Citation: Assani, N.; Mati´c, P.;
Katalini´c, M. Ship’s Digital Twin—A
Review of Modelling Challenges and
Applications. Appl. Sci. 2022, 12, 6039.
https://doi.org/10.3390/
app12126039
Academic Editors: Zhihan Lv, Kai Xu
and Zhigeng Pan
Received: 26 May 2022
Accepted: 13 June 2022
Published: 14 June 2022
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Review
Ship’s Digital Twin—A Review of Modelling Challenges
and Applications
Nur Assani * , Petar Mati´c and Marko Katalini´c
Faculty of Maritime Studies, University of Split, Ru
¯
dera Boškovi´ca 37, 21000 Split, Croatia; pmatic@pfst.hr (P.M.);
mkatalin@pfst.hr (M.K.)
* Correspondence: nassani@pfst.hr; Tel.: +385-(0)97-694-2401
Abstract:
The Ship’s Digital Twin (SDT) is a digital record of a ship’s behaviour or a software clone,
which can be used to simulate scenarios that are expensive or hardly feasible to perform on a real
object and especially in real time. The purpose of the SDT is to achieve cost reduction, obtain timely
warnings of irregularities, and optimise individual ship system performances or the operation of the
whole ship and to assist ship management. The aim of this paper is to describe the concept of the
SDT and clarify some perplexities that may occur from initial introduction to concept. To that end,
the paper identifies the steps in the SDT formulation process and methods used in each step of the
process. Furthermore, a four-step iterative procedure for the SDT development is proposed. The
applications of the concept are numerous, and some of them are presented in a review analysis in this
paper. The presented analysis leads to a conclusion that should give some direction to future research
in this area.
Keywords:
ship; digital twin; development procedure; modelling methods; applications; review analysis
1. Introduction
Although the concept of a digital twin (DT) can be found described in the literature,
e.g., as in [
1
], and although a digital twin as a term is being used increasingly in different
fields of technical sciences, the concept remains unclear mostly in the way of differentiating
a DT concept from an ordinary computer simulation model. Furthermore, the concept is
sometimes related to a cyber-physical system (CPS) as described in [
2
–
5
], a part of the CPS
as described in [
6
], or as a digital model and digital shadow, which can be combined to
form a DT as described in [7].
What makes a digital twin of a ship (SDT) and how to create one in a systematic and
reliable fashion were motives for this research. Therefore, this paper presents a review
analysis of the SDTs developed so far, based on the available literature. It presents the
concept, identifies the steps and methods used in the SDT formulation process, as well as
communication protocols used in different stages of the process. The applications of the
SDT are numerous, and some of them are presented in this paper.
Furthermore, the paper proposes a four-step iterative procedure for the SDT develop-
ment that is based on data acquisition, data processing, modelling, and model validation.
Recalibration of the model using the new data is possible, thus making the process iterative,
and it is performed once the new input data become available. In the same way, SDT
outputs are used on a real object depending on the level of connectivity between the SDT
and the ship. Thus, the connectivity and communication level between the ship and its DT
is essential.
The SDT concept relies on data it would expect for the advanced data modelling
methods, such as artificial intelligence, used in [8–12], and data-driven modelling (DDM),
used in [
12
–
14
], to take prime in this area. However, conventional mathematical models
have often been used for the purposes of creating an SDT, as in [15–22].
Appl. Sci. 2022, 12, 6039. https://doi.org/10.3390/app12126039 https://www.mdpi.com/journal/applsci
