METHOD AND DEVICE FOR OPERATING AN INTERNAL COMBUSTION ENGINE HAVING A COMMON-RAIL INJECTION SYSTEM

A method for operating an internal combustion engine having a common-rail injection system as a function of a quantity of fuel injected. The method includes determining an information item about a relative-pressure characteristic from a characteristic of an absolute rail pressure in a high-pressure reservoir of the common-rail injection system; determining the quantity of fuel injected as a function of the information item about the relative-pressure characteristic, and with the aid of a trained functional model, in particular, a nonparametric functional model or a neural network; operating the internal combustion engine as a function of the quantity of fuel injected.