• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.282-286
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• 2000

In this paper, magneto-rheological(MR) damper is studied for vibration control of large infra structures under earthquake. Generally, active control devices need a large control force and a high power supply system to reduce the vibration effectively. Large and miss tuned control force may induce the dangerous situation such that the generated large control force acts to amplify the structural vibration. Recently, to overcome the weaknesses of the active control, the semi-active control method is suggested by many researchers. Semi-active control uses the passive control device of which the characteristics can be modified. Control force of the semi-active device is not generated from the actuator with power supply. It is generated as a dynamic reaction force of the device same as in the passive control case, so the control system is inherently stable and robust. Unlike the case of passive control, control force of semi-active control is adjusted depending on the measured response of the structure, so the vibration can be reduced more effectively against various unknown environmental loads. Magneto-rheological(MR) damper is one of the semi-active devices. Dynamic characteristics of the MR material can be changed by applying the magnetic fields. So the control of MR damper needs only small power. Response time of MR to the input voltage is very short, so the high performance control is possible. MR damper has a high force capacity so it is adequate to the vibration control of large infra structure. Because MR damper has a nonlinear property, normal control method used in active control may not be effective. Clipped optimal control, modified bang-bang control etc. have been suggested to MR damper by many researchers. In this study, sliding mode fuzzy control(SMFC) is applied to MR damper. Genetic algorithm is used for the controller tuning. To verify the applicability of MR damper and suggested algorithm, numerical simulation on the aseismic control is carried out. Simulation model is three-story building structure, which was used in the paper of Dyke, et al. The control performance is compared with clipped optimal control. The present results indicate that the SMFC algorithm can reduce the earthquake-induced vibration very effectively.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2016-2021
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• 2003

This paper deals with a control technique of eliminating the transient vibration with respect to a waist axis of an articulated robot. This control technique is based on a model-based control in order to establish the damping effect on the driven mechanical part. The control model is composed of reduced-order electrical and mechanical parts related to the velocity control loop. The parameters of the control model can be obtained from design data or experimental data. This model estimates a load speed converted to the motor shaft. The difference between the estimated load speed and the motor speed is calculated dynamically, and it is added to the velocity command to suppress the transient vibration. This control method is applied to an articulated robot regarded as a time-invariant system. The effectiveness of the model-based control integrated into the position control loop is verified by simulations. Simulations show satisfactory control results to reduce the transient vibration at the end-effector.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.318-320
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• 2006

A control valve with deadband characteristics influences on the control dynamics. A control loop with deadband component shows cyclic control results and causes the wears of mechanical parts. A valve on the important process that require nonstop operation cannot be improved during operation. In case of control loops with deadband dynamics, the optimal control parameters based on the performance only are not sure of the good operation in point of protecting the control component. To improve the control performance and control oscillation, the control parameters should be changed to meet both control qualify and protection of control components.

• The Journal of Information Systems
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• v.23 no.4
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• pp.25-47
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• 2014

The purpose of this study is to identify and comprehensively explain the SCM-related factors involved in the realization of RTE, including the quality of information concerning SCM, the quality of SCM partnerships, and relationship controlling factors (planning control, behavioral control, and outcome control). This study systematizes the interactions among these factors into a form of a model, elucidating how these interactions affect and shape RTE characteristics. To validate the research model proposed in the study, filed survey was conducted with 79 staffs in Korean company using SCM. The findings of the study can be summarized as follows: First, the quality of information concerning SCM had significant effect on the quality of SCM partnerships, planning control, behavioral control, and outcome control. Not only does the quality of SCM information directly influence the quality of SCM partnerships, planning control, behavioral control, and outcome control; but it also indirect influence on forecasting, agility, and visibility of SCM though its influence on the different forms of relationship control. Second, the quality of SCM partnerships also had significant effect on planning control, behavioral control, and outcome control. In addition to directly influencing these forms of relationship control, the quality of SCM partnerships also indirectly influenced forecasting, agility, and visibility though its influence on relationship control. Third, planning control significantly influenced forecasting, agility and visibility. Fourth, behavioral control significantly influenced forecasting, but neither agility nor visibility. Fifth, outcome control had significant influence on forecasting, agility, and visibility.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.5
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• pp.597-607
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• 2014

This paper proposes active power control and frequency support control schemes of wind turbine generation system by using modified Maximum Power Point Tracking(MPPT) of Permanent Magnet Synchronous Generator(PMSG). Most wind turbine generation system is completely decoupled from the power system and power output control with pitch control. According to the frequency deviation, however, MPPT control can not contribute to the frequency change of the power system due to its active power output control. For solving this, the de-loaded(DL) control scheme is constructed for the frequency support control, which is based on applying the active power output control in the rotor speed control of PMSG. The rotor speed by used in the proposed DL control scheme is increased more than the optimal rotor speed of MPPT, and then this speed improvement increases the saved kinetic energy(KE). In order to show the effectiveness of the proposed control scheme, the case studies have been performed using the PSCAD/EMTDC. The results show that the proposed active power output control scheme(DL control and KE discharge control) works properly and the frequency response ability of the power system can be also improved with the frequency support of wind farm.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.581-584
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• 1996

This paper presents the robust control of robot manipulators using a decentralized control scheme. The control scheme decouples the coupling dynamics between the joints and compensates the joint variable errors without any computation of the dynamics. The performance of the control scheme is compared with that of other control schemes such as the computed torque scheme and the adaptive control scheme by simulation.

• Culinary science and hospitality research
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• v.2
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• pp.5-24
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• 1996

Today, hotel industry has to consider the importance of physical resources as indispensible control factor. This study is focused on search of the directions to control effectively the physical resources. For that purpose, this study set a serious of control system. Problems is selected at the basic of that control system. Thoses are as follows. A. Control Philosophy B. Control Procedure C. Quality Control D. A line of Responsibility As a result, this study turns to a different direction on physical resources control. Those are as follows. A. Reconsideration of Control Environment B. Revaluation of Quantity required C. Reorganization of Control Effect Assessment D. Foundation of Total Control System

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.76-76
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• 2004

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.11
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• pp.1067-1073
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• 2011

In this paper, the methodology of a CA (Control Allocation) based FTNCS (Fault-Tolerant Networked Control System) is proposed. Control allocation is a control surface management technique by redistributing the redundant control surfaces in overactuated systems. In modern high performance aircrafts, they adopt many redundant control surfaces to provide high performance and to satisfy various tactical requirements. Moreover, redundant control surfaces provide an opportunity to compensate performance degradation due to failures in more than one actuator by re-allocating redundant control surfaces. Simulation results with an F-18 HARV demonstrate that the proposed CA based FTNCS can achieve a fast and accurate tracking performance even in the presence of actuator faults.

• International Journal of Control, Automation, and Systems
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• v.4 no.2
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• pp.139-145
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• 2006

A multi-variable Golden-Section adaptive controller is proposed for the tracking control of robotic manipulators with unknown dynamics. With a small sample time, the unknown dynamics of the robotic manipulator are denoted equivalently by a characteristic model of a 2-order multivariable time-varying difference equation. The coefficients of the characteristic model change slowly with time and some of their valuable characteristic relationships emerge. Based on the characteristic model, an adaptive algorithm with a simple form for the control of robotic manipulators is presented, which combines the multi-variable Golden-Section adaptive control law with the weighted least squares estimation method. Moreover, a compensation neural network law is incorporated into the designed controller to reduce the influence of the coefficients estimation error on the control performance. The results of the simulations indicate that the developed control scheme is effective in robotic manipulator control.