• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
• /
• pp.338-341
• /
• 1994

This paper presents a Fuzzy-PID controller based on Fuzzy logic. Up to now PID controller has had the difficulty of obtaining the optimal gain, and Fuzzy controller has had the difficulty of determining scale factor affecting the performance of control. So that a Fuzzy-PID controller is presented here self tuning of the scale factor and optimal gain. The results of simulation show a good performance in comparison with Ziegler-Nichols controller, having the generality of determining the components of scale factor in Fuzzy rule.

• 한국지능시스템학회논문지
• /
• 제6권2호
• /
• pp.3-12
• /
• 1996

탁월한 비선형 제어 특성을 가지고 있는 슬라이딩 모우드 제어기는 제어 대상 플랜트의 모델링 과정에서 발생하는 부정확성과 각종 외란등으로 인하여 제어 입력 신호가 매우 높은 주파수의 비연속적인 특성을 가진다. 이를 방지하기 위하여 슬라이딩 평면에 얇은 경계층을 도입하는 방법을 많이 사용하고 있지만 이 경우에는 원하지 않는 정상 상태 오류가 유발될 수도 있다. 이때의 정상 상태 오차는 경계층의 폭에 비례해서 증가하는 특성이 있다. 본 논문에서는 정상 상태 오차와 제어 입력 신호의 불연속성 사이에는 구해지는 경계층의 폭을 정상 상태에 접근할수록 퍼지 규칙베이스에 의해 자동으로 감소시키는 자기동조형 경계층을 가지는 슬라이딩 모우드 제어기를 제안하였다. 그리고 제안된 알고리즘의 성능을 역진자 계통의 추적 제어 시뮬레이션을 통하여 입증하였다.

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

• 한국소음진동공학회논문집
• /
• 제19권7호
• /
• pp.667-672
• /
• 2009

This paper is concerned with the development of linear magnetic actuator for active vibration control. The newly developed linear magnetic actuator consists of permanent magnets and copper coils. On the contrary to the voice-coil type actuator, the linear magnetic actuator utilizes magnetic flux to generate the shaft movement. In this study, experiments on the prototype linear magnetic actuator were carried out to investigate its dynamic characteristics. Block and inertia forces generated by the actuator were measured. The experimental results show that the actuator can be used as both actuator and active tuned-mass damper. The linear magnetic actuator was attached to a cantilever as the active-tuned mass damper and active vibration control experiment was carried out. The experimental results show that the newly developed linear magnetic actuator can be effectively used for the active vibration control of structures.

• 전력전자학회논문지
• /
• 제9권6호
• /
• pp.602-611
• /
• 2004

본 논문에서는 속도 오차의 최소화와 안정된 응답 특성을 가진 선형 영구자석형 동기 전동기를 이용한 시스템을 구성하기 위해서 속도 오차와 속도 오차의 미분항을 입력 변수로 하고 PI 룩업-테이블(look up table)을 이용한 퍼지(fuzzy) 기반 자기동조(self-tuning) PI 속도 제어기를 제안 하였다. 부하가 변동되는 제어 환경이나 시스템에 비선형성 외란이 가해지는 경우, 고정된 최초의 이득 설정 또는 NC 공작기에서 사용되는 속도에 따른 가변이득 조절 방식만으로는 원하는 제어특성을 기대하기가 어렵다. 본 연구의 타당성을 검증하기 위해서 기존의 고정이득 방식 및 속도 변동량에 따른 가변이득 방식을 제안한 방식과 시뮬레이션 및 4상한 운전 실험을 통해 비교함으로써 제안된 방식이 기존의 방식들보다 안정되고 빠른 속도 응답특성을 가짐을 확인하였다.

• 제어로봇시스템학회논문지
• /
• 제8권3호
• /
• pp.199-207
• /
• 2002

In this paper, a self-tuning gain-scheduled skyhook control for semi-active suspension systems is investigated. The dynamic characteristics of a continuously variable damper including electro-hydraulic pressure control valves is analyzed. A 2-d.o.f. time-varying quarter-car model that permits variations in sprung mass and suspension spring coefficient is considered. The self-tuning skyhook control algorithm proposed in this paper requires only the measurement of body acceleration. The absolute velocity of the sprung mass and the relative velocity of the suspension deflection are estimated by using integral filters. The skyhook gains are gain-scheduled in such a way that the body acceleration and the dynamic tire force are optimized. An ECU prototype is discussed. Experimental results using a 1/4-ear simulator are discussed. Also, a suspension ECU prototype targeting real implementation is provided.

• 제어로봇시스템학회논문지
• /
• 제11권2호
• /
• pp.160-166
• /
• 2005

In this paper, to overcome drawbacks of FLC a self tuning fuzzy sliding mode controller is proposed, which controls the position of excavator's attachment, which can be regarded as an ill-defined system. It is reported that fuzzy logic theory is especially useful in the control of ill-defined system. It is important in the design of a FLC to derive control rules in which the system's dynamic characteristics are taken into account. Control rules are usually established using trial and error methods. However, in the case where the dynamic characteristics vary with operating conditions, as in the operation of excavator attachment, it is difficult to find out control rules in which all the working condition parameters are considered. Experiments are carried out on a test bed which is built around a commercial Hyundai HX-60W hydraulic excavator. The experimental results show that both alleviation of chattering and performance are achieved. Fuzzy rules are easily obtained by using the proposed method and good performance in the following the desired trajectory is achieved. In summary, the proposed controller is very effective control method for the position control of the excavator's attachment.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.248-252
• /
• 2003

This paper has a control method proposed for the effective self-tuning fuzzy speed control based on neural network of the induction motor indirect vector control. The vector control of an induction motor provides the decoupled control of the rotor flux magnitude and the torque producing current to performance is desirable. But, the drive performance often degrades for the machine parameter variations and its condition give rise to coupling of flux and torque current. The fuzzy speed control of an induction motor has the robustness about machine parameter variations compared with conventional PID speed control in a way. That proved to be some waf from the true. The purpose of this paper is to improve the adaptation by offering self-turning function to fuzzy speed controller. In this paper, the adaptive mechanism of fuzzy speed control in used ANN(Artificial Neural Network) technique is applied in an IFO induction machine drive, such that the machine can follow a reference model (an ideal field oriented machine) to achieve desired speed. In this paper proved the self-turning method of fuzzy controller has the robustness about parameter variation and the wide range of adaptation by simulation.

• 한국정밀공학회지
• /
• 제22권1호
• /
• pp.61-72
• /
• 2005

In this paper, we develop anti-sway control in proposed techniques for an ATC system. The developed algorithm is to build the optimal path of container motion and to calculate an anti-collision path for collision avoidance in its movement to the finial coordinate. Moreover, in order to show the effectiveness in this research, we compared NNP PID controller to be tuning parameters of controller using NN with 2 DOF PID controller. The experimental results for an ATC simulator show that the proposed control scheme guarantees performances, trolley position, sway angle, and settling time in NNP PID controller than other controller. As a result, the application of NNP PID controller is analyzed to have robustness about disturbance which is wind of fixed pattern in the yard. Accordingly, the proposed algorithm in this study can be readily used for industrial applications

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
• /
• pp.61-64
• /
• 1996

This paper presents a new approach to the design of self-tuning adaptive control system that is robust to the changing dynamic configuration as well as to the load variation factors using Digital signal processors for robot manipulators. TMS32OC50 is used in implementing real-time adaptive control algorithms to provide advanced performance for robot manipulator. In this paper, an adaptive control scheme is proposed in order to design the pole-placement self-tuning controller which can reject the offset due to any load disturbance without a detailed description of robot dynamics. Parameters of discrete-time difference model are estimated by the recursive least-square identification algorithm, and controller parameters are determined by the pole-placement method. Performance of self-tuning adaptive controller is illustrated by the simulation and experiment for a SCARA robot.