Patents by Inventor Homer D. Stevens

Homer D. Stevens 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: 6570535
    Abstract: A system and method for RF autotracking multiple antennas (preferably located on a spacecraft) to compensate for disturbances experienced by the antennas. The system and method estimate high frequency errors associated with all of the antennas. The high frequency errors may be estimated using a currently selected antenna and a high-pass filter. The high frequency errors may be estimated using a sensor mounted on the spacecraft, such as a gyro or star tracker, or may be estimated using information, such as planned thruster firings, for example, from a spacecraft attitude control system. Alternatively, the high frequency information may be estimated using any combination of data from these sources. Low frequency errors are estimated using measurements from each selected antenna. The algorithm implemented in the present invention explicitly accounts for the frequency content of each disturbance source.
    Type: Grant
    Filed: March 13, 2002
    Date of Patent: May 27, 2003
    Assignee: Space Systems/Loral, Inc.
    Inventors: Homer D. Stevens, Keith Reckdahl, Xenophon Price
  • Patent number: 6477450
    Abstract: An attitude control system comprising a controller and a noise screen device coupled to the controller. The controller is adapted to control an attitude of a vehicle carrying an actuator system that is adapted to pulse in metered bursts in order to generate a control torque to control the attitude of the vehicle in response to a control pulse. The noise screen device is adapted to generate a noise screen signal in response to the control pulse that is generated when an input attitude error signal exceeds a predetermined deadband attitude level. The noise screen signal comprises a decaying offset signal that when combined with the attitude error input signal results in a net attitude error input signal away from the predetermined deadband level to reduce further control pulse generation.
    Type: Grant
    Filed: February 13, 2001
    Date of Patent: November 5, 2002
    Assignee: Space Systems/Loral, Inc.
    Inventors: John J. Rodden, Homer D. Stevens, David P. Hong, Philip C. Hirschberg
  • Publication number: 20020111722
    Abstract: An attitude control system comprising a controller and a noise screen device coupled to the controller. The controller is adapted to control an attitude of a vehicle carrying an actuator system that is adapted to pulse in metered bursts in order to generate a control torque to control the attitude of the vehicle in response to a control pulse. The noise screen device is adapted to generate a noise screen signal in response to the control pulse that is generated when an input attitude error signal exceeds a predetermined deadband attitude level. The noise screen signal comprises a decaying offset signal that when combined with the attitude error input signal results in a net attitude error input signal away from the predetermined deadband level to reduce further control pulse generation.
    Type: Application
    Filed: February 13, 2001
    Publication date: August 15, 2002
    Inventors: John J. Rodden, Homer D. Stevens, David P. Hong, Philip C. Hirschberg
  • Patent number: 6205378
    Abstract: An attitude control system and method operative with a thruster controls the attitude of a vehicle carrying the thruster, wherein the thruster has a valve enabling the formation of pulses of expelled gas from a source of compressed gas. Data of the attitude of the vehicle is gathered, wherein the vehicle is located within a force field tending to orient the vehicle in a first attitude different from a desired attitude. The attitude data is evaluated to determine a pattern of values of attitude of the vehicle in response to the gas pulses of the thruster and in response to the force field. The system and the method maintain the attitude within a predetermined band of values of attitude which includes the desired attitude. Computation circuitry establishes an optimal duration of each of the gas pulses based on the pattern of values of attitude, the optimal duration providing for a minimal number of opening and closure operations of the valve.
    Type: Grant
    Filed: July 29, 1999
    Date of Patent: March 20, 2001
    Assignee: Space Systems/Loral, Inc.
    Inventors: John J. Rodden, Homer D. Stevens, Stephane Carrou