Patent US3857535A successfully refreshed from Google Patents.
US3857535A
Expired / Lapsed
US
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Monitor for the elastic mode stabilizing channels of an automatic flight control system
Assignee: Honeywell Inc
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Filing: 1972-09-22
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Granted: 1974-12-31
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Expires: 1992-09-22
Abstract
Abstract Automatic flight control systems for flexible craft often include an elastic mode stabilizing channel that provides signals to craft control surfaces so as to reduce craft bending motions. The invention comprises a sensing system for effectively detecting the characteristics of the control activity applied by the elastic mode stabilizing channel and determining whether that control activity is achieving the desired elastic mode stabilization. When a signal generated by this sensing system exceeds a specified threshold level, it is indicative of a failure within the elastic mode stabilization channel and the logic obtained thereby is used to disable the elastic mode stabilization channel. A turbulence sensor is included for providing a signal to adjust the threshold in accordance with the level of turbulence experienced by the craft.
Inventors
- 👤 S Osder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:40
CPC Classifications
G; G05; G05D; G05D1/00; G05D1/08; G05D1/0808; G05D1/0816
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
194 words
In an automatic flight control system for aeroelastic navigable craft having a control surface, said automatic flight control system having an elastic mode stabilizing channel for controlling said control surface in a manner normally to reduce bending motions of said craft, the combination comprising sensor means for effectively detecting the level of control activity applied to said control surface and providing a sensor signal in accordance therewith, frequency spectrum shaping means responsive to said sensor signal for transmitting only elastic mode frequencies within the normal elastic mode bandwidth of said craft to provide a filtered sensor signal representative of the level of control activity applied by said elastic mode stabilizing channel to said control surface, means for establishing a threshold greater than the normal level of said control activity, detector means responsive to said filtered sensor signal and to said threshold for providing a disabling signal in accordance with said filtered sensor signal exceeding said threshold, and disabling means responsive to said disabling signal for disabling said elastic mode stabilizing channel in accordance with said filtered sensor signal exceeding said threshold, thereby rendering said elastic mode stabilizing channel ineffective in controlling said control surface.
Claim 2
Dependent Claim
194 words
In an automatic flight control system for aeroelastic navigable craft having a control surface, said automatic flight control system having an elastic mode stabilizing channel for controlling said control surface in a manner normally to reduce bending motions of said craft, the combination comprising sensor means for effectively detecting the level of control activity applied to said control surface and providing a sensor signal in accordance therewith, frequency spectrum shaping means responsive to said sensor signal for transmitting only elastic mode frequencies within the normal elastic mode bandwidth of said craft to provide a filtered sensor signal representative of the level of control activity applied by said elastic mode stabilizing channel to said control surface, means for establishing a threshold greater than the normal level of said control activity, detector means responsive to said filtered sensor signal and to said threshold for providing a disabling signal in accordance with said filtered sensor signal exceeding said threshold, and disabling means responsive to said disabling signal for disabling said elastic mode stabilizing channel in accordance with said filtered sensor signal exceeding said threshold, thereby rendering said elastic mode stabilizing channel ineffective in controlling said control surface.
Claim 3
Dependent Claim
31 words
In the system of claim 1 further including turbulence sensor means responsive to the turbulence experienced by said craft for adjusting said threshold in accordance with the level of sAid turbulence.
Claim 4
Dependent Claim
31 words
In the system of claim 2 in which said turbulence sensor means includes turbulence computer means for computing the RMS value of said turbulence and adjusting said threshold in accordance therewith.
Claim 5
Dependent Claim
38 words
In the system of claim 1 in which said sensor means includes transducer means responsive to motion of said control surface for providing said sensor signal to said frequency spectrum shaping means, thereby providing said filtered sensor signal.
Claim 6
Dependent Claim
38 words
In the system of claim 1 in which said sensor means includes transducer means responsive to bending motions of said craft for providing said sensor signal to said frequency spectrum shaping means, thereby providing said filtered sensor signal.
Claim 7
Dependent Claim
52 words
In the system of claim 1 further including turbulence sensor means for detecting the level of turbulence experienced by said craft and providing a turbulence signal in accordance therewith, and said means for establishing a threshold further including adjusting means responsive to said turbulence signal for adjusting said threshold in accordance therewith.
Claim 8
Dependent Claim
31 words
In the system of claim 6 in which said adjusting means comprises means for increasing and decreasing said threshold in accordance with increases and decreases, respectively, in said level of turbulence.
Claim 9
Dependent Claim
56 words
In the system of claim 6 in which said turbulence sensor means comprises accelerometer means for sensing the normal acceleration of said craft and providing a normal acceleration signal in accordance therewith, and turbulence computer means coupled to said accelerometer means for computing the root-mean-square value of said normal acceleration signal thereby providing said turbulence signal.
Claim 10
Dependent Claim
40 words
In the system of claim 8 in which said turbulence sensor means further includes bandpass filter means coupling said accelerometer means to said turbulence computer means for selectively enhancing turbulence frequencies and rejecting maneuvering signal frequencies and bending mode frequencies.
Claim 11
Dependent Claim
91 words
In the system of claim 8 in which said turbulence computer means comprises squaring means responsive to said normal acceleration signal for generating the square thereof, first integrator means coupled to receive said squared normal acceleration signal for providing the integral thereof, second integrator means responsive to said integral from said first integrator means for providing the integral thereof, said integral from said second integrator means being applied in substractive fashion as an input to said first integrator means, said integral from said second integrator means thereby providing said turbulence signal.
Claim 12
Dependent Claim
57 words
In the system of claim 1 in which said automatic flight control system further includes a plurality of channels for stabilizing the rigid body modes of said craft, said disabling means comprising means for disabling only said elastic mode channel in accordance with said control activity exceeding said threshold while maintaining said rigid body mode channels active.
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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) | 1977-12-30 | 1978-07-01 | 1978-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-30 | 1982-07-01 | 1982-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-30 | 1986-07-01 | 1986-12-31 | $7700.00 | Window Closed / Lapsed |