Method for operating an internal combustion engine with gaseous fuel, computer program product and control unit

A non-transitory computer-readable medium on which is stored a computer program including commands for operating an internal combustion engine having a plurality of combustion chambers, in which gaseous fuel is supplied using an injection from a fuel rail and via a fuel injector assigned to a particular combustion chamber, and in which gaseous fuel is supplied to the fuel rail substantially continuously from a fuel supply system, the commands, when executed by a computer, causing the computer to perform the following steps:

• ascertaining, within at least one operating cycle, respective pressure drops of the pressure in the fuel rail that respectively occur during an injection into the corresponding combustion chambers of the combustion chambers;
• ascertaining open durations, assigned to each of the respective pressure drops, of the corresponding fuel injectors;
• ascertaining a total duration of the operating cycle;
• ascertaining respective mass indicators from the ascertained pressure drops, the ascertained open durations, and the ascertained total duration.

A control unit for controlling and/or regulating the operation of an internal combustion engine, the control unit comprising:

• at least one processor;
• at least one non-transitory memory in which is stored a computer program including commands for operating the internal combustion engine which has a plurality of combustion chambers, in which gaseous fuel is supplied using an injection from a fuel rail and via a fuel injector assigned to a particular combustion chamber, and in which gaseous fuel is supplied to the fuel rail substantially continuously from a fuel supply system, the commands, when executed by a computer, causing the computer to perform the following steps:
• ascertaining, within at least one operating cycle, respective pressure drops of the pressure in the fuel rail that respectively occur during an injection into the corresponding combustion chambers of the combustion chambers;
• ascertaining open durations, assigned to each of the respective pressure drops, of the corresponding fuel injectors;
• ascertaining a total duration of the operating cycle;
• ascertaining respective mass indicators from the ascertained pressure drops, the ascertained open durations, and the ascertained total duration.