New trend of indicating analysis on vehicle: exploitation of the engine speed signal, opportunities and limits

In a context of more and more demanding technical regulations worldwide on emissions and constraints on fuel consumption on the one hand, and in order to continuously improve the drivability of the car on the other, dynamic engine testing in real driving situations is organized more and more often.
Test engines mounted in test vehicles must be equipped with indicating testing devices: mainly cylinder pressure sensors, current clamps and crank angle sensor. Physical combustion analysis parameters are analyzed and optimized, like AI50, IMEP, knocking... In these conditions the space available in the engine compartment is extremely limited: a conventional solution of a high-resolution optical crank angle encoder is often problematic. The use of the engine speed sensor (generally a 60-2 engine speed sensor, as the one used in the present study) can be a viable alternative, although it delivers a much lower resolution.
In this paper, based on a fine study realized on a Weber 2-cylinder engine, we will first find practical recommendations to ensure the best use of the 60-2 engine speed sensor to provide the most accurate crank angle synchronization. Then we will check the viability of this solution from the engine development engineer. To this, the state-of-the art 3-cylinder turbocharged PSA Peugeot-Citroën engine EB2DTS was used. This paper has been written together by PSA Peugeot-Citroën and KISTLER.