• Journal of the Society of Naval Architects of Korea
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• v.32 no.1
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• pp.94-102
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• 1995

The active control system of structural vibration using a hydraulic actuator is developed. The developed system consists of three parts : a hydraulic unit, an actuator unit and a control unit. Structural vibration is sensored by the accelerometer attached to the structure and reduced by the optimally controlled motion of active mass giving anti-phase inertia force to the structure. It is experimentally confirmed that the vibration level of model structure is reduced to about 1/6 by the developed active control system.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.7 s.124
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• pp.617-623
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• 2007

This paper presents an active vibration control of a dynamic system using hybrid mount which consists of elastic rubber-piezostack actuator and elastic rubber-electromagnetic actuator, respectively. After identifying stiffness, damping properties of the elastic rubber, PZT actuator and electromagnetic element, a mathematical model of the hybrid mount is established. The mount model is then incorporated into the dynamic system and the governing equation of motion is obtained in a state space. A sliding mode controller is designed in order to actively attenuate the vibration of the system. Control responses such as acceleration and transmitted force of the dynamic system are experimentally evaluated and presented in time and frequency domains.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.1131-1136
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• 2007

This paper presents an active vibration control of a 1-DOF system using hybrid mount which consists of elastic rubber and PZT(piezostack) actuator and elastic rubber and electromagnetic actuator, respectively After identifying stiffness, damping properties of the elastic rubber, PZT actuator and electromagnetic element, a mathematical model of the hybrid mount is established. The mount model is then incorporated into the 1-DOF system and the governing equation of motion is obtained in a state space. A sliding mode controller is designed in order to actively attenuate the vibration of the system. Control responses such as acceleration and transmitted force of the 1-DOF system are experimentally evaluated and presented in time and frequency domains.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.778-783
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• 2003

The problem considered in this paper is about the collocation of sensor and actuator for the active control of sound and vibration. It is well-known that a point collocated sensor-actuator pair offers an unconditional stability with very high performance when it is used with a direct velocity feedback (DVFB) control, because the pair has strictly positive real (SPR) property. In order to utilize this SPR characteristics, a matched piezoelectric sensor and actuator pair is considered, but this pair suffers from the in-plane motion coupling problem with the out-of$.$plane motion due to the piezo sensor and actuator interaction. This coupling phnomenon limits the stability and performance of the matched pair with DVFB control. As a new alternative, a point sensor and piezoelectric actuator pair is also considered, which provides SPR property in all frequency range except at the first resonance in very low frequency. This non-SPR resonance could be minimized by applying a phase lag compensator.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.1
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• pp.263-270
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• 1995

The use of the shape memory alloy, Nitinol wire, is investigated as an actuator for enhancing the damping in structural vibration systems. The first-order mathematical model of the Nitinol wire is obtained from the experimental data for an actuator. Finite element method is utilized for the strain gage sensor model, which is installed at the root of cantilever beam. A simple system, cantilever beam, is built as a flexible structural system to implement a control law with the Nitinol wire actuator. The system model including sensor and actuator is derived, which agrees with the experimental results. The actuator dynamics is augmented with the system so as to design PI controller and the one of robust controllers, LQG/LTR controller, and the control laws are implemented experimentally. The experimental study shows the feasibility of utilizing the Nitinol wire as an actuator for the purpose of vibration control.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.6
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• pp.169-174
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• 2001

Optimization of the collocated piezoceramic sensor/actuator placement is investigated numerically and verified experimentally for vibration control of laminated composite plates. The finite element method is used for the analysis of dynamic characteristics of the laminated composite plates with the piezoceramic sensor/actuator. The structural damping index(SDI) is defined from the modal damping(2$\omega$ζ) . It is chosen as the objective function for optimization. Weights for each vibrational mode are taken into account in the SDI calculation. The gradient method is used for the optimization. Optimum location of the piezoceramic sensor/actuator is determined by maximizing the SDI. Numerical simulation and experimental results show that the optimum location of the piezoceramic sensor/actuator is dependent upon the outer layer fiber orientations of the plate, and location and size of the piezoceramic sensor/actuator.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.7 s.124
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• pp.587-595
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• 2007

Performance evaluation of advanced piezoelectric composite actuator is conducted with its application of structural vibration control. Characteristics of MFC(macro fiber composite) actuator are investigated by comparing traditional piezoceramic patch actuator. Finite element modeling is used to obtain equations of motion and boundary effects of smart hull structure with MFC actuator. Dynamic characteristics of the smart hull structure are studied through modal analysis and experimental investigation. LQG control algorithm is employed to investigate active damping of hull structure. It is observed that vibration of hull structure is suppressed effectively by the MFC actuators.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.1119-1124
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• 2007

Performance evaluation of advanced piezoelectric composite actuator is conducted with its application of structural vibration control. Characteristics of MFC (macro fiber composite) actuator are investigated by comparing traditional piezoceramic patch actuator. Finite element modeling is used to obtain equations of motion and boundary effects of smart hull structure with MFC actuator. Dynamic characteristics of the smart hull structure are studied through modal analysis and experimental investigation. LQG control algorithm is employed to investigate active damping of hull structure. It is observed that vibration of hull structure is suppressed effectively by the MFC actuators.

• Journal of KSNVE
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• v.7 no.2
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• pp.311-317
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• 1997

In this paper the active vibration control system using a linear oscillatory actuator(LOA) is studied to suppress structural vibration. In the LOA, the AC-power-energized armature generates a shift field in an air gap, which produces a oscillating force to the mover in the magnetic field generated by high density permanent magnets. LOA has relatively simple structure with almost maintenance free, compared with a hydraulic actuator. Performance test of the active vibration control system using a LOA is carried out on a steel test structure under base excitation. From this test, it is confirmed that the acceleration level of the test structure is drastically reduced near the resonant region.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.152.3-152
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• 2001

This paper describes an application of an air-pulse actuator for vibration control of a framed structure. Dynamic characteristics of the prototype actuator that utilizes an air-jet reaction force pulsated by an electromagnetic valve were investigated to use it as a control actuator. Using a control law based on the sliding mode control theory, experiments of the vibration control were carried out. The experimental results verified the validity of the actuator performance.