• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.9
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• pp.414-419
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• 2006

This paper presents a design of a multi-sensor data fusion filter for a Flight Test System. The multi-sensor data consist of positional information of the target from radars and a telemetry system. The data fusion filter has a structure of a federated Kalman filter and is based on the Singer dynamic target model. It consists of dedicated local filter for each sensor, generally operating in parallel, plus a master fusion filter. A fault detection and correction algorithms are included in the local filter for treating bad measurements and sensor faults. The data fusion is carried out in the fusion filter by using maximum likelihood estimation algorithm. The performance of the designed fusion filter is verified by using both simulation data and real data.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.265-270
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• 2006

Recently, inertial sensors like gyros and accelerometers have been quite miniaturized by Micro Electro-Mechanical Systems (MEMS) technology. JAXA is developing a MEM-based GPS/INS hybrid navigation system named Micro-GAIA. The navigation performance of Micro-GAIA was evaluated through off-line analysis by using flight test data. The estimation errors of the roll, pitch, and azimuth were $0.03^{\circ}$, $0.05^{\circ}$, $0.05^{\circ}$ $(1{\sigma})$, respectively. he horizontal position errors after 60-second GPS outages were reduced to 25 m CEP. The attitude errors and position errors are nearly half of ones reported previously[2]. Furthermore, using the adaptive Kalman filters, the robustness against the uncertainty of the measurement noise was improved. Comparing the innovation-based and residual-based adaptive Kalman filters, it was confirmed that the latter is robuster than the former.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.3
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• pp.388-396
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• 2010

Generally, flight information is transmitted by voice signal over legacy UHF radio in ground to air communication system. In this paper, we have implemented the transceiver of TDL(tactical data link) which transmits tactical information, such as flight information, using digital signal. For transmitting digital information over radio path, we have designed data modem that is processing CPFSK modulation, and TDMA(Time Division Multiple Access) network for Synchronization among multi user(platform). By simulating aeronautical propagation modeling with the environment of Korea terrain, it is predicted the maximum performance of communication range of the transceiver. As result of the transceiver's aviational boarding test, it is proved that the transceiver of TDL over legacy UHF radio transmits and receives the tactical information in TDMA network within communication range of 160km.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.8
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• pp.50-55
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• 2005

An advanced method of Relaxed Static Stability (RSS) is utilized for improving the aerodynamic performance of modern version supersonic jet fighter aircraft. The laws of flight control system utilize RSS criteria in both longitudinal and lateral-directional axes to achieve performance enhancements. Particularly, the design of longitudinal control laws for utilizing RSS methods greatly affects the performance of the aircraft in Air-to-Air Tracking and Air-to-Ground modes, which improves weapon delivery. In the area of Air-to-Air Tracking, the development of longitudinal control laws aids in the fine tracking and gross acquisition of other aircraft. This paper proposes that new concept of longitudinal control law introduce in order to improve fine tracking performance in air-to-air tracking maneuver. Result of HQS pilot simulation and flight test, fine tracking performance improve without degradation of gross acquisition when new concept of control law is applied.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.8
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• pp.53-59
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• 2022

In this study, an experimental device was fabricated to evaluate the hovering flight performance of a single rotor on a hexacopter used for river surveillance, and a thrust performance test was conducted. In addition, the 3D profile of the propeller was extracted by 3D scanning and CFD analysis was performed using ANSYS CFD 14.5 based on the extracted 3D model of the propeller. The aerodynamic characteristics were compared with the results of the performance tests and CFD analysis, and the vortex structure corresponding to each motor rotational speed in revolutions per minute (rpm) was identified. In the future, we plan to provide valuable data for multicopter propeller design and performance verification.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.4
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• pp.79-84
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• 2011

This paper presents development activities of the T700/701K turbo-shaft engine for Korean Utility Helicopter(KUH). The T700/701K is the first rear-drive variant of the GE's T700 engine which is proven for military applications in the world. The main workscope of the development includes a modification from a front-drive engine to a rear-drive one, an performance enhancement of the power turbine and an incorporation of two channel FADEC(Full Authority Digital Engine Control) system for more reliable operation. The first engine run for development and qualification test was successfully completed in 2008. Since the PFRT(Preliminary Flight Rating Test) has been completed, the first flight of the engine installed in the first prototype of KUH has been successfully demonstrated in March, 2010 and the engine installation compatibility tests are being carried out during KUH flight test. The test and evaluation for qualification has been done except for the low cycle fatigue test up to date.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.506-511
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• 2010

This paper presents development activities of the T700/701K turbo-shaft engine for Korean Utility Helicopter(KUH). The T700/701K is the first rear-drive variant of the GE's T700 engine which is proven for military applications in the world. The main workscope of the development includes a modification from a front-drive engine to a rear-drive one, an performance enhancement of the power turbine and an incorporation of two channel FADEC(Full Authority Digital Engine Control) system for more reliable operation. The first engine run for development and qualification test was successfully completed in 2008. Since the PFRT(Preliminary Flight Rating Test) has been completed, the first flight of the engine installed in the first prototype of KUH has been successfully demonstrated in March, 2010 and the engine installation compatibility tests are being carried out during KUH flight test. The test and evaluation for qualification of the engine has been done except for the LCF test up to date.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.7
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• pp.527-534
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• 2018

The endurance of the multi-copter is one of the important variables that determine the mission performance. Therefore, accurate endurance should be defined as essential for performing effective missions. In this paper, we present the results of the study on the flight performance of the aircraft, especially the hovering of the drone(multi-copter). Unlike conventional aircraft, which consider aerodynamic performance by the fuselage, the multi-copter is mostly determined by the propulsion system. Therefore, the research method classifies the various parts constituting the drone system into functions, analyzes the performance of the unit parts and obtains the experimental data by sorting out the specifications and functions at the component level and mathematical formulation, The results of this study are as follows. In addition, the 5kg class quad copter was used to predict and verify the voltage change with endurance through analysis of in situ flight. By predicting endurance under various conditions, it can help design/build the right Multi-copter for mission.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.3
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• pp.391-400
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• 2016

In satellite operations, stable maneuvering of a satellite's onboard antenna to prevent undesirable vibrations to the satellite body is required for high-quality high-resolution images. For this reason, the onboard antenna's angular rate is typically minimized while still satisfying the system requirement that limits the speed of the onboard antenna. In this study, a simple yet effective method, called the ground station searching method, is proposed to reduce the angular rate of a satellite's onboard antenna. The performance of the proposed method is tested using real flight data from the KOMPSAT-3 satellite. Approximately 83% of arbitrarily selected real flight scenarios from 66 test cases show reductions in the onboard antenna's azimuth angular rates. Additionally, reliable solutions were consistently obtained within a reasonably acceptable computation time while generating an onboard antenna tracking profile. The obtained results indicate that the proposed method can be used in real satellite operations and can reduce the operational loads on a ground operator. Although the current work only considers the KOMPSAT-3 satellite as a test case, the proposed method can be easily modified and applied to other satellites that have similar operational characteristics.

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.195-207
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• 2012

This paper deals with attitude controller design and integrated performance tests on the nitrogen gas reaction control system of KSLV-I. Some major factors which are necessarily required in designing a stabilizing controller of reaction control system are investigated, and the corresponding equations are given. Experimental configurations and test conditions for system level integrated performance tests of the KSLV-I nitrogen gas reaction control system are summarized. It is shown that, based on the experimental data, operational performances of nitrogen gas reaction control system can be analyzed in terms of gas consumption, thrusting force, time delay, and specific impulse. It is also shown that a conformance of the controller to flight can be evaluated. Finally the onboard controller of KSLV-I reaction control system is shown to perform normally with enough stability margin via the first flight test result.