TANKENTLUEFTUNGSANLAGE FUER EIN KRAFTFAHRZEUG SOWIE VERFAHREN UND VORRICHTUNG ZUM UEBERPRUEFEN VON DEREN FUNKTIONSFAEHIGKEIT

摘要

A process for establishing the efficiency of a tank ventilation system of a motor vehicle subjects the signals for the flow volume through the tank ventilation valve (18) and the signals for the pressure difference between the inside of the tank and the environmental pressure to a cross-covariance analysis. Here, said signals are shaped by a high-pass before the cross-covariant function is formed and the maximum or mean of the cross-covariant function concerning the product of the two input values is found. The variant mass is found for the signal of the flow volume through the tank ventilation valve (18) and a transfer factor is calculated from the variant mass and the mean or maximum. If the transfer range lies in a predetermined field, the tank ventilation system is regarded as efficient. One advantage of the process lies in its independence of pressure variations in the tank which are not caused by flow volume changes through the tank ventilation valve. The main changes concerned here are those caused by the sudden development of gas in the tank (10) which, for instance, can be brought about by fuel swash.