Honeywell International Inc.

Honeywell G.m.b.h.

Other

Honeywell International Inc. Intellectual Property - Patent Services

Lee Kevin Strandjord

Glen Aaron Sanders

Tiequn Qiu

Jianfeng Wu

Norman Gerard Tarleton

Marc Smiciklas

Clarence E Laskoskie

Bogdan Szafraniec

Mary Salit

John R Feth

Neil A Krueger

Andrew W Kaliszek

Grenville Hughes

Chuck Croker

Thomas Charles Greening

James N Blake

Ralph A Bergh

Thomas R Keyser

Charles H Lange

Jerry L Page

Darryl Busch

Rudolf C Dankwort

Dick Ang

Gregory W Keith

Richard J August

Chellappan Narayanan

Waymon Ho

Daniel L Sugarbaker

Kevin B Dimond

Matthew Wade Puckett

Karl D Nelson

James F Detry

Chung-Jen Chen

Mitchell Novack

Nick Anthony Demma

Yellapu Anjan

Tamim F El-Wailly

Austin Taranta

David A Doheny

Scott A Anson

Edward Summers

Simon Ayotte

Stephan Enzone

Matthew P Newlin

Steve J Sanders

Gary W Adams

Norman G Tarleton, Jr

Jenni Strabley

Rudy Dankwort

Barbara Vizenor

Tiequniu Qiu

Clarence Eugene Laskoskie

Mary K Salit

John Feth

Grenville Hugues

Tiequn Oiu

Glen A c/o Honeywell International Inc Sanders

Tiequn Qui

Norman Tarleton

Steve Sanders

Thomas C c/o Honeywell Intern Inc Greening

Systems and methods for reducing rotation sensing errors from laser source signal and modulation cross-talk are provided herein. An RFOG includes a fiber optic resonator; a first laser source that produces a first light wave at a first carrier frequency and a first cross-talked portion at a second carrier frequency wave for propagating in a first direction, wherein a second cross-talked portion propagates in a second direction that is opposite to the first direction; a second laser source that produces a second light wave for propagating in the second direction at a second carrier frequency, and having a third cross-talked portion that propagates in the first direction, a first modulator that modulates the first light wave by suppressing light at the first carrier frequency and the second cross-talked portion at the second carrier frequency, and photodetectors that generate signals from the modulated first light wave and the second light wave.

Reducing rotation sensing errors from laser source signal and modulation cross-talk

Systems and methods for an injection locking RFOG are described herein. In certain embodiments, a system includes an optical resonator. The system also includes a laser source configured to launch a first laser for propagating within the optical resonator in a first direction and a second laser for propagating within the optical resonator in a second direction that is opposite to the first direction, wherein the first laser is emitted at a first launch frequency and the second laser is emitted at a second launch frequency. Moreover, the system includes at least one return path that injects a first optical feedback for the first laser and a second optical feedback for the second laser, from the optical resonator, into the laser source, wherein the first and second optical feedbacks respectively lock the first and second launch frequencies to first and second resonance frequencies of the optical resonator.

Injection locking resonator fiber optic gyroscope

Improvements to optical power regulation in a gyroscopic system are described. The system can include an optical assembly (e.g., optical bench) which couples opposing optical signals to a resonator coil. The system can monitor the power of the optical signals through the resonator coil by including signal extraction optics in the optical assembly which are configured to extract a portion of the optical signals. The portions can be extracted via a single beamsplitter, wherein the beamsplitter reflects the portions at a single common surface, and can also reflect the portions to a respective photodetector in free space free from intervening optical components, such as polarizers or beamsplitters. One or more processors can be coupled to the optical assembly, wherein the processor(s) are configured to adjust the power of the optical signals in response to detecting a power difference between the optical signals.

Systems and methods for enhanced optical power control

Systems and methods are provided to reduce at least one differential harmonics of a resonance tracking modulation in a resonant fiber optic gyroscope (RFOG). The fundamental frequency of the resonance tracking modulation of each of the clockwise and counter clockwise optical signals is substantially identical; however, the amplitude and phase of the Nth harmonic of a clockwise (CW) resonance tracking modulation and the Nth harmonic of a clockwise (CCW) resonance tracking modulation may differ due to non-linearities in the RFOG. Embodiments of the invention diminish, e.g., reduce to zero such vectoral difference. Differential harmonics may be generated at one or more harmonics.

Systems and methods to reduce differential harmonics of resonance tracking modulation in a resonant fiber optic gyroscope

In one embodiment, a phase lock loop circuit includes a control circuit, wherein the control circuit is configured to input an estimation having a second frequency and a second phase. The second frequency is selected from a range of frequencies including a first frequency from an acquired signal. A numerically controlled oscillator is coupled to the control circuit, wherein the control circuit is configured to control an output response of the numerically controlled oscillator. The numerically controlled oscillator is configured to receive the estimation from the control circuit and generate an output signal in response to the estimation. A phase detector is coupled to the control circuit and the numerically controlled oscillator, wherein the phase detector is configured to compare the first signal and the output signal and produce a comparison output, the comparison output indicative of a phase difference between the first signal and the estimation.

High-bandwidth phase lock loop circuit with sideband rejection

A resonator fiber optic gyroscope (RFOG) that includes at least one laser, a resonator and a resonator hopping control system is provided. The resonator is in operational communication with the at least one laser to receive a clockwise (CW) laser light and counterclockwise (CCW) laser light produced by the at least one laser. The resonance hopping control system is in communication with an output of the resonator and the at least one laser. The resonance hopping control system is configured to control an output of the at least one laser to periodically unlock, hop and lock frequencies of the laser light traveling in the CW and CCW directions in the resonator to resonance frequencies of the resonator to mitigate bias errors due to resonance asymmetries.

Gyroscope with reduced bias errors due to resonance asymmetries

Systems and methods for performing resonator fiber optic gyroscope (RFOG) resonance hopping are described herein. For example, an RFOG includes a fiber optic resonator. The RFOG also includes a plurality of laser sources that each launch a respective laser for propagation within the fiber optic resonator. Further, the RFOG includes a threshold detector that determines when the operation of at least one laser source in the plurality of laser sources exceeds a threshold associated with the operational range of an aspect of the at least one laser source. Additionally, the RFOG includes a hop control logic that adjusts the frequency of at least one laser produced by the at least one laser source one or more resonant modes of the fiber optic resonator such that the aspect of the at least one laser moves away from the threshold towards a nominal value within the operational range.

RFOG resonance hopping

Systems and methods for performing SHD switching for RFOGS are provided herein. A system includes a resonator in which light resonates; at least one laser source that produces first and second optical beams; heterodyne modulators that modulate the first and second optical beams at a heterodyne frequency plus a modulation frequency offset to produce multiple sideband optical beams, wherein the modulation frequency offset has a different sign for the first and second optical beams; a frequency switching controller that alternatingly switches the signs of the modulation frequency offset applied to the first and second optical beams, wherein the heterodyne modulation of the first and second optical beams are on average at the heterodyne frequency; at least one coupler that couples the sideband optical beams into the resonator; a feedback control that detects the sideband optical beams transmitted from the resonator and, in response, adjusts frequencies of the optical beams.

Sideband heterodyne switching for resonator fiber optic gyroscopes (RFOGs)

Techniques are provided for correcting for time varying changes to a gyroscope incorporating a resonator and/or to an environment in which the gyroscope is located, and which affect the resonator. Free spectral range of the gyroscope, which varies with such changes, is determined and is used to correct at least one of gyroscope bias and scale factor.

Systems and methods for correcting errors in gyroscopes

A method comprises receiving a first optical signal and a second optical signal at or near an optical resonator, where the first optical signal includes a clockwise (CW) optical signal and the second optical signal includes a counter clockwise optical signal; injecting the first optical signal and the second optical signal into a resonator loop closure optics system of the optical resonator; sampling a portion of the first optical signal and a portion of the second optical signal; combining the portion of the first optical signal and the second optical signal; converting the combined optical signals to an analog electrical signal; digitizing the analog electrical signal; storing an estimated frequency of a beat signal created by a combination of the CW optical signal and the CCW optical signal; and using the stored estimated beat signal frequency, digitally phase lock to a frequency of the beat signal.

Apparatus for enhanced beat note detection

A hyperbolic modulation offset reducer circuit for a resonator fiber optic gyro (RFOG) is provided. The circuit includes a first demodulation circuit that is configured to demodulate a received transmission signal from a resonator at twice a sideband heterodyne detection modulation frequency to reject signals due to backscatter. A slave resonance tracking loop of the circuit is coupled to an output of the first demodulation circuit. The slave resonance tracking loop is configured to create an offset frequency signal from the transmission signal that is applied to an optical phase lock loop of a RFOG. A hyperbolic modulator offset control loop is also coupled to the output of the first demodulation circuit. The hyperbolic modulator offset control loop is configured to create a subharmonic common modulation signal from the transmission signal that is coupled to a common phase module in a silicon photonics chip of the RFOG.

Hyperbolic modulation offset error reducer for an RFOG

A resonance fiber-optic gyro (RFOG) with quadrature error reducer is provided. The RFOG with quadrature error reducer includes a laser assembly, a fiber resonator assembly, a resonance tracking loop and a quadrature error reducer circuit. The resonance tracking loop, coupled to an output of the finder resonator assembly, is used to generate a resonance frequency signal that is coupled to an OPLL mixer in one of a CCW OPLL or the CW OPLL of the laser assembly. The quadrature error reducer circuit includes an amplitude control loop and a second harmonic phase control loop. The amplitude control loop is used to generate a common modulation signal. An output of the amplitude control loop is coupled to a common phase modulator in the laser assembly. The second harmonic phase control loop is used to selectively adjust a phase of a second harmonic modulation signal in the amplitude control loop at startup.

Resonator fiber-optic gyro with quadrature error reducer

A resonant fiber optic gyroscope comprises: a ring resonator including a fiber coil fabricated from a first type of hollow core fiber; a light source to produce at least two light beams, wherein a first light beam is configured to travel in a clockwise direction in the ring resonator and a second light beam is configured to travel in a counterclockwise direction in the ring resonator; a filter resonator assembly coupled between the light source and the ring resonator including: at least two short pieces of optical fiber shorter in length than the fiber coil, the at least two short pieces of optical fiber fabricated from the first type of hollow core fiber; and wherein prior to the beams entering the ring resonator, a plurality of reflective devices are configured to condition the beams such that they excite the fundamental mode of the hollow core fiber within the ring resonator.

Resonant fiber optic gyroscope with hollow core fiber

An interferometer including a master laser, a slave laser and optical elements is provided. The optical elements direct and combine a master laser beam and a slave laser beam into a sensing phase measurement loop to provide a sensing beat signal and a reference phase lock loop to provide a reference beat signal. An electronic circuit portion is coupled to receive the sensing and reference beat signals. The electronic circuit portion includes a clock, at least one numerically controlled oscillator, at least one mixer and an interferometer output. The at least one numerically controlled oscillator has a clock input coupled to the clock. The at least one mixer has a first input to receive the sensing beat signal and a second input to receive an output of the at least one numerically controlled oscillator. The interferometer output is coupled to receive an output of the at least one mixer.

Large range, high resolution interferometer for wide range of sensing applications

An optical resonator is provided. The optical resonator comprises: an optical resonator coil comprising a first port and a second port; wherein the optical resonator coil comprises antiresonant nodeless fiber; a resonator loop closure optics system; and wherein the antiresonant nodeless fiber has a length such that the resonant frequencies the optical resonator of the desired polarization state of light and of the undesired polarization state of light are separated by between a tenth of a free spectral range and nine tenths of a free spectral range to minimize gyroscope errors.

Resonant fiber optical gyroscope using antiresonant nodeless fiber

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Tonka Bay, MN, United States of America

Lee Kevin Strandjord