Patent ID: 7913666
Filing Date: 2011-03-29
Classification: F02D

Abstract:
1. A method for control of an injection valve, with a deviation between a predetermined setpoint value and an actual value of an amount of fuel injected into a combustion chamber of a internal combustion engine being compensated for, the method comprising the step of: injecting the fuel into the internal combustion engine with the aid of a number of injection valves of an injection system during the operation of a motor vehicle wherein the deviation between the predetermined setpoint value and the actual value of the amount of fuel injected being determined by detecting a drop in pressure in a fuel rail of the injection system by the steps of: during an overrun cut-off phase, initiating a test phase in which a defined, stable status is initially set in the fuel rail, after the stable status has been reached, determining a first pressure value in the fuel rail with a first pressure measurement, determining a leakage flow value based on the first pressure measurement, using a model to calculate a modeled pressure value resulting from a simulated test injection with a predetermined setpoint value, the calculated modeled pressure value accounting for the determined leakage flow value, subsequently selecting at least one injection valve which is activated for the test injection with the predetermined setpoint value, after the test injection, determining a second pressure value with a second pressure measurement in the fuel rail, computing a difference value between the calculated modeled pressure value and the determined second pressure value, and determining a correction factor from the computed difference value between the calculated modeled pressure value and the determined second pressure value, with which the activation of the selected injection valve is corrected.