Patent ID: 7076360

Claim:
A method of controlling an internal combustion engine when operating in a controlled auto-ignition mode, the method comprising the steps of: before the commencement of an engine compression phase determining a target crank angle from a predetermined data table and from current engine operating conditions, the data table providing a plurality of auto-ignition timing crank angle data relating to a plurality of engine operating conditions; determining a plurality of engine operating parameters; iteratively performing the steps of (i) utilizing the plurality of engine operating parameters, computing a predicted compression temperature which would be reached by the combustible charge at the target crank angle during the compression phase of the engine cycle; (ii) comparing the predicted compression temperature with a target temperature; (iii) modifying a computational value of at least one settable engine operating parameter; (iv) returning to step (i) until a combination of parameters is found which would result in the predicted compression temperature matching the target temperature at the target crank angle; and setting at least one of the actual engine operating parameters for the engine cycle in accordance with the final values ascertained by the iterative calculation process.