• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제40권5호
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• pp.431-438
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• 2012

Non-linear turbojet engine controller with high operational performance has been designed for the high maneuverability UAV. The turbojet engine dynamic performance code has been developed to reflect the non-linear characteristics on controller design, by which the necessity of non-linear controller design was justified by investigating the limitation of linear model derived from the dynamic performance. The PI-like fuzzy controller was designed and enhanced by combining with conventional derivative control. This designed fuzzy controller proves its effectiveness by showing superior control performances over the conventional PID controller along with guaranteeing the safe operation within compressor surge, flame out and turbine temperature limits etc.

• Proceedings of the Korea Society for Simulation Conference
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• 한국시뮬레이션학회 2000년도 춘계학술대회 논문집
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• pp.180-185
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• 2000

발전소 등의 대규모 공정 플랜트에서 사용하고 있는 대부분의 상용 제어기는 PID 제어기이며, 온도 루프를 제외한 대부분의 제어루프가 PI 제어기를 채용하고 있다. 제어 시스템의 성능이 제어기 파라미터의 값에 의해 결정되므로, PI 제어기의 튜닝이 중요하다. 한편, 실제 현장에서의 PI 제어기의 튜닝은 많은 시간과 노력을 필요로 하는 시행착오에 의해서 이루어지고 있으며, 각 제어 루프 제어기 파라미터의 초기값 설정에 어려움을 갖고 있는 실정이다. PI 튜닝 기법이 많이 나와 있지만 시험 신호의 인가 문제로 인해 현장 활용에는 많은 어려움을 가지고 있다. 본 논문에서는 단순한 시험 신호로부터 PI 초기 설정값을 산출할 수 있는 방법에 대해서 알아본다. 또한 발전소에 적용된 국산 분산 제어 시스템을 보면, 대부분 데이터 로깅 시스템으로서만 활용되고 있고, 제어 시스템으로의 활용은 거의 이루어지지 않고 있으며, PID제어기에 대한 구현도 완벽하지 못하여 디지털 PI 제어기의구현 방법에 대한 고찰도 요구되고 있다. 본 논문에서는 디지탈 PI 제어기를 구현하는데 있어서 필요한 사항들, 즉 아날로그 제어기의 디지털 등가 제어기로의 변환 기법, 샘플링 주기의 결정 방법, 그리고 그 외에 공정 제어기가 가져야할 기능들에 대해서 언급한다. 그리고나서 PI 튜닝 기법과 아날로그 제어기의 디지털 등가 제어기로의 변환기법, 샘플링 주기 결정 방법 등에 대해 플랜트 모델을 선정하고 시뮬레이션을 통해 그 효용성을 보인다.

• 전자공학회논문지 IE
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• 제47권3호
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• pp.26-34
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• 2010

In this study, a neuro-fuzzy controller based on the characteristics of fuzzy controlling and structure of artificial neural networks(ANN). This neuro-fuzzy controller has each advantage from fuzzy and ANN, respectively. Plus, it can handle their own shortcomings and parameters in the controller can be tuned by on-line. To verify the proposed controller, it has applied to the AC servo motor which is popular item in robot control field. General PID and fuzzy controller are also applied to the same motor so stability and good characteristic of the proposed controller are compared and proved. Especially, the experiment for variable load is investigated and performance result is proved also.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제15권3호
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• pp.536-544
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• 2011

In this paper, a controller for two wheeled inverted pendulum type robot is designed to have more stable balancing capability than conventional controllers. Traditional PID control structure is chosen for the two wheeled inverted pendulum type robot, and proper gains for the controller are obtained for specified user's weights using trial-and-error methods. Next a neural network is employed to generate PID controller gains for more stable control performance when the user's weight is arbitrarily selected. Through simulation studies we find that the designed controller using the neural network is superior to the conventional PID controller.

• Proceedings of the KIEE Conference
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.3178-3180
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• 2000

In this thesis, a controller which is appropriate for uses of scanner with small error and high speed response is proposed. Recently the application field of scanner is on increase. In case of applying to laser marking, the error of scanner has bad effect to quality. Also it can make difficulties in applying laser show that makes images, unless the high speed response is not realized. For these reasons, a controller that can adjust error and response is need. Because scanner must respond to step input that is put between a few millisecond and hundreds of microsecond with small revolution angle ranges, it is advantageous to have small inertia and large torque. First, the property of scanner is treated, and then using Op-amp and passive components and applying feedback compensation PID controller to design, the effects by controller coefficients are introduced.

• Journal of Institute of Control, Robotics and Systems
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• 제4권3호
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• pp.321-328
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• 1998

When we control the level of the steam generator in the nuclear power plants, a swell and shrink arises from many disturbances such as feed water rate, feed water temperature, main steam flow rate, and coolant temperature. If we use the conventional type of PI controller in this system, we will not have stability during controlling at lower power, the removal function of disturbances, and a load follow-up control effectively. In this paper, we study the application of a 2-Degree of Freedom(2-DOF) PID controller to the level control of the steam. generator of nuclear power plants through the simulation and the experimental steam generator. We use the parameters $\alpha$, $\beta$, $\gamma$ of the 2-DOF PID controller for the removal of disturbances and the parameters Kp,Ti,Td of the conventional type of PID controller for controlling setpoint. The back-propagation learning algorithm of neural network is used for tuning the 2-DOF PID controller. We can find satisfactory results of the removal of the disturbances and the tracking function in the change of setpoint through the simulation and experimental steam generator.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제17권3호
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• pp.25-31
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• 2003

In this paper, proposed is a control system for a galvanometer which is widely used fer laser display, laser processing and marking systems. The galvanometer with mirror is modeled as a second-order dynamic system Based on frequency responses and time domain responses of the developed model, a conventional PID controller is designed And it is implemented using a DSP(TMS320C32) chip with precision A/D and D/A converters. Through frequency response and experimental results, it is convinced that the proposed control system works well in real environment. Furthermore it is very easy to be connected to any PC because of USB communication port, and the cost of the marking system can be lowered very much because the DSP do the all the jobs for generating font motion as well as controlling the galvanometer.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.289-292
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• 2005

PID controllers, which have been widely used in industry, have a simple structure and robustness to modeling error. But it is difficult to have uniformly good control performance in system parameters variation or different velocity command. In this paper, we propose an adaptive PID controller based on a gradient descent learning. This algorithm has a simple structure like conventional PID controller and robustness to system parameters variation. To verify performances of the proposed adaptive PID controller, the speed control of nonlinear DC motor is performed. The simulation results show that the proposed control systems are effective in tracking a command velocity under system parameters variation.

• Proceedings of the KIPE Conference
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.452-454
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• 2007

PSP를 이용한 의자로봇 시스템은 거동이 불편한 노약자의 이동을 돕기 위하여 제작된 지능형 이동로봇이다. 원하는 곳으로 이동이 가능한 지능형 로봇은 안정적인 움직임을 위해 실시간 장애물 회피 및 적절한 경로 계획이 필요하다. 본 논문에서 구현한 의자로봇은 IR센서와 초음파 센서를 이용하여 환경 정보를 얻어오고, 환경 지도 작성 및 경로 계획을 통해 목표 지점으로 이동하도록 하였다. 또 구동부의 부드러운 움직임을 위하여 PID제어기를 사용하였다. 서비스 로봇은 개발에 용이하고 사용자가 쉽게 제어 할 수 있는 인터페이스 장치가 필요하다. PSP는 여러 개의 버튼을 가졌고, 디스플레이를 위한 LCD 있다. 또 무선랜 환경에서 사용할 수 있기 때문에 PSP를 이용한 제어 방법을 구현하였다. PSP를 이용한 제어 방법에는 두 가지 모드가 존재하는데 하나는 의자 로봇의 지능을 이용한 이동방법이고 또 하나는 사용자가 직접 제어하는 방법이다. 위의 두 가지 방법으로 실내 환경에서 주행 테스트를 했으며, 성공적으로 동작함을 확인하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제10권8호
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• pp.1993-1997
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• 2009

Robust control for DC servo motor is needed according to the highest precision of industrial automation. However, when a motor control system with PID controller has an effect of load disturbance, it is very difficult to guarantee the robustness of control system. As a compensation method solving this problem, in this paper, PID-neural network hybrid control method for motor control system is presented. The output of neural network controller is determined by error and rate of error change occurring in load disturbance. The robust control of DC servo motor using neural network controller is demonstrated by computer simulation.