Patent US4222270A successfully refreshed from Google Patents.
US4222270A
Expired / Lapsed
US
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Gyroscope rate range switching and control system
Assignee: Honeywell Inc
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Filing: 1978-09-05
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Granted: 1980-09-16
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Expires: 1998-09-05
Abstract
Abstract In a digital strapped down inertial reference system, a plurality of strapped down, force-rebalanced rate sensors is used to sense aircraft body rates, wherein each gyroscope pick-off signal is fed back to a gyro torquer in a manner to maintain the pick-off signal essentially nulled, the torquer currents thus being proportional to sensed aircraft rates. A precision digital count proportional to the effective current supplied to the torquer is achieved by using a high frequency clock to quantize a lower frequency square wave which has been pulse width modulated in accordance with the gyro pick-off signal and by means for enabling a digital counter synchronously with the state of that square wave. The same high frequency clock signal is used to derive the counter's clock frequency, the counter output being the digital equivalent of the analog square wave which corresponds to the currents supplied to the gyro torquer. Precision currents for supply to the gyro torquer in accordance with the pulse width modulated square wave are achieved by using guard bands which account for the rise and fall times of such currents and the precision turn on and turn off characteristics of VMOS transistor power switches. An automatic rate range switching and control system controlled from the precision digital count adapts the full range cabaility of the gyroscopic rate sensor to a range consistent with the precision range of the analog-to-digital conversion apparatus.
Inventors
- 👤 Arnold R. Allen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:41
CPC Classifications
G; G01; G01C; G01C19/00; G01C19/02; G01C19/04; G01C19/28
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
249 words
Apparatus for use with an inertial sensor of the force rebalance type wherein the current supplied to the sensor torquer required to nullify the sensor pick-off signal indicative of an inertial force acting thereon is proportional to such inertial force, said apparatus comprising: timing signal generator means for providing a plurality of time related signal frequencies, pulse width modulator means responsive to a first of said timig signal frequencies and to said sensor pick-off signal for providing substantially square wave signal pulses having positive and negative pulse durations proportional to said pick-off signal with a duty cycle corresponding to the period of said first signal frequency, means responsive to said square wave pulses for providing corresponding currents to said sensor torquer in a sense to null said sensor pick-off signal, means responsive to a second of said timing signal frequencies, substantially higher than said first frequency, for quantizing at least one of said cyclic signal pulse durations in accordance with said second frequency, guard band pulse generating means responsive to said first timing signal and coupled with said pulse width modulator means for limiting the maximum and minimum durations of said square wave pulses to predetermined portions of said duty cycle whereby to limit the maximum and minimum pulse durations supplied to said torquer current providing means, and counter means responsive to said quantized pulse duration signal as limited by said pulse generating means for providing a count during the effective pulse duration of said one signal pulse duration.
Claim 2
Dependent Claim
249 words
Apparatus for use with an inertial sensor of the force rebalance type wherein the current supplied to the sensor torquer required to nullify the sensor pick-off signal indicative of an inertial force acting thereon is proportional to such inertial force, said apparatus comprising: timing signal generator means for providing a plurality of time related signal frequencies, pulse width modulator means responsive to a first of said timig signal frequencies and to said sensor pick-off signal for providing substantially square wave signal pulses having positive and negative pulse durations proportional to said pick-off signal with a duty cycle corresponding to the period of said first signal frequency, means responsive to said square wave pulses for providing corresponding currents to said sensor torquer in a sense to null said sensor pick-off signal, means responsive to a second of said timing signal frequencies, substantially higher than said first frequency, for quantizing at least one of said cyclic signal pulse durations in accordance with said second frequency, guard band pulse generating means responsive to said first timing signal and coupled with said pulse width modulator means for limiting the maximum and minimum durations of said square wave pulses to predetermined portions of said duty cycle whereby to limit the maximum and minimum pulse durations supplied to said torquer current providing means, and counter means responsive to said quantized pulse duration signal as limited by said pulse generating means for providing a count during the effective pulse duration of said one signal pulse duration.
Claim 3
Dependent Claim
75 words
The apparatus as set forth in claim 1 wherein said sensor is adapted for operation in high and low sensing modes, further comprising: means coupled with current supply means for altering the range of current levels supplied to said torquer means consistent with said high and low sensing ranges, and means responsive to said counter means output for determining said high and low modes of operation and for correspondingly controlling said current level altering means.
Claim 4
Dependent Claim
107 words
The apparatus as set forth in claim 1 wherein said pulse width modulator means includes: ramp signal generator means and wherein said guard band pulse generating means includes: means responsive to said timing signal generator means for providing a first guard band pulse having a repetitive frequency corresponding to said first timing signal frequency and a pulse width that is a small fraction of said duty cycle, and means responsive to said first guard band pulse for terminating and initiating the ramp signal of said ramp signal generating means whereby to limit the maximum duration of said one square wave pulse supplied to said current supplying means.
Claim 5
Dependent Claim
85 words
The apparatus as set forth in claim 3 wherein said guard band pulse generating means further includes: further means responsive to said timing signal generator means for providing a second guard band pulse having a repetition frequency corresponding to said first timing signal frequency and a pulse width that is a small fraction of said duty cycle, and means responsive to said second guard band pulse for limiting the maximum duration of the other of said square wave pulses supplied to said current providing means.
Claim 6
Dependent Claim
31 words
The apparatus as set forth in claim 4 further including logic circuit means responsive to said first and second guard band pulses for supplying said quantizing pulses to said counter means.
Claim 7
Dependent Claim
59 words
The apparatus as set forth in claim 5 further comprising counter control means responsive to said first and second guard band pulses for resetting said counter after a predetermined number of duty cycles whereby the quantizing pulse count accumulated by said counter is proportional to the average currents supplied to said torquer over said predetermined number of duty cycles.
Claim 8
Dependent Claim
27 words
The apparatus as set forth in claim 3 wherein the pulse width of said first guard band pulse is substantially ten percent of said duty cycle period.
Claim 9
Dependent Claim
31 words
The apparatus as set forth in claim 3 wherein the pulse width of each of said first and second guard band pulses is substantially ten percent of said duty cycle period.
Claim 10
Dependent Claim
37 words
The apparatus as set forth in claim 3 wherein said pulse width modulator means further comprises synchronizing means responsive to said quantizing pulse frequency for synchronizing the initiation of said square wave pulses with said quantizing pulses.
Claim 11
Dependent Claim
243 words
Apparatus for use with an inertial sensor of the force rebalance type operable in a high sensing mode and a low sensing mode wherein the current supplied to the sensor torquer required to nullify the sensor pick-off signal indicative of an inertial force acting thereon is proportional to such inertial force, said apparatus comprising: timing signal generator means for providing a plurality of time related signal frequencies, pulse width modulator means responsive to a first of said timing signal frequencies and to said sensor pick-off signal for providing substantially square wave signal pulses having positive and negative pulse durations proportional to said pick-off signal with a duty cycle corresponding to said first signal frequency, means responsive to said square wave pulses for providing corresponding currents to said sensor torquer in a sense to null said sensor pick-off signal, means responsive to a second of said timing signal frequencies, substantially higher than said first frequency, for quantizing at least one of said signal pulse durations in accordance with said second frequency, counter means responsive to said quantizing means for providing an output count proportional thereto and hence proportional to said torquer current, means coupled with said current supply means for altering the range of current levels supplied to said torquer means consistent with said high and low sensing modes, and means responsive to said counter output for determining said high and low modes of operation and for correspondingly controlling said current level altering means.
Claim 12
Dependent Claim
243 words
Apparatus for use with an inertial sensor of the force rebalance type operable in a high sensing mode and a low sensing mode wherein the current supplied to the sensor torquer required to nullify the sensor pick-off signal indicative of an inertial force acting thereon is proportional to such inertial force, said apparatus comprising: timing signal generator means for providing a plurality of time related signal frequencies, pulse width modulator means responsive to a first of said timing signal frequencies and to said sensor pick-off signal for providing substantially square wave signal pulses having positive and negative pulse durations proportional to said pick-off signal with a duty cycle corresponding to said first signal frequency, means responsive to said square wave pulses for providing corresponding currents to said sensor torquer in a sense to null said sensor pick-off signal, means responsive to a second of said timing signal frequencies, substantially higher than said first frequency, for quantizing at least one of said signal pulse durations in accordance with said second frequency, counter means responsive to said quantizing means for providing an output count proportional thereto and hence proportional to said torquer current, means coupled with said current supply means for altering the range of current levels supplied to said torquer means consistent with said high and low sensing modes, and means responsive to said counter output for determining said high and low modes of operation and for correspondingly controlling said current level altering means.
Claim 13
Dependent Claim
68 words
The apparatus as set forth in claim 10 wherein said means for determining said high and low sensing modes includes: decoding means responsive to said counter output for detecting predetermined count bands corresponding to predetermined sensing ranges of said sensor in each of said modes, and logic circuit means responsive to counts outside of said count bands for switching from one mode to the other and vice versa.
Claim 14
Dependent Claim
33 words
The apparatus as set forth in claim 11 wherein said logic circuit means includes synchronizing means responsive to said guard band pulses for synchronizing said mode switching with said duration-limited square wave pulses.
Claim 15
Dependent Claim
86 words
The apparatus as set forth in claim 11 wherein said decoding means comprises: first decoding logic means for detecting a count in excess of a first count band in said low sensing mode and for supplying a logic signal to said logic means for establishing said high mode of operation, and second decoding logic means for detecting a count below a second count band in said high sensing mode and for supplying a logic signal to said logic means for re-establishing said low mode of operation.
References Cited (Backward Citations)
US4062004A
Cited
US4063141A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-09-16 | 1984-03-17 | 1984-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-16 | 1988-03-17 | 1988-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-16 | 1992-03-17 | 1992-09-16 | $7700.00 | Window Closed / Lapsed |