Patents by Inventor William K. Morita, Jr.

William K. Morita, Jr. 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: 7808200
    Abstract: A technique can recover from motor stalls caused by misalignment of motor position sensors such as Hall-effect sensors. In a normal operating mode, a motor controller provides motor drive current to the motor windings based on the sensor signals according to a normal commutation sequence, and monitors for occurrence of a motor stall condition. Upon detecting the motor stall condition, the motor controller first momentarily drives the windings according to one of an advanced commutation state and a delayed commutation state each adjacent to the given commutation state in the normal commutation sequence, and determines whether the motor stall condition persists. If the stall condition persists, then the motor controller next momentarily drives the windings according to the other of the advanced commutation state and the delayed commutation state.
    Type: Grant
    Filed: September 6, 2007
    Date of Patent: October 5, 2010
    Assignee: Woodward HRT, Inc.
    Inventors: Raymond Y. Liu, Estella C. Chung, William K. Morita, Jr.
  • Publication number: 20090066274
    Abstract: A technique can recover from motor stalls caused by misalignment of motor position sensors such as Hall-effect sensors. In a normal operating mode, a motor controller provides motor drive current to the motor windings based on the sensor signals according to a normal commutation sequence, and monitors for occurrence of a motor stall condition. Upon detecting the motor stall condition, the motor controller first momentarily drives the windings according to one of an advanced commutation state and a delayed commutation state each adjacent to the given commutation state in the normal commutation sequence, and determines whether the motor stall condition persists. If the stall condition persists, then the motor controller next momentarily drives the windings according to the other of the advanced commutation state and the delayed commutation state.
    Type: Application
    Filed: September 6, 2007
    Publication date: March 12, 2009
    Applicant: HR TEXTRON INC.
    Inventors: Raymond Y. Liu, Estella C. Chung, William K. Morita, JR.
  • Patent number: 7230422
    Abstract: Systems, methods, and computer-readable media are disclosed for error-compensated counting of Hall states for motor position feedback and/or commutation. An indicated Hall state is detected by digital Hall state sensors and a duration of the Hall state is compared to a specified time period. When the duration exceeds the specified time period, the indicated Hall state is compared to one or more valid Hall states and a position counter is changed for valid states. When the indicated Hall state is invalid, the position counter is not changed. The Hall state sensors may be connected to logic means and may detect the position of a rotor of a permanent magnet motor relative to a stator. When noise induces a change in an indicated Hall state, corresponding noise-induced effects on the position counter may be may be removed through error-compensated counting.
    Type: Grant
    Filed: April 28, 2006
    Date of Patent: June 12, 2007
    Assignee: HR Textron, Inc.
    Inventors: William K. Morita, Jr., Raymond Y. Liu, Estella C. Chung
  • Patent number: 7049813
    Abstract: Systems, methods, and computer-readable media are disclosed for error-compensated counting of Hall states for motor position feedback and/or commutation. An indicated Hall state is detected by digital Hall state sensors and a duration of the Hall state is compared to a specified time period. When the duration exceeds the specified time period, the indicated Hall state is compared to one or more valid Hall states and a position counter is changed for valid states. When the indicated Hall state is invalid, the position counter is not changed. The Hall state sensors may be connected to logic means and may detect the position of a rotor of a permanent magnet motor relative to a stator. When noise induces a change in an indicated Hall state, corresponding noise-induced effects on the position counter may be may be removed through error-compensated counting.
    Type: Grant
    Filed: May 19, 2004
    Date of Patent: May 23, 2006
    Assignee: HR Textron Inc.
    Inventors: William K. Morita, Jr., Raymond Y. Liu, Estella C. Chung