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1 INTRODUCTION
Ship supports human life by transporting many
things such as product, passenger, and energy
resource. Shipping industry is very important and
closetoourlife.However,theshippingindustryhas
manyproblemssuchasreductionofmariners,aging
mariners officer, and labor expenses (Fukuto et al.
2007,Nishiietal.2014).
Aspreviousstudy, One Person Bridge Operation
hadbeendevelopedforimprovingtheproblems.One
Person Bridge Operation had been aim
ed at
controlling ship by one mariner (Imazu et al. 2010).
However, One Person Bridge Operation remained
technologicalproblemsandonemanerror(Shimono
etal.2009,Shimonoetal.2010,Ya
bukietal.2016).On
theotherhand,recently, informationabout
unmannedshiphas been announced by RollsRoyce
(RollsRoyce 2016). However, unmanned ship also
has problems such as law, insurance, autopilot, and
shipbuilding cost. Therefore, it takes more time to
buildunmannedship.
In this pa
per, the concept of telexistence (Tachi
2009,Tachi etal.2010,Tachi etal.2011)isadaptedto
ship from another aspect to solve the problems of
shipping industry. The concept of telexistence on a
shipistomaneuverashipbetweenlandandshipby
atleast two mariners such as navigation officer and
helmsman (Sasaki et al. 2016). Navigation officer
works on a ship as usual, and helmsman supports
shipfromland.Therefore, thetel
existenceonashipis
oneofthesolutionforreductionofmariners,agingof
mariners, and labor expenses. Moreover, the
problems of One Person Bridge Operation and
unmannedshipsuchasonema
nerror,technological
improvementmightbesolved. Therefore,asthefirst
step of telexistence on a ship, remote maneuvering
system considering communication delay was
Development of Telexistence on a Ship by Using
Satellite Communication
S.Sasaki&T.Okazaki
TokyoUniversityofMarineScienceandTechnology,Tokyo,Japan
ABSTRACT:Nowadaysshippingindustryhasproblemssuchasreductionofmariners,agingofmariners,and
laborexpenses.Tosolvetheproblems,OnePersonBridgeOperationwasdevelopedasnavigationsupporting
system. However, One Person Bridge Operation remained technological problems and one man error.
Therefore,inthi
sstudy,telexistenceonashipwasproposedbyusingsatellitecommunication.Telexistenceon
ashipisaconceptofmaneuveringbetweenlandandshipwithatleasttwomarinerssuchasnavigationofficer
and helmsman. Navigation officer works on ship as usual and helmsman supports ship from land. In thi
s
paper,remotemaneuveringsystemwasdevelopedasthefirststepoftelexistenceonaship.Forevaluatingthe
effectiveness,shipexperimentwascarriedout.Fromtheresult,navigationofficerandhelmsmancouldalter
ship’scourseto20degreeswithin60secondsandlessthan5%overshootintheproposedremotemaneuvering
system.
http://www.transnav.eu
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 11
Number 1
March 2017
DOI:10.12716/1001.11.01.21
176
developed by using satellite communication. Then,
ship experiment was carried out for evaluating the
effectiveness of the proposed remote maneuvering
system.Astheresult,totaltimeof20degreesaltering
course was within 60 seconds in the less than 5%
overshoot in the proposed remote maneuvering
system.
In this paper,
first, ordinary maneuvering and
remote maneuvering is described in Section 2 and
Section 3. In remote maneuvering, communication
delay influences maneuvering a ship. Therefore,
remote maneuvering system considering
communicationdelayisproposedin Section4.Then
theeffectivenessoftheproposedremotemaneuvering
system is indicated from experimental result in
Section 5. Finally, future work for telexistence on a
ship is indicated as consideration in Section 6, and
conclusionofthisstudyisdescribedinSection7.
2 ORDINARYMANEUVERING
In ordinary maneuvering, navigation officer usually
maneuvers a ship with helmsman (Ito et al. 2012).
Navigation officer orders rudder angle, then
helmsmansteersfollowing navigationofficerʹsrudder
order(Kobayashietal.2012).Inthissection,ordinary
maneuveringby navigation officer andhelmsman is
described.
2.1 OrdinaryManeuvering
Sea transportation does not exist visible route like
landtransportation.Therefore,navigationofficeruses
nautical chart and writes down course line from
present
port to next port as objective course.
Navigation officer maneuvers a ship while
recognizing the course line, and then navigation
officer sometime alters shipʹs course in the situation
suchaswindingincapeandbays,andavoidingother
ships(Hashiomotoetal.2012).
2.2 Alteringcourse
In altering course, first,
navigation officer orders
rudderangletohelmsman.Thehelmsmanrepeatsthe
rudder angle after understanding what navigation
officer ordered. Then the helmsman steers while
obeying the rudder order. After confirming ship’s
rudderangle,thehelmsmanreportstothenavigation
officer.Forexample,inthecaseoftakingrudderof10
degrees on the starboard side, navigation officer
orders as “starboard 10” to helmsman. Next, the
helmsman repeats “starboard 10” to the navigation
officer,andthenthehelmsmansteersof10degreeson
the starboard side. Finally, after confirming rudder
angle,thehelmsmanreportstothenavigationofficer
as“starboard10,sir”
becauseship’srudderdoesnot
changeinstantly.ThisprocedureisshowninFigure1.
InFigure1,t1indicatestimewhennavigationofficer
ordered, t2 indicates repeat time of ordered rudder
angle,t3indicatestimewhenhelmsmansteers,andt4
indicates time when helmsman confirms ship’s
rudder angle and reports
to navigation officer. For
instance,whennavigationofficeraltersshipʹscourse
to 20 degrees from present course, the navigation
officer orders rudder angle in several times to
helmsman. First, navigation officer orders rudder
angle as “starboard 10” for turning to the target
course. Second, the navigation officer orders rudder
angle
as “midships” reducing rate of turn on
starboardsideatthetimewhentheship’scoursehas
been changed to 15 degrees. Then the navigation
officer orders rudder angle as “port 5” for stopping
turning on starboard side at the time of changing
shipʹs heading to 19 degrees. Finally,
the navigation
officer orders rudder angle as “midships”. In the
altering,helmsman steers, repeats and reports while
obeyingrudderorderfromnavigationofficer.
Figure1.Procedureofordinarymaneuvering
3 REMOTEMANEUVERING
Ordinary maneuvering is conducted by navigation
officer and helmsman as shown in section 2.
Navigation officer orders rudder angle, and
helmsman steers while obeying what navigation
officerordered.Navigationofficerandhelmsmanalso
need to maneuver a ship as usual in remote
maneuvering. Therefore, in remote maneuvering
system,
mastersystemandslavesystemaresetupin
landandshiprespectively,andconnectedbysatellite
communication as shown in Figure 2. Navigation
officerordersrudderangleontheshipintheremote
maneuvering. On the other hand, helmsman steers
and checks the ship state on land by observing
information which is sent from the slave system by
satellitecommunication.
Figure2.Satellitecommunicationbetweenlandandship
3.1 ConfigurationofRemoteManeuveringSystem
Configuration of remote maneuvering system is
showninFigure3.Theremotemaneuveringsystemis
consistedofmastersystemonlandandslavesystem
177
onaship,andthemastersystemandtheslavesystem
areconnectedbyusing satellitecommunication. The
master system is consisted of handle for steering,
microphoneforvoiceinput,speakerforvoiceoutput,
andhostPCformanaginginformation.Ontheother
hand,theslavesystemisconsistedof
microphonefor
voice input, speaker for voice output, client PC for
managinginformation,andshipmeasurementcontrol
server for observing and controlling ship. For
telexistenceona ship,a robotis necessaryasoneof
theslavesystemforsupportingnavigationofficerand
obtaining va rious information. However, remote
maneuveringsystem
isonlyconsistedofhostPCand
client PC for communicating ship information
becausethispaperisfocusedonmaneuveringasthe
firststepfortelexistenceonaship.
Figure3.Configurationofremotemaneuveringsystem
3.2 AlteringCourseinRemoteManeuveringSystem
Altering course in remote maneuvering system is
basicallysameastheordinarymaneuveringinsection
2. First, navigation officer orders rudder angle to
slavesystem.Therudderorderisrecognizedbyvoice
recognitionat slave system, and the rudder order is
changedtosimple
codeforreducingpacketsize.Then
the code is sent to master system by using satellite
communication. At the master system, the code is
changed to voice output for helmsman. After
helmsman recognized the rudder order of voice
output, the helmsman repeats the rudder angle,
steers,andreportstonavigation
officer.Thesignalsof
repeat, steering, and completion report are also sent
fromthemastersystemtotheslavesystembyusing
satellite communication. The procedure of remote
maneuveringby navigation officer andhelmsman is
showninFigure4.InFigure4,t1indicatestimewhen
navigationofficerordered,s1indicates
timeofvoice
recognition, satellite communication, and voice
outputfromtheslavesystemtothemastersystem,