• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제4권2호
• /
• pp.187-192
• /
• 2004

In this paper, we proposed the method to design fuzzy controller using the experience of the operating expert and experimental numeric data for the robust control about the noise and disturbance instead of the traditional PID controller for the main steam temperature control of the thermal power plant. The temperature of main steam temperature process has to be controlled uniformly for the stable electric power output. The process has the problem of the hunting for the cases of various disturbances. In that case, the manual action of the operator happened to be introduced in some cases. We adopted the TSK (Takagi-Sugeno-Kang) model as the fuzzy controller and designed the fuzzy rules using the informations extracted directly from the real plant and various operating condition to solve the above problems and to apply practically. We implemented the real fuzzy controller as the Function Block module in the DCS(Distributed Control System) and evaluated the feasibility through the experimental results of the simulation.

• 한국항공우주학회지
• /
• 제40권5호
• /
• pp.431-438
• /
• 2012

고기동 무인항공기용 터보제트엔진의 고성능 운용을 위한 비선형 제어기를 설계하였다. 제트엔진의 비선형특성을 제어기 설계에 반영하기 위해 당해엔진의 동적해석코드를 개발하였고 이를 이용한 선형모델로부터 선형해석의 한계성을 검증함으로써 비선형 제어기 설계의 당위성을 보였다. PI형 퍼지제어기를 일반 미분제어기와 결합하여 효율적인 퍼지제어기를 설계하였으며, 일반 PID제어기와 비교하여 압축기서지 및 연소정지영역, 터빈온도의 제한 등 안전운전 범위 내 운전을 보장하면서도 월등한 제어성능을 보임으로써 설계된 퍼지제어기의 유용성을 입증하였다.

• 유공압시스템학회논문집
• /
• 제8권1호
• /
• pp.19-25
• /
• 2011

This study presents the design of digital amplifier.controller for a proportional control valve and the development of PID discrete control scheme by using RCP(Rapid Controller Prototyping) system. RCP system is the device to embed the control code developed in PC into the microcontroller on-site. Ramp input test using the digital amplifier.controller developed in this study was carried out for the proportional control valve of domestic production and Bosch Rexroth respectively. The instability problem occurred around maximum displacement of localized valve spool at ramp input test was solved by supplementing offset current to the duty ratio of PWM(Pulse Width Modulation) driving signal to the solenoid. The comparison of test results between localized proportional control valve and Bosch Rexroth's product shows that the characteristics obtained by ramp input test and static flow gains are alike each other. Two valves are about the same in dead bands and hysteresis characteristics.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제52권1호
• /
• pp.38-44
• /
• 2003

In this study, the balance beam control subsystem, new type of construction machinery using the mechanism of CMG (control moment gyro), for the attitude control of an unstructured object such as a beam carried by a tower crane, is designed and implemented. The balance beam controller consists of a wheel spinning at high speed and an outer gimbal for controlling the attitude of the wheel. Two motors, one for the wheel and the other for the gimbal, are used. Applying force to the spin axis of the wheel, as an input of the system, leads the torque about the axis because of the gyro effects. This torque is used to control the attitude of the unstructured object in this study. For the stabilizer function, in addition, holding the load at the current position, the attitude of the wheel is freed by cutting the power applied to the gimbal motor of the balance beam controller, which result in the braking force to stop the load by gyro effect. The works presented here include the mechanical system of the balance beam controller, the remote controller, the servo controller and the control software for the system. We also present experimental results to show that the system we proposed is useful as a new construction machinery which can control the attitude of the beam hanging from a tower crane.

• 대한전기학회논문지:전력기술부문A
• /
• 제48권4호
• /
• pp.395-401
• /
• 1999

In this paper, a temperature controller for a semiconductor test handler is proposed. First, a handware system for identification and control is established using RTD sensors, an A/D converter, solid state relays, a heater, and a computer system. Second, using ARMAX model and least square method, a chamber model for the design of a controller is identified through experiments. The identified model is verified to describe the real plant very well in the sense that it shows very similar input-output responses to those of the real system. With the identified model an LQG controller is designed. Frequency response of the designed controller shows that it has 15 dB of gainmargin and (-50˚, +50˚) of phase margin. Experiment with a real test handler demonstrates a good performance in the sense that its overshoot and steady state error are smaller and response time is faster, compared with those of a conventional PID controller.

• 한국산학기술학회논문지
• /
• 제17권2호
• /
• pp.325-333
• /
• 2016

본 연구는 솔더링 시스템에서 세라믹 인두기의 온도 제어를 위한 제어기 설계 알고리즘을 제안하고, 제어 실험으로 그 유효성을 보였다. 솔더링 시스템의 세라믹 인두기 온도 응답 특성이 매우 느리며 제어 입력에 비선형인 특성을 갖고 있어 정밀한 모델링과 제어기 설계에 어렵다. 본 연구에서는 전제부 변수가 제어 입력이고 결론부가 전달함수인 퍼지 규칙들로 구성된 TSK 퍼지 모델로 세라믹 인두기 온도 특성을 표현하였다. 퍼지 모델 결론부의 전달함수는 계단 입력 응답으로부터 구한다. 세라믹 인두기 온도 응답 특성이 매우 느리므로 완전한 계단 입력 응답을 구하기가 어렵다. 불완전한 계단 입력 응답으로 전달함수를 구하는 방법으로 유전적 알고리즘(GA)을 사용하는 것을 제안하며, 예제들로 제안한 그 유효성을 보였다. 또한 TSK 퍼지 모델로부터 퍼지 제어기를 설계하는 방법도 제안하며 그 유효성을 예제 시뮬레이션으로 확인하였다. 제안한 방법들을 세라믹 인두기 온도 제어에 적용하여 실험 하였다. 퍼지 모델의 규칙은 7개로 구성되었으며 퍼지 제어기의 결론부는 PI 제어기로 하였다. 제안한 퍼지 제어기의 실험 결과는 선형 제어기보다 우수하였으며 퍼지 PID 제어기를 사용한 기존 연구 결과에 못지않았다.

• 제어로봇시스템학회논문지
• /
• 제18권12호
• /
• pp.1101-1105
• /
• 2012

This study proposes a method for improvement of PD type fuzzy controller. The method includes self tuner using gradient algorithm that is one of the optimization algorithms. The proposed controller improves simple Takagi-Sugeno type FLC (Fuzzy Logic Control) system. The simple Takagi-Sugeno type FLC system changes nonlinear characteristic to linear parameters of consequent membership function. The simple FLC system could control the system by calibrating parameter of consequent membership function that changes the system response. While the determination on parameter of the simple FLC system works well only partially, the proposed method is needed to determine parameters that work for overall response. The simple FLC system doesn't predict the response characteristics. While the simple FLC system works just like proportional part of PID, our system includes derivative part to predict the next response. The proposed controller is constructed with P part and D part FLC system that characteristic parameter on system response is changed by self tuner for effective response. Since the proposed controller doesn't include integral part, it can't eliminate steady state error. So we include a gain to eliminate the steady state error.

• 한국산업융합학회 논문집
• /
• 제21권2호
• /
• pp.53-62
• /
• 2018

This study propose a new approach to control the optimal working path of vertical type articulated robot with translation joint for trimming working process automation in forging manufacturing process. The basic structure of the proposed robotic joints controller consists of a Proportional-Intergral controller and a Proportional-Derivative controller in parallel. The proposed control scheme takes advantage of the properties of the fuzzy PID controllers. The proposed method is suitable to control of the trajectory and path control in cartesian space for vertical type articulated robot manipulator. The results illustrates that the proposed fuzzy computed torque controller is more stable and robust than the conventional computed torque controller. The reliability is varified by simulation test for vertical type s articulated robot with seven joints including one trqanslation joint.

• 한국정밀공학회지
• /
• 제30권8호
• /
• pp.831-838
• /
• 2013

This paper focused on the design of an efficient temperature controller for a plant with a wide range of operating temperatures. The greater the temperature difference a plant has, the larger the nonlinearity it is exposed to in terms of heat transfer. For this reason, we divided the temperature range into five sections, and each was modeled using ARMAX(auto regressive moving average exogenous). The movement of the dominant poles of the sliced system was analyzed and, based on the variation in the system parameters with temperature, optimal control parameters were obtained through simulation and experiments. From the configurations for each section of the temperature range, a temperature-based gain-scheduled controller (TBGSC) was designed for parameter variation of the plant. Experiments showed that the TBGSC resulted in improved performance compared with an existing proportional integral derivative (PID) controller.

• 대한기계학회논문집A
• /
• 제28권8호
• /
• pp.1203-1211
• /
• 2004

A traction control systems (TCSs) composed of either a wheel slip controller or a throttle valve controller or an integrated controller of both systems are proposed in this study. To validatethe dynamic characteristics of a vehicle and TCS, a full car model that can simulate the responses of both front wheel drive (2WD) and four wheel drive (4WD) vehicle is also developed. The wheel slip controller uses a sliding mode control scheme and the throttle valve is controlled by a PID controller. The results shows that tHe brake TCS and the engine TCS achieve rapid acceleration, and reduce slip angle on slippery road. When a vehicle is cornering and accelerating maneuver with the brake or engine TCS, understeer or oversteer occur, depending on the driving conditions. The integrated TCS prevents most of these problems and improves the stability and controllability of the vehicle.