US3622764A
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Method of determining the drift of a gyrocompass
Assignee: Rockwell Collins Deutschland GmbH
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Filing: 1970-08-18
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Granted: 1971-11-23
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Expires: 1990-08-18
Abstract
Abstract The drift of a directional gyro with a stationary gyro carrier is determined by making a plurality N of measurements of the alignment angle Alpha of the gimbal bearing the gyro rotor with respect to a reference axis determined by the position of the gyro carrier at equal time intervals within a predetermined period of time, producing electrical value signals, preferably pulse sequences, proportional to the measured angular values, and adding the electrical signals to provide a sum which is a measure of the gyro drift. If the alignment angle Alpha 0 at the beginning of the measuring periot T is other than zero, the sum is modified to provide compensation for the initial alignment angle Alpha 0.
Inventors
- 👤 Horst Brendes
- 👤 Waltraud Bar
- 👤 Egon Funk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 00:57
CPC Classifications
G; G01; G01C; G01C19/00; G01C19/02; G01C19/34; G01C19/38; Y; Y10; Y10T; Y10T74/00; Y10T74/12
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
127 words
A method of determining the drift of a directional gyro with a stationary gyro carrier by means of angular measurements comprising, in combination: within a predetermined period of time T, taking a plurality N of measurements of the alignment angle Alpha of the gimbal bearing the gyro rotor with respect to a reference axis given by the position of the gyro carrier at equal time intervals; producing electrical values proportional to these measured values; algebraically adding these electrical values to provide a sum thereof which represents a measure of the drift of the gyrocompass; and modifying said sum to provide compensation for the initial alignment angle Alpha 0 in the event said angle Alpha 0 is other than zero at the beginning of the measuring period T.
Claim 2
Independent Claim
127 words
A method of determining the drift of a directional gyro with a stationary gyro carrier by means of angular measurements comprising, in combination: within a predetermined period of time T, taking a plurality N of measurements of the alignment angle Alpha of the gimbal bearing the gyro rotor with respect to a reference axis given by the position of the gyro carrier at equal time intervals; producing electrical values proportional to these measured values; algebraically adding these electrical values to provide a sum thereof which represents a measure of the drift of the gyrocompass; and modifying said sum to provide compensation for the initial alignment angle Alpha 0 in the event said angle Alpha 0 is other than zero at the beginning of the measuring period T.
Claim 3
Dependent Claim
37 words
The method as defined in claim 1 wherein the electrical values proportional to the measured values of the angle Alpha are generated as pulse sequences having a number of pulses which is proportional to the measured values.
Claim 4
Dependent Claim
42 words
The method as defined in claim 2 wherein, when the angle Alpha 0 is other than zero at the beginning of the measuring period, the sum of the electrical values is modified by deducting an electrical value equal to N Alpha 0.
Claim 5
Dependent Claim
99 words
The method as defined in claim 2 wherein when the angle Alpha 0 is other than zero at the beginning of the measuring period T, the sum of the electrical values is modified by adding the pulses corresponding to the measured values during the second half of the measuring period T to the sum of the pulses produced during the first half of the measuring period with the opposite sign so as to form a sum equal to the difference between the respective sums of the pulses producEd during the first and second halves of the measuring period T.
Claim 6
Dependent Claim
57 words
The method as defined in claim 4 wherein said modification of the sum of said pulses is provided by adding said pulses in a forward-backward counter which is controlled to count in one direction during the first half of the measuring period T and in the other direction during the second half of the measuring period T.
Claim 7
Dependent Claim
55 words
The method as defined in claim 2 wherein the number of measurements per unit time, the measuring period T and the frequency of the pulse sequences of the generator producing said electrical pulses are so tuned to one another that the desired resolution in portions of angular degrees or other units of counting is produced.
Claim 8
Dependent Claim
28 words
The method as defined in claim 2 including the additional step of filtering said electrical value signals prior to the summation thereof to eliminate erroneous or error signals.
Claim 9
Dependent Claim
98 words
The method as defined in claim 7 wherein said filtering step comprises: storing the number of pulses within each pulse sequence in a first counter; comparing the numerical value of the pulses stored in the first counter with the numerical value of the preceding measurement stored in a memory; providing a numerical value signal corresponding to that in said first counter for summation purposes when equivalence between the two compared numerical values results; and providing a numerical value corresponding to the last previous equivalence comparison for summation purposes when no equivalence between the two compared numerical values results.
Claim 10
Dependent Claim
95 words
The method as defined in claim 8 wherein the numerical value signals resulting from the comparison of the signals in the first and second counters are provided by: entering the numerical value signal stored in the first counter into a first register, for subsequent transmittal to an adding mechanism, whenever the comparison of the contents of the first counter and the memory indicates equivalence; and retaining a numerical value in the first register equal to that last entered therein when the comparison of the contents of the first counter and the memory indicates no equivalence.
Claim 11
Dependent Claim
151 words
The method as defined in claim 9 wherein the numerical value signals proportional to the measured values are added by sequentially transferring the contents of the first register to an adding arrangement, including a second register, which adds the numerical values to provide a sum of the electrical values in the second register; and wherein, when the angle Alpha 0 is other than zero at the beginning of the measuring period T, the sum of the electrical values is modified by controlling the adding arrangement to add the pulses corresponding to the measured values during the second half of the measuring period T to the sum of the pulses produced during the first half of the measuring period with the opposite sign so as to form a sum equal to the difference between the respective sums of the pulses produced during the first and second halves of the measuring period T.
Claim 12
Dependent Claim
71 words
The method as defined in claim 10 wherein said step of algebraically adding the electrical values to provide a sum includes the steps of (1) transferring the numerical values stored in said first and second registers to an adder, (2) transferring the numerical value corresponding to the resultant sum to the second register, and (3) repeating steps (1) and (2) until all of the N numerical values have been added together.
Claim 13
Dependent Claim
55 words
The method as defined in claim 10 wherein said second register is a forward-backward counter, and wherein said step of algebraically adding the electrical values to provide a sum includes sequentially transferring the numerical values stored in said first register to said second register until all of the N numerical values have been added together.
Claim 14
Dependent Claim
142 words
The method as defined in claim 10 including the further steps of: transferring the numerical value corresponding to the sum presEnt in the second register at the end of the measuring period T to a further memory; comparing the numerical content of said further memory with the numerical content of a counter which is continuously counting a train of input pulses to provide a first output signal when equivalence occurs between the momentary numerical value in the counter and the numerical value stored in the further memory; providing a second output signal when the counter changes from its highest count position to its lowest count position; and utilizing said first and second output signals to enable and block a gate whereby the pulse width determined by opening and closing of the gate is a measure of the drift of the directional gyro.
Claim 15
Dependent Claim
77 words
The method as defined in claim 2 including the additional steps of: prior to the beginning of the measuring period T, determining whether the drift angle Alpha to be measured lies in the vicinity of the 0/360* angular direction; and changing the length of the pulse sequences corresponding to the measured angular values by an amount corresponding to 180* if the angle to be measured lies within a predetermined range on either side of the 0/360* line.
Claim 16
Dependent Claim
51 words
The method as defined in claim 9 including the steps of: prior to the beginning of the measuring period T, measuring the momentary angle Alpha at least twice in succession until equivalence between two successive measured numerical values is determined, and transferring the measured value at equivalence to the first register.
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) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |