• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.5
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• pp.1169-1181
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• 1994

Vibration isolation of mechanical systems, in general, is achieved through passive or active vibration isolators. Passive vibration isolator has an inherenrt performance limitation. Whereas, active vibration isolator provides significantly superior vibration-isolation performance at the cost of energy sources and sensors. Recently, in many cases, such as suspension system, precision machinery ... etc, active isolation system outweighs its limitation. Therefore, many studies, researches, and applications are carried out in this field. In this study, vibration-isolation characteristics of an active vibration control system using electromagnetic force actuator are investigated. Several control algorithms including optimal, feedforward are used for active vibration isolation. From the experimental results of each algorithm, effective control algorithms for this active vibration-isolation system are proposed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.10a
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• pp.179-183
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• 2001

Vibration isolation of mechanical systems, in general is achieved through either passive or active vibration control system. Although passive vibration isolators offer simple and reliable means to protect mechanical system from vibration environment, passive vibration isolator has inherent performance limitation. Whereas, active vibration isolator provide significantly superior vibration-isolation performance. Recently, many studied and applications are carried out in this field. In this study, vibration-isolation characteristics of active vibration control system using electromagnetic force actuator are investigated. Some control algorithms. Optimal Feedforward are used for active vibration isolation. Form the experimental results of each control algorithms, active vibration isolation characteristics are investigated.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1998.10a
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• pp.274-285
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• 1998

Increasing flexibility and lightness of recently built high-rise buildings make the structures susceptible to loads such as earthquakes and winds. Therefore, higher performance vibration control systems to reduce the vibration levels are demanded more than any time in the past. One of typical active vibration control systems is the active mass damper(AMD). In this paper, an active vibration control system consisting of small shaking table, building model, sensors, signal processing board and AMD is constructed. The dynamic characteristics of these individual systems are investigated through the experimental study. The performance of the active vibration control system is verified through harmonic resonant load excitation on building model.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.228-230
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• 2005

In this paper, we address an active vibration control system, which suppresses the vibration engaged by magnetically levitated stage. The stage system consists of a levitating platen with four permanent magnetic linear synchronous motors in parallel. Each motor generates vertical force for suspension against gravity and propulsion force horizontally as well. This stage can generate six degrees of freedom motion via the vertical and horizontal forces. In the stage system, which represents the settling-time critical system, the motion of the platen vibrates mechanically. We designed an active vibration control system for suppressing vibration due to the stage moving. The command feedforward with inertial feedback algorithm is used for solving stage system's critical problems. The components of the active vibration control system are accelerometers for detecting stage tables's vibrations, a digital controller with high precise signal converters. and electromagnetic actuators.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.476-481
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• 2001

This research is concerned with development of the active vibration absorber using piezoelectric actuators. This active isolation system consists of a-pairs of PZT actuators bonded on a S-shaped aluminum plate and the passive damping material. The active system is connected to the passive system in series. In this paper, one of the popular control techniques which have been successfully applied to the smart structure is the Positive Position Feedback(PPF) control. The digital PPF control lows downloaded to the DSP chip and a main program, which runs SISO PPF algorithm. The structure and dynamic characteristics of the proposed active vibration isolation system and described in detail. To demonstate the effectiveness of the active vibration control, the PPF controller is first employed. Experimental results show that the active vibration isolation is possible by means of the proposed system.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.8
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• pp.768-773
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• 2011

This work presents an experimental investigation on vibration control of the active hybrid mount system for naval ships. To reduce unwanted vibrations, this paper proposes an active mount which consists of rubber element, piezostack actuator and inertial mass. The rubber element supports a mass. The piezostack actuator generates a proper control force and supply it to the mount system. To avoid being broken piezostack actuator, an actuator of the proposed mount is devised as an inertial type, in which a piezostack actuator is positioned between inertial mass and rubber element. Vibration control performances of the active mount system are evaluated via experiment. To attenuate the unwanted vibrations transferred from upper mass, the feedforward control is designed. In order to implement a control experiment, the active mount system supported by four active mounts is constructed. For realization of the controller, one-chip board is manufactured and utilized. Subsequently, vibration control performances of the proposed active mount system are experimentally evaluated in frequency domains.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.274-279
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• 2000

Driving of the engine makes unbalance forces which induces vibration to the engine mount system. Active vibration control must be performed to reduce the vibration and the propagation of structure-born sound. In this study, the engine system is modeled as 3-dim. vibration system including flexible structures and an effective active noise control method is proposed. Also, appropriate actuator and sensor locations and types are selected. The miniature of the engine vibration system with multi-input multi-output is built and an active vibration control with multiple filtered-X LMS algorithm is applied to it. The applied control method was effective to reduce the transmitted vibration power through the rubber mount It showed the feasibility of the control of the engine vibration systems with flexible structures.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.936-939
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• 2006

The pneumatic isolator is widely adopted for anti-vibration of precision measuring and manufacturing equipments. But, when the precision demand on anti-vibration is extreme or the load is moving, the performance of anti-vibration can not meet satisfaction. In these cases, as a complementary, active vibration suppression system can be added for advanced performance. In this paper, an active control system is presented, which uses electromagnetic actuators for vibration suppression. The anti-vibration characteristic of pneumatic isolator is analyzed for system modeling and actuator specifying. The modeling and the 3D dynamic simulation is performed for control system design. For the electromagnetic actuator design, the magnetic flex density and the current-force characteristic analysis are achieved.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.121-124
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• 2004

In this paper, we address an active vibration control system, which suppresses the vibration engaged by magnetically levitated stage. The stage system consists of a levitating platen with four permanent magnetic linear synchronous motors in parallel. Each motor generates vertical force fer suspension against gravity and propulsion force horizontally as well. This stage can generate six degrees of freedom motion via the vertical and horizontal forces. In the stage system, which represents the settling-time critical system. the motion of the platen vibrates mechanically. We designed an active vibration control system for suppressing vibration due to the stage moving. The command feedforward with inertial feedback algorithm is used fer solving stage system's critical problems. The components of the active vibration control system are accelerometers for detecting stage table's vibrations, a digital controller with high precise signal converters, and electromagnetic actuators.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.6
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• pp.918-924
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• 2009

This paper deals with the experimental assessment of the vibration suppression of the smart structures. First, we have presented the paper about the new high-speed active control system that we have developed using the DSP320C6713 microprocessor and a peripheral system composed of a data acquisition system, A/D and D/A converters, piezoelectric (PZT) actuator/sensors, and drivers using PA95. Since fast data processing is very important in the active vibration control of the structures, we utilized the fast processing DSP320C6713 microprocessor as a main processor to the controller and fast peripheral devices for fast control loop. To realize a fast active vibration control, we have analyzed and tested the processing time of the peripheral devices and provided the corresponding test results. Especially, we have focused on achieving the fast signal amplification of the PA95 device since it takes most of loop times of the control system. Finally, we performed numerous experiments of active vibration control of the aluminum plate to validate the superior performance of the developed control system based on previous mode tests of the plate.