Internal combustion engine with injection quantity control

A method for operating an internal combustion engine, comprising:

• supplying a combustion chamber of the internal combustion engine with liquid fuel;
• sensing at least one measurement variable from an injector for injecting liquid fuel and disposed in the internal combustion engine;
• calculating based on input variables and an injector model, a state of the injector;
• comparing the state of the injector with a target state;
• and depending on the result;
• and producing a state signal characteristic of a change in the state of the injector that occurs during an intended use of the injector, an unforeseen change in the state of the injector, or a combination thereof;
• wherein the input variables comprise at least the actuator control signal and the measurement values of the sensor, wherein the injector model comprises;
• pressure progressions in the volumes of the injector filled with the liquid fuel;
• mass flow rates between the volumes of the injector filled with the liquid fuel;
• a kinematic variable of a needle of the injector comprising a position of the needle relative to a needle seat;
• and
• dynamics of an actuator of the needle.

A controller of an internal combustion engine, the controller configured to:

• supply a combustion chamber of the internal combustion engine with liquid fuel;
• sense at least one measurement variable from an injector for injecting liquid fuel and disposed in the internal combustion engine;
• calculate based on input variables and an injector model, a state of the injector;
• compare the state of the injector with a target state;
• and depending on the result;
• and
• produce a state signal characteristic of a change in the state of the injector that occurs during an intended use of the injector, an unforeseen change in the state of the injector, or a combination thereof;
• wherein the input variables comprise at least the actuator control signal and the measurement values of the sensor, wherein the injector model comprises;
• pressure progressions in the volumes of the injector filled with the liquid fuel;
• mass flow rates between the volumes of the injector filled with the liquid fuel;
• a kinematic variable of a needle of the injector comprising a position of the needle relative to a needle seat;
• and
• dynamics of an actuator of the needle.