Interpretation of Engine Cycle-To-Cycle Variation By Chaotic Time Series Analysis

In this paper we summarize preliminary results from applying a new mathematical technique- chaotic time series analysis (CTSA)- to cylinder pressure data from a spark-ignition (SI) four-stroke engine fueled with both methanol and iso-octane. Our objective is to look for the presence of “deterministic chaos” dynamics in peak pressure variations and to investigate the potential usefulness of CTSA as a diagnostic tool. Our results suggest that sequential peak cylinder pressures exhibit some characteristic features of deterministic chaos and that CTSA can extract previously unrecognized information from such data.