Patent ID: 7003391

Claim:
A method for operating an internal combustion engine ( 10 ), wherein: at least one outlet valve ( 36 ) is opened with the aid of an actuator upon termination of a working stroke, thereby releasing exhaust gas from at least one combustion chamber ( 14 ); a pressure value is determined which is indicative of the gas pressure in the combustion chamber ( 14 ) during the working stroke; characterized in that: an actual value (hact) of the lift of the outlet valve ( 36 ) is determined together with actual operating parameters (tm, Toil, Poil, nmot, wao, pabg) of the internal combustion engine that affect the valve lift (hact); and an actual gas pressure (paoact) of the gas pressure in the combustion chamber ( 14 ) at the time of an opening of the outlet valve ( 36 ) is determined at least approximately based on the determined actual valve lift (hact) of the outlet valve ( 36 ) and the determined actual operating parameters (tm, Toil, Poil, nmot, wao, pabg) of the internal combustion engine ( 10 ), wherein on the basis of a set of operating parameters (BG) of the internal combustion engine ( 10 ) which are effective for a future working stroke, an estimated gas pressure (paopred) in the combustion chamber ( 14 ) is determined for the future working stroke, wherein termination of this working stroke, the estimated gas pressure (paopred) determined for this working stroke is compared with the actual gas pressure (paoact) determined for this working stroke, and wherein, depending on a result of the comparison, a method (func paopred) is adapted by which the estimated gas pressure (paopred) is determined.