Patent US4094481A successfully refreshed from Google Patents.
US4094481A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fail passive dual servo with continuous motor speed and acceleration and monitoring
Assignee: Honeywell Inc
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Filing: 1977-06-30
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Granted: 1978-06-13
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Expires: 1997-06-30
Abstract
Abstract The servomotor outputs of two substantially identical servo channels, are connected through a differential mechanism to position an attitude control surface of an aircraft in response to common or separate command signals applied to the respective channels. The dual channels are continuously monitored in such a manner that if the velocities and accelerations of the two servomotor outputs do not track each other within predetermined ratio limits, appropriate servo brakes will clamp the output of the servomotor with the highest acceleration, or the failed channel. The rapidity with which the failed channel is detected and the servo brakes applied assures that essentially no control surface motion occurs and hence no attitude or flight path transients are evident by reason of the failure. Clamping of the failed servomotor, moreover, assures that the remaining servo channel may remain operative. In addition to and simultaneous with the clamping of the failed channel, the pilot is warned by appropriate alerting devices of the failure so that he may disconnect the autopilot and manually take over control.
Inventors
- 👤 Michael P. DeWalt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:28
CPC Classifications
G; G05; G05D; G05D1/00; G05D1/0055; G05D1/0077
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
170 words
A monitored multiple channel automatic pilot for aircraft having a control surface controlled thereby for controlling the attitude and flight path of the aircraft comprising first and second substantially identical closed loop control channels responsive to attitude and flight path control signals and including corresponding first and second servomotors normally supplying substantially identical outputs for controlling said control surface, differential means having first and second inputs responsive respectively to the outputs of said first and second servomotors and an output connected to drive said control surface for controlling the attitude and flight path of said aircraft in response to said control signals, and monitor means continuously responsive to the ratio of the absolute values of the accelerations of said first and second servomotors and the ratio of the absolute values of the velocity difference between said first and second servomotor outputs and the velocity of each of said servomotors outputs for clamping that input to said differential means having the highest acceleration when said velocity ratio exceeds a predetermined value.
Claim 2
Dependent Claim
170 words
A monitored multiple channel automatic pilot for aircraft having a control surface controlled thereby for controlling the attitude and flight path of the aircraft comprising first and second substantially identical closed loop control channels responsive to attitude and flight path control signals and including corresponding first and second servomotors normally supplying substantially identical outputs for controlling said control surface, differential means having first and second inputs responsive respectively to the outputs of said first and second servomotors and an output connected to drive said control surface for controlling the attitude and flight path of said aircraft in response to said control signals, and monitor means continuously responsive to the ratio of the absolute values of the accelerations of said first and second servomotors and the ratio of the absolute values of the velocity difference between said first and second servomotor outputs and the velocity of each of said servomotors outputs for clamping that input to said differential means having the highest acceleration when said velocity ratio exceeds a predetermined value.
Claim 3
Dependent Claim
53 words
The monitored multiple channel automatic pilot as set forth in claim 1 further comprising tachometer generator means responsive to said first and second servomotor outputs for supplying signals respectively proportional to the velocities thereof, and circuit means responsive to said velocity signals for providing signals proportional respectively to the acceleration of said servomotors.
Claim 4
Dependent Claim
39 words
The monitored multiple channel automatic pilot as set forth in claim 2 further comprising means for clamping the respective inputs of said differential means, and logic means responsive to said acceleration and velocity ratios for actuating said clamping means.
Claim 5
Dependent Claim
92 words
The monitored multiple channel automatic pilot as set forth in claim 3 further comprising means responsive to said velocity signals for providing respective velocity value signals proportional to the absolute values thereof and a further value signal proportional to the absolute value of the difference therebetween, and ratio detector means responsive to said further value signal and each of said respective velocity value signals for providing logic signals to said logic means when the ratio of said further value signal and one of said respective velocity value signals exceeds a predetermined value.
Claim 6
Dependent Claim
65 words
The monitored multiple channel automatic pilot as set forth in claim 4 further comprising means responsive to said acceleration signals for providing signals respectively proportional to the absolute values thereof, and ratio detector means responsive to each of said absolute value signals for providing logic signals to said logic means when the ratio of one of said signals to the other exceeds a predetermined value.
Claim 7
Dependent Claim
63 words
The monitored multiple channel automatic pilot as set forth in claim 5 further including means for supplying bias signals to each of said ratio detector means for biasing one of the absolute value signals supplied to said ratio detector means for preventing nuisance outputs of said ratio detector means when the absolute velocity and accelerations of said servomotor outputs are of low values.
Claim 8
Dependent Claim
60 words
The monitored multiple channel automatic pilot as set forth in claim 3 further including flip flop means responsive to output signals from said logic means for supplying a first output signal for operating said clamping means, pilot warning means, and further logic means responsive to a second output signal from said flip flop means for operating said pilot warning means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-12 | 1981-12-12 | 1982-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-12 | 1985-12-12 | 1986-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-12 | 1989-12-12 | 1990-06-13 | $7700.00 | Window Closed / Lapsed |