Measurement and Analysis of Knock in a SI Engine Using the Cylinder Pressure and Block Vibration Signals 940146
In this study, spark-ignition engine knock was studied experimentally. Cylinder pressure and cylinder block vibration of a four cylinder SI engine were measured. Knock characteristics, such as knock intensity, knock cycle percentage, knock occurrence crank angle, were determined from pressure and vibration signals using different analysis methods.
Methods using band-pass filter, third derivative and step method, which was developed in this study, were shown to be the most suitable. The step method only used signals above threshold value during knocking and, as a result, both pressure and vibration signal analysis results with this method showed good signal-to-noise ratio.
The knock intensities calculated from cylinder pressure and block vibration were proportional to each other over a wide range. It was confirmed in this study that vibration signals were useful in knock detection. More accurate results were achieved by using narrow band-pass filtering frequency range which avoided engine's resonance frequencies.
Citation: Chun, K. and Kim, K., "Measurement and Analysis of Knock in a SI Engine Using the Cylinder Pressure and Block Vibration Signals," SAE Technical Paper 940146, 1994, https://doi.org/10.4271/940146. Download Citation
Author(s):
Kwang Min Chun, Kyung Woon Kim
Pages: 9
Event:
International Congress & Exposition
ISSN:
0148-7191
e-ISSN:
2688-3627
Also in:
Electronic Engine Controls 1994-SP-1029, SAE 1994 Transactions: Journal of Engines-V103-3
Related Topics:
Engine cylinders
Knock
Spark ignition engines
Vibration
Pressure
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