Method for determining the remaining partial pressure in the combustion chamber of an internal combustion engine

The value of residual gas indicating the residual gas partial pressure, evaluated in a test field for an early inlet valve timing angle (FRWE), is provided in a first graph (FU) for early overlap. It is also provided for a later outlet valve timing angle (SPPA) in a second graph (SU) for a late overlap. From the inlet timing angle and the outlet timing angle settings (VWE, VWA), an angle of overlap, during which both inlet- and outlet valves are open, is calculated. A centroid factor (FWV) is also calculated, indicating an adjustment. To determine the residual gas value for timing angle adjustment between FRWE and SPWA, an interpolation is made between the two curves (FU, SU), in conjunction with the factor (FVW).