• Aerospace Engineering and Technology
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• v.12 no.1
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• pp.22-31
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• 2013

Flight tests on flight control performance of helicopter, conversion and airplane mode for the Smart UAV were completed. Automatic take-off and landing, automatic return home as well as automatic approach to hover were performed in helicopter mode. Climb/descent, left/right turn using speed and altitude hold mode were performed in each $10^{\circ}$ tilt angle in conversion mode. The rotor speed in airplane mode was reduced to 82% from 98% RPM in order to increase rotor efficiency with reducing Mach number at tip of rotors. It reached to the designed maximum speed, $V_{TAS}$=440 km/h at 3 km altitude. This paper presents the flight test result on full envelopment of Smart UAV. Detailed test plan and test data on control performance were also presented to prove that all data meets the flying qualities requirement.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.481-482
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• 2015

모터의 효율 규제에 따른 영구자석형 동기전동기의 사용확대에 따라서 유도기에 적용되었던 기술들이 동일하게 동기기에도 필요하게 되었다. 이 중에서 정전시 전동기가 자유회전하는 상태에서 복전된 후에 전동기를 재기동할 때 회전자의 현재 속도부터 지령속도로 제어해주는 방법을 속도써치라고 한다. 유도기에 사용되었던 방법을 동기기에 그대로 적용하기에는 무리가 있어 영구자석이 회전시에 발생하는 역기전력을 이용한 회전자 위치 및 속도 판별 방법에 대해서 설명하고 기존의 방법을 최소 자승법을 사용하여 개선하였다.

• Proceedings of the KIEE Conference
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• summer
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• pp.1510-1512
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• 2004

본 연구는 농형 유도 발전기와 양방향 PWM 인버터를 가진 WECS (Wind Energy Conversion System)시스템을 모델링하고 이 모델에 기초하여 제어 법칙을 제안하였다. 제어 법칙은 풍속 따라 작용하는 최적 팁 속도비에 의해 효율이 최대가 되도록 제어하는 것이다. WECS은 바람의 변동이 있어도 최적치에 팁 속도비를 유지하기 위해 터빈의 회전 속도 제어하여 행한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2625-2632
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• 2009

Recently, a speed control method of induction motor by vector control theory is applied to highly efficient industrial field. The speed sensors attached to motor are used for detection of rotating speed. In the case using speed sensor, the installation of cable for minimization of electric noise, weaken maintenance, increase of price are demerit. Therefore the study of speed sensorless vector control theory performed activity. The design of sensorless vector controller for induction motor using tabu search is studied. The proposed sensorless vector control for Induction Motor is composed of two parts. The first part is for optimizing the speed estimation with initial PI parameters. The second part is for optimizing the speed control with initial PI parameters using tabu search. Proposed tabu search is improved by neighbor solution creation using Triangular random distribution. In order to show the usefulness of the proposed method, we apply the proposed controller to the sensorless speed control of an actual AC induction Motor System. The performance of this approach is verified through simulation and the experiment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.512-513
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• 2017

In this paper, an automatic sowing system which arranges the seeds gathered using inhaling technique, on the upper part of cells in trays, is developed to improve the sowing efficiency. In the system, the seeds in inhaled into the vacuum drum, then the seeds are exhausted and arranged on the rotating tray, resulting in rapid sowing system. Also, the velocity control algorithm for the conveyor belt transporting tray is developed to compensate the velocity error generated while the belt is carrying the tray. The velocity control algorithm controls the pulses applying to the stepper motor rotating the drum.

• Journal of Advanced Navigation Technology
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• v.10 no.4
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• pp.319-326
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• 2006

In this paper, a fuzzy inference control system is proposed for a turbojet engine with fuel flow control input only. The proposed control system provides a practical fuel flow control method to prevent surge or flame out during engine acceleration or deceleration. A fuzzy logic is designed to obtain the fast acceleration and deceleration of the engine under the condition that the operating point should stay between the surge line and flame out control line. With using both engine rotating speed error and surge margin as fuzzy input variables, the desired engine rotating speed can be achieved to rapidly follow the engine control line without engine stall. Computer simulation using the MATLAB is realized to prove the proposed control performance to the turbojet engine which is linear modelized using DYGABCD program package.

• 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.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.182.1-182.1
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• 2010

본 논문에서는 3kW 영구 자석형 동기발전기(PMSG)를 이용한 풍력 터빈 시뮬레이터 개발에 대해 기술하였다. 풍력발전 시스템은 블레이드를 포함한 회전부, 동력 전달부, 발전기, 전력변환기로 크게 나눌 수 있으며, 시뮬레이터는 유도 모터와 PMSG, 인버터-컨버터와 제어 시스템으로 이루어진다. 시뮬레이터를 운전하기 위해서는 특정 속도의 바람 모델을 적용하여 풍력 발전기의 회전부에 걸리게 되는 토크와 회전 속도 값이 요구된다. 풍력 터빈 모델로부터 계산값을 시뮬레이터에 맞게 스케일링하여 유도 모터를 구동 한다. 발전기측 컨버터는 MPPT(Maximum Power Point Tracking) 알고리즘을 통해 제어하고 계통측 인버터는 유효 전력과 무효 전력을 제어하도록 한다. PSIM과 MATLAB/SIMULINK를 이용하여 컴퓨터 시뮬레이션으로 그 결과를 증명하였다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.533-536
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• 2009

The power control system of Smart UAV is similar to the propeller pitch governing concept of turboprop aircraft. The pilot inputs the engine power directly and the pitch governor controls the rotational speed of proprotor. In this paper, the engine status data from ground test of Smart UAV, such as the relationship of PLA vs. Gas generator speed and power are compared with the result of engine performance calculation program.

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.229-231
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• 2006

본 논문은 매입형 영구자석 전동기의 고정자 전압방정식으로부터 관측기를 구성하고, 회전자 좌표계상에서 추정속도를 구하여 퍼지제어기를 이용한 속도 보상 센서리스제어를 수행하였다. 전동기의 전압방정식과 퍼지제어기만을 이용하기 때문에 전동기의 기계적 방정식에서 발생하는 기계적 제정수의 영향에 대해 강인한 특성을 갖는다. 제안된 알고리즘의 타당성과 강인함은 실제 구동을 통하여 증명한다.