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公开(公告)号：CA2241463A1
公开(公告)日：1999-01-14
申请号：CA2241463
申请日：1998-06-22
Applicant: LITTON SYSTEMS INC
Inventor： LEE CHARLES A , FLAMM JUERGEN K P , TAZARTES DANIEL A , WYSE STANLEY F
IPC: G01C19/5705 , G01C19/5776 , G01P3/00 , G01P15/00 , G01P3/16 , G01P3/44 , G01P3/489
Abstract: A dithered Coriolis acceleration sensor system has a proof mass that is free of feedback in the accelerometer servo loop at the dither frequency by totally notching out all feedback torque at this frequency. The proof mass relative motion is then a direct measure of the rate because there is no feedback torque to alter the proof mass response to the acceleration. The feedback modulation system according to the invention captures the Coriolis-sensor output such that the phase and gain of the signal generated from the sensor are of no concern in maintaining good scale factor.
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公开(公告)号：DE4212998C2
公开(公告)日：1998-08-13
申请号：DE4212998
申请日：1992-04-21
Applicant: LITTON SYSTEMS INC
Inventor： MARK JOHN G , TAZARTES DANIEL A , EBNER ROBERT E , DAHLEN NEAL J , DATTA NIBIR K
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公开(公告)号：DE69406239D1
公开(公告)日：1997-11-20
申请号：DE69406239
申请日：1994-07-20
Applicant: LITTON SYSTEMS INC
Inventor： MARK JOHN G , MCLANE DANIEL P , TAZARTES DANIEL A , WYSE STANLEY F
Abstract: A closed-loop accelerometer (10) has a rebalance loop (14) controlled by a first clock and the output of which loop is supplied to a utilization circuit (24) controlled by a second clock (22). The loop and the utilization circuit are coupled by a converter which converts the output of the loop into a stream of pulses distributed over one accelerometer rebalance-cycle period, these pulses being sampled over the period of the second clock and counted to produce a count which is delivered to the utilization circuit (24). There are means (29) responsive to the output of the second clock (22) for gating the pulse count to the utilization circuit (24).
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公开(公告)号：CA2195811A1
公开(公告)日：1997-09-19
申请号：CA2195811
申请日：1997-01-23
Applicant: LITTON SYSTEMS INC
Inventor： TAZARTES DANIEL A , MARK JOHN G
Abstract: The invention is a method for compensating for coning in a strapdown inertial navigation system which utilizes groups of five successive incremental angles of rotation of a body-fixed coordinate system as measured by orthogonally-mounted gyros at regular measurement intervals, each group of five measurements being obtained during a group interval equal to five measurement intervals. The coning-compensated angular displacement of the body-fixed coordinate system about a fixed axis in space during a p'th group interval is obtained by summing the five measured incremental angles and a coning compensation term. The coning compensation term consists of the sum of: (1) one-half the cross-product of a first and a second vector sum, the second vector sum being the sum of the five incremental angles of rotation in a group and the first vector sum being the sum of the second vector sum over p groups; and (2) the weighted sum of three vector cross-products, the multiplier and the multiplicand of each vector cross-product being a weighted sum of five measured incremental angles. The coning-compensated angular displacement can be summed over p to obtain an accurate estimate of the vector angle of rotation over a plurality of group intervals.
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公开(公告)号：DE4126905A1
公开(公告)日：1992-07-16
申请号：DE4126905
申请日：1991-08-14
Applicant: LITTON SYSTEMS INC
Inventor： MARK JOHN G , TAZARTES DANIEL A
IPC: G01C19/66
Abstract: A ring laser gyro having a ring laser that preferably has four legs and four corner mirrors. At least one of the corner mirror is partly transmissive, and the transmitted beam is sensed and converted into a digital signal. The digital signal is fed back in two computer loops to at least one digital-to-analog converter, and thence to a transducer which drives at least one corner mirror inward and outward. One of the computer loops includes a stepped demodulator having four steps per cycle. The steps have voltages at the operating voltage of the transducer, that voltage plus an increment, the operating voltage, and that voltage less a decrement. The first loop sends an operating voltage to the digital-to-analog converters. The second loop demodulates the beam signal at a second harmonic of the demodulation of the first loop to produce a voltage signal which controls the amplitude of dithering of the movable mirrors. A stepped modulator, in synchronism with the demodulator of the first loop, delivers a modulation signal to the digital-to-analog converters to step the movable mirrors. The operating voltage moves the mirrors into a position wherein the laser cavity operates at its intensity mode peaks.
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Patent Agency Ranking
公开(公告)号：FR2648556A1
公开(公告)日：1990-12-21
申请号：FR9004897
申请日：1990-04-17
Applicant: LITTON SYSTEMS INC
Inventor： TAZARTES DANIEL A , MARK JOHN G , EBNER ROBERT E
Abstract: A dither drive system for a ring laser gyroscope includes a computer, a digital to analog converter, a filter, and a power amplifier. The system senses the dither frequency of the gyro frame and produces a digital signal that corresponds to a specified dither drive signal and toggles the dither drive signal to drive the flexure at its resonant frequency. The dither drive system generates digital waveforms that approximate the sine function and digital waveforms that approximate the cosine function and applies the digital waveforms in quadrature to the flexure.
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公开(公告)号：CA2009788A1
公开(公告)日：1990-12-19
申请号：CA2009788
申请日：1990-02-12
Applicant: LITTON SYSTEMS INC
Inventor： TAZARTES DANIEL A , MARK JOHN G , EBNER ROBERT E
Abstract: A dither drive system for a ring laser gyroscope includes a computer, a digital to analog converter, a filter, and a power amplifier. The system senses the dither frequency of the gyro frame and produces a digital signal that corresponds to a specified dither drive signal and toggles the dither drive signal to drive the flexure at its resonant frequency. The dither drive system generates digital waveforms that approximate the sine function and digital waveforms that approximate the cosine function and applies the digital waveforms in quadrature to the flexure.
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公开(公告)号：DE69735973T2
公开(公告)日：2007-01-18
申请号：DE69735973
申请日：1997-03-10
Applicant: LITTON SYSTEMS INC
Inventor： TAZARTES DANIEL A , MARK JOHN G
IPC: G01C21/16
Abstract: The invention is a method for compensating for coning in a strapdown inertial navigation system which utilizes groups of five successive incremental angles of rotation of a body-fixed coordinate system as measured by orthogonally-mounted gyros at regular measurement intervals, each group of five measurements being obtained during a group interval equal to five measurement intervals . The coning-compensated angular displacement of the body-fixed coordinate system about a fixed axis in space during a p'th group interval is obtained by summing the five measured incremental angles and a coning compensation term. The coning compensation term consists of the sum of: (1) one-half the cross-product of a first and a second vector sum, the second vector sum being the sum of the five incremental angles of rotation in a group and the first vector sum being the sum of the second vector sum over p groups; and (2) the weighted sum of three vector cross-products, the multiplier and the multiplicand of each vector cross-product being a weighted sum of five measured incremental angles. The coning-compensated angular displacement can be summed over p to obtain an accurate estimate of the vector angle of rotation over a plurality of group intervals.
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公开(公告)号：DE69735973D1
公开(公告)日：2006-07-06
申请号：DE69735973
申请日：1997-03-10
Applicant: LITTON SYSTEMS INC
Inventor： TAZARTES DANIEL A , MARK JOHN G
IPC: G01C21/16
Abstract: The invention is a method for compensating for coning in a strapdown inertial navigation system which utilizes groups of five successive incremental angles of rotation of a body-fixed coordinate system as measured by orthogonally-mounted gyros at regular measurement intervals, each group of five measurements being obtained during a group interval equal to five measurement intervals . The coning-compensated angular displacement of the body-fixed coordinate system about a fixed axis in space during a p'th group interval is obtained by summing the five measured incremental angles and a coning compensation term. The coning compensation term consists of the sum of: (1) one-half the cross-product of a first and a second vector sum, the second vector sum being the sum of the five incremental angles of rotation in a group and the first vector sum being the sum of the second vector sum over p groups; and (2) the weighted sum of three vector cross-products, the multiplier and the multiplicand of each vector cross-product being a weighted sum of five measured incremental angles. The coning-compensated angular displacement can be summed over p to obtain an accurate estimate of the vector angle of rotation over a plurality of group intervals.
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公开(公告)号：DE69826373D1
公开(公告)日：2004-10-28
申请号：DE69826373
申请日：1998-06-24
Applicant: LITTON SYSTEMS INC
Inventor： WYSE STANLEY F , TAZARTES DANIEL A , FLAMM JUERGEN K P , LEE CHARLES A
IPC: G01C19/5705 , G01C19/5776 , G01C19/56 , G01P9/04
Abstract: A dithered Coriolis acceleration sensor system has a proof mass that is free of feedback in the accelerometer servo loop at the dither frequency by totally notching out all feedback torque at this frequency. The proof mass relative motion is then a direct measure of the rate because there is no feedback torque to alter the proof mass response to the acceleration. The feedback modulation system according to the invention captures the Coriolis-sensor output such that the phase and gain of the signal generated from the sensor are of no concern in maintaining good scale factor.
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