CIVILICA We Respect the Science
Publisher of Iranian Journals and Conference Proceedings

fault diagnosis of internal combustion engine valve train based on hypothesis tests

Credit to Download: 1 | Page Numbers 8 | Abstract Views: 1139
Year: 2012
COI code: ISAV02_169
Paper Language: English

How to Download This Paper

For Downloading the Fulltext of CIVILICA papers please visit the orginal Persian Section of website.

Authors fault diagnosis of internal combustion engine valve train based on hypothesis tests

m.h gharavian - Acoustics Research Laboratory, Mechanical Engineering Department, Amirkabir
A.R Ohadi -
  H.R. Amindavar - Department of Electrical Engineering, Amirkabir University of Technology, Tehran, Iran
B. Sakhaei -


Internal combustion engine noise has oriented from several sources. The reciprocating mass-es are one of them. Pistons, valves and injectors are most familiar ones. Valves are small mass compared to pistons but their impact noise at the beginning and end of the lift duration made them as one of the noise sources especially at engine idle speed. Moreover, the valve lift deviation from designed curve has a strong influence on engine performance. The valve operation can be monitored through studying of emitted noise. Analyzing of this noise shows valves opening and closing which is helps for valve train fault diagnosis. For rigid tappets, if these events detect properly, the valve operation will be estimated.This paper introduces a new method based on hypothesis test to detect the opening and clos-ing events of the valves. Most of engine events are match to a specific crank angle, so; ac-quired signal from engine cylinder head resample to the crank angle axis and partitioned into the determined length (windowing). Each window may be consisting of engine noise only (Null Hypothesis) or engine noise plus valve-induced vibration (Alternative Hypothesis). Therefore, the problem of finding valve event timing is stated as finding that which one of mentioned hypothesis is best choice for the desired window. For each window, a representa-tive called sufficient statistics is calculated from samples lie on it. This value will compare to a threshold, which is results of multiplying of the estimated noise power and a gain. The gain is calculated using Neyman-Pearson decision rule to reach a specific false alarm rate. Noise power must be estimated carefully. If noise power underestimated, false alarm rate is bigger than the desired value. Otherwise, overestimated noise power can make several prob-lems too. Missing of true events is a consequent of overestimating.


fault diagnosis; engine valve train; Neyman-Pearson decision rule; hypothesis tests

Perma Link
COI code: ISAV02_169

how to cite to this paper:

If you want to refer to this article in your research, you can easily use the following in the resources and references section:
gharavian, m.h; A.R Ohadi; H.R. Amindavar & B. Sakhaei, 2012, fault diagnosis of internal combustion engine valve train based on hypothesis tests, 2nd International Conference on Acoustics and Vibration, تهران, دانشگاه صنعتي شريف, the text, wherever referred to or an achievement of this article is mentioned, after mentioning the article, inside the parental, the following specifications are written.
First Time: (gharavian, m.h; A.R Ohadi; H.R. Amindavar & B. Sakhaei, 2012)
Second and more: (gharavian; Ohadi; Amindavar & Sakhaei, 2012)
For a complete overview of how to citation please review the following CIVILICA Guide (Citation)

Research Info Management

Export Citation info of this paper to research management softwares

New Related Papers

Iran Scientific Advertisment Netword

Share this paper


COI is a national code dedicated to all Iranian Conference and Journal Papers. the COI of each paper can be verified online.