Litton Systems, Inc.

Northrop Grumman Systems Corporation

Gm Global Technolgoy Operations, Inc.

Delco Electronics Corporation

Northrop Grumman Guidance and Electronics Company, Inc.

David Dexter Lynch

Anthony Robert Matthews

Guy Thomas Varty

Alexander A Trusov

Edward J Loper, Jr

Stanley F Wyse

David Michael Rozelle

Youngmin Albert Choi

Stephen J Kiselewich

Douglas D Turner

Chung-Ming Li

Ryan R Savava

Paul C Nguyen

James J Campanile

Porfirio Garcia, Jr

Rex P Brumbach, Jr

James F Long

Anthony Matthews

One embodiment includes a gyroscope system. The system includes a sensor system comprising a vibrating-mass and electrodes each arranged to provide one of a driving force and a force-rebalance to the vibrating-mass in each of three orthogonal axes. The system also includes a gyroscope controller that generates a drive signal provided to a first electrode of the electrodes to provide the driving force to facilitate an in-plane periodic oscillatory motion of the vibrating-mass along a first axis of the three orthogonal axes. The gyroscope controller also generates a force-rebalance signal provided to each of a second electrode and a third electrode of the plurality of electrodes associated with a respective second axis and a respective third axis of the three orthogonal axes to calculate a rotation of the gyroscope system about the respective second axis and the respective third axis of the three orthogonal axes.

Vibrating-mass gyroscope system

One example includes a hemispherical resonator gyroscope (HRG). The HRG includes a sensing system comprising a plurality of electrodes arranged in a symmetrical annular arrangement about a sensitive axis and configured to electrostatically force a resonator into a substantially periodic motion based on a plurality of forcer signals applied to the plurality of electrodes. The plurality of electrodes are configured to provide an indication of rotation about a sensitive axis of the HRG. The HRG also includes a controller configured to generate the plurality of forcer signals in a phase-disparate manner to provide the substantially periodic motion in a vibration pattern such that a ratio of the plurality of electrodes and the vibration pattern is a non-integer number, and to measure the rotation about the sensitive axis of the HRG in response to the plurality of forcer signals.

Hemispherical resonator gyroscope

Embodiments of the present system encompass: a hemispherical resonator gyro (HRG); digital control loop algorithms which operate in two, distinct modes, Force to Rebalance (FTR) and Whole Angle (WA); and a closed-loop slewing-voltage phase control that reduces quadrature error when the hemispherical resonator gyro transitions from WA to FTR.

Hemispherical resonator gyro control

An exemplary vibrating mass gyroscope uses a mass disposed for movement along an x-axis and y-axis. First and second electrodes are disposed adjacent surfaces of the mass along an x-axis and y-axis. Circuitry, coupled to the first and second electrodes, provides during a first mode a dither driving voltage on one of the first and second electrodes causing vibrating displacement of the mass along the one of the x-axis and y-axis. The measurement voltage is sensed on the other of the first and second electrodes where the measurement voltage represents a first angular rate value. During a second mode, the circuitry provides a dither driving voltage on the other of the first and second electrodes causing vibrating displacement of the mass along the other of the x-axis and y-axis and measurement voltage is sensed on the one of the first and second electrodes where the measurement voltage represents a second angular rate value. A combiner coupled to the circuitry receives the first and second angular rate values, and generates a resulting angular rate value based on both the first and second angular rate values wherein common bias errors are canceled. The common bias errors cancel because the pickoff sensing axis is coincident with the forcing axis when the same electrode is used for both the forcing and for the pickoff.

Vibrating mass gyroscope and method for minimizing bias errors therein

The invention is a vibratory rotation sensor comprising a housing, a resonator attached to the housing, first and second sets of electrodes, and a signal processor. One set of electrodes are attached to the housing and the other set of electrodes are attached to the resonator, the first set opposing the second set. Each set consists of one or more electrodes. The signal processor has one or more input ports capacitively connected to one or more of the first set of electrodes, the signal processor extracting from the signals appearing at the one or more input ports one or more double-frequency sinusoids having frequencies of twice the frequency of oscillation of the resonator.

Extraction of double-oscillation-frequency sinusoids in vibratory

The invention is an apparatus for sensing rotation comprising a housing, a resonator attached to the housing, a first set of electrodes consisting of one or more electrically-connected electrodes, and a second set of N electrodes. The resonator is a rotationally-symmetric, thin-walled object capable of vibrating in at least one of a plurality of standing-wave modes. The orientation of a standing wave with respect to a reference point on the resonator is specified by an orientation angle. The first set of electrodes are attached to either the resonator or the housing. The N electrodes of the second set are attached around the circumference of either (1) the housing if the first set of electrodes is attached to the resonator or (2) the resonator if the first set of electrodes is attached to the housing. The n'th electrode of the second set is attached at angular position .theta..sub.n with respect to the reference point on the resonator, opposing one or more of the second set of electrodes. The apparatus further comprises driving electronics which supplies driving signals to one or more of the second set of electrodes and sensing electronics which receives the first-set signal appearing on the first set of electrodes as a result of the capacitive coupling between the first- and second-set electrodes. The sensing electronics also supplies one or more signals to the driving electronics.

Vibratory rotation sensor with novel electrode placements

The invention is a method for obtaining linear measures of one or more parameters p.sub.m of a device having one or more input ports i and an output port where m takes on integer values from 1 to M, M being an integer equal to or greater than 1, and i takes on integer values from 1 to I, I being an integer equal to or greater than 1. The device causes one or more input signals G.sub.i (p.sub.m)E.sub.ei (t) fed into one or more input ports to be transformed into an output signal comprising a summation over i of G.sub.i (p.sub.m)H.sub.i (p.sub.m)E.sub.oi (t) at the output port. The function G.sub.i (p.sub.m) is a weighting function associated with the i'th input port, E.sub.ei (t) is an excitation signal associated with the i'th input port, and E.sub.oi (t) is the transformation of the excitation signal E.sub.ei (t) that results from E.sub.ei (t) traversing the path from the input port i to the output port. The signals E.sub.ei (t) and E.sub.oi (t) are both independent of the parameter p.sub.m. The product function G.sub.i (p.sub.m)H.sub.i (p.sub.m) is representable by a power series of order N.sub.im in p.sub.m, the value of N.sub.im depending on a specified accuracy of representation. The method comprising the steps (1) generating one or more linearizing weighting functions G.sub.il (p.sub.m) for which the output signal is a linear measure of the parameter p.sub.m to the specified accuracy of representation, (2) feeding the input signals G.sub.il (p.sub.m)E.sub.ei (t) into the device; and (3) using a component of the output signal as a linear measure of each of the one or more parameters p.sub.m.

Vibratory rotation sensor utilizing linearized flexure measures

The invention is a vibratory rotation sensor comprising a resonator and a housing to which the resonator is attached and a method for reading out the standing-wave orientation angle utilizing a tracking angle which is maintained equal to the orientation angle on average. The resonator is a rotationally-symmetric thin-walled object that can be made to vibrate in a plurality of standing-wave modes. The method includes applying driving voltages to housing electrodes and determining the orientation of a standing wave by performing operations on the resonator signal that arrives at a single resonator output port from one or more electrodes in close proximity to the housing electrodes. A driving voltage may include either a pair of excitation voltages or a forcing voltage or both. An excitation voltage has essentially no effect on the resonator dynamics but carries information pertaining to the tracking angle and the standing-wave parameters when it arrives at the resonator output port. A forcing voltage causes forces to be applied to the resonator and thereby affects the dynamics of the resonator and the standing-wave parameters. The driving voltages applied to the housing electrodes are brought together into a single resonator signal as a result of being transmitted through the housing-electrode-resonator-electrode capacitances to the resonator output port. In order to extract the standing-wave orientation angle, the excitation and forcing voltages are designed to be separable by appropriate operations performed on the resonator signal.

Vibratory rotation sensor with whole-angle tracking

The invention is a method for applying forces to the resonator of a vibratory rotation sensor (VRS) by establishing an ac voltage between conducting regions of a surface of the resonator and one or more forcer electrodes opposing the conducting regions. The method comprises the steps of generating a first ac voltage having a first frequency and a first phase, generating a second ac voltage having a second frequency, and establishing the difference of the first and second ac voltages between conducting regions of a surface of the resonator and the one or more forcer electrodes. The first and second ac voltages are synchronized to the displacement of a point on the resonator when the resonator is vibrating. The ratio of the vibrational frequency of the VRS to either the difference or the sum of the first and second frequencies is a ratio of integers.

Vibratory rotation sensor with AC forcing voltages

A pattern recognition system is utilized in a supplementary inflatable restraint (SIR) system to distinguish between deployment and non-deployment events. The pattern recognition system preferably includes dedicated hardware or a microprocessor programmed to perform a neural network simulation utilizing crash data in the form of vehicle acceleration data. Training and trial vectors are generated from the data to train and, subsequently, test the neural network.

Method and apparatus for distinguishing between deployment events and

A vibratory rotation sensor includes a heimspherical resonator, a ring forcer electrode and a plurality of discrete forcer and pick-off electrodes. A vibratory or flexural standing wave pattern is established in the resonator and signals from the pick-off electrodes are combined to produce first (E.sub.c) and second (E.sub.s) signals that represent two independent components of the vibration pattern. A reference phase generator generates timing signal that are used to demodulate E.sub.c and E.sub.s to obtain in-phase and quadrature components thereof. The quadrature components are transformed in a computer to generate nodal and antinodal quadrature signals. The nodal quadrature signal is used as the error signal in a quadrature control loop that keeps both components of the vibration pattern in phase. The antinodal quadrature signal is used as the error signal in a phase-locked loop that keeps the phase of the reference phase generator locked to the phase of the vibration.

Vibratory rotation sensor

A vibratory gyro including a hemispherical high Q resonator supported by an inner housing carrying a circular forcer electrode and sixteen discrete forcer electrodes. The orientation of the vibrating pattern in the resonator is electrostatically sensed by eight pickoff electrodes located on the inner spherical surface of an outer housing which establish two pickoff axes separated by 45.degree.. Signals obtained from the pickoff electrodes are utilized to develop a drive signal to the circular forcer electrode to electrostatically maintain a predetermined amplitude of pattern vibration and to develop drive signals for appropriate groups of discrete forcer electrodes to eliminate any phase error between components of the pattern along the two pickoff axes.

Growing community of inventors

Santa Barbara, CA, United States of America

David Dexter Lynch