• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1092-1097
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• 2005

In this paper, design approach of PID controller with rejection function against external disturbance in motor control system is proposed using bacterial foraging based optimal algorithm. Up to the present time, PID Controller has been used to operate for AC motor drive because of its implementational advantages in practice and simple structure. However, it is not easy to achieve an optimal PID gain with no experience, since the gain of the PID controller has to be manually tuned by trial and error in the industrial system with disturbance. To design disturbance rejection tuning, disturbance rejection conditions based on $H_{\infty}$ are illustrated and the performance of response based on the bacterial foraging is computed for the designed PID controller as ITSE (Integral of time weighted squared error). Hence, parameters of PID controller are selected by bacterial foraging based optimal algorithm to obtain the required response

• Journal of Mechanical Science and Technology
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• v.14 no.4
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• pp.393-400
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• 2000

In this paper, a new algorithm for noninteracting control system design is proposed and applied to ship propulsion system control. For example, if a ship diesel engine is operated by consolidated control with controllable pitch propeller (CPP), the minimum fuel consumption is achieved satisfying the demanded ship speed. For this, it is necessary that the ship is operated on the ideal operating line which satisfies the minimum fuel consumption, and the both pitch angle of CPP and throttle valve angle are controlled simultaneously. In this context of view, this paper gives a controller design method for a ship propulsion system with CPP based on noninteracting control theory. Where, linear matrix inequality (LMI) approach is introduced for the control system design to satisfy the given $H_{\infty}$, constraint in the presence of physical parameter perturbation and disturbance input. To the end, the validity and applicability of this approach are illustrated by the simulation in the all operating ranges.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.301-305
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• 1996

$\mu$ theory can handle the parametric uncertainty and produces more non-conservative controller than H$_{\infty}$ control theory. However an existing solution of the theory, D-K iteration, creates a controller of huge order and cannot handle the real or mixed real-complex perturbation sets. In this paper, we use genetic algorithms to solve these problems of the D-K iteration method. The Youla parameterization is used to obtain all stabilizing controllers and the genetic algorithms determines the values of the state feedback gain, the observer gain, and Q parameter to minimize $\mu$, the structured singular value, of given system. From an example, we show that this method produces lower order controller which controls a real parameter-perturbed plant than D-K iteration method.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.115-118
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• 1996

This paper studies on an active noise control to reduce noise sound level in a small cavity. Ideally, high gain control solves this problem, but, in practice, there exist nonlinear characteristics and modelling errors of the small cavity, which make the control more complicated. H$_{\infty}$ control can be used in an uncertain system after determining uncertain boundary and solved algebraically or numerically. In this paper, the numerical one, LMI(Linear Matrix Inequality), is used to get controller. Finally, experiment result shows the performance of the controller..

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.10
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• pp.988-993
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• 2009

In this paper, we deal with a tracking gain-up controller design problem to control effectively the shake of tracking actuator after a track seek. A minimum tracking gain-up open-loop gain can be calculated by estimating the shake of tracking actuator and a desired transient specification is considered to diminish effectively the shake of actuator. A tracking gain-up controller is designed by considering a robust $H_{\infty}$ control problem with a regional stability constraint. The proposed tracking gain-up controller design method is applied to the track-following system of a DVD recording device and is evaluated through the experimental results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.2
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• pp.242-249
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• 2001

In this study, a methodology of synchronous control has been developed that can is applied to position synchronization of a two-axes driving system such as overhead crane. The synchronous error is caused by model uncertainties and torque load at each axis. To overcome these problems, the synchronous control system has been composed of two disturbance observers to calculate the torque disturbance and one synchronous controller to eliminate synchronous error. By considering model uncertainties of each axis, the synchronous controller has been designed using H(sub)$\infty$ control theory. The effectiveness of the proposed method has been verified through simulation.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.34.2-34
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• 2001

There are many control methods guaranteeing the robustness of systems. Among them, H$\infty$ control, sliding mode control and disturbance observer have been used widely. Especially, disturbance observer(DOB) is one of the most popular methods because it is easy to apply and the cost to pay is low due to its simplicity. Conventional DOB utilizes output signal as a feedback signal. But in Optical Disk Drive(ODD) systems, the Position Error Signal(PES) is the only available one. So conventional DOB is not applicable. If we use error signal in stead of output signal, another form of DOB is made. We call it as Error based Disturbance Observer(EDOB). We show in this paper the difference between two systems, namely conventional DOB system and the EDOB system, and also show the effectiveness of EDOB through experiment.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.10
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• pp.1051-1059
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• 2013

In general, lateral ride comfort of railway vehicle is mainly influenced by a secondary suspension placed between the bogie and carbody. Higher operating speeds of train results in increased vibration of carbody, which has a negative impact related to the ride comfort. To solve this problem, researches to replace the conventional passive suspension with (semi)active technology in the secondary suspension of a railway vehicle have been carried out. The semi-active suspension using the magneto-rheological damper is relatively simpler system and has advantage in maintenance compared to the hydraulic type semi-active damper. This study was performed to reduce lateral vibration acceleration of carbody related to ride comfort of railway vehicles with a semi-active suspension system. The numerical analysis was conducted by replacing passive lateral damper with semi-active MR damper, and robust control with the MR damper was applied to the 1/5 scaled railway vehicle model.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.38.2-38
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• 2001

Recent trend of increasing automated factories needs supply of high quality power from the utilities. Among the items of the power quality, voltage sag can be compensated by Dynamic Voltage Restorer(DVR). The key feature of the DVR is high response with less transient period to recover from the voltage sag due to the lightning or line-to-ground faults. In this paper we report that H controller is very premising for the practical application to the controller of DVR. Experiment al results shown in this paper was obtained by applying the control algorithm to 20 kVA DVR system. The experimental set consist s of IGBT - based three phase inverter and the TMS320C32- 60 DSP used for main processor of the control board. T$\infty$ simulate the 50% voltage ...

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.621-626
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• 2019

The driver's steering wheel maneuver is a typical disturbance that causes excessive body motion and traveling instability of a vehicle. Abrupt and extreme operation can cause rollover depending on the geometric and dynamic characteristics, e.g., SUV vehicles. In this study, to cope with the performance limitation of conventional cars, fundamental research on the structurization of a control system was performed as follows. Mathematical modeling of the lateral behavior induced by driver input was carried out. A controller was designed to reduce the body motion based on this model. An algorithm was applied to secure robust control performance against modeling errors due to parameter uncertainty, $H_{\infty}$. Using the decoupled 1/4 car, a dynamic load simulating model considering the body moment was suggested. The simulation result showed the validity of the load-simulating model. The framework for a lateral behavior control system is proposed, including an experimental 1/4 vehicle unit, load simulating module, suspension control module, and hardware-in-the-loop simulation technology.