Patents by Inventor Gilsu Choi

Gilsu Choi 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).

  • Active masking of tonal noise using motor-based acoustic generator to improve sound quality
    Patent number: 10319360
    Abstract: In various embodiments, methods, systems, and vehicles are provided for masking a tonal noise of a motor. In certain embodiments, a vehicle includes a drive system and an active masking acoustic signal generator (AMAG). The drive system includes a motor generating a tonal noise. The AMAG is configured to at least facilitate masking the tonal noise, by introducing a complementary harmonic tone, injecting dithering into the motor, or both.
    Type: Grant
    Filed: March 6, 2018
    Date of Patent: June 11, 2019
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Song He, Yo Chan Son, Gilsu Choi, Caleb W. Secrest, Aja Anjilivelil, Scott M. Reilly, John P. Miller
  • Apparatus and method for monitoring magnet flux degradation of a permanent magnet motor
    Patent number: 10295599
    Abstract: A method in a motor controller for an electric motor is disclosed. The method includes receiving a motor current measurement, a motor reference voltage or measured voltage, and an estimated temperature from the electric motor, determining a reference flux linkage estimate (?pm,ref) from a lookup table based on the motor current measurement and the estimated temperature, determining a back-EMF (electromotive force) estimate based on the motor current measurement, the motor voltage and the estimated temperature, determining an observed flux linkage estimate (?pm,obs) from the back-EMF estimate, determining a magnetic strength as a ratio of the observed flux linkage estimate to the reference flux linkage estimate, and determining that a rotor magnet has been demagnetized to an unacceptable level when the magnetic strength is below a threshold level.
    Type: Grant
    Filed: August 11, 2017
    Date of Patent: May 21, 2019
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Gilsu Choi, Anno Yoo, Dwarakanath V. Simili
  • APPARATUS AND METHOD FOR MONITORING MAGNET FLUX DEGRADATION OF A PERMANENT MAGNET MOTOR
    Publication number: 20190049517
    Abstract: A method in a motor controller for an electric motor is disclosed. The method includes receiving a motor current measurement, a motor reference voltage or measured voltage, and an estimated temperature from the electric motor, determining a reference flux linkage estimate (?pm,ref) from a lookup table based on the motor current measurement and the estimated temperature, determining a back-EMF (electromotive force) estimate based on the motor current measurement, the motor voltage and the estimated temperature, determining an observed flux linkage estimate (?pm,obs) from the back-EMF estimate, determining a magnetic strength as a ratio of the observed flux linkage estimate to the reference flux linkage estimate, and determining that a rotor magnet has been demagnetized to an unacceptable level when the magnetic strength is below a threshold level.
    Type: Application
    Filed: August 11, 2017
    Publication date: February 14, 2019
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Gilsu Choi, Anno Yoo, Dwarakanath V. Simili