sis
QiuqinYue
1
and Jielin Zhou
2
1
Chongqing College of Electronic Engineering, Chongqing, 401331, China
2
Chongqing University, Chongqing,400044, China
yqq622@163.com
Keywords: Engine Health Monitoring, Fault Diagnosis, Vibration Signal Analysis, Wireless Acceleration Sensor, Fast
Fourier Transform.
Abstract: Aiming at research on engine health monitoring and fault diagnosis based on the characteristics of the
surface vibration signals measured from the engine, a measured method by using wireless acceleration
sensor is proposed in this paper. The basic characteristics of engine vibration signal taking the Chevrolet
Epica 2HO automotive engine as an example was measured in this paper. The original measured data was
pre-processed using the Fast Fourier Transform (FFT) to suppress abnormal interference of noise, and avoid
the pseudo mode functions. Finally, the vibration signals of automotive engine are analyzed and the results
show that the method is feasible and effective in feature extraction and condition evaluation of engine health
monitoring and fault diagnosis.
1 INTRODUCTION
More and more importance of health monitoring and
fault diagnosis has been realized, which is no longer
a supplementary accessory to the system, but a
necessary and essential element to ensure reliability
and productivity in an effective and cost-efficient
way (Jin, 2014). Gasoline engines, as one of the key
equipment in a variety of applications, have always
been popular as the subject of condition health
monitoring. Engine contains abundant fault
messages. Thus the gasoline engine health
monitoring and fault diagnosis technique based on
the characters of engine vibration signal is adopted
to enhance the operation reliability and reduce the
blindness of the maintenance work. Actually, engine
is a complicated mechanical system with various
vibration excitations and different corresponding
excitation mechanisms. For instance, automotive
engine is chosen as an illustrative case study. In
normal condition, the gas pressure and inertia force
are the most common and immediate excitation
sources of the automotive engine. They act on the
automotive engine with their own effect rule and
frequency and cause a wide variety range of
vibration signal. Specifically, the gas pressure acts
mainly on the cylinder head and the frequency band
covers from tens to thousands Hz; but the inertia
force acts on the cylinder block and manifest a slow
frequency harmonic oscillations. So the accurate
extraction of vibration signals is very important to
the engine health monitoring and fault diagnosis
(Chandroth, 1999; Taglialatela,2013; Gravalos,
2013; Geng, 2003).
Recently, In order to monitor engine health and
further diagnose faults in gasoline engines, various
successful methodologies have been developed. S. P.
Mitchell Lebold et al intensively investigated several
different methods to analyse faults based on injector
signal, vibration signal, and speed encoder signal.
Misfire faults have been successfully identified
using time domain, frequency domain and order
domain analysis tools. Signals of each category of
every method were presented to show the difference
between normal and faulty condition, and the
quantization of the difference is later formulated. All
the approaches had the ability to identify the faulty
cylinder location (Jin, 2014). Mollazade et al.
presented a fault diagnosis method for external gear
hydraulic pumps based on a fuzzy inference system
(FIS)
(2009). Sakthivel et al. used decision tree and
other machine learning algorithms for fault detection
of mono-block centrifugal pump. Ahmadi and
Mollazade investigated fault diagnosis of an electro-
pump in a marine ship using vibration analysis
(2010). Muralidharan and Sugumaran presented a