Patent US3686555A successfully refreshed from Google Patents.
US3686555A
Expired / Lapsed
US
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Open loop flight control system
Assignee: CENTURY FLIGHT SYSTEMS Inc A TX CORP
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Filing: 1970-09-08
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Granted: 1972-08-22
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Expires: 1990-09-08
Abstract
Abstract This disclosure is directed to a flight control system for an aircraft. A control sensor is responsive to movement of the aircraft about a preselected axis to produce a control signal. An amplifier channel includes a saturable amplifier unit which operates on the control signal and drives a servo motor unit. The servo motor unit actuates a control surface of the aircraft to cause movement of the aircraft about the preselected axis. The amplifier channel has a delaying feedback loop for adding a delayed representation of the amplifier channel output signal to the control signal to vary the transfer characteristic of the amplifier channel in order to produce a servo driving signal which matches the speed-versus-input characteristics of the servo motor unit. Displacement of the control surface is thus proportional to the control signal to eliminate the requirement of a follow-up element. A novel nonlinear circuit is also provided in the feedback loop to nonlinearly control the servo motor unit.
Inventors
- 👤 James R Younkin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:58
CPC Classifications
G; G05; G05D; G05D1/00; G05D1/08; G05D1/0808
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
97 words
A nonlinear circuit comprising: a. first and second transistors of opposite conductivity type having the emitters thereof commonly connected in a complementary configuration, b. means for supplying a bias voltage to the bases of said transistors, c. means for applying an input signal to said commonly connected emitters of said transistors, wherein said input signal is representative of deviation of an aircraft from a desired position, and d. an output terminal connected to receive nonlinear output signals from said collectors of said transistors, wherein said nonlinear output signals operate a roll motor for control of the aircraft.
Claim 2
Dependent Claim
97 words
A nonlinear circuit comprising: a. first and second transistors of opposite conductivity type having the emitters thereof commonly connected in a complementary configuration, b. means for supplying a bias voltage to the bases of said transistors, c. means for applying an input signal to said commonly connected emitters of said transistors, wherein said input signal is representative of deviation of an aircraft from a desired position, and d. an output terminal connected to receive nonlinear output signals from said collectors of said transistors, wherein said nonlinear output signals operate a roll motor for control of the aircraft.
Claim 3
Dependent Claim
102 words
A flight control system for an aircraft having a control surface movable with respect to said aircraft to cause movement thereof about a predetermined axis which comprises: a. a control device responsive to movements of said aircraft about said axis to produce a control signal, b. a servo motor unit for actuating said control surface, c. an amplifier channel interconnecting said control device and said servo unit, d. a degenerative feedback loop around said amplifier channel, and e. a nonlinear circuit in said feedback loop including means for selectively varying the point at which signal modification of said amplifier channel is begun.
Claim 4
Dependent Claim
102 words
A flight control system for an aircraft having a control surface movable with respect to said aircraft to cause movement thereof about a predetermined axis which comprises: a. a control device responsive to movements of said aircraft about said axis to produce a control signal, b. a servo motor unit for actuating said control surface, c. an amplifier channel interconnecting said control device and said servo unit, d. a degenerative feedback loop around said amplifier channel, and e. a nonlinear circuit in said feedback loop including means for selectively varying the point at which signal modification of said amplifier channel is begun.
Claim 5
Dependent Claim
29 words
The control system of claim 2 wherein said nonlinear circuit comprises: first and second transistors of opposite conductivity type having the emitters thereof commonly connected in a complementary configuration.
Claim 6
Dependent Claim
152 words
A flight control system for an aircraft having a control surface movable with respect to said aircraft to cause movement thereof about a predetermined axis and having a normally balanced summing network which comprises: a. a control device responsive to a change in attitude of said craft relative to said axis to produce an attitude change signal which is applied to said normally balanced summing network to produce an error signal therefrom, b. a servo amplifier connected to said network to amplify said error signal, c. an integrating servo actuator excited by the output of said servo amplifier and operationally connected to said control surface, d. a degenerative feedback network having the transfer characteristic of a low pass filter connected between said servo amplifier output and said network for opposing said attitude change signal, and e. a nonlinear circuit connected in said feedback network and including means to vary the nonlinearity thereof.
Claim 7
Dependent Claim
152 words
A flight control system for an aircraft having a control surface movable with respect to said aircraft to cause movement thereof about a predetermined axis and having a normally balanced summing network which comprises: a. a control device responsive to a change in attitude of said craft relative to said axis to produce an attitude change signal which is applied to said normally balanced summing network to produce an error signal therefrom, b. a servo amplifier connected to said network to amplify said error signal, c. an integrating servo actuator excited by the output of said servo amplifier and operationally connected to said control surface, d. a degenerative feedback network having the transfer characteristic of a low pass filter connected between said servo amplifier output and said network for opposing said attitude change signal, and e. a nonlinear circuit connected in said feedback network and including means to vary the nonlinearity thereof.
Claim 8
Dependent Claim
94 words
The system of claim 4 wherein said nonlinear circuit comprises: first and second complementary electronic switching devices having like electrodes connected, means for supplying a voltage bias across said devices, means for supplying a varying signal input to said like electrodes of said devices, each of said devices operable to become conductive in responSe to a signal input of a different polarity, and terminal means connected across said devices whereby a nonlinear output signal is produced on said terminal means in dependence upon the relative magnitudes of said voltage bias and said signal input.
Claim 9
Dependent Claim
70 words
The system of claim 4 wherein said nonlinear circuit comprises: first and second transistors of opposite conductivity type having the emitters thereof commonly connected in a complementary configuration, means for supplying a bias voltage to the bases of said transistors, means for applying an input signal to said commonly connected emitters of said transistors, and an output terminal connected to receive nonlinear output signals from said collectors of said transistors.
Claim 10
Dependent Claim
27 words
The system of claim 6 and further comprising: isolation means connected across the collectors of said transistors to prevent undesirable electrical signals from passing through said transistors.
Claim 11
Dependent Claim
27 words
The system of claim 7 wherein said isolation means comprises: a pair of series connected diodes connected across said collectors, said output terminal connected between said diodes.
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) | 1975-08-22 | 1976-02-21 | 1976-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-22 | 1980-02-21 | 1980-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-22 | 1984-02-21 | 1984-08-22 | $7700.00 | Window Closed / Lapsed |