Patents by Inventor KeXiu Liu

KeXiu Liu 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).

  • Vibration Compensation Based on Identification of Vibration Frequency
    Publication number: 20080262658
    Abstract: A shock detection circuit housed in an electronic device includes an output shock signal that is indicative of vibration amplitude. To compensate for vibrations that are experienced by the electronic device, the output shock signal is analyzed. The analysis of the output shock signal allows a vibration frequency of the output shock signal to be identified and used in vibration compensation.
    Type: Application
    Filed: April 17, 2007
    Publication date: October 23, 2008
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Mingzhong Ding, KianKeong Ooi, KeXiu Liu, YiLei Wu, ShuYu Cao
  • Adaptive voltage-mode controller for a voice coil motor
    Patent number: 7199964
    Abstract: A voltage-mode VCM controller is provided comprising an Infinite Impulse Response (IIR) filter that modifies a servo control voltage signal to a voltage driver in response to an adaptive compensator that configures the IIR filter in relation to an observed VCM velocity and an actual VCM velocity. An associated method is provided comprising modeling a velocity response of a VCM to a voltage input; inputting the observed velocity and an actual VCM velocity to an adaptive compensator that computes a gain and a VCM response pole frequency in relation to the VCM resistance and inductance; configuring an IIR filter in relation to the computed gain and pole frequency values; and using the IIR filter to modify a voltage command from a servo controller to a power driver.
    Type: Grant
    Filed: June 29, 2005
    Date of Patent: April 3, 2007
    Assignee: Seagate Technology LLC
    Inventors: KeXiu Liu, MingZhong Ding, KianKeong Ooi, QingWei Jia
  • Adaptive voltage-mode controller for a voice coil motor
    Publication number: 20070013337
    Abstract: A voltage-mode VCM controller is provided comprising an Infinite Impulse Response (IIR) filter that modifies a servo control voltage signal to a voltage driver in response to an adaptive compensator that configures the IIR filter in relation to an observed VCM velocity and an actual VCM velocity. An associated method is provided comprising modeling a velocity response of a VCM to a voltage input; inputting the observed velocity and an actual VCM velocity to an adaptive compensator that computes a gain and a VCM response pole frequency in relation to the VCM resistance and inductance; configuring an IIR filter in relation to the computed gain and pole frequency values; and using the IIR filter to modify a voltage command from a servo controller to a power driver.
    Type: Application
    Filed: June 29, 2005
    Publication date: January 18, 2007
    Inventors: KeXiu Liu, MingZhong Ding, KianKeong Ooi, QingWei Jia
  • Phase-advanced filter for robust resonance cancellation
    Patent number: 6710965
    Abstract: A filter for attenuating a resonance mode without substantial phase margin loss. The filter comprises a transfer function having an additional pole, such that the phase of the input signal is advanced. The phase-advanced filter substantially attenuates all frequencies above a selected center frequency while avoiding substantial phase margin loss.
    Type: Grant
    Filed: January 22, 2002
    Date of Patent: March 23, 2004
    Assignee: Seagate Technology LLC
    Inventors: Mingzhong Ding, KeXiu Liu, KianKeong Ooi
  • Phase-advanced filter for robust resonance cancellation
    Publication number: 20030076615
    Abstract: A filter for attenuating a resonance mode without substantial phase margin loss. The filter comprises a transfer function having an additional pole, such that the phase of the input signal is advanced. The phase-advanced filter substantially attenuates all frequencies above a selected center frequency while avoiding substantial phase margin loss.
    Type: Application
    Filed: January 22, 2002
    Publication date: April 24, 2003
    Applicant: Seagate Technology LLC
    Inventors: Mingzhong Ding, KeXiu Liu, KianKeong Ooi