Patents by Inventor John Mark

John Mark 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: 6904377
    Abstract: System and method for measuring force-dependent gyroscopic sensitivity. A force-effect model of the effects of acceleration on the output of a gyro triad is determined. Rotation sequences are then devised to permit excitation and observation of force-effect model parameters in order to provide calibration information for these parameters. A state diagram containing the gyro triad force-effect model parameters is derived from the force-effect model, where moving from one position in the state diagram to another position indicates the gyro triad error which would occur in rotating the gyro triad according to a corresponding motion. Searching for all possible closed loop paths achievable through the state diagram, by a multiple-axes rate table with a specified number of rotations, to separate gyro triad error calibration from the accelerometer calibration.
    Type: Grant
    Filed: March 17, 2003
    Date of Patent: June 7, 2005
    Assignee: Northrop Grumman Corporation
    Inventors: G. Kevin Liu, John Mark, Daniel A. Tazartes
  • Publication number: 20050104756
    Abstract: A method of distinguishing an analog drive signal from a pickoff signal for attenuating the effect of electrical cross-coupling between the analog drive signal and the pickoff signal. The method may include receiving a periodic digital signal at a first frequency in the form of a stream of digital data values, randomly inverting at least one of the digital data values and converting the stream of digital data values to a stream of analog data values to form an analog drive signal. The method may also include driving a sensor, physically coupled to a resonant member configured to oscillate at a second frequency, using the analog drive signal and sensing changes in the movement of the resonant member detected by the sensor for producing a pickoff signal.
    Type: Application
    Filed: November 14, 2003
    Publication date: May 19, 2005
    Inventors: Daniel Tazartes, John Mark
  • Publication number: 20040186676
    Abstract: System and method for measuring force-dependent gyroscopic sensitivity. A force-effect model of the effects of acceleration on the output of a gyro triad is determined. Rotation sequences are then devised to permit excitation and observation of force-effect model parameters in order to provide calibration information for these parameters. A state diagram containing the gyro triad force-effect model parameters is derived from the force-effect model, where moving from one position in the state diagram to another position indicates the gyro triad error which would occur in rotating the gyro triad according to a corresponding motion. Searching for all possible closed loop paths achievable through the state diagram, by a multiple-axes rate table with a specified number of rotations, to separate gyro triad error calibration from the accelerometer calibration.
    Type: Application
    Filed: March 17, 2003
    Publication date: September 23, 2004
    Inventors: G. Kevin Liu, John Mark, Daniel A. Tazartes
  • Patent number: 6424419
    Abstract: A system and method for controlling the cavity length of a ring laser gyroscope to properly tune the resonant wavelengths of the ring laser gyroscope during moments when experiencing sudden shocks or high g force accelerations. The system controls the position of a movable mirror in the laser cavity of the gyroscope to control the length of the laser cavity. The system measures the acceleration experienced by the laser cavity, wherein the position of the movable mirror is adjusted to counteract the effects of the acceleration on the movable mirror in a real-time response to the measured acceleration. By adjusting the position of the movable mirror, the resonant wavelengths propagating in the ring laser gyroscope will be maintained at their desired intensity and continue to lase even after experiencing this acceleration.
    Type: Grant
    Filed: July 28, 2000
    Date of Patent: July 23, 2002
    Assignee: Northrop Grumman Corporation
    Inventors: Daniel Tazartes, John Mark, Albert V. Scappaticci, Michael W. Denice, Jr.