1. • Department of Mechanical Engineering
• Third year
• Semester 6
• Academic Year: 2022-2023
• Prepared by: Walaa Ghanem
• Subject: vibrtions
• Dr:Mohamad Naja

2. Condition monitoring of valve
clearance fault on a small
four strokes petrol engine
using vibration signals
Songpon Klinchaeam1 and Pornchai Nivesrangsan2
Received 10 February 2010; Accepted 24 August 2010

3. Abstract
• Condition monitoring technique for small.
• Vibration .
• Time domain and energy analysis used for fault identification ,
with future focus on signal analysis techniques and result accuracy
verification .

4. Introduction
Topic : vibration analysis for
condition monitoring of internal
combustion engines .
Challenges : complexity and non-
stationary nature of vibration signals
in internal combustion engines .
Methods : non-intrusive sensor
measurement techniques in time
and crank angle domain .
Data analysis : reduction of large
data using signal processing
techniques .

5. Signal Processing
• signal energy is calculated to improve signal resolution for
identifying fault conditions on the following figure :
Ex = 0
𝑡
𝑥2 𝑡 𝑑𝑡
where x t( ) is time domain waveform at time, t

6. Experiment
Figure : schematic diagram of a data acquisition system .
graphical representation of the vibration signals obtained
from the small four-stroke petrol engine during the
condition monitoring process of valve clearance fault.
Charge
amplifier
Proximity
sensor
Terminal
block

7. Result and Discussion
• Indicates various simulation errors in
intake valve clearances.
• Detailed analysis of these signals
provides insight into the effects of
valve clearance errors on engine
vibration characteristics, which is
helpful in the case of engine
monitoring.
Figure: Various vibration signals acquired from
the engine speed at 1500 rpm (A) Normal (B) IV
Fault 1 (C) IV Fault 2 and (D) IV Fault 3

8. • Overall, the authors demonstrated that vibration signals can be
used to understand engine processes and identify abnormal
conditions in a small four-stroke petrol engine. The results provide
insights into the relationship between engine events, valve
clearance, and vibration signals, and highlight the potential of
vibration analysis for engine diagnostics

9. Conclusions
• Vibration technique shows potential for investigating engine
behavior.
• Energy analysis of vibration signals can identify engine condition.
• More powerful techniques needed for accurate engine state
monitoring.

10. Thank you for your attention !