Northrop Grumman Systems Corporation

Litton Systems, Inc.

Northrop Grumman Guidance and Electronics Company, Inc.

Other

Charles A Lee

Robert E Stewart

Daniel A Tazartes

Stanley F Wyse

A Douglas Meyer

David Michael Rozelle

Charles H Volk

Mostafa A Karam

Juergen K Flamm

Juergen K P Flamm

Fredrick J Arnato

David Rozelle

One embodiment of the invention includes a CVG system. A plurality of electrodes electrostatically force a resonator into a periodic motion based on a drive axis forcer signal applied to a first set of the plurality of electrodes and a sense axis force-rebalance signal applied to a second set of the plurality of electrodes, and provides a sense axis pickoff signal and a drive axis pickoff signal. A gyroscope controller generates the drive axis forcer signal based on the drive axis pickoff signal and calculates an angular rate of rotation about an input axis based on the sense axis force-rebalance signal. The gyroscope controller modulates a predetermined disturbance signal component onto the sense axis force-rebalance signal and to control a modulation phase of the sense axis force-rebalance signal based on detection of the predetermined disturbance signal component in the sense axis force-rebalance signal to substantially mitigate bias and scale-factor error.

Bias and scale-factor error mitigation in a Coriolis vibratory gyroscope system

One embodiment of the invention includes an inertial system. The system includes at least one inertial sensor configured to measure an inertial parameter associated with each of at least one axis. The system also includes a calibration system configured to sequentially measure an inertial calibration parameter at each of a plurality input axes. The system further includes an inertial processor configured to calculate motion of the inertial system based on the inertial parameter associated with each of the respective at least one axis and the sequential measurements of the inertial calibration parameter at each of the plurality of input axes.

Continuous calibration of an inertial system

A sensor system uses ground emitters to illuminate a projectile in flight with a polarized RF beam. By monitoring the polarization modulation of RF signals received from antenna elements mounted on the projectile, both angular orientation and angular rate signals can be derived and used in the inertial solution in place of the gyroscope. Depending on the spacing and positional accuracies of the RF ground emitters, position information of the projectile may also be derived, which eliminates the need for accelerometers. When RF signals of ground emitter/s are blocked from the guided projectile, the sensor deploys another plurality of RF antennas mounted on the projectile nose to determine position and velocity vectors and orientation of incoming targets.

GPS independent guidance sensor system for gun-launched projectiles

First and second inertial instruments have parallel sense axes and produce respective first and second output signals using associated first and second scale factors. Bias errors are estimated using the change in state of sign of the first and second scale factors. A substitute scale factor is determined to be an equivalent of the second scale factor and is based on the first scale factor and a difference between the first and second scale factors. Errors in the second scale factor are calculated based on the first scale factor and the substitute scale factor where a sign of one of first and second scale factors changes going from the first time interval to the succeeding time intervals. First and second corrected output signals are generated based on the respective first and second output signals and correction of the second scale factor error.

Real time error determination for inertial instruments

A safety valve for a lawn sprinkler system having at least one subterranean flow line and at least one head for spraying irrigation water. The valve includes a tubular member connected between the flow line and the head. The tubular member has an axial passage therethrough for the flow of water from the flow line to the head. A seat is located within the passage. A ball is located in the passage upstream of the seat. The ball is axially movable from an open position upstream of the seat to a closed position in engagement with the seat if the water flowing through passage reaches a selected flow rate. A coiled spring in the passage is in engagement with the ball for urging the ball toward the open position.

Water line safety valve

An exemplary inertial measurement apparatus incorporates self-calibrating bias correction signals. First and second inertial instruments generate respective input signals representative of an inertial attribute to be measured. A bias estimator generates first and second bias correction signals. First and second summation nodes receive the respective input signals and the respective first and second bias correction signals. The first and second summation nodes provide respective summed signals to the first and second inertial instruments. The first and second inertial instruments generate respective output signals representative of a value of the inertial attribute based on the respective summed signals. The bias estimator calculates the first and second bias correction signals based on first and second measurements made during respective first and second time intervals where a sign of one of the first and second bias error signals changes from one state during the first time interval to the other state during the second time interval.

Self-calibration for an inertial instrument based on real time bias estimator

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.

Growing community of inventors

Camarillo, CA, United States of America

Charles A Lee