Method for determining the position of a movable shut-off element of an injection valve

摘要

A method for determining the position of a movable shut-off element, in particular a valve needle, of an injection valve in a motor vehicle engine. The shut-off element is driven by means of a piezo element for the opening or closing of the injection valve. A voltage signal assigned to an electrical voltage detected at the piezo element is determined and used for determining the position of the shut-off element. By means of a model, a modelled variation of the voltage is determined and is likewise used for determining the position of the shut-off element. In particular, the determination of the position of the shut-off element takes place by using the difference from the modelled variation of the voltage and the determined voltage signal.