US3680355A
Expired / Lapsed
US
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Method and apparatus for performance monitoring of dual platform inertial navigation systems
Assignee: Kearfott Guidance and Navigation Corp
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Filing: 1970-10-07
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Granted: 1972-08-01
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Expires: 1990-10-07
Abstract
Abstract The performance of a dual platform inertial navigation system of the type wherein each platform is stabilized by two, two degreeof-freedom gyros is monitored by utilizing the redundant axis gyro output of each platform to produce an attitude error indication of the GO/NO GO operating condition of the platform about the redundant axis of the platform. The redundant gyro axes of the two platforms are aligned with two, mutually-perpendicular inertial reference axes and the rate output of each redundant axis gyro is sensed, compared with a computed rate output for the corresponding navigation gyro axis, and integrated to provide an attitude error indication for each platform about the redundant axis for that platform. Signals from the roll and pitch synchros of each platform are compared and the difference signals resolved into two attitude error signals representing the attitude error about each of the two inertial reference axes, so that the two redundant axis error signals may be logically compared with the two attitude error signals derived from the synchros to provide a GO/NO GO fault warning signal for each platform.
Inventors
- 👤 Murray S Goldstein
- 👤 Harold Lerman
- 👤 Robert Acker
- 👤 Herbert S Ross
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:20
CPC Classifications
G; G01; G01C; G01C21/00; G01C21/10; G01C21/12; G01C21/16; G01C21/183; G01C21/188; G01C21/166
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
196 words
The method of monitoring the performance of inertial navigation systems of the type having dual inertial platforms, wherein each platform is defined by two, two degree-of-freedom gyros so that one gyro on each platform has a redundant axis, and wherein each platform has a pAir of pickoff devices arranged to indicate the respective attitude of said platform, and wherein the redundant axis gyro on each platform has means adapted to provide an output indicating the attitude error of its platform about its redundant axis, comprising the steps of aligning the redundant gyro axes of said platforms along a pair of mutually-perpendicular inertial reference axes, so that said redundant axes are mutually-perpendicular; deriving a first pair of attitude error signals from the platform pickoff devices to indicate the difference in attitude between platforms about each of said pair of inertial reference axes; deriving a second pair of attitude error signals from the redundant axis gyro outputs to indicate the attitude error of each platform about the redundant axis associated therewith; and logically comparing said first and second pairs of attitude error signals to obtain fault warning output signals representing the operating condition of each of said platforms.
Claim 2
Independent Claim
196 words
The method of monitoring the performance of inertial navigation systems of the type having dual inertial platforms, wherein each platform is defined by two, two degree-of-freedom gyros so that one gyro on each platform has a redundant axis, and wherein each platform has a pAir of pickoff devices arranged to indicate the respective attitude of said platform, and wherein the redundant axis gyro on each platform has means adapted to provide an output indicating the attitude error of its platform about its redundant axis, comprising the steps of aligning the redundant gyro axes of said platforms along a pair of mutually-perpendicular inertial reference axes, so that said redundant axes are mutually-perpendicular; deriving a first pair of attitude error signals from the platform pickoff devices to indicate the difference in attitude between platforms about each of said pair of inertial reference axes; deriving a second pair of attitude error signals from the redundant axis gyro outputs to indicate the attitude error of each platform about the redundant axis associated therewith; and logically comparing said first and second pairs of attitude error signals to obtain fault warning output signals representing the operating condition of each of said platforms.
Claim 3
Dependent Claim
51 words
The performance monitoring method claimed in claim 1, wherein said first pair of attitude error signals are derived by sensing the output signals from said platform pickoff devices, and resolving said signals into components representing the difference in attitude between said platforms about each of said pair of inertial reference axes.
Claim 4
Dependent Claim
87 words
The performance monitoring method claimed in claim 1, wherein said second pair of attitude error signals are derived by rate capturing the redundant axis gyros to produce attitude rate signals for platform movements about said redundant axes, comparing each of the attitude rate signals with a computed rate signal representing the attitude rate of the corresponding non-redundant axis gyro output to produce a rate difference signal representing the difference therebetween, and integrating each of said rate difference signals to produce said second pair of attitude error signals.
Claim 5
Dependent Claim
45 words
The performance monitoring method claimed in claim 3, wherein said computed rate signal is derived from the computed torquing rate of the said non-redundant axis gyro output and includes earth rate velocity and gyro drift components to convert the inertial coordinates to earth fixed coordinates.
Claim 6
Dependent Claim
255 words
A performance monitoring arrangement for a dual platform inertial navigation system of the type wherein each inertial platform is stabilized by two, two degree-of-freedom gyros, so that one gyro on each platform has a redundant axis, and wherein each platform has a pair of pickoff devices arranged to indicate the respective attitude of said platform, and wherein the redundant axis gyro on each platform has means adapted to provide an output indicating the attitude error of its platform about its redundant axis, comprising means for aligning the redundant gyro axes along a pair of mutually-perpendicular inertial reference axes lying in the plane of the platform, so that one of the redundant axes gyros is adapted to sense platform attitude error of one platform about one of said pair of inertial reference axes and the other redundant axis gyro is adapted to sense platform attitude error of the other platform about the other inertial reference axis; means coupled to the redundant axis output of each of said redundant axis gyros for producing a logical signal whenever the platform attitude error sensed by the gyro exceeds a prescribed level; means coupled to the platform pickoff devices of each platform for producing logical signals whenever the difference in platform attitude between said platforms about each of said pair of inertial reference axes exceeds prescribed levels; and logic circuit means coupled to each of said logical signal producing means for comparing said logical signals to produce fault warning output signals representing the operating condition of each of said platforms.
Claim 7
Dependent Claim
255 words
A performance monitoring arrangement for a dual platform inertial navigation system of the type wherein each inertial platform is stabilized by two, two degree-of-freedom gyros, so that one gyro on each platform has a redundant axis, and wherein each platform has a pair of pickoff devices arranged to indicate the respective attitude of said platform, and wherein the redundant axis gyro on each platform has means adapted to provide an output indicating the attitude error of its platform about its redundant axis, comprising means for aligning the redundant gyro axes along a pair of mutually-perpendicular inertial reference axes lying in the plane of the platform, so that one of the redundant axes gyros is adapted to sense platform attitude error of one platform about one of said pair of inertial reference axes and the other redundant axis gyro is adapted to sense platform attitude error of the other platform about the other inertial reference axis; means coupled to the redundant axis output of each of said redundant axis gyros for producing a logical signal whenever the platform attitude error sensed by the gyro exceeds a prescribed level; means coupled to the platform pickoff devices of each platform for producing logical signals whenever the difference in platform attitude between said platforms about each of said pair of inertial reference axes exceeds prescribed levels; and logic circuit means coupled to each of said logical signal producing means for comparing said logical signals to produce fault warning output signals representing the operating condition of each of said platforms.
Claim 8
Dependent Claim
122 words
A performance monitoring arrangement as claimed in claim 5, wherein said platform pickoff devices are the roll and pitch pickoffs of each of said platforms and the logical signal producing means coupled to said pickoffs comprise means for sensing the difference in output between the roll pickoffs of the platforms to produce a roll difference signal, means for sensing the difference in output between the pitch pickoffs of the platforms to produce a pitch difference signal, and means for resolving said roll and pitch difference signals into a first logic output signal representing the difference in attitude of said platforms about said one inertial axis and a second logic output signal representing the difference in platform attitudes about said other inertial axis.
Claim 9
Dependent Claim
100 words
A performance monitoring arrangement as claimed in claim 6, wherein said logical signal producing means coupled to each of the redundant axis gyro outputs comprises sensing means for producing a rate signal representing the rate of movement of the platform about the redundant axis of the gyro, means for comparing said rate signal with a computed rate signal representing the rate of the corresponding non-redundant axis gyro for that platform to produce a rate difference signal and means for integrating said rate difference signal to produce an attitude difference signal representing platform attitude error about one of said inertial axes.
Claim 10
Dependent Claim
45 words
A performance monitoring arrangement as claimed in claim 7, wherein said computed rate signal is the gyro torquing signal for said corresponding non-redundant axis gyro and includes earth rate, velocity and gyro drift components to convert the inertial axis rate signals to earth-fixed coordinate signals.
References Cited (Backward Citations)
US3398586A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-01 | 1976-01-31 | 1976-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-01 | 1980-01-31 | 1980-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-01 | 1984-01-31 | 1984-08-01 | $7700.00 | Window Closed / Lapsed |