Analyzing and Modeling of Disturbances for In-Cylinder Pressure Measurement with a Gasoline Injector

In an earlier publication, the prototype of a piezo gasoline injector has been presented, which allows to measure the combustion pressure without causing additional weight and production costs. The capability of this system to reconstruct the pressure history has been demonstrated in that publication. However, it has been pointed out that the quality of the reconstructed signal crucially depends on the quality of a disturbance model, which allows to subtract the occuring disturbances from the measured signal. In this paper we derive, using physical considerations, a simple disturbance model with a minimum number of parameters that have to be adapted. This yields a fast and efficient method to obtain a high-quality pressure history from the measured signal. The model is evaluated with measurements at a test bench.