US3847026A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cross product pickoff for ball gyros of the electrostatic levitation type
Assignee: Boeing North American Inc
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Filing: 1970-11-12
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Granted: 1974-11-12
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Expires: 1990-11-12
Abstract
Abstract The invention is directed to a cross-product pickoff mechanism for an electrostatically supported ball type gyroscope, wherein the pickoff determines the attitude (i.e., angular orientation) of the ball spin axis relative to the gyroscope case for any arbitrary attitude. The gyroscope case is provided with a set of electrostatic electrodes arrayed in three-dimensional space. A levitating electric field is maintained between the ball and the electrodes. The ball is so constructed as to be unbalanced about its spin axis. Under such conditions, as the ball spins, it orbits, and its surface alternately advances towards and recedes from any given electrode at the spin frequency, producing a field modulation signal. The amplitude and phase pattern of the modulation signals at the several electrodes is a unique function of the attitude of the spin axis relative to the electrodes. Means are provided for processing the in-phase and quadrature fundamental modulation signals occuring in each of the levitation channels so as to determine the attitude of the ball.
Inventors
- 👤 J Boltinghouse
- 👤 F Pelteson
- 👤 J Pinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:06
CPC Classifications
G; G01; G01C; G01C19/00; G01C19/02; G01C19/04; G01C19/28; F; F16; F16C; F16C32/00; F16C32/04; F16C32/0404; F16C2370/00; Y; Y10; Y10T; Y10T74/00; Y10T74/12; Y10T74/1261; Y10T74/1275
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
295 words
In combination with a pickoff system for an electrostatic gyroscope of the type wherein there is provided, a case, a set of at least six electrodes in symmetrical array with respect to the case, a ball adpted to spin about a spin axis within the electrode array with the ball constructed and arranged to have its center of mass displaced laterally from the spin axis so that the ball orbits at the spin frequency with circuit means for establishing electrical fields between the electrodes and the ball, which fields are modulated at the spin frequency, the improvement which comprises: a. means 11, 14, 30 for detecting the modulated fields between the electrodes and said ball to provide signals proportinal to said detected fields; b. means 40, 41, 42, 51, 52, 53 for transforming the detected modulated field signals into signals representing a modulated field resolved into components along three mutually orthogonal axes; c. reference carrier signal generating means (90, 91, 92, 111) for generating a first reference signal which is substantially proportional to the spin frequency of said ball and a second reference signal which is displaced in time phase quadrature relative to said first reference signal; d. first demodulator means for demodulating each of said mutually orthogonal signal components with respect to said first generated carrier signal; e. second demodulator means for demodulating each of said mutually orthogonal signal components with respect to said second generated carrier signal; and f. means (70, 71, 72, 73, 74, 75, 80, 81, 82) for coMbining the demodulated signals from said first and said second demodulator in vector cross-product relationship to form signals proportional to the direction cosines of said spin axis which combined signals define the orientation of said spin axis with respect to said electrode array.
Claim 2
Dependent Claim
295 words
In combination with a pickoff system for an electrostatic gyroscope of the type wherein there is provided, a case, a set of at least six electrodes in symmetrical array with respect to the case, a ball adpted to spin about a spin axis within the electrode array with the ball constructed and arranged to have its center of mass displaced laterally from the spin axis so that the ball orbits at the spin frequency with circuit means for establishing electrical fields between the electrodes and the ball, which fields are modulated at the spin frequency, the improvement which comprises: a. means 11, 14, 30 for detecting the modulated fields between the electrodes and said ball to provide signals proportinal to said detected fields; b. means 40, 41, 42, 51, 52, 53 for transforming the detected modulated field signals into signals representing a modulated field resolved into components along three mutually orthogonal axes; c. reference carrier signal generating means (90, 91, 92, 111) for generating a first reference signal which is substantially proportional to the spin frequency of said ball and a second reference signal which is displaced in time phase quadrature relative to said first reference signal; d. first demodulator means for demodulating each of said mutually orthogonal signal components with respect to said first generated carrier signal; e. second demodulator means for demodulating each of said mutually orthogonal signal components with respect to said second generated carrier signal; and f. means (70, 71, 72, 73, 74, 75, 80, 81, 82) for coMbining the demodulated signals from said first and said second demodulator in vector cross-product relationship to form signals proportional to the direction cosines of said spin axis which combined signals define the orientation of said spin axis with respect to said electrode array.
Claim 3
Dependent Claim
44 words
The pickoff system according to claim 1 and further comprising: carrier frequency control means responsive to the frequency of said demodulated signals for controlling the frequency of the signals from said reference carrier signal generating means proportional to the spin frequency of said ball.
Claim 4
Dependent Claim
34 words
The pickoff system according to claim 1 and further comprising: low pass filter means for filtering high frequency signal components from said demodulated signals before said signals are forwarded to said means for combining.
Claim 5
Dependent Claim
127 words
The pickoff system according to claim 1 and further comprising: a. delay means for receiving each of the demodulated signals from said first demodulator means and for delaying each signal by a fixed amount; b. difference means for providing a signal which is the difference between the signal from said first demodulator means and the signal from said delayed means; c. multiplier means for multiplying each of said difference signals from said difference means by the corresponding demodulated signal from second demodulator means; and d. summing means for summing the product signals from said multiplier means to form a control signal which is fed to said reference carrier signal generating means to control the phase relationship between the modulated field signals and the generated reference carrier signals.
Claim 6
Dependent Claim
57 words
The pickoff system according to claim 4 and further comprising: a. a variable bias signal source; and b. a second summing means for summing the signal from the first named summing means with the signal from said variable bias source to provide a control signal which can be varied in phase relationship with said modulated field signals.
Claim 7
Dependent Claim
183 words
In combination with a pickoff system for an electrostatic gyroscope of the type wherein there is provided, a case, a set of electrodes in symmetrical array with respect to the case, a ball adapted to spin about a spin axis within the electrode array with the ball constructed and arranged to have its cente of mass displaced laterally from the spin axis so that the ball orbits at the spin frequency with circuit means for establishing electrical fields between the electrodes and the ball, which fields are modulated at the spin frequency, the improvement which comprises: a. means for detecting the modulated fields between the electrodes and said ball and for providing signals proportional to said detected fields; b. means for transforming the detected modulated field signals into signals having components along three mutually orthogonal axes; c. means for rotating by 90* the sigals along said three mutually orthogonal axes; and d. means for forming a vector cross product of the rotated and non-rotated orthogonal signals which cross product is the direction cosines of said spin axis with respect to said levitation electrodes.
Claim 8
Dependent Claim
183 words
In combination with a pickoff system for an electrostatic gyroscope of the type wherein there is provided, a case, a set of electrodes in symmetrical array with respect to the case, a ball adapted to spin about a spin axis within the electrode array with the ball constructed and arranged to have its cente of mass displaced laterally from the spin axis so that the ball orbits at the spin frequency with circuit means for establishing electrical fields between the electrodes and the ball, which fields are modulated at the spin frequency, the improvement which comprises: a. means for detecting the modulated fields between the electrodes and said ball and for providing signals proportional to said detected fields; b. means for transforming the detected modulated field signals into signals having components along three mutually orthogonal axes; c. means for rotating by 90* the sigals along said three mutually orthogonal axes; and d. means for forming a vector cross product of the rotated and non-rotated orthogonal signals which cross product is the direction cosines of said spin axis with respect to said levitation electrodes.
Claim 9
Dependent Claim
127 words
Apparatus for determining the spin vector orientation of an electrostatically supported spinning mass unbalanced ball with respect to pairs of symmetrically positioned levitation electrodes comprising in combination: a. means for detecting the modulated fields existing between the electrodes and the spinning ball and providing signals proportional thereto; b. means for transforming the detected signals into signals having components along three mutually orthogonal axes, said three mutually orthogonal signals representing a first vector; c. means for rotating the three mutually orthogonal signals 90* to represent a second vector; and d. means for forming a cross-product signal of said first and said second vectors utilizing said rotated and non-rotated orthogonal signals such that the cross-product signaL defines the location of said spin axis with respect to said levitation electrodes.
Claim 10
Dependent Claim
127 words
Apparatus for determining the spin vector orientation of an electrostatically supported spinning mass unbalanced ball with respect to pairs of symmetrically positioned levitation electrodes comprising in combination: a. means for detecting the modulated fields existing between the electrodes and the spinning ball and providing signals proportional thereto; b. means for transforming the detected signals into signals having components along three mutually orthogonal axes, said three mutually orthogonal signals representing a first vector; c. means for rotating the three mutually orthogonal signals 90* to represent a second vector; and d. means for forming a cross-product signal of said first and said second vectors utilizing said rotated and non-rotated orthogonal signals such that the cross-product signaL defines the location of said spin axis with respect to said levitation electrodes.
Claim 11
Independent Claim
182 words
The method of determining the spin vector orientation of an electrostatically supported spinning mass unbalanced ball with respect to pairs of symmetrically positioned levitation electrodes comprising the steps of: a. detecting the modulated field existing between the electrodes and the spinning ball; b. transforming the detected modulated signals into signals indicative of the motion of said ball along three mutually orthogonal axes which are fixed with respect to the levitation electrodes; c. demodulating each of said three orthogonally oriented signals, first with a first carrier reference signal which is related to the spin frequency of the ball to provide a first demodulated signal and second, to demodulate each of said three orthogonally oriented signals with respect to a second carrier signal similarly related to the spin frequency as the first carrier reference signal and in time phase quadrature with such first carrier reference signal to provide second demodulated signals; and d. combining and transforming each of the first and second demodulated signals by vector cross product to form direction cosine signals of the spin vector orientation with respect to the levitation electrodes.
Claim 12
Independent Claim
182 words
The method of determining the spin vector orientation of an electrostatically supported spinning mass unbalanced ball with respect to pairs of symmetrically positioned levitation electrodes comprising the steps of: a. detecting the modulated field existing between the electrodes and the spinning ball; b. transforming the detected modulated signals into signals indicative of the motion of said ball along three mutually orthogonal axes which are fixed with respect to the levitation electrodes; c. demodulating each of said three orthogonally oriented signals, first with a first carrier reference signal which is related to the spin frequency of the ball to provide a first demodulated signal and second, to demodulate each of said three orthogonally oriented signals with respect to a second carrier signal similarly related to the spin frequency as the first carrier reference signal and in time phase quadrature with such first carrier reference signal to provide second demodulated signals; and d. combining and transforming each of the first and second demodulated signals by vector cross product to form direction cosine signals of the spin vector orientation with respect to the levitation electrodes.
Claim 13
Dependent Claim
32 words
The method of claim 8 and further comprising the step of: combining each of the first and second demodulated signals in vector dot product form to provide signals containing detectable error components.
Claim 14
Dependent Claim
26 words
The method of claim 8 and further comprising the step of: low pass filtering each of said demodulated signals before the step of combining and transforming.
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) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |