• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.5
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• pp.23-29
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• 1994

The design procedure for fuzzy logic controller depends on the expert's knowledge or trial and error. Moreover, it is very difficult to guarantee the stability and robustness of the system due to the linguistic expression of fuzzy control. However, fuzzy logic control has succeeded in many control problems that the conventional control theory has difficulties to deal with. As a result, this control theory is applied to the engine control system which a mathematical model is difficult. In this study, the fuzzy logic is applied to obtain the gain of PI control at idle speed control system, and a simple engine model is developed in order to perform simulation. Experimental results show that the response to reach the target engine speed at idle speed control system is improved by adopting the gain obtained with fuzzy logic.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.2
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• pp.76-80
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• 2005

In this paper, a Direct Learning Control (DLC) method is proposed for linear feedback systems to improve the tracking performance when the task of the control system is repetitive. DLC can generate the desired control input directly from the previously learned control inputs corresponding to other output trajectories. It is assumed that all the desired output functions given to the system have some relations called proportionality and it is shown by mathematical analysis that DLC can be utilized to genera additional control efforts for the perfect tracking. To show the validity and tracking performance of the proposed method, some simulations are performed for the tracking control of a linear system with a PI controller.

• Proceedings of the KIEE Conference
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• 2001.07e
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• pp.116-119
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• 2001

In this research, we detect the charge state within $0.1{\sim}0.3[A]$ and develop the intelligent digital charge device by applying a fine pulse signal using PWM inverter and Proportional-Integral(PI) controller which uses micro -processor and intelligent technique. The ripple rate is within ${\pm}1%$, and the indicator error rate of full charge state is within ${\pm}1%$, and the voltage stability is within ${\pm}0.1[V]$, and the accuracy of voltage detect is 48[V] and ${\pm}0.5[V]$ in the reference of 100[A].

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1024-1026
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• 2006

This paper designed a robust control of an induction motor using a disturbance cancellation observer of a feedforward control. The speed response of conventional PI controller characteristic is affected by variations of load torque disturbance. In the proposed system, the speed control characteristic using a feedforward control isn't affected by a load torque disturbance. High speed calculation and processing for vector control is carried out by ADMC300 digital signal processor. Validity of the proposed control method is verified through simulation and experimental result.

• The KSFM Journal of Fluid Machinery
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• v.16 no.6
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• pp.5-11
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• 2013

Torque control methods of wind turbine are mainly classified into two methods: torque-mode and speed-mode methods. The traditional torque-mode method, in which generator torque proportional to square of generator speed is determined, has been chosen in many wind turbines but its response is slower as they are larger in multi-MW size. Torque control methods based on both speed-mode and torque-mode can be used to make response of wind turbine faster. In this paper, two torque control methods based on the traditional torque-mode method are applied to a 2.75 MW wind turbine. It is shown through some simulation results for real turbulence wind speeds that torque control method based on torque-mode has the merit of reducing fluctuations of generated power than PI controller based on speed-mode.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.10
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• pp.1002-1007
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• 2014

This paper deals with the adaptive backstepping hovering control for a quadrotor with model parameter uncertainties. In this paper, the backstepping based technique is utilized to design a nonlinear adaptive controller which can compensate for the motor thrust factor and the drag coefficient of a quadrotor. First, the quadrotor nonlinear dynamics is derived using Newton-Euler formulation. In particular, we use the ${\pi}/4$ shifted coordinate for x- and y-axis of a quadrotor. Second, an adaptive backstepping based attitude and altitude tracking control method is presented. The system stability and the convergence of tracking errors are proven using the Lyapunov stability theory. Finally, the simulation results are given to verify the effectiveness of the proposed control method.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.336-339
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• 2005

This paper presents a PM type BLDC(Brushless DC) Motor servo drive system using high performance DSP TMS320F2812. The DSP controller with 150MIPS enables an enhanced real time implementation and increased efficiency and high performance for motor drive. The suggested drive system consists of PI action for the constant speed control and PID action for the current control with only 3 Halls, no encoders. The developed servo drive control system shows a good response speed characteristics at high speed up to 10000 [rpm].

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.1
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• pp.57-66
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• 2012

This paper proposes a performance improvement of grid-connected inverter system using sliding-mode based direct power control with a variable gain. The proposed control method determine variable gain of PI controller by using modeling at direct power control (DPC) applied to space vector modulation method. Also, this method use sliding-mode control to maintain excellent dynamic response of character of direct power control (DPC). The validity of the proposed algorithm are verified by simulations and experiments.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.491-492
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• 2013

본 연구는 STATCOM을 이용하여 고속철도 급전 계통의 전압 변화를 보상하는 기법에 관한 것이다. 기존의 PI 제어기를 이용한 제어기법를 대신하여 본 연구에서는 퍼지제어기(FLC) 적용을 제안하며, 퍼지제어기와 PI제어기의 제어결과를 비교한다. 퍼지제어기를 통해 내부 파라미터 변동이나 외부의 환경 변화 등 계통의 변화시에 정상상태 편차, 정상상태 도달 시간 등을 최소화 시킬 수 있음을 보인다.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.12
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• pp.663-670
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• 2003

This paper deals with speed control of DC servo motor using a Adaptive high gain obserber. In this parer, the gain of the observer is properly set up using the fuzzy control and adaptive high gain observer that have a superior transient characteristic and is easy to implement compared the existing method is designed. In order to verify the performance of the Adaptive high gain observer which is proposed in this paper, it is compared estimate performance of High-gain Observer and Adaptive High Gain Observer with the computer simulation. Effectiveness of the proposed high gain observer is proved from the experiment to compare the case with a speed sensor to the case with Adaptive high gain observer in the speed control of DC servo motor.