Method for determining the current trimming of the intake tract of an internal combustion engine during operation

A method for determining a current trimming of an intake tract of an internal combustion engine during operation, the method comprising:

• measuring, by a pressure sensor, dynamic pressure oscillations of a cylinder of the internal combustion engine at a defined operating point during normal operation, the pressure sensor positioned in the intake tract or in an outlet tract of the internal combustion engine,
• simultaneously:
• generating, at an electronic control unit, a pressure oscillation signal from the measured dynamic pressure oscillations, and
• determining, at the electronic control unit, a crankshaft phase angle signal of the internal combustion engine,
• determining, at the electronic control unit, an actual value of a characteristic of a selected signal frequency of the measured dynamic pressure oscillations in relation to the crankshaft phase angle signal based on the pressure oscillation signal and using discrete Fourier transformation,
• determining, at the electronic control unit, the current trimming of the intake tract of the internal combustion engine based on the actual value of the characteristic and reference value characteristic maps stored in a memory of the electronic control unit, the reference value characteristic maps including reference values of the characteristic of the selected signal frequency corresponding to different trimmings of the intake tract, and
• modifying, at the electronic control unit, control parameters of the internal combustion engine based on the current trimming of the intake tract of the internal combustion engine.