Patents by Inventor Thomas Wittefeldt

Thomas Wittefeldt 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).

  • Method and apparatus for air fuel ratio adjustment
    Patent number: 7474955
    Abstract: The air fuel ratio of an engine adapted to run on a mixture of alcohol and gasoline can be adapted by a method wherein the air fuel ratio is controlled using an ethanol adaptation value, including reducing the enrichment factor from an initial value until a lean switch from rich conditions to lean conditions is detected, determining a first enrichment factor value at which the lean switch occurs, increasing the enrichment factor until a rich switch from lean conditions to rich conditions is detected, determining a second enrichment factor value at which the rich switch occurs, calculating the average value between the first enrichment factor value and the second enrichment factor value, adjusting the air fuel ratio using the average value.
    Type: Grant
    Filed: January 22, 2007
    Date of Patent: January 6, 2009
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Thomas Wittefeldt, Richard Backman, Erik Sunnegårdh, Staffan Seth
  • Method and apparatus for air fuel ratio adjustment
    Publication number: 20070185641
    Abstract: The air fuel ratio of an engine adapted to run on a mixture of alcohol and gasoline can be adapted according to the invention, by a method, wherein said air fuel ratio is controlled by means of an ethanol adaptation value, comprising the following steps: reducing the enrichment factor from an initial value until a lean switch from rich conditions to lean conditions is detected, determining a first enrichment factor value at which the lean switch occurs, Increasing the enrichment factor until a rich switch from lean conditions to rich conditions is detected, determining a second enrichment factor value at which the rich switch occurs, calculating the average value between the first enrichment factor value and the second enrichment factor value, adjusting the air fuel ratio by means of said average value.
    Type: Application
    Filed: January 22, 2007
    Publication date: August 9, 2007
    Inventors: Thomas Wittefeldt, Richard Backman, Erik Sunnegardh, Staffan Seth