US3725691A
Expired / Lapsed
US
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Electronic devices for forming algebraic sums
Assignee: FAB D INSTR DE MESURE SFIM SOC
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Filing: 1971-07-16
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Granted: 1973-04-03
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Expires: 1991-07-16
Abstract
Abstract An electronic device is arranged to correct the angle A of gyroscopic heading for variations in the magnetic deviation angle a, thereby producing the angle (A + a). A synchro transmitter generates a sin A and a cos A signal which are subsequently modulated by a modulator. The modulated signals are then integrated between two sets of limits each of which is a function of the angle a and the operational frequency of the modulator. The relationship between the angle a and operational frequency is such as to provide four output signals respectively representing various combinations of the product between different pairs of the functions sin A, cos A, sin a and cos a. By appropriate summing in accordance with trigonametric equations, signals of sin (A + a) and cos (A + a) can be produced.
Inventors
- 👤 J Delaunay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 01:06
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/12; G06G7/22
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
170 words
An electronic device for forming the algebraic sum of two variable angles (A and a), comprising first means for representing one (A) of the angles in the form of two modulated voltages, X and Y, such that: X U sin A sin (2 pi /T)t Y U cos A sin (2 pi /T)t in which U is a constant and T the modulation period; second means for generating timing signals at instants t1, t2, t3 and t4, where t1 (a/2 pi )T t2 t1 + T/2 t3 t1 + T/4 t4 t1 + 3T/4 means connected to the first and second means for integrating both said modulated voltages X and Y each between the limits t1 and t2 and between the limits t3 and t4, the two integrals of the voltage X comprising voltages X1 and X2, and summing means connected to the integrating means for producing the sums X'' X1 - Y1 Y'' X2 + Y2 which are respectively sine and cosine functions of the angle (A + a).
Claim 2
Dependent Claim
170 words
An electronic device for forming the algebraic sum of two variable angles (A and a), comprising first means for representing one (A) of the angles in the form of two modulated voltages, X and Y, such that: X U sin A sin (2 pi /T)t Y U cos A sin (2 pi /T)t in which U is a constant and T the modulation period; second means for generating timing signals at instants t1, t2, t3 and t4, where t1 (a/2 pi )T t2 t1 + T/2 t3 t1 + T/4 t4 t1 + 3T/4 means connected to the first and second means for integrating both said modulated voltages X and Y each between the limits t1 and t2 and between the limits t3 and t4, the two integrals of the voltage X comprising voltages X1 and X2, and summing means connected to the integrating means for producing the sums X'' X1 - Y1 Y'' X2 + Y2 which are respectively sine and cosine functions of the angle (A + a).
Claim 3
Dependent Claim
90 words
A device according to claim 1, in which the second means comprises means for producing a signal whose value represents the numerical value of the angle a, reference means for generating a sinusoidal reference signal of period T, timing means connected to the reference means for dividing each cycle of the reference signal into a plurality of reference pulses, and comparing means connected to the timing means and the angle value producing means for comparing the number of reference pulses with the value of the signal representing the angle a.
Claim 4
Dependent Claim
88 words
A device according to claim 2, in which the second means comprises: a pulse generator operative to generate pulses numerically representative of each change in the magnitude of the angle a, means for generating a sign signal representing the sign of variation of the angle a, a counter connected to the pulse generator and the sign signal generating means, for receiving the pulses from the pulse generator and the said sign signal to cause the counter to store a number constituting the said signal representing the angle a.
Claim 5
Dependent Claim
83 words
A magnetic supervision device comprising a correction unit having a first input for receiving gyroscopic heading information and a second input for receiving magnetic detector information concerning heading deviation, the correction unit being operable to process the information received at the first and second inputs to provide an output signal representing the gyroscopic heading for angle of deviation, the correction unit comprising an electronic device according to claim 1, in which angle A represents the gyroscopic heading and angle a the heading deviation.
Claim 6
Dependent Claim
158 words
A magnetic supervision device according to claim 4, in which the said second means of the electronic device comprises a pulse generator operative to generate pulses representative of each change in the magnitude of the angle a and also to provide a sign signal representative of the sense in which the magnitude of angle a changes, a counter connected to the pulse generator to receive the generated pulses and the sign signal, the counter summing the said pulses algebraically in accordance with the said sign signal, reference means operative to produce a reference signal having a period T and to divide each cycle of the reference signal into a plurality of reference pulses, and a comparator connected to the counter and the reference means to compare the result of the calculation effected in the counter with the number of pulses occurring during each cycle of the reference signal, the result of this comparison constituting the said timing signals.
Claim 7
Dependent Claim
26 words
A device as claimed in claim 5, in which the said pulse generator is selectively operable to generate pulses at a plurality of different discrete frequencies.
Claim 8
Dependent Claim
41 words
A device according to claim 6 in which the said pulse generator is operable to generate pulses at such a frequency as to communicate a change in the magnitude of the angle a of between 10* and 50* in 1 second.
Claim 9
Dependent Claim
41 words
A device according to claim 6 in which the said pulse generator is operable to generate pulses at such a frequency as to communicate a change in the magnitude of the angle a of between 15* and 20* in one second.
Claim 10
Dependent Claim
42 words
A device according to claim 7 in which the said pulse generator is also operable to generate pulses at such a frequency as to communicate a change in the magnitude of the angle a of between 0.5* and 4* in 1 minute.
Claim 11
Dependent Claim
42 words
A device according to claim 8 in which the said pulse generator is also operable to generate pulses at such a frequency as to communicate a change in the magnitude of the angle a of between 1* and 2* in 1 minute.
Claim 12
Dependent Claim
30 words
A device according to claim 5, in which the said pulse generator is operable to generate pulses at a frequency proportional to the sine of the latitude of the heading.
Claim 13
Dependent Claim
86 words
A device according to claim 4, including a modulator producing two carriers each having a period T and so connected to the summing means that the said output voltages X'' and Y'' modulate respective carriers, a transformer connected to the modulator to convert the two 90*-diSplaced modulated voltages X'' and Y'' into three output signals forming three components which are phase displaced by 120*, and three amplifiers connected to the transformer to respectively receive the three components and feed the three components to the magnetic detector.
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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |