Article
citation information:
Wójcik, A. Conversations processes
in the system of automatic communication at sea. Scientific Journal of Silesian University of Technology. Series Transport.
2020, 107, 217-223. ISSN: 0209-3324.
DOI: https://doi.org/10.20858/sjsutst.2020.107.17.
Anna WÓJCIK[1]
CONVERSATIONS
PROCESSES IN THE SYSTEM OF AUTOMATIC COMMUNICATION AT SEA
Summary. The progressing automation of maritime transport,
including the introduction of autonomous and/or unmanned ships, calls for the
development of communication principles, particularly conversations currently
carried out verbally. The work in this field is intended to improve the safety
of maritime transport. This article describes research on automatic
communication in the form that will support navigators responsible for ship
conduct. The processes of inference and conversation management are described.
The developed methods are based on standard marine communication phrases. The
presented example conversation between navigators is supported by an automatic
communication system. The work herein described aims at the creation of
procedures for communication at sea between autonomous ships.
Keywords: autonomous ships, automatic communication,
inference processes
1. INTRODUCTION
Navigational accidents, mainly collisions, have been
analysed for years to identify the causes, learn lessons and thus enhance the
safety of maritime transport [3, 4]. According to an annual summary of marine
accidents and incidents, prepared by the European Maritime Safety Agency (EMSA)
in 2017, the basic causes of accidents and incidents involve the human factor
(Fig. 1).
Fig. 1. Distribution of accident
causes [1]
Of the overall number of
investigated 1170 events, 60.5% were attributed to human error. Aimed at safety
improvement, decision support systems have been dynamically developed to help
ship navigators minimise the number of possible errors. One example of such
systems, NAVDEC, operates in real-time and is handled by the navigator [6]. The
system watches its ship and the environment and records information about the
current navigational situation. Based on this, it identifies and assesses the
navigational situation and generates solutions to ensure safe navigation.
Frequently during the encounter of ships, the navigators have to establish verbal communication to exchange additional information and agree on how to solve the collision situation. Unfortunately, difficulties such as reduced concentration, misunderstanding, stress and fatigue sometimes make the communication incorrect, thus posing risks of making wrong decisions. The problems with correct verbal communication are not only related to misunderstanding of a message due to insufficient knowledge of English and standard marine communication phrases. Other communication problems include:
• lack
of communication,
•
misinterpretation of the information received,
•
failure to consider all necessary information due to its excess,
•
wrong assessment of the navigational situation,
• wrong
decision made.
These errors are made sometimes due
to limitations of the human mind, as the human mind has limited ability to
process and simultaneously use a large number of information items. The
solution to this problem may be a system supporting communication or conducting
it automatically.
2. COMMUNICATION PROCESSES AT SEA
What characterises voice
communications at sea is that the sender and the receiver do not have the
ability to use certain communication tools, such as facial expression, body
language, while voice tone and timbre are limited due to equipment quality. The
process of communication between people carries the risk of making errors
related, inter alia, to incorrect reception and misinterpretation. Therefore,
the developed principles of communication at sea hold that the messages sent
should contain single pieces of information. To avoid misunderstanding,
navigators are required to use standard marine communication phrases (SMCP)
[2]. The SMCP was adopted by 22. Assembly of the International Maritime
Organisation (IMO) in November 2001 as Resolution A.918 (22). Prior to the
SMCP, standard marine navigational vocabulary had been developed for use by
seafarers as an effect of the agreement that one common language - English -
should be established for navigational purposes, where language difficulties
arise. The SMCP was created as a more comprehensive, structured language
covering all main verbal safety-related communications.
The SMCP contains words that were
selected to cover the main safety-related ship-to-ship and ship-to-shore
communications. The purpose of the SMCP was to address the problem of language
barriers at sea and avoid misunderstanding that could cause accidents.
Unfortunately, many navigators fail
to master the English language to a satisfactory level and/or possibly use
standardised phrases in a comprehensible manner, which carries the risk of
accident [7].
Therefore, it is purposeful to
develop a system that could support navigators' communications.
3. THE SYSTEM OF AUTOMATIC COMMUNICATION
The developed system of automatic
communication is an expert system enabling semi- or fully automatic
communication, thus supporting the navigator conning the ship. In the case of
semi-automatic communication, the generated message is displayed so that before
sending it the navigator confirms the information contained in it. Any
suggested actions resulting from the operation of the system are also presented
to the navigator for his acceptance. In the fully automatic communication
system, the navigator is informed of the generated and sent message and
proposed actions, while the navigator's confirmation is not required (Fig. 2).
Fig. 2. System of automatic
communication, ship-to-ship communication
The system of automatic
communication is composed of four main modules:
• module
of communication,
• module
of navigational systems,
• COLREGs module,
• module
of simulation of the navigational decision system.
The module of communication is the
main element responsible for conversation implementation and management. Its
operation is built on a knowledge base and an inference mechanism, both created
by using experts' knowledge. Inference is executed following the manner of
human reasoning, hence, the inference block of the communication module is a
form of virtual navigator. The module of navigational systems is an element
receiving data from shipboard systems. The module allows the automatic
communication system to have access to the ship's data: speed, course,
ship-manoeuvring parameters. Once the user interface is developed, the module
will also display to the navigator the messages and suggested actions. The
COLREGS module is responsible for the classification of the navigational
situation based on applicable regulations. The module indicates if the ship has
the right of way or not, while the simulation module of the navigational
decision system calculates the manoeuvres to be performed by the navigators
and, inter alia, the ships' trajectories are worked out and verified.
The correct functioning of the automatic communication
system requires the development of procedures for the exchange of data between
the said modules for the management of the conversation.
4. THE MANAGEMENT OF CONVERSATION
The exchange of data between the
modules is created for inference processes. The notation of data exchange is
this:
sender_receiver_action=value
In the above notation, the sender
and the receiver are one element of the NO set, action is an element of the set
D, while the value is one single element or the corresponding pair of the
elements from the set W, defined as follows:
NO={KO,
SYS, SIM, COL}, where KO – module of communication, SYS – module of
navigational systems, SIM – module of the navigational decision system
simulation, COL – module of the Collision Regulations.
W={parameter_set,
parameter_set_value, trajectory, trajectory_value, maneuver,
maneuver_value,…}
D={give,
notify, update, request, demand, check, find, propose, warning,…}
Depending on the connection of the
sender and the receiver, various actions with the corresponding values are
possible.
The exchange of data between the
module of navigational systems and the module of communication mainly includes
communication related to the delivery of basic parameters (parameter_set,
parameter_set_value) and manoeuvres (maneuver, maneuver_value) and
communicating to the navigator requests from the other ship (for example,
keep_course, keep_speed) (Tab. 1).
The exchange of data between the
COLREGs module and the module of communication refers to the classification of
the navigational situation, thus, the data that is exchanged is related to
verification of which ship is the give-way vessel. The value give_way_true
means that our ship, according to the regulations, is the give-way ship, and
give_way_false means that our ship is not the give-way ship.
Tab. 1
Exchange of data between the KO and
SYS modules (fragment)
|
Sender |
Receiver |
Action |
Example values |
|
SYS |
KO |
give |
parameter_set |
|
SYS |
KO |
notify |
parameter_set, parameter_set_value |
|
KO |
SYS |
give |
parameter_set |
|
KO |
SYS |
update |
parameter_set, parameter_set_value |
|
KO |
SYS |
request |
keep_coursekeep_speed |
|
KO |
SYS |
demand |
maneuver_own_value, maneuver_other_value |
Tab. 2
Exchange of data between the KO and
COL modules (fragment)
|
Sender |
Receiver |
Action |
Example values |
|
KO |
COL |
classify |
give_way |
|
COL |
KO |
classify |
give_way_true |
|
COL |
KO |
classify |
give_way_false |
The most complex data exchange is
the one between the KO and SIM modules, performed to establish required
manoeuvres and trajectories of the ships. The manoeuvres and trajectories sent
must be verified and confirmed, and if an agreement is not given for a proposed
manoeuvre or trajectory, the reason designated P should be given as well as
requirements (marked R) to be met by the new proposal, so the relevant notation
is this: trajectory_other_value_false_P_R or maneuver_other_value_false_P_R
(Table 3).
Tab. 3
Exchange of data between the KO and
SIM modules (fragment)
|
Sender |
Receiver |
Action |
Example values |
|
KO |
SIM |
give |
maneuver_own, maneuver_other |
|
SIM |
KO |
notify |
maneuver_own_value, maneuver_other_value |
|
KO |
SIM |
check |
trajectory_other_value |
|
SIM |
KO |
check |
trajectory_other_value_true maneuver_other_value_true, trajectory_other_value_false_P_R maneuver_other_value_false_P_R |
|
KO |
SIM |
find |
maneuver_R |
|
SIM |
KO |
warning |
trajectory_contradiction, speed_contradiction, course_contradiction, colision, |
|
KO |
SIM |
update |
maneuver_other_value |
Based on the MMSI numbers, the names
'own' and 'other' are sent, enabling correct interpretation of the data.
5. AN EXAMPLE
Let us consider an encounter situation of two ships
Alpha (A) and Beta (B), proceeding on collision courses. Additionally, let us
suppose that the situation takes place in an open sea area and under good
weather conditions. Aboard both ships, the automatic communication systems are
in operation, ship B is the give-way vessel, and the situation is viewed from
ship A (own ship). Let us examine an example scenario of a conversation that
was held automatically between the systems of both ships, and a record of data
exchange between the modules of the automatic communication system (Table 4).
As the ships approach each other, the communication is
established to exchange basic parameters of the ships. A message is generated,
containing information about the parameters of ship A. At the same time, a requirement
is identified to obtain the parameters of ship B; therefore, a request for
those parameters is generated too. The messages with the parameters are
exchanged. Having these data, the system is capable of transmitting the need to
identify the navigational situation to the COL module. Based on the Collision
Regulations, it is determined that ship B is the give-way vessel, so it sends
information about planned manoeuvres. The data on the manoeuvres are analysed
using the simulation module, which confirms the consent to such actions of ship
B. A message to ship B is generated along with information for the navigator of
ship A.
Tab. 4
An example scenario of a
conversation with data exchange
|
Lp |
Exchange of
data between the modules |
Communication |
|
1. 1 |
SYS_KO_notify=parameter_set,
parameter_set_value |
A:tell,information,
parameter_set, parameter_set_value |
|
2 |
SYS_KO_give=parameter_set, |
A:question,information,
parameter_set |
|
3 |
|
B:answer,information,
parameter_set, parameter_set_value |
|
4 |
KO_SYS_update=parameter_set,
parameter_set_value |
|
|
5 |
COL_KO_classify=give_way_false |
|
|
6 |
|
B:tell,intention, maneuver_value |
|
7 |
KO_SIM_check=maneuver_other_value |
|
|
8 |
SIM_KO_check=maneuver_other_value_true |
|
|
9 |
KO_SYS_update=
maneuver_other_value |
A:tell, permission, maneuver_value |
The outcome of the communication carried out in this
way is a solution – safe, collision avoiding and clear for both ships.
6. CONCLUSIONS AND
DIRECTION FOR FURTHER WORK
Human errors are a major cause of
navigational accidents. The minimisation of their occurrence is the goal of
many research teams. Today, attempts are made to develop and introduce marine
autonomous and/or unmanned remotely supervised ships, which involves the
elaboration of communication principles, particularly in reference to verbally
conducted exchanges. This article contributes to the research on automatic
communication, which has a form that supports ships' navigators. The data
exchange executed between the elements of the automatic communication system
was described and illustrated. The presented example conversation between the
navigators illustrates the way the system is and will be developed. The system
improves processes of communication, consequently, enhances the safety of
maritime transport. Further work on the automatic communication system should
focus on procedures for communications on sea-going autonomous and/or unmanned
remotely supervised ships.
References
1.
EMSA.
2017. Annual review of marine casualties
and incidents in 2017.
2.
International
Maritime Organization IMO. 2016. Standard
phrases for communication at sea. Szczecin: Wydawnictwo
naukowe Akademii Morskiej w Szczecinie.
3.
Krile S., N.N. Maiorov. 2019. “Work analysis of
maritime passenger terminals for particular region based on circos plot”.
Nase More 66(226):
57-61.
4.
Krile S., D. Mišković. 2018. “Optimal
use of container ships for servicing among small ports”. Nase More 65(120): 18-23.
5.
Pietrzykowski Z.,
G. Hołowiński, J. Magaj, J. Chomski. 2011. “Automation of
Message Interchange Processes in Maritime Transport”. International Journal on Marine Navigation
and Safety of Sea Transportation 5(2).
6.
Pietrzykowski A., P. Wołejsza, P. Borkowski.
2017. “Decision Support in Collision Situations at Sea”. The Journal of Navigation 70(3):
447-464.
7.
Ziarati R., M. Ziarati, B. Çalbaş. 2009.
“Improving safety at sea and ports by developing standards for maritime
English”. Bridge Conference.
Received 24.02.2020; accepted in revised form 30.04.2020
Scientific
Journal of Silesian University of Technology. Series Transport is licensed
under a Creative Commons Attribution 4.0 International License