In-cylinder pressure estimation using structural vibration measurements of spark ignition engines

The knowledge of in-cylinder pressure of spark ignition engines can be used for various tasks in engine management, e.g. misfire detection, optimal spark timing, etc. Unfortunately direct measurement is still to expensive. We present a novel approach to reconstruct the in-cylinder pressure of a spark ignition engine from measurements of structural vibrations. A method for identifying the transfer function from pressure to vibration is presented. Once the transfer function is known, the pressure can be reconstructed from measurements of vibration. Real data experiments show the capability of the proposed methods.