Extraction of peak pressure position information from the spark-plug ionization signal

The possibility of constructing an indirect measurement algorithm of in-cylinder peak pressure position in a combustion engine, based on ionization signal processing is investigated; indeed, automobile manufacturers are in need of low cost combustion diagnoses to enhance engine control. To this end, a procedure for high dimensional data analysis derived as an extension of exploratory projection pursuit, is described and shown to be a profitable tool. Finally, results are presented that demonstrate the quality and the stability of the low complexity /spl alpha/P/sub max/ estimator we derived, for a wide range of engine states.