Z-FREQ: SIGNAL ANALYSIS-BASED GASOLINE ENGINE MONITORING TECHNIQUE USING PIEZO-FILM SENSOR

This paper provides an application of fundamental statistical analysis named Zfreq technique about fault detection in a gasoline engine. In engine condition monitoring, early detection of failure symptom is an important function to prevent decreasing of engine performance during operation. Signal was measured using hardware named SO signal analyzer which is capable of recording voltage in milliVolt (mV), and validation was made to determine the engine speed and misfire fault. The data were analyzed using modified statistical analysis Z-notch filter based on frequency content (Z-freq) concerning the variation of engine speeds and misfire on one of the engine cylinders. This output is to determine the degree of data scattering for the vibration signals. Based on calculated results, vibration characteristic can be presented using voltage generated and 2D graphical representation of Z-freq. Experimental results of two parameters showed that the values of Z-freq coefficient increased as the speed increased from low to high and identical value for normal and misfire condition. It was found that diagnosis of the engine cylinder wall using novel signal analysis-based was successful using low cost and space saving piezo-film sensors, and analyzing with Z-freq technique as a result shown an identical pattern of data measured.