A method of combined identification of a piston stroke phase difference, an intake valve lift phase difference, and an exhaust valve lift phase difference of an internal combustion engine

摘要

A method for the combined identification of a piston-stroke phase difference, an intake valve phase difference and an exhaust valve phase difference of a cylinder of an internal combustion engine, wherein cylinder-assignable dynamic pressure oscillations in the intake and / or Auslasstrakt are measured in operation and wherein the pressure vibration signal generated therefrom using Discrete Fourier transform the phase position of selected signal frequencies of the measured pressure oscillations with respect to a crankshaft phase angle signal are determined. On the basis of the determined phase positions, lines of the same phase positions are created and brought to a common point of intersection by phase shifting. From the determined common point of intersection, the intake valve lift phase difference and the exhaust valve lift phase difference are determined, and from the completed phase shift, the piston stroke phase difference is determined. This makes it possible to carry out a particularly accurate identification of the timing in a simple and cost-effective manner, whereby advantages in terms of emissions, consumption, smoothness and performance, as well as an improvement in the controllability and control of the engine can be achieved.