Method for operating an internal combustion engine for a motor vehicle, and a system for an internal combustion engine

A system for an internal combustion engine having a cylinder, comprising:

• a cylinder pressure sensor which is arranged in the internal combustion engine of the motor vehicle and whose measurement signals are representative of a pressure in the cylinder of the internal combustion engine;
• and
• a device and memory coupled thereto, the device being configured to:
• receive measurement signals of the cylinder pressure sensor which are representative of a pressure in a cylinder of the internal combustion engine,
• determining cylinder pressure fluctuations in the cylinder of the internal combustion engine as a function of the received measurement signals of the cylinder pressure sensor,
• increasing an exhaust gas recirculation rate of the internal combustion engine as a function of the determined cylinder pressure fluctuations until a predefined limiting value of the cylinder pressure fluctuations is reached,
• determining an actual value of the exhaust gas recirculation rate if the predefined limiting value of the cylinder pressure fluctuations is reached, and storing the determined actual value in the memory as a setpoint value for the exhaust gas recirculation rate of the internal combustion engine,
• determine a center of combustion as a function of the received measurement signals of the cylinder pressure sensor, and
• adapt the setpoint value of the exhaust gas recirculation rate as a function of the determined center of combustion.