Patent US3734432A successfully refreshed from Google Patents.
US3734432A
Expired / Lapsed
US
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Suppression of flutter
Assignee: Individual
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Filing: 1971-03-25
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Granted: 1973-05-22
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Expires: 1991-03-25
Abstract
Abstract An active aerodynamic control system to control flutter over a large range of oscillatory frequencies unaffected by mass, stiffness, elastic axis, or center-of-gravity location of the system, mode of vibration or subsonic Mach number consisting of one or more pairs of leading edge and trailing edge hinged or deformable control surfaces, each pair operated in concert by a stability augmentation system. Torsion and bending motions or deflections of the fluttering member are sensed and converted by the stability augmentation system into leading and trailing edge control surface deflections which produce lift forces and pitching moments to suppress flutter.
Inventors
- 👤 G Low
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:38
CPC Classifications
G; G05; G05D; G05D1/00; G05D1/40; G05D1/49; B; B64; B64C; B64C13/00; B64C13/02; B64C13/16; G05D1/08; G05D1/0808; G05D1/0816; Y; Y02; Y02T; Y02T50/00; Y02T50/40
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
276 words
Apparatus for flutter suppression, gust alleviation and stability augmentation on a vehicle, having at least one liftproducing member, moving in a fluid comprising: a first control member movably attached to the leading edge of said lift-producing member, a secoNd control member movably attached to the trailing edge of said lift-producing member, sensor means attached to said lift-producing member for producing signals indicative of the motion of said liftproducing member caused by flutter, gusts and vehicle instability; computer means, receiving said produced signals from said sensor means, for producing first and second signals indicative of the movement of said first and second control members, respectively, necessary to damp out said motion caused by flutter, gust and vehicle instability; said computer means is a computer that receives the outputs from said sensor means and produces said first and second signals in accordance with the following two equations: Beta (C(1,1) + iG(1,1)) h/b + (C(1,2) + iG(1,2)) Alpha delta (C(2,1) + iG(2,1)) h/b + (C(2,2) + iG(2,2)) Alpha where Beta is said first signal, delta is said second signal, h and Alpha are indicative of the linear and angular components, respectively, of said motion caused by flutter, gusts and vehicle instability, b is a constant proportional to the chord of said lift-producing member, i represents a 90* phase lead, and C(1,1), C(1,2), C(2,1), C(2,2), G(1,1), G(1,2), G(2,1) and G(2,2) are predetermined transfer functions; means receiving said first signal for moving said first control member proportional to said first signal; and means receiving said second signal for moving said second control member proportional to said second signal whereby the motion caused by flutter, gusts and vehicle instability is damped out.
Claim 2
Dependent Claim
276 words
Apparatus for flutter suppression, gust alleviation and stability augmentation on a vehicle, having at least one liftproducing member, moving in a fluid comprising: a first control member movably attached to the leading edge of said lift-producing member, a secoNd control member movably attached to the trailing edge of said lift-producing member, sensor means attached to said lift-producing member for producing signals indicative of the motion of said liftproducing member caused by flutter, gusts and vehicle instability; computer means, receiving said produced signals from said sensor means, for producing first and second signals indicative of the movement of said first and second control members, respectively, necessary to damp out said motion caused by flutter, gust and vehicle instability; said computer means is a computer that receives the outputs from said sensor means and produces said first and second signals in accordance with the following two equations: Beta (C(1,1) + iG(1,1)) h/b + (C(1,2) + iG(1,2)) Alpha delta (C(2,1) + iG(2,1)) h/b + (C(2,2) + iG(2,2)) Alpha where Beta is said first signal, delta is said second signal, h and Alpha are indicative of the linear and angular components, respectively, of said motion caused by flutter, gusts and vehicle instability, b is a constant proportional to the chord of said lift-producing member, i represents a 90* phase lead, and C(1,1), C(1,2), C(2,1), C(2,2), G(1,1), G(1,2), G(2,1) and G(2,2) are predetermined transfer functions; means receiving said first signal for moving said first control member proportional to said first signal; and means receiving said second signal for moving said second control member proportional to said second signal whereby the motion caused by flutter, gusts and vehicle instability is damped out.
Claim 3
Dependent Claim
44 words
The apparatus of claim 1 wherein the lift-producing member is an airfoil and said first and second control members are hinged leading edge and trailing edge flapped controls which are operated in concert to change the lift and pitching moment produced by said airfoil.
Claim 4
Dependent Claim
14 words
Apparatus according to claim 1 wherein said sensor means includes first and second accelerometers.
Claim 5
Dependent Claim
14 words
Apparatus according to claim 3 wherein said first and second accelerometers are linear accelerometers.
Claim 6
Dependent Claim
21 words
Apparatus according to claim 3 wherein said first accelerometer is a linear accelerometer and said second accelerometer is an angular accelerometer.
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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) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |