Determining the value of the valve lift of the valve of a single cylinder of an internal combustion engine with multiple cylinders

Abstract

The present invention describes a method and an apparatus for determining the value of the valve lift of a valve of a single cylinder of an internal combustion engine having multiple cylinders. The method has the following steps: in a first operating state of the internal combustion engine, a first exhaust gas lambda value for fuel ignition in a single cylinder is determined, wherein the first exhaust gas lambda value without artificial changes in the air / fuel ratio It is determined by means of cylinder-by-cylinder and time-triggered detection of the lambda value. The method also includes the step of determining the air quantity which is drawn in by all cylinders of the internal combustion engine in the first operating state. Among other things, the method has the step of determining a value for the valve lift of the valve of the individual cylinder based on the first exhaust gas lambda value, the determined air quantity and a correction value, wherein the correction value is based on the valve lift and the associated air quantity drawn in by all cylinders of the internal combustion engine. Furthermore, the invention describes a method for controlling the valve lift of a valve of a single cylinder of an internal combustion engine with a plurality of cylinders, an engine controller for a vehicle with an internal combustion engine and a computer program for implementing the method.

Description

technical field [0001] The invention relates to a method for determining a value for a valve lift of a valve of an individual cylinder of an internal combustion engine having a plurality of cylinders. The invention also relates to a device for determining a value for the valve lift of a valve of an individual cylinder of an internal combustion engine having a plurality of cylinders. The invention also relates to an engine controller for a vehicle with an internal combustion engine and a computer program for controlling the internal combustion engine. Background technique [0002] In order to further reduce the fuel consumption and harmful gas emissions of modern internal combustion engines, internal combustion engines with variable valve lift systems for variable control of the lift of intake valves and / or exhaust valves are increasingly being used. In these systems, load control is possible without throttling by the throttle valve in a large operating range of the internal...

AI Technical Summary

Problems solved by technology

[0003] Manufacturing-related deviations or tolerances in valve drives and valves can lead to malfunctions during cylinder filling

Especially in the lower load range and in idling, where the lift of the intake valve is very small in unthrottled operation, slight faults during cylinder filling can already be noticeable as perceivable torque differences, which limited driving comfort

This torque difference, which can occur not only between different internal combustion engines but also between cylinders of the same internal combustion engine, leads in the worst case to perceivable running roughness in the lower load range and in idling and thus to Limitations of driving comfort

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