Patent ID: 7831374

Claim:
A method of controlling combustion of an internal combustion engine during a lean mode of the engine, comprising: storing, in a control unit, at least one combustion control table that defines at least one combustion control value in terms of the following variables: engine speed, representative temperature value, and representative torque; during operation of the engine, receiving values representing engine speed, temperature, and intake air flow; calculating a representative in-cylinder fresh air oxygen value and a representative temperature value; wherein the representative in-cylinder fresh air oxygen value is calculated at least in part from the measured intake air flow; using the representative in-cylinder fresh air oxygen value, the representative temperature value, and the engine speed value to calculate the representative torque value; accessing the combustion control table, such that the representative torque value, the representative temperature value, and the engine speed value are used to determine at least one combustion control value; and using the combustion control value from the previous step to control an associated combustion control mechanism.