US5378974A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vibration damping system
Assignee: United States Department of the Air Force
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Filing: 1993-07-02
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Granted: 1995-01-03
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Expires: 2013-07-02
Abstract
Abstract The smart patch includes two piezoceramic actuators which operate on both sides of a structural member at the same fixed distance from the neutral axis to produce a bending method. The piezoceramic actuators are configured such that when subjected to a voltage, one shrinks and one expands. This provides the moment. One piezoceramic could also be used to provide half the moment provided that it was the same distance from the neutral axis of the structural member. There is a piezoceramic sensor that senses the vibrational mode to be suppressed. Finally there are control electronics that consist of a charge amplifier, a two pole low pass filter and a bridge amplifier. All of these elements are integrated into one entity.
Inventors
- 👤 Steven F. Griffin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 00:48
CPC Classifications
F; F16; F16F; F16F15/00; F16F15/005; G; G05; G05D; G05D19/00; G05D19/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
207 words
In combination with a mechanical structure which experiences motion-induced vibration, a vibration damping system comprising; means for electrically sensing the motion-induced vibration in the mechanical structure to produce thereby an electrical vibration measurement signal; a pair of piezoceramic actuators which are fixed on opposite sides of the mechanical structure at contact points and responding to composite motion command signals to counter all motion induced vibration at their contact points; a charge amplifier which is electrically connected with said sensing means to receive and amplify the electrical vibration measurement signal therefrom and which produces an amplified vibration measurement signal thereby; a variable frequency low pass filter which converts the amplified vibration measurement signal of the charge amplifier into a pair of motion command signals; a bridge amplifier which is electrically connected between the variable frequency low pass filter and the pair of piezoceramic actuators and which receives and amplifies the pair of motion command signals for the pair of piezoceramic actuators; and an internal means for providing electrical power to said sensing means, said piezoceramic actuators, said charge amplifier, said low pass filter and said bridge amplifier, wherein said sensing means and said pair of piezoceramic actuators is powered using four 8 volt batteries as said providing means.
Claim 2
Dependent Claim
207 words
In combination with a mechanical structure which experiences motion-induced vibration, a vibration damping system comprising; means for electrically sensing the motion-induced vibration in the mechanical structure to produce thereby an electrical vibration measurement signal; a pair of piezoceramic actuators which are fixed on opposite sides of the mechanical structure at contact points and responding to composite motion command signals to counter all motion induced vibration at their contact points; a charge amplifier which is electrically connected with said sensing means to receive and amplify the electrical vibration measurement signal therefrom and which produces an amplified vibration measurement signal thereby; a variable frequency low pass filter which converts the amplified vibration measurement signal of the charge amplifier into a pair of motion command signals; a bridge amplifier which is electrically connected between the variable frequency low pass filter and the pair of piezoceramic actuators and which receives and amplifies the pair of motion command signals for the pair of piezoceramic actuators; and an internal means for providing electrical power to said sensing means, said piezoceramic actuators, said charge amplifier, said low pass filter and said bridge amplifier, wherein said sensing means and said pair of piezoceramic actuators is powered using four 8 volt batteries as said providing means.
Claim 3
Dependent Claim
39 words
A vibration damping system, as defined in claim 1, wherein each of said sensing means comprises a piezoceramic sensor which is fixed to said mechanical structure near said contact points to measure the motion-induced vibration at the contact points.
Claim 4
Dependent Claim
116 words
In combination with a mechanical structure which experiences motion-induced vibration, a vibration damping system comprising: means for electrically sensing the motion-induced vibration in the mechanical structure to produce thereby an electrical vibration measurement signal; a pair of piezoceramic actuators which are fixed on opposite sides of the mechanical structure at contact points and responding to composite motion command signals to counter all motion induced vibration at their contact points; and a means for electrically converting the electrical vibration measurement signal of the sensing means into the composite motion command signals for the pair of piezoceramic actuators, wherein said converting means, said sensing means and said pair of piezoceramic actuators is powered using four 8 volt batteries.
Claim 5
Dependent Claim
116 words
In combination with a mechanical structure which experiences motion-induced vibration, a vibration damping system comprising: means for electrically sensing the motion-induced vibration in the mechanical structure to produce thereby an electrical vibration measurement signal; a pair of piezoceramic actuators which are fixed on opposite sides of the mechanical structure at contact points and responding to composite motion command signals to counter all motion induced vibration at their contact points; and a means for electrically converting the electrical vibration measurement signal of the sensing means into the composite motion command signals for the pair of piezoceramic actuators, wherein said converting means, said sensing means and said pair of piezoceramic actuators is powered using four 8 volt batteries.
Claim 6
Dependent Claim
146 words
In combination with a mechanical structure which experiences motion-induced vibration, a vibration damping system comprising; means for electrically sensing the motion-induced vibration in the mechanical structure to produce thereby an electrical vibration measurement signal wherein each of said sensing means comprises a piezoceramic sensor which is fixed to said mechanical structure near said contact points to measure the motion-induced vibration at the contact points; a pair of piezoceramic actuators which are fixed on opposite sides of the mechanical structure at contact points and responding to composite motion command signals to counter all motion induced vibration at their contact points; and a means for electrically converting the electrical vibration measurement signal of the sensing means into the composite motion command signals for the pair of piezoceramic actuators, wherein said converting means, said sensing means and said pair of piezoceramic actuators is powered using four 8 volt batteries.
Claim 7
Dependent Claim
146 words
In combination with a mechanical structure which experiences motion-induced vibration, a vibration damping system comprising; means for electrically sensing the motion-induced vibration in the mechanical structure to produce thereby an electrical vibration measurement signal wherein each of said sensing means comprises a piezoceramic sensor which is fixed to said mechanical structure near said contact points to measure the motion-induced vibration at the contact points; a pair of piezoceramic actuators which are fixed on opposite sides of the mechanical structure at contact points and responding to composite motion command signals to counter all motion induced vibration at their contact points; and a means for electrically converting the electrical vibration measurement signal of the sensing means into the composite motion command signals for the pair of piezoceramic actuators, wherein said converting means, said sensing means and said pair of piezoceramic actuators is powered using four 8 volt batteries.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-01-02 | 1998-07-04 | 1999-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-02 | 2002-07-04 | 2003-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-02 | 2006-07-04 | 2007-01-03 | $7700.00 | Window Closed / Lapsed |