Patents by Inventor Robert E. Stewart

Robert E. Stewart has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20120265481
    Abstract: An accelerometer system can include a sensor element comprising first and second proofmasses, the first proofmass accelerating in a first direction and the second proofmass accelerating in a second direction opposite the first direction in response to an external acceleration. A force rebalance controller applies control signals to at least one control element to provide a first force to accelerate the first proofmass toward a first null position and to at least one control element to provide a second force to accelerate the second proofmass toward a second null position. The force rebalance controller can also generate opposite polarity first and second output signals associated with respective displacements of the first and second proofmasses relative to the respective first and second null positions. An acceleration component calculates the external acceleration based on the first and second output signals.
    Type: Application
    Filed: April 13, 2011
    Publication date: October 18, 2012
    Inventors: ROBERT E. STEWART, Daryl Sakaida, Michael D. Bulatowicz, Ming Li, John Thomson Douglass
  • Patent number: 8136382
    Abstract: The method and apparatus in one embodiment may have: operating one of two resonators of a class II coriolis vibratory gyro in a closed loop mode and another of the two resonators in an open loop whole angle mode; sensing an angular rate by each of the two resonators; calibrating the scale factor of the closed loop resonator to yield the same integrated whole angle as measured by the open loop resonator; reversing operation of the two resonators such that the one of two resonators is operated in an open loop mode and the another of the two resonators in a closed loop whole angle mode; and alternately proceeding between open and closed loop operation of the two resonators, thereby self-calibrating scale factors respectively of the two resonators.
    Type: Grant
    Filed: May 7, 2010
    Date of Patent: March 20, 2012
    Assignee: Northrop Grumman Guidance and Electronics Company, Inc.
    Inventor: Robert E. Stewart
  • Patent number: 8109145
    Abstract: One embodiment is a micro hemispheric resonator gyro having: a plurality of pickoff and forcer electrodes; a hemispheric resonator; a guard ring having first and second opposed sides, the guard ring containing the plurality of pickoff and forcer electrodes, and the hemispheric resonator; a top cover operatively coupled to the first side of the guard ring; and a bottom cover operatively coupled to the second side of the guard ring; wherein the plurality of pickoff and forcer electrodes, the hemispheric resonator, the guard ring, the top cover and the bottom cover form a micro hemispheric resonator gyro.
    Type: Grant
    Filed: July 31, 2007
    Date of Patent: February 7, 2012
    Assignee: Northrop Grumman Guidance and Electronics Company, Inc.
    Inventor: Robert E. Stewart
  • Publication number: 20110238366
    Abstract: An apparatus in one example comprises one or more sensors that produce one or more signals based on one or more joint motions of an individual, and one or more processing components that employ one or more of the one or more signals to make a determination of a positional change of the individual.
    Type: Application
    Filed: June 1, 2011
    Publication date: September 29, 2011
    Inventor: Robert E. Stewart
  • Publication number: 20110219729
    Abstract: In one implementation, a chamber is selected that accommodates an array of die structures that comprises one or more cavities. An inner chamber of the chamber is maintained at a first temperature. An alkali metal source of the chamber is maintained at a second temperature greater than the first temperature. An outer chamber of the chamber is maintained at a third temperature greater than the first temperature and the second temperature. The one or more cavities of the array of die structures are filled with a portion of the alkali metal source. The one or more cavities of the array of die structures are sealed to comprise the portion of the alkali metal source.
    Type: Application
    Filed: May 16, 2011
    Publication date: September 15, 2011
    Inventors: Henry C. Abbink, William P. Debley, Christine E. Geosling, Daryl K. Sakaida, Robert E. Stewart
  • Patent number: 8011246
    Abstract: A control component of an apparatus in one example is configured to signal a plurality of electrodes arranged in at least first, second, third, and fourth radial electrode groups along first, second, third, and fourth axes at approximately 0, 45, 90, and 135 degrees, respectively, around the planar resonator. During a first time period, the control component is configured to signal: the first radial electrode group to induce a drive oscillation in the planar resonator, the third radial electrode group to sense the drive oscillation, the second radial electrode group to sense a Coriolis force induced oscillation, and the fourth radial electrode group to null the Coriolis force induced oscillation.
    Type: Grant
    Filed: September 22, 2008
    Date of Patent: September 6, 2011
    Assignee: Northrop Grumman Guidance and Electronics Company, Inc.
    Inventor: Robert E. Stewart
  • Patent number: 7980115
    Abstract: A self-calibrating laser accelerometer system that continuously removes bias errors from acceleration measurements under dynamic operating conditions has a frame with a pair of essentially identical mass modulated accelerometers positioned within the frame. Each accelerometer includes a proof mass mounted to the sensing element frame by a flexure suspension. The proof mass is arranged to rotate about an output axis in response to acceleration of the sensing element frame along an input axis. The first proof mass includes a secondary mass that is movable between a first stable position on a first side of the output axis and a second stable position on a second side of the output axis to provide mass modulation of the first proof mass and to provide a selectively reversible polarity to the input axis and to provide self-calibration of bias.
    Type: Grant
    Filed: May 30, 2008
    Date of Patent: July 19, 2011
    Assignee: Northrop Grumman Guidance and Electronic Co, Inc.
    Inventors: Robert E. Stewart, David B. Hall, A. Douglas Meyer
  • Patent number: 7981057
    Abstract: An apparatus in one example comprises one or more sensors that produce one or more signals based on one or more joint motions of an individual, and one or more processing components that employ one or more of the one or more signals to make a determination of a positional change of the individual.
    Type: Grant
    Filed: October 8, 2003
    Date of Patent: July 19, 2011
    Assignee: Northrop Grumman Guidance and Electronics Company, Inc.
    Inventor: Robert E. Stewart
  • Patent number: 7973611
    Abstract: An apparatus in one example comprises a die structure that comprises a middle layer, a first outside layer, and a second outside layer. The middle layer comprises a cavity that holds an alkali metal, and one of the first outside layer and the second outside layer comprises a channel that leads to the cavity. The middle layer, the first outside layer, and the second outside layer comprise dies from one or more wafer substrates.
    Type: Grant
    Filed: September 11, 2007
    Date of Patent: July 5, 2011
    Assignee: Northrop Grumman Guidance and Electronics Company, Inc.
    Inventors: Henry C. Abbink, William P. Debley, Christine E. Geosling, Daryl K. Sakaida, Robert E. Stewart
  • Publication number: 20110100121
    Abstract: The method and apparatus in one embodiment may have: providing a two-dimensional axisymmetric oscillator having a beam containing two principal elastic axes and two principal damping axes; driving the beam with drive components to oscillate across corners of the beam at approximately 45 degrees to sides of the beam, the drive components having forcer components that provide drive and pickoff components that provide feedback; and oscillating the beam in a normal mode and a reverse mode.
    Type: Application
    Filed: January 3, 2011
    Publication date: May 5, 2011
    Inventors: Stanley F. Wyse, Robert E. Stewart
  • Patent number: 7886598
    Abstract: The method and apparatus in one embodiment may have: providing a two-dimensional axisymmetric oscillator having a beam containing two principal elastic axes and two principal damping axes; driving the beam with drive components to oscillate across corners of the beam at approximately 45 degrees to sides of the beam, the drive components having forcer components that provide drive and pickoff components that provide feedback; and oscillating the beam in a normal mode and a reverse mode.
    Type: Grant
    Filed: August 7, 2006
    Date of Patent: February 15, 2011
    Assignee: Northrop Grumman Guidance and Electronics Company, Inc.
    Inventors: Stanley F. Wyse, Robert E. Stewart
  • Patent number: 7874209
    Abstract: The apparatus in one embodiment may have capacitive bulk acoustic wave disk gyro operated in a closed loop mode. A self-calibration system may be operatively coupled to the capacitive bulk acoustic wave disk gyroscope. Self-calibration of gyro bias of the gyro may be implemented by interchanging an anti-nodal axis with a nodal axis of the gyro.
    Type: Grant
    Filed: January 8, 2008
    Date of Patent: January 25, 2011
    Assignee: Northrop Grumman Guidance and Electronics Company, Inc.
    Inventor: Robert E. Stewart
  • Publication number: 20100218587
    Abstract: The method and apparatus in one embodiment may have: operating one of two resonators of a class II coriolis vibratory gyro in a closed loop mode and another of the two resonators in an open loop whole angle mode; sensing an angular rate by each of the two resonators; calibrating the scale factor of the closed loop resonator to yield the same integrated whole angle as measured by the open loop resonator; reversing operation of the two resonators such that the one of two resonators is operated in an open loop mode and the another of the two resonators in a closed loop whole angle mode; and alternately proceeding between open and closed loop operation of the two resonators, thereby self-calibrating scale factors respectively of the two resonators.
    Type: Application
    Filed: May 7, 2010
    Publication date: September 2, 2010
    Inventor: Robert E. Stewart
  • Patent number: 7739896
    Abstract: The method and apparatus in one embodiment may have: operating one of two resonators of a class II coriolis vibratory gyro in a closed loop mode and another of the two resonators in an open loop whole angle mode; sensing an angular rate by each of the two resonators; calibrating the scale factor of the closed loop resonator to yield the same integrated whole angle as measured by the open loop resonator; reversing operation of the two resonators such that the one of two resonators is operated in an open loop mode and the another of the two resonators in a closed loop whole angle mode; and alternately proceeding between open and closed loop operation of the two resonators, thereby self-calibrating scale factors respectively of the two resonators.
    Type: Grant
    Filed: March 15, 2007
    Date of Patent: June 22, 2010
    Assignee: Northrop Grumman Guidance and Electronics Company, Inc.
    Inventor: Robert E. Stewart
  • Patent number: 7728587
    Abstract: The method and apparatus in one embodiment may have: a gyro housing containing a bias field; a bias field that generates a stable axial magnetic field; Xenon or other gas contained within at least a portion of the axial magnetic field, Xenon or other gas nuclear spins precessing at a constant angular rate with respect to the gyro housing in response to the axial magnetic field; wherein reversing a polarity of the bias field reverses a polarity of the magnetic field and a polarity of the precession of the Xenon or other gas nuclear spin, and wherein a reversing of the polarity of the gyro scalefactor thereby results without reversing a polarity of the gyro bias.
    Type: Grant
    Filed: July 31, 2007
    Date of Patent: June 1, 2010
    Assignee: Northrop Grumman Guidance and Electronics Company, Inc.
    Inventors: Robert E. Stewart, Edward Kanegsberg
  • Publication number: 20100116275
    Abstract: The breathing bag has an upper region; a lower region; a conduit for delivering exhaled air to the lower region and a conduit for withdrawing breathable air from the upper region. The device also has a baffle mounted therein for entrapping exhaled air in the lower region and for causing the exhaled air to remain in a low turbulence mode, for promoting a separation of oxygen and carbon dioxide from the exhaust air by stratification and for causing carbon dioxide to accumulate in the lower region of the bag. Consequently, the breathable air rising from the lower region of the bag has a higher oxygen content. In another aspect of the invention, a method for separating carbon dioxide and oxygen by stratification from exhaled air is also described.
    Type: Application
    Filed: October 27, 2009
    Publication date: May 13, 2010
    Inventor: Robert E. Stewart
  • Publication number: 20100071465
    Abstract: A control component of an apparatus in one example is configured to signal a plurality of electrodes arranged in at least first, second, third, and fourth radial electrode groups along first, second, third, and fourth axes at approximately 0, 45, 90, and 135 degrees, respectively, around the planar resonator. During a first time period, the control component is configured to signal: the first radial electrode group to induce a drive oscillation in the planar resonator, the third radial electrode group to sense the drive oscillation, the second radial electrode group to sense a Coriolis force induced oscillation, and the fourth radial electrode group to null the Coriolis force induced oscillation.
    Type: Application
    Filed: September 22, 2008
    Publication date: March 25, 2010
    Inventor: Robert E. Stewart
  • Patent number: 7668997
    Abstract: An apparatus comprises a plurality of ports wherein each port is adapted to couple to a device. At least one port connects by way of first and second unidirectional, point-to-point communication links with a device. The first unidirectional, point-to-point communication link transfers data from the device to the central logic unit and the second unidirectional, point-to-point communication link transfers data from the central logic unit to the device.
    Type: Grant
    Filed: June 14, 2005
    Date of Patent: February 23, 2010
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Raj Ramanujan, James B. Keller, William A. Samaras, John DeRosa, Robert E. Stewart
  • Patent number: 7658579
    Abstract: A nut and retainer fastener assembly includes a one-piece retainer having a flat base with an opening and a plurality of retainer clips extending from the base around the opening. At least one flange nut is secured to the base between adjacent clips and offset from the opening in the base. The opening preferably is polygonal, most preferably rectangular (including square), and the clips preferably are disposed at corners of the opening. The clips preferably have integral spring fingers that extend from ends of the clips toward the base and at an angle away from the opening to capture the mounting wall between the base and the ends of the spring clips. The base preferably has an ear extending away from the opening, most preferably laterally opposed ears extending away from the opening, and a flange nut mounted on each of the ears for alignment with a fastener opening in the mounting wall when the nut and fastener assembly is secured to the wall.
    Type: Grant
    Filed: October 16, 2006
    Date of Patent: February 9, 2010
    Assignee: Alpha Stamping Company
    Inventors: Robert E. Stewart, Charles Lee Dardas
  • Patent number: 7640786
    Abstract: The method and apparatus in one embodiment may have: a sensing element for an accelerometer having a bias, the sensing element having a rectangular plate supported by flexures which allow rotation about a transverse center line thereof; a center of mass (CG) of the sensing element having two stable positions, one on each side of an axis of rotation defined by a centerline of suspension; a secondary mass within a proofmass translates in-plane to move the center of mass to thereby effect a self-calibration mechanization that continuously measures and nulls the accelerometer's bias under dynamic operating conditions.
    Type: Grant
    Filed: March 28, 2007
    Date of Patent: January 5, 2010
    Assignee: Northrop Grumman Guidance and Electronics Company, Inc.
    Inventor: Robert E. Stewart