• 대한전기학회논문지:시스템및제어부문D
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• 제54권2호
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• pp.61-68
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• 2005

This paper is concerned with attitude control of 2 rotor 1 DOF aerial vehicle. The proposed controller consists of two parts: the attitude estimation filter part and PID controller part. For attitude estimation, performance of 3 different filters (complementary filters, Kalman filter, indirect Kalman filters) are tested and compared. For the PID controller, characteristic ratio assignment methods are used to assign PID coefficients. Through experiments, it is shown that attitude of the vehicle successfully follows the step command.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권1호
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• pp.9-15
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• 2003

To improve the performance of PID controller of high order systems by model reduction, we proposed two model reduction methods. One, Original model with two point $({\angle}G(jw)=\;-{\pi}/2,\;-{\pi})$ in Nyquist curve used gradient base method and genetic algorithm. The other, Original model without two point$({\angle}G(jw)=\;-{\pi}/2,\;-{\pi})$in Nyquist curve used to add very small dead time. This method has annexed very small dead time on the base model for reduction, and we remove it after getting the reduced model, and , we improved Smith-predictor for a dead-time compensator using genetic algorithms. This method considered four points$({\angle}G(jw)=0,\;-\pi/2,\;-\pi,\;-3\pi/2)$ in the Nyquist curve to reduce steady state error between original and reduced model. It is shown that the proposed methods have more performance than the conventional method.

• Kyungpook Mathematical Journal
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• 제55권3호
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• pp.563-586
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• 2015

In this research work, a seven-term 3-D novel jerk chaotic system with two quadratic nonlinearities has been proposed. The basic qualitative properties of the novel jerk chaotic system have been described in detail. Next, an adaptive backstepping controller is designed to stabilize the novel jerk chaotic system with two unknown parameters. Moreover, an adaptive backstepping controller is designed to achieve complete chaos synchronization of the identical novel jerk chaotic systems with two unknown parameters. MATLAB simulations have been shown in detail to illustrate all the main results developed for the 3-D novel jerk chaotic system.

• ETRI Journal
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• 제39권3호
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• pp.364-372
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• 2017

For the reliability of controllers in a software defined network (SDN), a dynamic and self-learning schedule method (DSL) is proposed. This method is original and easy to deploy, and optimizes the combination of multiple controllers. First, we summarize multiple controllers' combinations and schedule problems in an SDN and analyze its reliability. Then, we introduce the architecture of the schedule method and evaluate multi-controller reliability, the DSL method, and its optimized solution. By continually and statistically learning the information about controller reliability, this method treats it as a metric to schedule controllers. Finally, we compare and test the method using a given testing scenario based on an SDN network simulator. The experiment results show that the DSL method can significantly improve the total reliability of an SDN compared with a random schedule, and the proposed optimization algorithm has higher efficiency than an exhaustive search.

• 한국정밀공학회지
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• 제31권9호
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• pp.821-829
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• 2014

This paper describes the development of a wireless communication controller of gripper contact signal for industrial robot. The wireless communication gripper controller is composed of a robot wireless communication controller and a gripper wireless transmitting/receiving controller. The robot wireless communication controller transmits the data of gripper sensors, and the gripper wireless communication controller receives the data. And the controller sends the data to the robot controller of industrial robot. As a result of the characteristics test of the wireless communication gripper controller, it is thought that the robot wireless communication controller A transmits and receives three gripper wireless transmitting/receiving controller A1, A2, A3 another. Thus, the developed wireless communication gripper controller can be used for transmitting/ receiving the data of gripper sensors for industrial robot.

• 한국지능시스템학회논문지
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• 제22권3호
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• pp.361-366
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• 2012

본 논문은 퍼지 제어기를 이용하여 전기 이륜차의 속도를 제어한다. 전기 이륜차는 스로틀에 대하여 빠른 응답성과, 정속주행 시 안정성이 요구 된다. 그러나 현재 양산중인 전기 이륜차는 1.5KW(50cc)급으로 탑승자 및 수화물 중량, 도로 상태(비포장 길, 아스팔트 길) 및 바람의 저항 등 부하 변동에 따라 속도 변화가 매우 크므로 정속 주행이 어려우며, 오르막길과 내리막길의 경사도에 따라 급격한 속도 변화가 발생된다. 이러한 문제점을 해결하기 위하여 속도의 오차와 오차의 변화량을 퍼지 제어기의 입력 값으로 사용하고, 모터의 Q축 제어 량을 퍼지 제어기의 출력 값으로 설정 하여 퍼지 제어기를 구성하였다. 모터의 D축 제어 량은 Q축 제어 량에 비례적으로 설정하여 매입형 영구 자석 동기 전동기(Interior Permanent Magnet synchronous Motor, IPMSM)를 장착한 전기 이륜차를 구동하였다. 본 논문에 적용된 제어 대상은 1.5KW급 전기이륜차로서 모터의 속도 제어를 위하여 제안된 알고리즘을 이용한 퍼지 제어기를 사용 하였으며, 매입형 영구 자석 동기전동기의 토크 제어를 위하여 D, Q축 전류 제어기를 사용 하였다. 제안된 알고리즘을 이용한 퍼지 제어기는 설정된 속도를 잘 추종하였다.

• Journal of Power Electronics
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• 제15권3호
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• pp.695-701
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• 2015

Uninterruptible Power Supplies (UPSs) can be largely divided into the passive-standby, line-interactive and double-conversion methods. This paper proposes a double-conversion UPS with a low cost and high performance. This single phase UPS uses a single-loop robust voltage controller and 1-switch voltage doubler strategy PFC. The proposed UPS is composed of a single phase PFC, a half-bridge inverter, a battery charger and a battery discharger. Finally, the validity of proposed UPS was verified by various experimental tests.

• 전기전자학회논문지
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• 제22권3호
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• pp.716-722
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• 2018

This paper presents a voltage angle control strategy for surface permanent magnet synchronous motor (SPMSM) drives used in low-cost applications, wherein a current vector control is not employed. In the proposed method, the current vector control scheme, which requires high precision phase-current sensing units and a fast calculation capability of a motor drive controller, is replaced with the voltage angle controller. The proposed voltage angle controller calculates a d-axis voltage command to make the d-axis current zero by using a simple equation obtained from the voltage equation of SPMSM. The proposed method shows performance similar to the current vector controlled SPMSM drive during steady-states and its structure is very simple and thus it can be easily implemented with a low-cost microcontroller. The effectiveness of the proposed method is verified through simulations and experiments.

• Journal of Electrical Engineering and Technology
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• 제3권4호
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• pp.584-592
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• 2008

In this paper, we propose a new model of the magnetic control force exerted on the levitation object in magnetic levitation systems. The model assumes that the magnetic force is a function of the voltage applied to an electromagnet and the position of a levitation object. The function is not explicitly expressed but represented through a 2D lookup table constructed from the experimentally measured data. Unlike the conventional model that reveals only local characteristics of the magnetic force, the proposed model shows global characteristics satisfactorily. Specially devised measurement equipment is utilized in order to gather the data required for model construction. An experimental procedure to construct the model is presented. We apply the proposed model to designing a sliding mode controller for a lab-built magnetic system. The validity of the proposed model is illustrated by comparing the performances of the controller adopting the conventional model with that of the controller adopting the proposed model.

• 전력전자학회논문지
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• 제4권1호
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• pp.26-34
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• 1999

비선형 반도체 전력변화장치의 사용이 급증함에 따라 전원 측에 발생되는 고조파 및 무효전력을 보상하기 위한 능동전력필터에 관한 연구가 많이 이루어져 왔으며 실용화를 위한 노력이 계속 되고 있다. 그러나 수동필터 대비 능동전력필터의 가격이 아직까지는 고가이기 때문에 이의 상용화가 더디게 진전되고 있는 추세이며, 특히 소·중용량의 능동전력필터의 제어를 위하여 디지털 신호 처리용 프로세서인 DSP(digital signal processor)를 사용하는 경우 아직까지 그 가격이 고가이기 때문에 능동필터의 제어가격을 상승시키는 요인으로 작용한다. 한편 능동전력필터의 가격을 낮추기 위해 아날로그 제어기만을 도입하는 경우 제어회로가 너무 복잡해 지고 제어의 유연성이 떨어지는 단점을 수반하게 된다. 본 논문에서는 3상 5[kVA]급 농동전력필터의 저가형 제어기를 구현하기 위해 저가의 원칩 마이크로프로세서인 80C196KC를 사용하영 디지털 제어부를 구성하며 이를 통해 보상전류 성분의 계산 및 직류단 일정 전압제어를 수행하고, 능동필터 시스템의 전류제어를 위하여 아날로글 형태의 제어기인 히스테리시스 제어기를 함께 사용한다. 컴퓨터 시뮬레이션을 통해서 보상 시스템의 특성을 해석하였으며 실험에 의해 능동전력필터의 저가화를 위해 설계된 제어기가 고조파 및 무효전력 보상을 충실히 수행함을 확인하였다.