• Proceedings of the KSRS Conference
• /
• 2009.03a
• /
• pp.305-308
• /
• 2009

최근 카메라와 같은 센서가 장착된 UAV(Unmanned Aerial Vehicle, 무인항공기)를 이용하는 분야는 방재, 농업, 군사 분야 등 매우 다양해지고 있다. 그러나 고품질의 영상데이터를 취득하기 위해서는 가벼우면서도 우수한 성능을 지닌 고가의 MEMS 센서 그리고 센서가 안정적으로 데이터를 획득할 수 있도록 안정적인 비행이 가능한 대형 UAV플랫폼으로 구성된 시스템이 필요하기 때문에 시스템 구축비용이 클 수밖에 없다. 본 연구에서는 저비용으로 영상 데이터를 취득할 수 있는 UAV시스템을 구축하여 취득된 영상데이터의 처리를 통해 얻어지는 영상의 품질을 살펴보고 그 효용성을 시험해보았다. 이를 위해서 고가인 UAV를 대신해 비교적 가격이 저렴한 R/C헬기(Remote Control, 원격조종 헬기)를 플랫폼으로 선정하고, 영상데이터를 수집하는 카메라센서를 탑재하였다. 그리고 탑재된 센서가 안정적으로 데이터를 취득할 수 있도록, 센서와 플랫폼 사이에 Gimbal을 장착하였다. 이렇게 구축된 시스템을 이용하여 시험비행을 해보았으며, 그 결과 플랫폼에 탑재된 센서로부터 비교적 안정적이고 양질의 이미지를 획득할 수 있었다. 본 연구에서 구축한 R/C 헬리콥터 시스템을 통하여 저비용/고효율의 영상데이터를 취득할 수 있음을 확인하였다. 구축된 시스템은 근접한 거리에서 대상물의 영상을 취득하기 때문에 고품질의 3차원 모델데이터 생성에 매우 도움이 될 것으로 생각한다.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.3
• /
• pp.213-220
• /
• 2010

This paper presents the analysis results of trajectory, performance and attitude control based on the first flight data of the KSLV-I. The KSLV-I had a fairing separation problem and failed to inject spacecraft into the orbit. In this paper, the trajectory, flight performance, and attitude control was analyzed considering the influence of unseparated fairing. Moreover, the flight results and performance of the inertial navigation and guidance system were presented. As a results of post-flight analysis, any other problem besides the fairing separation problem was not happened and onboard equipment functioned normally.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.40 no.5
• /
• pp.461-466
• /
• 2012

This paper describes the development and test result of X-band Transmitter flight model(FM) of STSAT-3 by satellite research center(SaTReC), KAIST. The communication sub-system of STSAT-3 is consist of two different frequency band channels. S-band frequency is used for Telemetry & Command, and X-band frequency is used for mission data. Payload observations data in Mass Memory Unit (MMU) is modulated by QPSK modulator in X-band Transmitter, and then QPSK modulation signal is transmitted to antenna through transfer switch. In this Paper, we described the results of modulation, low-pass filter design, power amp development, and switch test. The FM XTU is delivered Spacecraft Assembly, Integration and Test(AIT) level through the completion of functional Test and environmental(vibration, thermal vacuum) Test successfully.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.41 no.9
• /
• pp.747-754
• /
• 2013

This paper describes SCTE(System and Control unit Test Equipment) as an integrated test equipment for airborne SAR system and control unit. SCTE enhances reusability of test equipment by modular design for required functions and strengthens automatic testing and test convenience by providing functions such as script-based testing function and report generation function. Also, it includes a navigation data simulator which can simulate various flight conditions. In this paper, we details SCTE requirements, H/W and S/W design, implementation, and test results with control unit and SAR system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.15 no.3
• /
• pp.311-318
• /
• 2004

It is required to design the RF link with sufficiently stable signal margin to minimize bit errors and improve the quality of received data in the telemetry system modulated digitally like PCM/FM. In case of the vehicle flying at a high speed, the variation of the gain pattern between transmitting and receiving antenna and the fee space loss due to flight distance cause the fluctuation of link. In this paper, KSR(Korea Sounding Rocket)- III, the first domestic liquid rocket which was successfully launched in Nov. 2002 is introduced. The SNR(signal-to-noise ratio) variation of the telemetry signal which was measured at S-band ground station, the one which was simulated considering the flight trajectory, and the attitude variation such as roll, pitch and yaw are compared, analyzed, and agree very well. In addition, two virtual flying situations are simulated and evaluated-only one antenna is equipped in one case, and rocket is roll-free in the other.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.32 no.7
• /
• pp.91-97
• /
• 2004

The first Korean liquid propellant rocket KSR-III successfully finished its flight test on Nov. 28, 2002. Herein, we summarize the results of range safety system operation which is employed for the first time in flight tests of rockets developed by Korea Aerospace Research Institute(KARI). During the flight, safety-critical flight data including instantaneous impact points are monitored in realtime by range safety officers utilizing Range Safety Display Systems. The recorded screen of the display system is presented for the explanation of safety operation. In addition, comparisons are made between onboard navigation system based and radar based results in calculating instantaneous impact points, and also errors from the finally recorded impact point are described.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.37 no.12
• /
• pp.1209-1216
• /
• 2009

This paper presents the pose estimation of a small UAV utilizing visual information from low cost cameras installed indoor. To overcome the limitation of the outside flight experiment, the indoor flight test environment based on multi-camera systems is proposed. Computer vision algorithms for the proposed system include camera calibration, color marker detection, and pose estimation. The well-known extended Kalman filter is used to obtain an accurate position and pose estimation for the small UAV. This paper finishes with several experiment results illustrating the performance and properties of the proposed vision-based indoor flight test environment.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.25 no.6
• /
• pp.825-833
• /
• 2021

In flight tests, aircraft moves in real time, so it is important that data from instrumentation/measurement equipment used to determine aircraft status are processed in necessary form and transmitted to flight control systems in real time. Therefore, through telemetry data processing time reduction and processing cycle improvement in flight test control computer data processing system, in order to provide faster slave-data and safety judgment information to radar/telemetry slave-data processing, flight safety analysis system, emergency destruction transmission system, etc., we developed a PCM processing system that can be operated independently by installing data processing software that can receive and process PCM data in current telemetry data processing system and radar information at the same time. In this paper, we explain classified software functions in detail, starting with overall structure of PCM data processing systems developed by supplementing existing systems. Additionally, PCM data processing system will be supplemented through system stabilization and test operation.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.45 no.8
• /
• pp.639-646
• /
• 2017

In this paper, a new load monitoring system for military aircraft is introduced. This system consists of sensors, an onboard device and an ground analysis equipment. The sensors and onboard device are mounted on the aircraft and the ground analysis equipment is operated on the ground. Through this system, structural static load can be estimated with flight parameters and structural responses can be measured by sensors due to static load, dynamic load and unexpected events. Especially, optical fiber sensors with mutiplexing capability are utilized. The onboard device was specially designed for complying the requirements of relevant military specifications and was verified through a series of the environment tests. This system was used and evaluated through ground structural tests before flight tests. In the near future, this system will be applied to military aircraft as a structural load monitoring system after flight test evaluation.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.50 no.10
• /
• pp.729-737
• /
• 2022

Melting and icing process of the PCMTCU(Phase Change Material Thermal Control Unit) installed on the NEXTSat-2, which is scheduled to be launched in the second half, was investigated through the results of satellite-level TVT(Thermal Vacuum Test). As a result of the test, it was confirmed that the latent heat of PCM contributes to the temperature stabilization of the heating components. The thermal model for numerical analysis of the PCMTCU was correlated to acquire a reasonable degree of accuracy using the collected temperature measurements during TVT. The periodic temperature variation of the PCMTCU in normal on-orbit operation was predicted with the correlated thermal model, and the quantitative contribution of the PCM on the thermal energy management was evaluated with the liquid fraction. It will receive flight telemetry from the NEXTSat-2 after the launch, and complete the space verification of the PCMTCU.