• 대한전기학회논문지:전력기술부문A
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• 제48권10호
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• pp.1251-1258
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• 1999

The water level control of a steam generator in the unclear power plant is an important process. Most of the water level controllers of the actual plant are PID controllers. But they have limitations in appling for tracking the set point and getting rid of disturbances, so there are some defects to apply in the actual ground even though many research works represented the resolutions to solve it. In this paper, it is suggested that the established simple PID controller in low power has the ability to remove disturbances and trace the set-point, and then possesses the real-time self-tuning function according to the variety of moving peculiarity of a plant. This function realized by making use of fuzzy logic. PID parameters are formulated by a variable ${\alpha}$ and made it fluctuate by a fuzzy inference according to level error and level error change. This mechanism makes application of actual plant effective as well as taking advantage of improving the efficiency of water level controller by way of adding the function of self-tuning instead of replacing PID controller. The computer simulation of this scheme shows the improved performance compare to conventional PID controller.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권12호
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• pp.691-696
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• 2002

This paper presents a neural network based self-tuning fuzzy PID control scheme with variable learning rate for induction motor speed control. When induction motor is continuously used long time, its electrical and mechanical Parameters will change, which degrade the Performance of PID controller considerably. This Paper re-analyzes the fuzzy controller as conventional PID controller structure, introduces a single neuron with a back-propagation learning algorithm to tune the control parameters, and proposes a variable learning rate to improve the control performance. Proposed scheme is simple in structure and computational burden is small. The simulation using Matlab/Simulink and the experiment using dSPACE(DS1102) board are performed to verify the effectiveness of the proposed scheme.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.1165-1168
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• 2002

This paper presents a neural network based self-tuning fuzzy PID control scheme with variable learning rate for sensorless vector controlled induction motor drives. MRAS(Model Reference Adaptive System) is used for rotor speed estimation. When induction motor is continuously used long time. its electrical and mechanical parameters will change, which degrade the performance of PID controller considerably. This paper re-analyzes the fuzzy controller as conventional PID controller structure, introduces a single neuron with a back-propagation learning algorithm to tune the control parameters, and proposes a variable learning rate to improve the control performance. The proposed scheme is simple in structure and computational burden is small. The simulation using Matlab/Simulink and the experiment using DS1102 board show the robustness of the proposed controller to parameter variations.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 전력전자학술대회
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• pp.115-117
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• 2019

In this paper, an intelligent control scheme based on Fuzzy PID controller is proposed for accurate power sharing in DC Microgrid. The proposed Fuzzy PID controller is designed with the aid of a closed loop control based on per unit power of each distributed generator (DG), and accurate power sharing is successfully realized in proportional to each DG's power rating regardless of the line resistance difference or the load change. Thanks to Fuzzy PID controller, the dynamic response becomes faster and the stability of the microgrid system are improved in comparison to conventional PID controller. The superiority of the proposed method is analyzed and verified by simulation in Matlab and Simulink.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1496-1499
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• 2005

In this paper, we applied step motor drive using a fuzzy logic control based on PID controller. A designed this controller's purpose is improved robust and autonomous characteristic in which the variation of external load affects plant parameter. Therefore, in this paper, using a fuzzy logic control based on PID controller of two fuzzy-PI and fuzzy-D is obtained decremental overshoot and a special response quality.

• 전기학회논문지
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• 제56권2호
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• pp.396-406
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• 2007

In this paper, we proposed development of improved model reduction and design of hierarchical controller using reduction model. The model reduction is considered that it is the transient response and the steady-state response through the use of nyquist curve. The hierarchical controller selected tuning of PID controller to ensure specified gain and phase margin and hybrid smith-predictor fuzzy controller using reduction model. Simulation examples are given to show the better performance of the proposed method than conventional methods.

• 항공우주시스템공학회지
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• 제4권4호
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• pp.18-27
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• 2010

Quadrotor is an aircraft which is possible in Vertical Take-off and Landing(VTOL). This aircraft can not only be created as an Unmanned Aerial Vehicle(UAV), but also can be easily used in various fields because of its simplicity of construction. This study is mainly conducted with two main purposes. The first goal is designing the quadrotor focusing on the lightweight and protecting the airframe. The second purpose is stabilizing the quadrotor's attitude by using the PID controller. MATLAB simulation is performed for obtaining PID gain based on equations of motion. We used the compensation filter technique for the calibration of sensor data. PID gain has been drawn out based on the MATLAB simulation. The efficiency of the attitude control is improved by calibration of sensor data.

• 전력전자학회논문지
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• 제7권1호
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• pp.55-64
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• 2002

인버터를 적용한 유압식 시스템은 펌프의 마찰과 실린더 패킹 및 탑승 카와 레일의 마찰특성으로 인하여 PID 제어기로는 제어가 되지 않는 데드 존이 생기게 된다. 본 논문에서는, 우선 유압시스템으로 구동되는 유압식 시스템의 극저속 속도영역(zero-crossing)에서 속도가 제어되지 않는 원인이 되는 실린더의 마찰특성을 고찰하고, 이러한 실린더의 마찰특성으로 인하여 기존의 PID 속도제어기로 제어 시 발생되는 문제점을 해결하기 위한 줌잉 퍼지 룰을 포함한 퍼지제어기를 설계한다. 마지막으로, 설계된 퍼지제어기와 기존의 PID 제어기를 결합하여 보다 성능이 향상된 하이브리드 퍼지제어기를 설계한다. 제안된 하이브리드 퍼지제어기는 정속주행구간에서는 정상상태제어성능이 우수한 PID 제어기를 적용하고 PID제어기로 제어되지 않는 극저속 속도구간에서는 퍼지제어기를 적용하여 유압식 시스템이 실린더의 마찰특성으로 인하여 극저속 속도영역(zero-crossing)에서 속도가 제어되지 않는 문제를 해결하고, 극저속 영역에서 뿐 아니라 정상상태를 포함한 전 운전영역에서의 제어성능이 우수함을 시뮬레이션과 실험을 통하여 보인다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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• pp.345-348
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• 1991

This paper describes a new auto tuning method for the intelligent PID control system. This new method is hosed on the settling time of the process and has been introduced into auto-tuning PID controller using fuzzy logic. The performance of the controller is measured by computer simulation. Simulation shows good results that controller searches well the optimal values of PID parameters in any conditions and the response characteristic of the control system is improved.

• 한국정밀공학회지
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• 제15권2호
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• pp.45-52
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• 1998

The contact roll is often used to regulate the winding tension as well as the entrained air in a wound roll by adjusting the contact force to the winding roll. But the contact force generated by other rolls, like assistant nip rolls, in a winding(or roll changing) process may act as disturbance to the control of the winding tension. In this paper, the mechanism of a roll change process is analysed. Ana, the behavior of the contact and the nip rolls are mathematically modeled. A nonlinear PID(NPID) controller is designed to control the winding tension and to reject the effect of disturbance generated by the nip roll on the winding tension variation. Computer simulation study showed that the performance of the suggested NPID controller is improved compared with that of the PID controller in controlling the winding tension and in rejecting the effect of the disturbance.