Patent ID: 7676317
Filing Date: 2010-03-09
Classification: F02D

Abstract:
1. A method for determining a corrective value (LAM_FAC_I[Z 1 -Z 4 ]) used to influence an air/fuel ratio in a respective cylinder of an internal combustion engine comprising a plurality of cylinders, injection valves assigned to the plurality of cylinders to apportion fuel and an exhaust gas probe disposed in an exhaust manifold and whose test signal is characteristic of the air/fuel ratio of the respective cylinder, comprising: detecting the test signal at a predetermined sampling crankshaft angle relative to a reference position of a piston of the respective cylinder; determining a control value used to influence the air/fuel ratio in the respective cylinder via a controller as a function of the test signal detected for the respective cylinders; determining a first adaptive value based on the control value, if predetermined first conditions are fulfilled, that include determining whether a temperature that represents a temperature of the respective injection valve falls within a predetermined second temperature range; determining a second adaptive value based on the control value, if predetermined second conditions are fulfilled, that include determining whether the temperature that represents the respective injection valve falls within a predetermined second temperature range; and determining the corrective value used to influence the air/fuel ratio in the respective cylinders as a function of the first and/or second adaptive value as a function of the temperature of the respective injection valve if the temperature, which is representative of the temperature of the respective injection valve, falls within one of the first second temperature ranges; and determining the corrective value based on a predetermined weighting of the first and second adaptive value, if the temperature, which is representative of the temperature of the respective injection valve, lies between the first and second temperature ranges.