Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

Vibration Monitoring Method of Ship Propulsion Shafting Based on Three-Axis Acceleration Sensor
Yu Xiaa, Ji Wanga,b,c,*, Fu Chena, Xiao Liua, Hongzhuang Wanga, Shoukang WangaaSchool of Naval Architecture and Ocean Engineering, Dalian University of Technology, Dalian, China
bCollaborative Innovation Center for Advanced Ship and Deep-sea Exploration, China
cState Key Laboratory of Structural Analysis for Industrial Equipment, China

ABSTRACTThis paper presents a new method for transverse and longitudinal
vibration monitoring of ship propulsion shafting based on three-axis
acceleration sensor. The acceleration sensor is directly placed on theshaft, and the signal is transmitted wirelessly. In addition, to verify theaccuracy of the method, shafting vibration experiments under different
rotational speeds were designed. The transverse vibration displacementof shafting is measured synchronously by eddy current sensor andcompared with the method proposed in this paper. The results suggested
that the displacement information obtained by the two methods was
similar in time-domain and no vibration information was lost in
frequency-domain.

KEY WORDS: Ship propulsion shafting; Vibration monitoring;
Acceleration sensor; Transverse vibration; Frequency domain analysis.
INTRODUCTION
Ships, as the most important transportation and logistics equipment on
the sea, play a major role in the global cargo trade transportation (Shi etal., 2010). Propulsion shafting is the heart of a ship, and the engine
supplies energy to the vibration of propulsion shafting all the time during
the operation, forming a self-excited oscillation system (Lee et al., 2013).
Its operation has a direct influence on the safety of the ship. Bearing andgear box in Marine propulsion shafting not only have to bear the hugeload, but also are in a very bad working environment, so the probabilityof failure is very high (Jiang et al., 2015). In case of failure, if not handled
in time, it may cause a series of chain reactions of ship equipment, andeven interrupt the normal operation of the whole ship system, which may
bring heavy losses of economic property at a light level and endanger
people's lives at a serious level (Xie et al., 2019). Compared with othermechanical parts, bearings, gear boxes, couplings and other parts of thepractical life of the discrete degree is very large, there may be someequipment parts have not reached the number of years but appear damage.
These faults can be reflected in the vibration characteristics of the ship's
pushing shafting (Lai et al., 2018). Therefore, it is of great significanceto monitor and analyze vibration signals of ship propulsion shafting inreal time. In addition, the use of sensors to measure shaft vibration is also
very important for recent studies on ice-induced vibration. (Polićab et al.,2019; Suominen et al., 2020; Zambon and Moro, 2022)

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Vibration of ship shafting mainly includes torsional vibration,
longitudinal vibration and transverse vibration. Since Geiger et al. (1972)
invented a mechanical vibrator, the vibration waveform could be visuallydisplayed on the paper through mechanical transmission, and thefrequency and order of torsional vibration can be obtained. Research on
vibration has entered the stage of measurement and test, but the accuracyof this test is still narrow in the frequency range and dynamic linear range,
and can only be manually analyzed. At present, the main measurement
method of torsional vibration is strain electric measurement technology,
which measures dynamic torsional strain and dynamic torque throughthe strain effect of resistance strain gauge. The key physical parameterof longitudinal vibration and transverse vibration is displacement.
Usually, eddy current sensor is used to measure the shaft displacement
directly, or the bearing vibration acceleration is measured by theacceleration sensor, and the operation status of shafting is analyzed by
the excitation coupling effect of the propulsion shaft and the bearing. Luet al. (2013) introduced the development and test method of longitudinal
vibration test device for Marine propulsion shafting. Jiang et al. (2015)
theoretically analyzed the vibration characteristics of ship's propulsion
shaft under the action of propeller and diesel engine. Huang et al. (2016,2019) used acceleration sensor to effectively measure bearing vibration,and discussed the coupling effect of transverse and longitudinal vibrationand longitudinal torsional vibration of ship propulsion shaft. Zhang et al.
(2019) conducted an experimental study on the vibration of ship
propulsion shaft under the excitation of ship hull deformation by eddy
current sensor. In those studies, though, ship propulsion shafting
vibration were effectively measured, but the eddy current sensor in theprocess of layout often need to rely on additional support to test.
Moreover, the bad environment of ship engine room makes thearrangement of sensors very complicated, and the limitation of support
also makes the arrangement of sensors lack of flexibility, so it is difficult
to monitor the vibration of ship propulsion shafting in real time. The
excitation and coupling effects of bearing and propulsive shaft arecomplex, which often requires effective analysis of experimental
properties in advance (Nikula et al., 2021).
More simple and effective vibration measurement methods are neededfor vibration monitoring of ship propulsion shafting. Yang and Liao.
(2008) proposed a method to measure torsional vibration of rotor bydirectly installing acceleration sensor on the rotor. This method has highprecision and can measure small amplitude torsional vibration, which
has been verified by experiments. However, due to the quality, power
supply, charge amplification and signal transmission problems of the