• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권11호
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• pp.671-679
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• 2004

This paper presents the on-line current controller tuning method of grid-connected inverter using PSO(particle swarm optimization) technique for minimizing the harmonic current. Synchronous frame PI current regulator is commonly used in most distributed generation. However, due to the source voltage distortion, specially in weak AC power system, current may contain large harmonic components, which increase THD(total harmonic distortion) and deteriorates power quality. Therefore, some tuning method is necessary to improve response of current controller. This paper used the PSO technique to tune the current regulator and through simulation and experiments, usefulness of the tuning method has been verified. Especially in simulating the tuning process, ASM(average switching model) of inverter is used to shorten execution time.

• 제어로봇시스템학회논문지
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• 제10권6호
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• pp.510-518
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• 2004

The PID trajectory tracking controller for robotic systems shows performance limitation imposed by inverse dynamics according to desired trajectory. Since the equilibrium point can not be defined for the control system involving performance limitation, we define newly the quasi-equilibrium region as an alternative for equilibrium point. This analysis result of performance limitation can guide us the auto-tuning method for PID controller. Also, the quasi-equilibrium region is used as the target performance of auto-tuning PID trajectory tracking controller. The auto-tuning law is derived from the direct adaptive control scheme, based on the extended disturbance input-to-state stability and the characteristics of performance limitation. Finally, experimental results show that the target performance can be achieved by the proposed automatic tuning method.

• 센서학회지
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• 제24권2호
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• pp.93-95
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• 2015

We present an optical detection method for the fundamental vibrational mode of a tuning fork crystal oscillator in air. A focused He/Ne laser beam is directed onto the edge of one vibrating tine of the tuning fork; its vibrating motion chops the incoming laser beam and modulates the intensity. The beam with modulated intensity is then detected and converted to an electrical signal by a high-speed photo-detector. This electrical signal is a sinusoid at the resonant frequency of the tuning fork vibration, which is 32.76 kHz. Our scheme is robust enough that the sinusoidal signal is detectable at up to $40^{\circ}$ of rotation of the tuning fork.

• 한국정밀공학회지
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• 제13권5호
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• pp.139-147
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• 1996

PID control has been widely used for real control systems. Particularly, there are many researches on control schemes of tuning PID gains. However, to the best of our knowledge, there is no result for discrete-time systems with unknown time-delay and unknown system parameters. On the other hand, Generalized predictive control has been reported as a useful self-tuning control technique for systems with unknown time-delay. So, in this study, based on minimization of a GPC criterion, we present a self-tuning PID control algorithm for unknown papameters and unknown time-delay system. A numerical simulation was presented to illustrate the effectiveness of this method.

• 전기학회논문지
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• 제56권11호
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• pp.2010-2016
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• 2007

PID control is windely used to control stable processes, However, its application to integrating processes is less common. In this paper, we proposed a stable PID controller tuning method for integrating processes with time delay using model reduction method. For proposed model reduction method, it disconnect an integrating factor from integrating processes and reduces separate process using reduction method. and it connect an integrating factor to reduced model. We can obtain stable integrating processes using P controller in inner feedback loop and PID tuning is then used to cancel the pole of the feedback loop. This guarantees both robustness and performance. Simulation examples are given to show the good performance of the proposed tuning method comparing with other methods.

• 전력전자학회논문지
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• 제9권3호
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• pp.240-245
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• 2004

본 연구에서는 SRM의 최대 토크 운전을 위한 자기동조 제어방법을 연구하였다. SRM은 비선형적인 특성이 강하여 해석적인 방법으로 특성을 고찰하거나 속도 및 토크 제어가 어려운 단점이 있다. 따라서 본 논문에서는 최대 토크 운전을 위한 적절한 턴-온/오프각 제어를 자기동조방식(self-tuning method)에 의해 결정하는 방식을 제안하였다. 그리고 턴-온/오프각을 제어하기 위해 귀환되는 신호는 각각 엔코더 펄스수와 상전류의 증분값을 사용하였으며, 운전 중에 스스로 적절한 턴-오프각을 먼저 추종하고 다음으로 턴-온각을 추종하게 된다. 턴-온/오프각은 서로 종속적인 관계에 있으므로 최대 토크 값을 유지하기 위한 턴-온/오프각을 실시간 자기동조방식으로 제어하였으며, 실험을 통해 제안된 방식이 타당함을 확인하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.317-318
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• 2010

• Journal of Advanced Marine Engineering and Technology
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• 제33권7호
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• pp.1003-1011
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• 2009

This study aims at precise control of oil outlet temperature in the oil cooler system of machine tools for enhancement of working speed and processing accuracy. PID control logic is adopted to obtain desired oil outlet temperature of the oil cooler system with hot-gas bypass method. We showed that the gains of PID controller could be easily determined by using gain tuning methods to get the gain of PID controller without any mathematical model. We also investigated various gain tuning methods to design the gains of PID and compared each control performance for selecting the optimal tuning method on the hot gas bypass method through experiments. Moreover, we confirmed excellent control performance with proposed PI controller gain even though disturbances were abruptly added to the experimental system.

• International Journal of Precision Engineering and Manufacturing
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• 제9권4호
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• pp.39-44
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• 2008

In this paper, through the study of discrete implementation of time delay control (TDC) and PID control algorithm, a new systematic gain selection method for PID controller is proposed. An important advantage of this method is that it may be applied to real systems with very simple and systematic procedure. The proposed method is derived for SISO systems and then extended to MIMO system. Through simulation for the second order non-linear plant and experiment on 2-DOF robot, the effectiveness of the proposed method is confirmed. The proposed method could solve the problem of difficulty in gain tuning of existing PID controller.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 춘계학술대회 학술발표 논문집
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• pp.43-46
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• 1998

This paper presents a new parameter tuning method for PID controller. The Ziegler-Nichols Parameter tuning has been widely known as a fairly heuristic method to good determine setting of PID controllers, for a wide range of common industrial processes It has a excessive overshoot in the set point response, set point weighting can reduced the overshoot to specified values. It will also be shown that set point weighting is superior to the conventional solution of reducing large overshoot by other method. In this paper, we will modified the Ziegler-Nichols tuning formula by fuzzy set. These method will give appreciable improvement in the performance of PID controllers.