×

Method and apparatus for controlling mode transition in a spark-ignition direct-injection internal combustion engine

  • US 7,565,892 B1
  • Filed: 02/01/2008
  • Issued: 07/28/2009
  • Est. Priority Date: 02/01/2008
  • Status: Active Grant
First Claim
Patent Images

1. Method for operating a spark-ignition, direct-fuel injection internal combustion engine, comprising:

  • commanding the engine to transition from operating in a stratified charge combustion mode to operating in a homogeneous charge combustion mode;

    substantially completely discontinuing external EGR flow;

    estimating an in-cylinder trapped air mass and in-cylinder EGR mass;

    determining trajectories for an air/fuel ratio and the in-cylinder EGR mass, and controlling throttle position and engine fueling to achieve said trajectories;

    monitoring the air/fuel ratio;

    initiating double-injection fueling for each combustion cycle when the air/fuel ratio is less than a first predetermined threshold; and

    initiating single-injection fueling for each combustion cycle and executing spark retard management to control the engine output torque when the air/fuel ratio is less than a second predetermined threshold.

View all claims
  • 12 Assignments
Timeline View
Assignment View
    ×
    ×