Patents by Inventor David O. Fellows

David O. Fellows 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).

  • Patent number: 7916302
    Abstract: A method for maintaining measurement accuracy of a ring laser gyroscope is disclosed. The method involves periodically measuring a path length control voltage in the ring laser gyroscope over a prescribed temperature range. When a first path length controlled by the path length control voltage deviates at least one wavelength from a nominal path length, the method detects the change in the path length as a mode shift. For each mode shift, the method applies a path length correction to maintain the first path length at a target path length over the prescribed temperature range. The method can apply a correction to a measurement signal output of the ring laser gyroscope by adjusting a calibrated scale factor depending on an actual integer number of wavelengths achieved during a mode shift.
    Type: Grant
    Filed: May 18, 2007
    Date of Patent: March 29, 2011
    Assignee: Honeywell International Inc.
    Inventors: David O. Fellows, Ying Tan, Timothy J. Callaghan, Christina M. Schober
  • Publication number: 20100014092
    Abstract: A method for maintaining measurement accuracy of a ring laser gyroscope is disclosed. The method involves periodically measuring a path length control voltage in the ring laser gyroscope over a prescribed temperature range. When a first path length controlled by the path length control voltage deviates at least one wavelength from a nominal path length, the method detects the change in the path length as a mode shift. For each mode shift, the method applies a path length correction to maintain the first path length at a target path length over the prescribed temperature range. The method can apply a correction to a measurement signal output of the ring laser gyroscope by adjusting a calibrated scale factor depending on an actual integer number of wavelengths achieved during a mode shift.
    Type: Application
    Filed: May 18, 2007
    Publication date: January 21, 2010
    Applicants: HONEYWELL, HONEYWELL INTERNATIONAL INC.
    Inventors: David O. Fellows, Ying Tan, Timothy J. Callaghan, Christina M. Schober
  • Patent number: 7388670
    Abstract: A method of stabilizing beam power in a ring LASER gyroscope (RKG) during high vibration is provided. The method comprises modifying an electrical signal output from an RLG photodetector to generate a direct current (DC) feedback signal, the DC levels of the feedback signal being proportional to RLG beam power. The method further comprises comparing the DC levels of the feedback signal to a DC reference signal, wherein the DC levels of the reference signal are proportional to a desired RLG beam power level. The method also comprises generating a difference signal representing a difference signal representing a difference between the DC levels of the reference signal and the feedback signal and adjusting RLG beam power based on the difference signal.
    Type: Grant
    Filed: December 5, 2005
    Date of Patent: June 17, 2008
    Assignee: Honeywell International Inc.
    Inventor: David O. Fellows
  • Publication number: 20080117426
    Abstract: A method of stabilizing beam power in a ring LASER gyroscope (RKG) during high vibration is provided. The method comprises modifying an electrical signal output from an RLG photodetector to generate a direct current (DC) feedback signal, the DC levels of the feedback signal being proportional to RLG beam power. The method further comprises comparing the DC levels of the feedback signal to a DC reference signal, wherein the DC levels of the reference signal are proportional to a desired RLG beam power level. The method also comprises generating a difference signal representing a difference signal representing a difference between the DC levels of the reference signal and the feedback signal and adjusting RLG beam power based on the difference signal.
    Type: Application
    Filed: December 5, 2005
    Publication date: May 22, 2008
    Applicant: Honeywell International Inc.
    Inventor: David O. Fellows