• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.1
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• pp.70-79
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• 2024

This paper describes the results of the development of the the unmanned aerial vehicle system integration laboratory(UAV SIL) for the integrated verification. This UAV SIL is designed to test the robustness of the UAV system including the operational logics and the flight control system behaviors under many abnormal and emergency conditions such as data-link losses, airborne subsystem failures, engine shut down conditions, and ground control station faults. This paper presents how to build the UAV SIL and how to verify the in-development UAV system through the UAV SIL.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.6
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• pp.455-466
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• 2020

In this study, we built a thermal model for SNIPE 6U nano-satellite which has scientific mission for measuring science data in near Earth space environment and described thermal design based on the thermal model. And the validity of the thermal design was verified through the on-orbit thermal analysis. The thermal design was carried out mainly on the passive thermal control techniques such as surface finishes, insulators, and thermal conductors in consideration of the characteristics of the nano-satellite. However, the components with narrow operating temperature range and directly exposed to the orbital thermal environments, such as a battery and thrusters, are accomodated with heaters to satisfy the temperature requirements. On-orbit thermal analysis conditions are based on the basic orbital conditions of the satellite, and thermal analysis was performed for Normal mode, Launch & Early Orbit Phase (LEOP), Safehold mode, and Maneuver mode which are classified by the power consumption and the attitude of the satellite according to the mission scenario. The analysis results for each mode confirmed that every component satisfies the temperature requirement. In addition, the heater capacity and duty cycle of the battery and thruster were calculated through the analysis results of the Safehold mode.

• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.5
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• pp.319-330
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• 2017

In remote USV (Unmanned Surface Vehicle) maritime operation, the remote operation and control technic and autonomous control technic is required and the emergency mode algorithm is needed certainly for sailing and accomplishing various surveillance, reconnaissance, and underwater search missions of USV. In this paper, we review the countermeasures in emergency situation of the existing USV system (Barracuda) and propose the emergency mode algorithm considering the operation and control, and autonomous control level for the stable USV operation in case of emergency. We analyzed the autonomous control level in view of the mission complexity and environmental difficulty, and human interface, and verified the performance of the autonomous control level when we apply four emergency mode algorithms. It is expected that more stable and reliable operation and cotrol are possible if the proposed algorithm is applied to the environments requiring the various multi-mission USV sailing and mission achievement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.703-709
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• 2017

Korea Utility Helicopter(KUH) is a project to replace the aging helicopter presently being operated by the military with a domestic helicopter. The auxiliary power unit is a device that supplies emergency power to the system by an alternator installed when the main generator fails and the start motor converts the electrical energy of the battery into mechanical rotational energy to rotate the auxiliary power unit engine. With continuing power and operation, defects of the starting motor were found and improvements were carried out to solve it. In the failure mode analysis, the causes of possible defects were classified into 5 categories. Analysis of the 5 factors revealed that the main cause of defects is mechanical wear, which was found to be related to spring pressure. 250 tests were conducted through the theoretically determined pressure and regression analysis was performed with 4 sampling.The results showed that pressure was related to wear rate. In conclusion, early wear and breakage due to wear can be controlled through spring force and test showed the prediction of wear and the validity of the result were confirmed.