• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.12
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• pp.971-980
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• 2021

Recently popularized drone technologies have revealed that low-cost small unmanned aerial vehicles(UAVs) can be a significant threat to prevailing power by operating in group or in swarms. Researchers in many countries have tried to utilize integrated swarm unmanned aerial system(SUAS) in the battlefield. Agency for Defense Development also identified four core technologies in developing SUAS: swarm control, swarm network, swarm information, and swarm collaboration, and the authors started researches on swarm control and network technologies in order to be able to operate vehicle platforms as the first stage. This paper introduces design and integration of SUAS consisting of small fixed-wing UAVs, swarm control and network algorithms, a ground control system, and a launcher, with which swarm control and network technologies have been verified by flight tests. 19 fixed-wing UAVs succeeded in swarm flight in the final flight test for the first time as a domestic research.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.10
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• pp.127-133
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• 2004

This paper described development of the portable ground control system(PGCS) for unmanned aerial vehicle. In the design of GCS, it upload mission planning that aircraft has to perform and has to receive position, attitude, state, navigation information all about the aircraft. Aircraft states and trajectory are displayed using this system on line. The PGCS is composed of commercial notebook computer, RF modem for communication between aircraft and PGCS, input/output board, remote control receiver, switches and lamps. Performance of this system is verified by flight test of small unmanned aerial vehicle.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.173-181
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• 2008

Gas turbine engine for aircraft are usually operated at the altitude condition which is quite different from the ground condition. In order to measure the precise performance data at the altitude condition, the engine should be tested at the altitude condition by a real flight test or an altitude simulation test with an altitude test facility. In this paper describes the design of altitude test facility for turbo shaft engine. This facility will be located in test cell #2 at the Korea Aerospace Research Institute. Test Cell #2 will be used for altitude testing engines with mass flow rate up to 40kg/s and inlet temperatures in the range from $-65^{\circ}C$ to $200^{\circ}C$. The existing compressor/exhauster station with heater & cooler system will be used to simulate altitude conditions in Test Cell #2.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.12
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• pp.1599-1606
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• 2011

It is possible to study the load characteristics of full-scale hingeless rotor with the changing of physical smallscaled configurations such as rectangular and paddle blades, and metal and composite hubs. In this study, a static test, and a ground and wind-tunnel test were carried out using small-scale rotor models. The static test was carried out to confirm structural stiffness, characteristics of inertia, natural frequency, and damping ratio of rotors, and the ground and wind-tunnel test was carried out to confirm the stability and aerodynamic characteristics under hovering and forward flight conditions. According to the test results, the vertical load in the case of a combination of a small composite hub with paddle blades was higher than that in the case of a metal hub with paddle blades at same condition. Further, it was confirmed that the restraint of the combination of composite hub can be more flexible than the metal hub for the motion of paddle blades.

• Korean Journal of Remote Sensing
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• v.35 no.3
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• pp.471-482
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• 2019

The mission of the high-resolution camera for the lunar exploration is to provide 3D topographic information. It enables us to find the appropriate landing site or to control accurate landing by the short distance stereo image in real-time. In this paper, the ground verification and analysis system using the multi-application stereo camera to develop the high-resolution camera for the lunar exploration are proposed. The mission test items and test plans for the mission requirement are provided and the test results are analyzed by the ground verification and analysis system. For the realistic simulation for the lunar orbiter, the target area that has similar characteristics with the real lunar surface is chosen and the aircraft flight is planned to take image of the area. The DEM is extracted from the stereo image and compose three dimensional results. The high-resolution camera mission requirements for the lunar exploration are verified and the ground data analysis system is developed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.2
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• pp.165-170
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• 2012

This paper contains the test method to obtain aerodynamic hinge moments acting on the control surface of air vehicle wing. During the flight, hinge moments make difference between actual control surface angle and control angle which is measured by sensor of actuator. The hinge moments can be obtained by using this difference. Static ground load test and calibration test were conducted to obtain torsional stiffness of control surface actuation system. This results are used to calculate hinge moments. In addition, the mechanical errors of actuation system such as slip angle of mounting point and backlash could be estimated. Using flight test results, this experimental measurement method of hinge moment acting on control surface is conducted. The results of this method are similar to those of numerical simulation method, and the validity of this method is proved.

• Bulletin of the Korean Space Science Society
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• 2003.10a
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• pp.51-51
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• 2003

인공위성의 개발 단계는 Prototype Model(PM), Engineering Model(EM), Qualification Model(QM) 그리고 Flight Model(FM)로 구분된다. 이때, Prototype 개발을 제외한 EM, QM, FM 개발단계는 반드시 종합조립시험(AIT)을 통하여 System Integration Test를 수행한다. 이 중에서 위성발사 전 최종 종합조립시험단계인 FM AIT는 위성의 최종시험단계이므로 Scenario Test를 포함한 지상에서 수행하여야 할 모든 시험을 수행한다. 이때, EM, QM 단계와는 다르게 FM AIT는 전기적 및 기계적 시험을 수행하나, 본 논문에서는 전기적 시험 과정과, Control Center 구성도 등을 포함하고 있는 Hardware 부분과, 관련 시험을 수행하게 될 Simulator를 포함한 Software 부분으로 나누어 소개하며, 기타 FM AIT 수행에 필요한 Electrical Ground Support System (EGSE) 전체 구성을 소개한다.

• Structural Engineering and Mechanics
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• v.20 no.5
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• pp.575-587
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• 2005

Using the nonlinear load transfer function for pile side soil and the linear load transfer function for pile end soil, a combined approach of the incremental load transfer matrix method and the approximate differential equation solution method is presented for the nonlinear analysis of interaction between flexible pile group and soil. The proposed method provides an effective approach for the solution of the nonlinear interaction between flexible pile group under rigid platform and surrounding soil. To verify the accuracy of the proposed method, a static load test for a nine-pile group under a rigid platform is carried out. The finite element analysis is also conducted for comparison purposes. It is found that the results from the proposed method match very well with those from the experimental test and are better in comparison with the finite element method.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2001.04a
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• pp.35-38
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• 2001

The aerothermodynamic characteristics of SCRamjet engine for the airbreathing populsion system of the next generation flight vehicle are described. As the flow is passing by, combustion caused the total pressure loss and the Mach number decrease, but nozzle exit velocity is large enough to produce net thrust. To simulate supersonic combustion test, preliminary design of ground-based blowdown type supersonic combustion tunnel is attained. Minimum allowable operating pressure and mass flow rate are calculated for the design Mach number of 2.5 at the test section of a supersonic combustion tunnel.

• Aerospace Engineering and Technology
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• v.10 no.2
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• pp.128-132
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• 2011

We can acquire the criteria of configuration tolerance on the Kick Motor system, KSLV-I upper stage propulsion system from the analysis results of the initial controllability on the KSLV-I upper stage. Also we can assign configuration tolerances on each subsystem from the configuration tolerance on the Kick Motor system. This article deals with the Kick Motor system configuration tolerance criteria and the results of configuration management on the both ground test models and flight test ones.