• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.1
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• pp.19-29
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• 2000

Because the previous simulation tool for attitude control of satellite was designed for the modeling of rigid body and PD controller, the attitude error can be made more than the limitation value for keeping for communication link, and then the communication link can be lost at moving of satellite. So, for rapid attitude restoration and design of stable and modernized controller, the modelling of rigid body and flexible body structure for moving GEO and LEO satellites were performed. Also the minimum time controller is designed for the rapid restoration of attitude error at communication broken and to minimize the disconnection period from ground communication system during the satellite stationkeeping. The linear regulator is designed using the space state vector that is better than accuracy and stability of PD controller. Firstly the simulation was performed for comparison of the rigid and stability of PD controller. Firstly the simulation was performed for comparison of the rigid and flexible models using PD controller and the case of the pitch angle changing by ground command, and the case of the periodic north-south stationkeeping are performed for the analysis of response characteristics of each controller when the attitude is changed. As a result, the flexible body model represents more sililar results of real situation than the rigid body model. The minimum time controller can restore 7 times rapidly than PD controller for its lost attitude. The linear regulator has several merits for capability of adaptation against the external disturbance, stability and response time. In future, we can check the estimated results using this satellite model and controller for real operation. Futhermore the development of new controller and training can be supported.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.2
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• pp.236-242
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• 2005

Dynamic Positioning(DP) system maintains ship's position (fixed location or predetermined track) exclusively by means of CPPs and thrusters. To generate the control input adequate to various situation an integrated controller for CPPs and thrusters is required. The integrated controller is composed of a thrust calculation algorithm and a thrust allocation algorithm. The thrust calculation algorithm generates thrusts in the surge direction and the sway direction from the desired forward and lateral speed and generates a moment about the yaw axis from desired heading angle. The thrust allocation algorithm allocates the generated thrusts and moment to each CPP and thruster. Computer simulations are executed to confirm the effectiveness of the suggested controller.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.4
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• pp.42-47
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• 2008

The power control system of Smart UAV is similar to the propeller pitch governing concept of turboprop aircraft. The pilot adjusts the engine power directly and the pitch governor controls the propeller pitch to maintain the propeller rotational speed. The electronic engine controller(EEC) of PW206C engine developed for helicopter is not fit for the power control concept of Smart UAV, and therefore the manual back-up system of PW206C engine is used for the engine power control of Smart UAV. Engine performance estimation program is used to predict the control range of power lever angle(PLA) according to the variation of engine output shaft speed, flight altitude and flight speed. These data provide a guide for the PLA control in manual mode operation.

• Proceedings of the Acoustical Society of Korea Conference
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• 1995.06a
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• pp.119-122
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• 1995

음소단위의 포만트 합성방식을 이용하여 한국어의 규칙합성에 대해 시험하였다. 포만트 합성방식으로는 Klatt가 제안한 직/병렬 합성기를 수정하여 사용하였으며, 운율 정보를 나타내는 피치값의 제어는 Fujisaki 모델을 이용하였다. 합성에 사용되는 각 파라미터들이 합성음의 음질 및 파형에 미치는 영향을 분석할 수 있도록 합성 파라미터와 음성파형 및 스펙트로그램을 화면에 나타내고 마우스를 이용하여 파라미터 값을 사용자가 적절히 변경한 후 합성할 수 있는 포만트 방식의 합성 Tool을 개발하였으며, 이를 이용하여 한국어 문자/음성변환 시스템을 지속적으로 연구하고자 한다.

• Korean Journal of Optics and Photonics
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• v.19 no.6
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• pp.422-428
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• 2008

The pitch tool provides superior surface roughness compared to other types of polishing tool. However, because of difficulty in handling the pitch tool, pitch tool polishing has rarely been analysed, which led many craftsman to eliminate the pitch tool from their experiences. We found that it was possible to use a pitch tool in the well-determined material removal after the completion of computer simulation and experiment. We could simulate the TIF of the pitch tool with 79% accuracy. Also, after five successive simulations of polishing process on a 280 mm optical flat, the surface p-v error was found to be reduced from $1{\mu}m$ to 168 nm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.1
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• pp.134-145
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• 2021

It is common to optimize the propulsion control system through a so-called tuning process that modifies the parameter values of the propulsion control software during a ship commissioning. However, during this process, if the error of the initial setting value is large, the tuning time may take too long, or the propulsion equipment can be seriously damaged. Therefore, we conducted research on the design of a propulsion controller that applied a Processor lever controller even for inexperienced people with relatively little experience in tuning propulsion control software to be able to reduce the tuning time while protecting the propulsion system. Through simulation, by comparing the execution result of propulsion control lever commands through the PI controller without applying the Processor lever controller. We analyzed the improvement of the Overshoot and propulsion performance. The simulation results showed that the safety of the propulsion system increased because Overshoot of approximately 9.74%, which occurred when the Processor lever function was not applied.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.72-77
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• 2008

The function of the Reaction Control System include roll, pitch and yaw control of the launch vehicles and fine control maneuvers and precision upper stage orientation before separation of one or more payload. This paper describes the overview of commercial launchers, current technology trend for RCS of launch vehicles, and development status of medium class thruster for RCS.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.1
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• pp.10-17
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• 2018

The size of commercial wind turbines has been increased. Generally, the pitch control is used to increase the efficiency of wind turbine. However, the pitch control has difficulty to control the local unsteady flow control which makes fatigue load and decreases the efficiency. In this research, Synthetic Jet Actuators(SJAs) are manufactured and applied into a wing section to delay flow separation and increase aerodynamic performances. The SJAs as a kind of zero-net mass-flux actuators injects and removes fluid through a small orifice with a given frequency. The SJA modules actuated by piezoelectric disks are manufactured and the aerodynamic performances are measured according to the shape of the orifice and the velocity of the jets through the wind tunnel test. It is confirmed that as the velocity of the jets are increased using rectangular shape orifice, drag force is decreased and lift force in increased.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.01a
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• pp.131-132
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• 2017

본 논문에서는 쿼드콥터 드론의 충돌방지를 위한 효율적인 자동제어 방법을 제안한다. 이 제어방법은 RC 조종기에서 노브를 이용하여 사용자가 제어하는 신호를 쿼드콥터의 리시버단에서 수신한 뒤 출력되는 PWM 신호들 중에서 쓰로틀, 피치, 롤 제어정보를 필요시 변경하는 방법으로 충돌을 방지한다. 충돌을 예측하기 위해서 전후, 좌우, 상하 6방향에 레이저 거리측정센서를 장착하고 주기적으로 거리를 측정한다. 그리고 측정 거리를 이용하여 장애물 유무를 판정하고 충돌이 예상되면 수신된 PWM 신호를 변경하여 쿼드콥터의 비행제어부로 전달함으로써 충돌을 방지하도록 한다. 본 논문에서 제안하는 충돌방지 방법을 쿼드콥터에 적용하여 실험을 통해 검증한 결과, 조종자 부주의 혹은 조종 미숙으로 인해 발생할 수 있는 충돌을 방지할 수 있어 안전성이 향상됨을 보였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.10
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• pp.79-88
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• 2003

The paper presented here covers the work associated with the flight control law design, ground based and in flight simulation and handling qualities assessment of the Fly-by-Wire type Aircraft (FBWA). The FBWA configurations are of the same generic form of the Korean advanced trainer. The normal acceleration (Nz) and pitch rate (q) feedback control system is employed for longitudinal axis and roll rate (p) and lateral acceleration (Ny) feedback flight control law is developed in lateral/ directional axis. The flight tests for the FBW A dynamics evaluation were executed for the target aircraft (FBWA) on the IFS (In-Flight-Simulator) aircraft . The test results showed that Level 1 handling qualities for the most unstable flight regime and Level 1/2 for the landing approach flight regime were achieved. And the designed FBWA flight control law has revealed acceptable CHR (Cooper-Harper handling qualities Ratings).