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Jeon, Han-Wook;Lee, Chong-Won;Seto, Kazuto
- Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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- 2008.04a
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- pp.290-293
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- 2008
This paper proposes a criterion to select the modes for modal truncated model of flexible rotor only supported by active magnetic bearings. The proposed approach relies on the concepts of minimum control input and output energy assuming that the system is subjected to transient disturbances. Accurate large order model for the levitated rotor is taken by finite element analysis and transformed to the modal equation. By proposed methodology, which modal states should be retained in the truncated model are investigated over the whole operational speed range by the calculation. Finally, the effectiveness is verified by checking the model error between original model and reduced model.
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Natarajan, Balakumaran;Eun, WonJong;Shin, SangJoon
- Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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- 2013.04a
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- pp.347-352
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- 2013
Seoul National University Flap (SNUF) blade is a small-scaled rotor blade incorporating a small trailing-edge flap control surface driven by piezoelectric actuators at higher harmonics for vibration attenuation. Initially, the blade was designed using two-dimensional cross-section analysis and a geometrically exact one-dimensional beam analysis, and material configuration was finalized. Flap deflection angle of ${\pm}45^{\circ}$ was established as the criterion for better vibration reduction performance based on an earlier simulation. Flap linkage mechanism design is carried out and static bench tests are conducted to verify the flap actuation mechanism performance. Different versions of test beds are developed and tested with the flap and chosen APA 200M piezoelectric actuators. Through significant improvements, a maximum deflection of ${\pm}3.7^{\circ}$ was achieved. High frequency experiments are conducted to evaluate the performance and transfer function of the test bed is determined experimentally. As the static tests are almost completed, rotor power required for testing the blade in whirl tower (centrifugal environment) is calculated and further preparations are under way.
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Jang, Seung-Ik;Shen, Yun-De;Kee, Chang-Doo
- Proceedings of the KSME Conference
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- 2003.11a
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- pp.1602-1607
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- 2003
Vibration causes noise and sometimes makes structure unstable. Especially, due to the efforts of lightening, deformation of flexible structure is increased in its shape. Just a little disturbance can cause vibration and low damping ratio makes residual vibration last long time. This research is concerned with the model reference neuro-controller design for the vibration suppression of smart structures. By using a model reference neurocontroller, which is one of the algorithms of adaptive control, we performed an adaptive control of flexible cantilever plate and opened box structure with piezoelectric materials. The proposed adaptive vibration control algorithm, a model reference neuro-controller, was proved in its effectiveness by applying to an opened box structure. The model reference neuro-controller is implemented with DSP, and the real-time adaptive vibration control experiment results confirm that the model reference neuro-controller is reliable.
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노용래
- Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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- 1992.10a
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- pp.92-97
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- 1992
Undesired vibratory motion of an electric connector is controlled in an active method with piezoelectric sensors and actuators. A special electric control box is developed which is suitable for the purpose. Experimental results show that the system can effectively reduce amplitude responses connector to external forces.
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Kim, Hyoun-Suk;Park, Youngjin
- 제어로봇시스템학회:학술대회논문집
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- 1995.10a
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- pp.43-46
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- 1995
Adaptive algorithms based on gradient adaptation have been extensively investigated and successfully jointed with active noise/vibration control applications. The Filtered-X LMS algorithm became one of the basic feedforward algorithms in such applications, but still is not fully understood. The error path model effect on the Filtered-X LMS algorithm has been under the investigation and some useful properties related stability has been discovered. We are interested in utilizing the fact that the model error caused by the way optimizing the error path model in a view point of convergence speed of Filtered-X LMS algorithm for pure tone noise suppression application without any performance loss at steady state.
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