Nostic method based on the analysis of vibration and acoustic emissions for internal combustion engines faults

This paper presents a diagnostic methodology for faults and combustion irregularities on internal combustion engines based on mechanical vibrations and acoustic emissions measurements. The purpose is to apply time-frequency techniques, such as envelope analysis and order tracking, to signals from an internal combustion spark ignited engine, to identify different operating conditions (angle advance) and misfiring piston problems. The analysis performed showed that these techniques can differentiate a misfiring piston from a signal measured with an acoustic emissions sensor, but not from the accelerometer, and cannot tell apart the different angle advance with any of the two sensors studied.