Blind separation of internal combustion engine vibration signals by a deflation method

• Published in: Mechanical systems and signal processing Vol. 22; no. 5; pp. 1082 - 1091
• Main Authors: Liu, Xianhua, Randall, Robert B., Antoni, Jérôme
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 01.07.2008; Elsevier
• Subjects: Acoustics; Applied sciences; Blind source separation; Deflation method; Engines and turbines; Exact sciences and technology; Fundamental areas of phenomenology (including applications); IC engine diagnostics; Internal combustion engines: gazoline engine, diesel engines, etc; Measurement and testing methods; Mechanical engineering. Machine design; Mechanics; Physics; Piston slap; Solid mechanics; Structural and continuum mechanics; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); Piston slap; Blind source separation; Deflation method; IC engine diagnostics; Vibration; Combustion; Knock(engine); Blind identification; Low frequency; Separation method; Least squares method; Signal processing; Internal combustion engine; High frequency; Vibration source
• ISSN: 0888-3270; 1096-1216; 1096-1216
• DOI: 10.1016/j.ymssp.2007.11.011

Internal combustion engines have several vibration sources, such as combustion, fuel injection, piston slap and valve operation. It is necessary to separate the different vibration sources and then analyze each of them individually. This paper attempts to separate the vibration sources by blind source separation techniques and proposes a combination of the Blind Least Mean Square algorithm with a deflation method to separate several sources. The combined methods are first verified on simulated sources and then applied to engine signals. Separation results show that cylinder pressure consists of two sources—one is a smooth low frequency part due to compression and expansion caused by piston movement; the other is the high frequency part due to combustion.