Patents by Inventor Liqun Na

Liqun Na 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: 10538169
    Abstract: A vehicle includes a traction motor having resonance frequency zones, an inverter including switches arranged to drive the traction motor, and a controller. The controller operates the switches only within specified sets of carrier frequencies such that noise side bands corresponding to the carrier frequencies fall outside the resonance frequency zones.
    Type: Grant
    Filed: June 4, 2018
    Date of Patent: January 21, 2020
    Assignee: Ford Global Technologies, LLC
    Inventors: Xuemei Sun, Jami J. Miller, Christopher Wolf, Liqun Na
  • Publication number: 20190366854
    Abstract: A vehicle includes a traction motor having resonance frequency zones, an inverter including switches arranged to drive the traction motor, and a controller. The controller operates the switches only within specified sets of carrier frequencies such that noise side hands corresponding to the carrier frequencies fall outside the resonance frequency zones.
    Type: Application
    Filed: June 4, 2018
    Publication date: December 5, 2019
    Inventors: Xuemei Sun, Jami J. Miller, Christopher Wolf, Liqun Na
  • Patent number: 10224017
    Abstract: Method and apparatus are disclosed for active sound desensitization to tonal noise in a vehicle. An example vehicle includes an electric motor, a microphone, speakers, and an active sound desensitizer. The active sound desensitizer (a) randomizes channels of the speakers based on multiple uncorrelated broadband sound profiles, (b) determine upper and lower frequency band limits for a band-limited filter, (c) generate a desensitizing sound based on the upper and lower frequency band limits and the randomized channels, and (d) broadcast the desensitizing sound via the speakers.
    Type: Grant
    Filed: April 26, 2017
    Date of Patent: March 5, 2019
    Assignee: Ford Global Technologies, LLC
    Inventors: Ming-Ran Lee, Ming-te Cheng, Ramasunder Krishnaswami, Liqun Na, Mingfeng Li
  • Patent number: 10121464
    Abstract: An active noise control (ANC) system includes a speaker and one or more processors. The one or more processors implement an adaptive subband filtered reference control algorithm that applies thresholds to reference and error feedback signal paths such that, in response to a series of broadband non-Gaussian impulsive reference signals indicative of road noise in the vehicle having an audible frequency range of 20 Hz to 20 kHz, weight coefficients defining an adaptive filter of the control algorithm converge and permit the ANC system to partially cancel the road noise via output of the speaker.
    Type: Grant
    Filed: December 8, 2014
    Date of Patent: November 6, 2018
    Assignees: Ford Global Technologies, LLC, University of Cincinnati
    Inventors: Ming-Ran Lee, Takeshi Abe, Ming-te Cheng, Frederick Wayne Vanhaaften, Liqun Na, Teik Lim, Mingfeng Li, Guohua Sun, Tao Feng
  • Publication number: 20180315413
    Abstract: Method and apparatus are disclosed for active sound desensitization to tonal noise in a vehicle. An example vehicle includes an electric motor, a microphone, speakers, and an active sound desensitizer. The active sound desensitizer (a) randomizes channels of the speakers based on multiple uncorrelated broadband sound profiles, (b) determine upper and lower frequency band limits for a band-limited filter, (c) generate a desensitizing sound based on the upper and lower frequency band limits and the randomized channels, and (d) broadcast the desensitizing sound via the speakers.
    Type: Application
    Filed: April 26, 2017
    Publication date: November 1, 2018
    Inventors: Ming-Ran Lee, Ming-te Cheng, Ramasunder Krishnaswami, Liqun Na, Mingfeng Li
  • Patent number: 9837065
    Abstract: An active noise control (ANC) system includes a speaker and one or more processors programmed to implement a delayless subband filtered-x least mean square control algorithm. The algorithm includes a variable bandwidth discrete Fourier transform filter bank having a number of subbands such that the system, in response to a broadband white noise reference signal indicative of road noise in the vehicle, exhibits a uniform gain spectrum across a frequency range defined by the subbands and partially cancels the road noise via output of the speaker.
    Type: Grant
    Filed: December 8, 2014
    Date of Patent: December 5, 2017
    Assignee: Ford Global Technologies, LLC
    Inventors: Ming-Ran Lee, Takeshi Abe, Ming-te Cheng, Frederick Wayne Vanhaaften, Liqun Na, Teik Lim, Mingfeng Li, Guohua Sun, Tao Feng
  • Publication number: 20160163305
    Abstract: An active noise control (ANC) system includes a speaker and one or more processors programmed to implement a delayless subband filtered-x least mean square control algorithm. The algorithm includes a variable bandwidth discrete Fourier transform filter bank having a number of subbands such that the system, in response to a broadband white noise reference signal indicative of road noise in the vehicle, exhibits a uniform gain spectrum across a frequency range defined by the subbands and partially cancels the road noise via output of the speaker.
    Type: Application
    Filed: December 8, 2014
    Publication date: June 9, 2016
    Inventors: Ming-Ran Lee, Takeshi Abe, Ming-te Cheng, Frederick Wayne Vanhaaften, Liqun Na, Teik Lim, Mingfeng Li, Guohua Sun, Tao Feng
  • Publication number: 20160163304
    Abstract: An active noise control (ANC) system includes a speaker and one or more processors. The one or more processors implement an adaptive subband filtered reference control algorithm that applies thresholds to reference and error feedback signal paths such that, in response to a series of broadband non-Gaussian impulsive reference signals indicative of road noise in the vehicle having an audible frequency range of 20 Hz to 20 kHz, weight coefficients defining an adaptive filter of the control algorithm converge and permit the ANC system to partially cancel the road noise via output of the speaker.
    Type: Application
    Filed: December 8, 2014
    Publication date: June 9, 2016
    Inventors: Ming-Ran Lee, Takeshi Abe, Ming-te Cheng, Frederick Wayne Vanhaaften, Liqun Na, Teik Lim, Mingfeng Li, Guohua Sun, Tao Feng