspective, the use of small unmanned aerial vehicles in terrorism and warfare is increasing, and the need for anti-drone shooting training targeting small UAVs is increasing. However, in reality, there are many cases in Korea where anti-drone shooting training is restricted, due to complaints such as noise. In this paper, we describe the development and testing of an electric-powered direct strike type high-speed, low-noise small aerial target drone. To achieve the flight speed and endurance required for shooting training, target drone sizing was performed, and aerodynamic performance analysis was conducted using a CFD program. Based on the performance analysis, the motor propulsion system was selected and a variable pitch propeller system was designed, and performance tests were performed on a ground test rig. Finally, the target flight speed, flight time, and flight noise level were confirmed through flight tests.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.5
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• pp.774-780
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• 2011

The guidance control module is needed for control of a GPS guided bombs to improve the accuracy and availability of a conventional bomb. In this paper, we present the development of hardware design, software design and test environments of it. And we also show the process of the tests and the results verifying and proving for its required functions and performances through ground tests and flight tests.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.491-494
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• 2005

This paper describes the fundamental research of hybrid-propellant rocket system focusing the flight. The performance of the hybrid-propellant rocket system (using the background of lab-scale tests) for a small-scale launch vehicle could have been validated by static thrust tests and flight tests. Based on this system, it was found that hybrid rocket propulsion system was available in an application to a launch vehicle system.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.7
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• pp.711-719
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• 2008

Although non-real time simulation and pilot based evaluations are available for the development of flight control computer prior to real flight tests, there are still many risky factors. The control law designed for prototype aircraft often leads to degraded performance from the initial design objectives, therefore, the proper evaluation methods should be applied such that flight control law designed can be verified in real flight environment. The one proposed in this paper is IFS(In-Flight Simulator). Currently, this system has been implemented into the F-18 HARV(High Angle of Attack Research Vehicle), SU-27 and F-16 VISTA(Variable stability. In flight Simulation Test Aircraft) programs. This paper addresses the concept of switching mechanism for FLCC(Flight Control Computer)-SWMC(Switching Mechanism Computer) using 1553B communication based on flight control law of advanced supersonic trainer. And, the fader logic of TFS(Transient Free Switch) and stand-by mode of reset '0' type are designed to reduce abrupt transient and minimize the integrator effect in pitch axis control law. It hans been turned out from the pilot evaluation in real time that the aircraft is controllable during the inter-conversion process through the flight control computer, and level 1 handling qualities are guaranteed. In addition, flight safety is maintained with an acceptable transient response during aggressive maneuver performed in severe flight conditions.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.2
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• pp.109-117
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• 2018

The experimental results are presented of an autonomous flight algorithm of a foldable quadcopter with airdrop launching functions. A foldable wing structure enabled the quadcopter to be inserted into a rocket container with limited space. The foldable quadcopter was then separated from the rocket in the air. The flight pattern was tracked using a global positioning system (GPS) with various sensors, including an inertial measurement unit (IMU) module until a designated target position was reached. Extensive field tests were conducted through an international rocket competition, ARLISS 2017, which was held in Black Rock Desert, Nevada, USA. The flight trajectory record of the experiments is stored in electrically erasable programmable read-only memory (EEPROM) embedded in the main control unit. The flight record confirmed that the quadcopter successfully separated from the rocket, executed flight toward the target for a certain length of time, and stably landed on the ground.

• Bulletin of the Korean Space Science Society
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• 2006.04a
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• pp.117-120
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• 2006

HAUSAT-2 flight software was developed by first analyzing the satellite requirements, and incorporating the results into the software. Coding and compiling is done after the software is completed, then individual and integrated tests are performed in order to verify the flight software algorithm. Currently, HAUSAT-2 flight software integrated test has been performed and the test result is serving as a basis for code modification nd additional developments. This paper describes the architecture, development process, and development environment of HAUSAT-2 flight software.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.4
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• pp.740-756
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• 2017

This paper proposes a feedback-linearization-based control algorithm for multirotor unmanned aerial vehicles (UAVs). The feedback linearization scheme is highly efficient for considering nonlinearity between the rotational and translational motion of multirotor UAVs. We also propose a dynamic equation that reflects the aerodynamic effects of the vehicles; the equation's parameters can be determined through curve fitting using actual flight data. We derive the feedback linearization controller from the proposed dynamic equation, and propose a Luenberger observer to attenuate measurement noises. The proposed algorithm is implemented using our in-house flight control computer, and we describe its implementation in detail. To investigate the performance of the proposed algorithm, we carry out two flight scenarios: the first scenario, an autonomous landing on a moving platform, is a test of maneuverability; the second, picking up and replacing an object, test the algorithm's accuracy. In these scenarios, the proposed algorithm precisely controls multirotor UAVs, and we confirm that it can be successfully applied to real flight environments.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.7
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• pp.629-634
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• 2008

This paper presents the flight test procedure and the results for the airspeed indicator calibration of a light airplane the name of ChangGong-91, which is the first type certified aircraft from Korean Ministry of Construction and Transportation, as a part of the flight test validation to get the certification. The flight tests for airspeed position error calibrations are conducted using tower fly by method in order to calibrate swivel head testboom which is attached to the right wing tip of the airplane. Also system to system method is applied in order to calibrate the airspeed indicator of the cockpit. The flight test is conducted at the basis of the 'Korean Airworthiness Standard' which is the regulation of Korean Ministry of Construction and Transportation. The airspeed error range for the testboom and the airspeed indicator are determined to $-0.75{\sim}+0.75$ knot and to $-4.0{\sim}+2.0$ knots, respectively. The calibration results are applied to ChangGong-91 Flight Operation Manual.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.19 no.3
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• pp.25-32
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• 2011

In order to study the effect of K-WAIS and FTD on flight aptitude, which we utilize to sort out good pilot candidates among applicants, we adopted Fuzzy regression model and expressed the result of flight aptitude tests in Fuzzy number by using maximum/minimum values and mean values. The 7 aspects of K-WAIS were broken down into three similar groups: mathematical ability, visualization ability and organization ability. While mathematical ability and organization ability showed a positive relevance with the FTD test with respect to flight aptitude, visualization ability of K-WAIS showed a negative(-) relevance with flight aptitude, which presented an opposite result to the previous research. Thus, we are to increase the number of samples and do the research thereof in the near future.