Patent ID: 6411885
Filing Date: 2002-06-25
Classification: F02B,F02D

Abstract:
A computer readable storage medium having stored data representing instructions executable by a computer to control a spark ignited direct injection internal combustion engine having an air intake with a throttle valve positioned therein and a plurality of cylinders operable in at least a homogeneous operating mode with a homogeneous air/fuel mixture and an associated range of allowable homogeneous air/fuel ratios and a stratified mode with a stratified air/fuel mixture and an associated range of allowable stratified air/fuel ratios, wherein the homogeneous range and stratified range do not overlap, the computer readable storage medium comprising:instructions for determining a desired value for an engine operating parameter based on current engine operating conditions wherein the desired value results in scheduling of an air/fuel ratio between the homogeneous range and stratified range of allowable air/fuel ratios; instructions for operating a first portion of the cylinders in the homogenous operating mode; and instructions for operating a second portion of the cylinders in the stratified operating mode such that a combined air/fuel ratio associated with the first and second portions of the cylinders approaches the scheduled air/fuel ratio.