625
1 INTRODUCTION
Duetotheincreaseinthenumber,size,andspeedof
ships,theproblemofcollisionavoidanceisbecoming
more complicated. Despite the measures taken,
including development of Collision Avoidance
SupportSystem(CASS),thisproblemisurgent. One
of the ways to solve this problem is to improve
information support for decisions, including the
development of recommendations for and mapping
the zones of acceptable values of manoeuvre
parameters, and a number of other elements. Such
mappingmakesiteasierfortheoperatortoevaluate
thesystemʹsrecommendationstoavoidcollisionand
tocorrectthem.
In the paper
[10], indicators of dangerous course
and velocity areas are presented to determine
effective actions in one of onboard CASS. In the
VisualizationbasedCASS[9],evasivemanoeuvresare
selected according to the diagram of own ship
velocityvectors,safefortargetspassing.Thismethod
is called Velocity Obstacle (VO) [2]. The
paper [8]
highlights an algorithm that allows, using the VO
method,tofindCOLREGcompliantmanoeuvres.The
creationofvisualaidsisalsoenvisagedinadditionto
the definition of recommendations by the methods
‘ArtificialPotentialField’[5],‘DynamicWindow’[1],
‘ModelPredictiveControl’[7],andothers[3,6,12,
13].
In the paper [13], the search for the optimalevasive
manoeuvre in terms of sailing time loss is based on
theenumerationmethod,andtablesareproposedthat
makeiteasierfortheoperatortoevaluateandcorrect
thefoundoption.Thecomplexesofgraphicelements
to facilitate the adoption
of anticollision decisions
developed still have drawbacks,and the questionof
theirimprovementisurgent.
Theobjectiveofthepaperistodevelopgraphical
tools to facilitate the selection, evaluation and
Graphical Tools to Facilitate the Selection of
Manoeuvres to Avoid Collision
L.L.Vagushchenko
1
&A.A.Vagushchenko
2
1
NationalUniversity“OdessaMaritimeAcademy”,Odessa,Ukraine
2
BSMCrewServiceCentre,Odessa,Ukraine
ABSTRACT:Graphicaltoolshavebeenproposedtofacilitatetheselection,evaluation,andcorrectionofanti
collision actions in situations with moving and stationary obstacles, assuming that such situations are not
extreme or ordinary with sailing vessels and that the target movement parameters are constant
or their
upcomingchangeisknown.ThechoiceofevasivecombinedZmanoeuvre(bothcourseandspeedchangeat
onepointandreturntotheoriginalvaluesoftheseparametersatanotherpoint)andonecombinedaction(both
course and speed alteration at the selected point) were considered. The graphical tools
developed contain
diagrams,showingeightzonesofactions,andspecialmarksoftargetsatthemomentoftheirclosestapproach
to the own ship. In view of the COLREG and good seamanship, these zones were arranged in order of
application priority. The results of the enumeration of a representative discrete
set of possible manoeuvre
variantswereusedtoconstructthediagrams.
http://www.transnav.eu
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 17
Number 3
September 2023
DOI:10.12716/1001.17.03.14
626
correctionofcombinedZmanoeuvre(CZM)andone
combinedaction(OCA)insituationwithmovingand
stationary obstacles, assuming that such situation is
not extreme, the target movement parameters are
constantortheirupcomingchangeisknown.
The following abbreviations are used: OS‐own
ship;TS‐targetship;CPA‐closest
pointofapproach;
DCPA‐distanceatCPA;TCPA‐timetoCPA;GWV
giveway vessel;SOVstandonvessel;XTD‐cross
track distance. For DCPA, TCPA and XTD the
symbolsδ,τandηarealsousedinthetext.Ownship
was given the number ‘0’, and the targets
were
numbered from 1 to n. The number of the most
dangerous (main) target was denoted byμ, and the
targetswithnumbersjandμweremarkedbyTS
Jand
TS
μ.Thesameindiceswereusedforthecharacteristics
of these ships.Theinitialcourse, speed of own ship
and TS
J were respectively marked K0, V0 and KJ, VJ.
Theownshipcourseandspeedontheevasionsection
weredenotedbyK
U,VU.TheRulesreferencedinthe
textarepartofCOLREG.
2 CONSIDARATIONOFREQUIREMENTSFOR
EVASIVEACTIONS
Collision avoidance actions include course or/and
speed changes. The anticollision manoeuvre