Autonomous ships are receiving significant attention
from the academic community and industry in recent
years. The new upsurge will have a profound impact
on maritime industry to great extent, in which it will
affect shipping companies, maritime operations,
shipbuilders and their operational mode. In 2012 and
2015, the funding of the "Maritime Unmanned
Navigation through Intelligence in Networks
(MUNIN)" project by the European Union [1] and
Rolls-Royce led "Advanced Autonomous Waterborne
Applications Initiative (AAWA)" [2] to outline the
concept of autonomous ships and the vision of
turning remote and autonomous shipping into a
reality. At the same time, International Maritime
Organization (IMO) also take some steps to
investigate safety, security and legal issues for
autonomous ships in IMO instruments [3-6, 29].
Regardless of the developing stage of autonomous
ships, the key issue needs to be emphasized is that
the ship be capable of an equivalent level of safety to
the conventional ships.
The ability of a ship to monitor its own health,
establish and communicate what is around it and
make decisions based on that information is vital to
autonomous operations. At the current stage, how to
better achieve autonomous navigation has become a
top priority. Fully autonomous navigation for the
Quantitative Processing of Situation Awareness for
Autonomous Ships Navigation
X.Y. Zhou
Dalian Maritime University, Dalian, China
National University of Singapore, Singapore
Z.J. Liu, Z.L. WU & F.W. Wang
Dalian Maritime University, Dalian, China
ABSTRACT: The first ever attempt at fully autonomous dock-to-dock operation has been tested and
demonstrated successfully at the end of 2018. The revolutionary shift is feared to have a negative impact on the
safety of navigation and the getting of real-time situation awareness. Especially, the centralized context
onboard could be changed to a distributed context. In navigation safety domain, monitoring, control,
assessment of dangerous situations, support of operators of decision-making support system should be
implemented in real time. In the context of autonomous ships, decision-making processes will play an
important role under such ocean autonomy, therefore the same technologies should consist of adequate system
intelligence. At the same time, situation awareness is the key element of the decision-making processes.
Although there is substantial research on situation awareness measurement techniques, they are not suitable to
directly execute quantitative processing for the situation awareness of autonomous ships navigation. Hence, a
novel quantitative model of situation awareness is firstly proposed based on the system safety control structure
of remotely controlled vessel. The data source is greatly limited, but the main result still indicates that the
probability of operator lose adequate situation awareness of the autonomous ship is significantly higher than
the conventional ship. Finally, the paper provides a probabilistic theory and model for high-level abstractions
of situation awareness to guide future evaluation of the navigation safety of autonomous ships.
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 13
Number 1
March 2019
DOI: 10.12716/1001.13.01.01
duration of the whole voyage is extremely difficult to
realize in recent years, which based on existing level
of technological development. Remote-controlled
mode will be a feasible solution. However, removal
of vessels from direct control and the visual field of
operator inevitably reduces their ability to directly
attain adequate situation awareness (SA) of the vessel
and its surroundings.
SA is a prerequisite to rational decision-making in
many contexts, from individual operator to team
cooperation, and reflects the ability of a human to
perceive elements in their environment, comprehend
their meaning and project their state in the near
future [7]. It plays a crucial role in effective risk
reduction for operators. Currently, because of the
complexity of real ship maneuvering system, there
are few research and method are applied to enhance
SA successfully in the maritime industry. Previous
research shows that the training procedure using
simulator is an positive way to improve SA,
operational effectiveness and safety [25]. In the
relatively advanced training framework, different
information can be collected from the simulator scene
and from the real world to provide data support
(Figure 1), such as audio, video, bio-metric data from
eye-trackers. Furthermore, the application of
Wearable Immersive Augmented Reality (WIAR)
technology [26] also offer a new solution of next
generation navigation system, enhanced and remote
monitoring, and improve operator performance.
Figure 1. The gaze plot when operator wearing eye-tracker
However, the emergence of the concept of
autonomous ships in remote-control mode, the
complexity in autonomous navigation systems
reaching a new high-level, and some unnecessary
complexity adds to captains' or operator's confusions
as it changes the context of the interaction. For
example, captain's responsibility from the bridge to
shore-based control centre (SCC), and the decision
support system is integrated to maintain safety of
navigation. For this reason, the centralized context
onboard would shift to a distributed context [27]. In
the substantive research of SA, the physics and
cognition of operators are considered to be fixed in a
centralized system. And few are paying attention to
how SA might be influenced in distributed working
domains. In such system, the operator needs to
maintain an adequate situation understanding to
ensure the safety of ships, which is critical.
At present, the research of remotely-controlled
ships navigation possesses very little in the way of
shore-based situation awareness and focus on
qualitative analysis. And the design of the system is
still being developed and the final structure remains
uncertain, therefore it is difficult to explore all the
possible scenarios that may arise from the
combination of components' behavior [8]. Any
inaccuracy situational representation will propagate
into decision-making process. When adding
autonomy in order to increase situation aware-ness, it
is important to take into account the possibility that
operators located on shore may be unfamiliar with
the technology or uncertain over its capability [9],
and over-reliance may skew the decision-making
In order to maintain an equivalent safety level,
better serve the construction of the remote control
system and the training of shore-based operators, it is
necessary to quantify the SA in autonomous ships
In this paper, we propose a novel model for
quantifying the SA of autonomous ships navigation
focuses on "remote control" mode. The next section
lays down the overview of autonomous ships and
determine the object in this paper. Section III
introduces the theoretical background of SA and
discuss the current SA measurement techniques.
Section IV proposes a new quantitative method for
modeling the SA of autonomous ships navigation
considering the probability with each known
awareness element. Section V discusses the result of
model. The paper ends with conclusions and
potential future works in section VI.
The idea of autonomous ships is partly derived from
the Unmanned Surface Vehicle (USV), and the
concept of autonomous ship was first described by
Schönknecht in 1983 [10]. Subsequently, Japan
explored this concept in more depth to minimize
crew costs and built several automated ships. Recent
technological advancements in big data and
communication infrastructure, intelligent ships have
entered people's field of vision as the highest level of
automation. Compared with conventional ship,
autonomous ship will be a highly integrated ship of
various systems, which is the advanced stage of
intelligent ship development.
According to the design concept of autonomous
ships, nearly all subsystems of autonomous ships will
be controlled by remote or autonomous mode,
including collision avoidance decision-making and
ship state monitoring. The vessel may be manned
with a reduced crew or unmanned with or without
supervision and have the capabilities to make
decisions and perform actions with or without
human in the loop. To a varying degree, it can
operate independent of human interaction. In
general, the control mode can be divided into four
categories (Figure 2). The remotely-controlled
merchant vessel will play an important role for
maritime transportation system, and become a reality
in recent years, even though there are many
challenges. In this paper, we focus on the "remote
control" mode supported by SCC.