• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.05a
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• pp.149-152
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• 2001

선박이 해상에서 운항시, 선체는 파도에 의해 심하게 동요되기 때문에 승선감과 안전성이 저하된다. 따라서 선박의 안전항해, 쾌적한 승선감, 구조적인 안전 보장을 위한 선체제어를 위한 필요성이 증대되어 왔다. 기존의 PID 제어기법 등은 정상편차가 적어 과도응답의 문제점 및 오차누적의 문제점이 있고, 퍼지제어 기법은 최적화가 어렵다는 단점을 가진다. 본 논문에서는 퍼지추론 기법을 이용한 선체자세 제어기법으로 운동체에 관한 전문가의 지식과 경험을 바탕으로 퍼지집합과 퍼지규칙을 설정하고 설계된 퍼지 추론을 통해 현재의 운동상황을 판단함으로써 효과적인 최적화와 자세계산을 수행할 수 있다. 본 논문에서는 퍼지추론을 이용한 자세제어 알고리즘을 제안하고 실시간 시뮬레이션을 통하여 시험한다.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.2
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• pp.130-137
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• 2013

In this paper, decoupled controller design for Autonomous Underwater Vehicle(AUV) and its simulated performance test results and Hardware In the Loop Simulation(HILS) results are presented. Control system design is done using the PD control scheme. Stability analysis and step response of closed loop system under uncertain parameter condition are also presented. The results of full coupled nonlinear model simulation show the well applicability of the designed controller. From the results of HILS, we can verify performance of real time processing and implemented hardware for AUV.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.1
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• pp.18-25
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• 2000

In the two-mass servo system driving a load through a flexible shaft, a shaft torsional vibration is often generated. PI controller has been generally used is speed control of such system because of the simplicity of structure and related theory. This paper presents the inertia ratio of the PI servo control system which can be designed by using optimal pole assignment method is fixed. Therefore, it's difficult to obtain the desired control characteristics for different systems only by PI control algorithm. To solve this problems the two-mass speed control system with PID controller is designed by using pole assignment method and an optimum PID parameters are derived by evaluating ITAE(Integral of time multiplied by the absolute error) performance index. But this design method has some problems due to a trade-off between the fast command following property and the attenuation of disturbances and vibrations. In this paper, 2-DOF PID control method which satisfies the command following property, the reduction of overshoot and the property of disturbance rejection at the same time is proposed. This is a practical speed controller using the desired value filter and the feedforward gain. From several simulations, it's clarified that the proposed 2-DOF PID controller is useful for the two-mass system, in comparison with the conventional PID controller.

• Journal of Aerospace System Engineering
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• v.17 no.5
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• pp.34-41
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• 2023

This paper applies the icing effect and wing rock uncertainty to small unmanned aerial vehicles (UAVs), which have recently attracted attention. Attitude control simulations were performed using various control methods. First, the selected platform, the Skywalker X8 UAV with blended wing-body (BWB) configuration, was linearized for both its baseline form, and a form with applied icing effects. Subsequently, using MATLAB SimulinkⓇ, simulations were conducted for roll and pitch attitude control of the baseline configuration and the configuration with icing effects, employing disturbance observer-based PID control, model reference adaptive control, and model predictive control. Furthermore, the study introduced wing rock uncertainty simultaneously with icing effects on the configured model-a combination not previously explored in existing research-and conducted simulations. The performance of each control Method was compared and analyzed.

• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.165-167
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• 2003

인터넷의 비약적인 발달은 제어시스템의 설계 및 운영에도 많은 영향을 미치게 되어 지금까지와는 전혀 다른 시스템 구현이 가능한 환경으로 만들어 가고 있다. 이와 같은 배경에서 본 연구에서는 그동안 실험연구용으로 사용하던 서보시스템의 PID 제어방법을 인터넷을 기반으로 한 새로운 방법의 원격제어 시스템으로 구현하였다. 본 논문에서는 NI사의 DAQ보드와 TY36A모터 보드를 사용하여 서보모터의 속도 위치를 web상에서 원격 제어하는 시스템 구현 방법을 제안하였다. LabVIEW 프로그래밍에서 인터페이스 부분은 Graphical한 프로그래밍 기법을 사용하여 모터의 제어와 작동상태의 모니터링이 용이하도록 하였으며, 최적한 PID 이득값을 설정하여 원하는 속도 및 위치응답 특성이 양호한 제어를 할 수 있게 하였다. 나아가 인터넷상에서 원격제어의 가능성을 활용하여 산업체에서의 활용범위를 넓히고, 가상 교육환경의 가능성을 열었다.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.1
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• pp.60-67
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• 1998

In this paper, a gain scheduling method of PID controller is proposed using fuzzy logic for balancing control of an inverted pendulum. First, gains of PID controller are calculated using pole-placement technique for the linearized model of an inverted pendulum and these gains are modified by fuzzy logic throughout control operations. A PD controller is used by switching near the set-point to improve the performance. It is illustrated by simulations that the proposed hybrid fuzzy control method yidels smaller rising time and overshoot compared to the fixed-gain PID controller or fuzzy logic-based only PID controller.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.50-50
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• 2008

본 연구에서는 전방항성 초음파 액추에이터의 제작, 시뮬레이션, 구동 드라이버 제작, 제어 방법에 대하여 연구하였다. 우선, 시뮬레이션 툴인 ATILA를 사용하여 전방향성 초음파 액추에이터를 설계하였고 구동 주파수, 어드미턴스 특성 그리고 액추에이터의 움직임을 분석하여 최적의 구동 주파수 영역을 파악하였다. 실제 구동을 확인하기 위하여 액추에이터 스테이지와 구동 드라이버를 개발 하였다. 전방항성 액추에이터 스테이지의 구조는 액추에이터와 4개의 볼 베어링이 알루미나 볼을 압착하는 형태이며 세라믹에 인가되는 사인파의 위상차에 의하여 4개의 방향으로 구동 할 수 있다. 또한, 액추에이터를 위치 제어를 위하여 로터리 엔코더 두 개를 사용하여 구의 움직임을 파악하였고 PID 제어기법을 사용하여 액추에이터의 움직임을 제어하였다. 스테이지 구조상 엔코더의 $70^{\circ}$ 내에서만 구동 가능하며, 실험 결과를 통하여 전방향성 초음파 액추에이터는 약 $1.2^{\circ}$의 분해능을 가지고 구동영역 내 원하는 좌표로의 이동이 가능했고, 향후 고 정밀 관절 및 인공 눈에 응용 가능할 것으로 사료된다.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.5
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• pp.543-550
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• 2014

In many industrial processes and operations, such as power plants, petrochemical industries and ships, shell and tube heat exchangers are widely used and probably applicable for a wide range of operating temperatures. The main purpose of a heat exchanger is to transfer heat between two or more medium with temperature differences. Heat exchangers are highly nonlinear, time-varying and show time lag behavior during operation. The temperature control of such processes has been challenging for control engineers and a variety of forms of PID controllers have been proposed to guarantee better performance. In this paper, a scheme to control the outlet temperature of a shell and tube heat exchanger system that combines the PID controller with feedforward control and anti-windup techniques is presented. A genetic algorithm is used to tune the parameters of the PID controller with anti-windup and the feedforward controller by minimizing the IAE (Integral of Absolute Error). Simulation works are performed to study the performance of the proposed method when applied to the process.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.1
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• pp.85-90
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• 2013

PID control for unstable processes with time delay is not easy to apply because of unstability due to the poles existing on left-hand side in s-plane and the effect of time delay. In this paper, the authors consider the PID controller design technique in case of predefining overshoot or rising time by designer according to control environment. To deal with constraint problem like this, in this paper, the RCGA incorporating the penalty strategy is used. This is the method that if the RCGA violates given constraints, the defined penalty function is summed to the evaluation function depending on the severity and then the given constraint problem is converted to non-constraints optimization problem. The proposed method is applied to the unstable FOPTD(First Order Plus Time Delay) system and simulations are accomplished to illustrate the set-point tracking performance.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.17-20
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• 2013

Many researches have been conducted in the field of constructing controllers for ships over 20 years. But still, ship automatic track-keeping controllers has not been designed for ship's automatic berthing as they considered nearly constant ship's speed. This study dealt with this problem to design track-keeping control on ship's model of SAE NURI using nonlinear mathematical expression. By using this control, the ship is auto track-kept in fare-way at reducing speed to anchorage place. The simulation results proved that this control can be adapted in ship's auto berthing in near future.