Lecture Notes: TTK 4190 Guidance and Control of Vehiclesfossen.biz/wiley/Ch1.pdf · 7 TTK 4190...
Transcript of Lecture Notes: TTK 4190 Guidance and Control of Vehiclesfossen.biz/wiley/Ch1.pdf · 7 TTK 4190...
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Professor Thor I. FossenDepartment of Engineering CyberneticsNTNU Centre for Autonomous Marine Operations and SystemsNorwegian University of Science and Technology (NTNU)
Lecture Notes: TTK 4190 Guidance and Control of Vehicles
Home page: http://www.fossen.biz/
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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Textbook and Notation
Fossen,T.I.(2011)HandbookofMarineCraftHydrodynamicsandMotionControl.JohnWiley&SonsLtd.
MSSToolbox:www.marinecontrol.org
xb
yb
zb
u ( )surge
r ( )yaw
v ( )sway
( )heavew
( )rollp
( )pitchq
ü SNAME(1950). NomenclatureforTreatingtheMotionofaSubmergedBodyThroughaFluid.TheSocietyofNavalArchitectsandMarineEngineers,TechnicalandResearchBulletinNo.1-5,April1950,pp.1-15.
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Useful Reference Book
ü Fossen,T.I.(1994). “GuidanceandControlofOceanVehicles”, JohnWiley&SonsLtd.ISBN0-471-94113-1
xb
yb
zb
u ( )surge
r ( )yaw
v ( )sway
( )heavew
( )rollp
( )pitchq
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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Goals for the Course:1. Mathematicalmodeling
ofvehicles.Thisincludes:§ Kinematics§ Kinetics§ Equationsofmotion
formarinecraftandaircraft
§ Wind,waveandoceancurrentmodels
§ Hydrodynamics:maneuveringandseakeepingtheory
Copyright © Bjarne Stenberg/NTNU
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
2. Designofguidance,navigation andmotioncontrolsystemsforalargenumberofapplications
3. Simulate themotionsofmarinecraftandaircraftinthetime-domainusinghydrodynamic/aerodynamicmodels
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Marine Craft in Operation
Copyright © Bjarne Stenberg/NTNULecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
7 TTK 4190 Guidance and Control (T. I. Fossen) Lecture Notes 2005Pipe-laying vessel
Geologicalsurvey
Heavy lift operations
Positionmooring
Pipe and cable laying
Marine Craft in Operation
ROV operations
Vibrationcontrolof marinerisers
Cable-layingvessel
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Italian supply ship Vesuviorefueling two ships at sea.
Courtesy: Hepburn Eng. Inc.
Path Following and Trajectory Tracking
Underactuated container ship in transit. Fully actuated supply ship cruising at low speed.
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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Formation Control/Underway Replenishment
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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Interdisciplinary: Rocket Launch / DP system / THCS
SMMarine Segment
Courtesy: SeaLaunchhttp://www.sea-launch.com
Courtesy: SeaLaunch LLC
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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Trim & Heel Correction System (THCS)
Process andMarine Control
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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NTNU Infrastructure
Copyright © Bjarne Stenberg/NTNU
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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ROV Minerva
Applied Underwater Robotics Laboratory
Hugin AUV
Remus 100 AUVLight AUV (LAUV)
ThefleetoftheAUR-LabatNTNUTrondheimhttps://www.ntnu.no/aur-lab
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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Marine Cybernetics Laboratory (MCLab)
MCLab Dimensions:
üThesoftwareisdevelopedbyusingrapidprototypingtechniquesandautomaticcodegenerationunderMatlab/Simulink™andRT-Lab™.
üThetargetPConboardthemodelscalevesselsrunstheQNX™real-timeoperatingsystem,whileexperimentalresultsarepresentedinreal-timeonahostPCusingLabview™.
L ! B ! D " 40 m! 6.5 m! 1. 5 m
Cybership II
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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NTNU Research Vessel Gunnerus31meterslongTopspeed13knots http://www.ntnu.edu/marine/gunnerus
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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UAV Factory Penguin B w/ Piccolo SL• 28 m/s cruise speed• Gasoline, 8 hr
endurance• MTOW 21 kg• 2-5 kg payload capacity• Large payload bay• 80W generator• Avionics system
integration made with Maritime Robotics based on Cloudcap technology
• Telemetry on 2.4 GHz radio, GPRS (and VHF)
• Catapult launch• Custom payload system
integration with avionics interface
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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Penguin equipped with Camera, INS and GPS Sensor Suite for Data Logging
Penguinnavigationpayload:TwoIMUs,opticalcamera,infraredcamera,RTKGPSandembeddedcontrollerfordatalogging
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Skywalker X8 w/Ardupilot• 18 m/s cruise speed• Catapult launch• Belly or net landing• Electric, 1hr
endurance• Large payload bay• >1 kg payload
capacity• Inexpensive• Flexible avionics and
payload system integration with ArduPilot open source autopilot and mission planning SW
• Currently telemetry on 433 MHz or 5.8 GHz radio for VLOS
• Can be set up for BLOS with GPRS and VHF radio links
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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3DRobotics hexa-copter w/Ardupilot• Electric, 5-10 min
endurance• 1 kg payload capacity• Inexpensive• Flexible system
integration with Ardupilot open source autopilot and mission planning SW
• Telemetry on 433 MHz og 5.8 GHz radio
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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Microdrone Quad-copter
• Turn-key solution• Various camera, video
and radio systems• Electric, 45 min
endurance• 2-3 kg payload
capacity
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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NTNU Airfield at AgdenesWealsousetheairportsatEggemoen andØrland
Located94kmNorth-WestofTrondheim
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Offshore UAV Launch and Recovery Systems
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Launching – The Easy Part“Human-Inspired Approach”
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Automatic Launch of the Penguin UAV
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Net Landing onboard a Research Vessel outside the Azores in 2016
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Coordinated Control: Master-Slave Principle: The fixed-wing aircraft acts like an master, while the cooperative multicopters is the slave following the master.
Virtually-Moving Airfield: The airfield/net is moved in an optimal manner vertically and horizontally to improve landing accuracy and reduce impact speed.
K. Klausen, J. B. Moe, J. C. van den Hoorn, A. Gomola, T. I. Fossen and T. A. Johansen. Coordinated Control Concept for Recovery of a Fixed-Wing UAV on a Ship using a Net Carried by Multirotor UAVs. Proc. of the 2016 International Conference on Unmanned Aircraft Systems (ICUAS'16), Arlington, VA, 7-10 June, 2016.
Cooperative Control: A suspended net is transported away from the ship to a safe distance by using two or more multicopters, which cooperates. They UAVSs are intelligent and share positions in order to control the tension of the net.
The NTNU AMOS Ship-Landing Concept
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The NTNU AMOS Ship-Landing ConceptTwo or more Multicopters Catches the UAV
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Marinecraft:ships,high-speedcraft,semi-submersibles,floatingrigs,submarines,remotelyoperatedandautonomousunderwatervehicles,torpedoesandotherpropelled/poweredstructuresforinstanceafloatingairfield.
Vehicles thatdonottravelonland(oceanandflightvehicles)areusuallycalledcraft.
Vessel: "hollowstructuremadetofloatuponthewaterforpurposesoftransportationandnavigation;especially,onethatislargerthanarowboat".
Thewordsvessel,shipandboatareoftenusedinterchangeably.InEncyclopediaBritannica,ashipandaboataredistinguishedbytheirsizethroughthefollowingdefinition:
Ship:"anylargefloatingvesselcapableofcrossingopenwaters,asopposedtoaboat,whichisgenerallyasmallercraft.Thetermformerlywasappliedtosailingvesselshavingthreeormoremasts;inmoderntimesitusuallydenotesavesselofmorethan500tonsofdisplacement.
Submarine: "anynavalvesselthatiscapableofpropellingitselfbeneaththewateraswellasonthewater'ssurface.
UnderwaterVehicle: "smallvehiclethatiscapableofpropellingitselfbeneaththewatersurfaceaswellasonthewater'ssurface.Thisincludesunmannedunderwatervehicles(UUV),remotelyoperatedvehicles(ROV)andautonomousunderwatervehicles(AUV).
Marine Craft Ref.EncyclopediaBritannica
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Marinevesselsarealsoclassifiedaccordingtotheirmaximumoperatingspeed.ForthispurposeitiscommontousetheFroudenumber
Marine Craft
Fn ! UgL
Thepressurecarryingthevesselcanbedividedintohydrostatic and hydrodynamicpressure.Thecorrespondingforcesare:
• Buoyancyforceduetothehydrostaticpressures(proportionaltothedisplacementoftheship)
• Hydrodynamicforceduetothehydrodynamicpressure(approximatelyproportionaltothesquareofthespeed)
Thenwecanclassifythevesselsaccordingto(Faltinsen 2005):
• Displacementvessels(Fn<0.4):Thebuoyancyforcedominates.• Semi-displacementvessel(0.4-0.5<Fn>1.0-1.2):Thebuoyancyforceisnotdominantatthemaximumoperatingspeed.
• Planningvessels(Fn>1.0-1.2):Thehydrodynamicforcemainlycarriestheweight.
U:shipspeedL:overall(submergedlengthoftheship)G:accelerationofgravity
Inthiscourse,onlydisplacementvesselsarecovered
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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Classification of ModelsSimulation Model: Thismodelisthemostaccuratedescriptionofasystem,forinstancea6-DOFhigh-fidelitymodelforsimulationofcoupledmotionsinthetimedomain.Itincludesthemarinecraftdynamics,propulsionsystem,measurementsystemandtheenvironmentalforcesduetowind,wavesandoceancurrents.
Themodelshouldbeabletoreconstructthetimeresponsesoftherealsystemanditshouldalsobepossibletotriggerfailuremodessoyoucansimulateaccidentsanderroneoussignalsetc.Simulationmodelswherethefluidmemoryeffectsareincluded(frequency-dependentmodels)typicallyconsistof50-200ODEswhileafrequency-independentmodelcanberepresentedin6DOFwith12ODEsforgeneralizedpositionandvelocity.
Inadditionyouneedsomestatestodescribetheenvironmentalloadsandactuatorsbutstillthenumberofstateswillbelessthan50forafrequency-independentvesselmodel
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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Classification of ModelsControl Design Model: Thecontrollermodelisareduced-orderorsimplifiedsimulationmodelthatisusedtodesignthemotioncontrolsystem.Initssimplestform,thismodelisusedtocomputeasetofconstantgainsforaPIDcontroller.Moresophisticatedcontrolsystemsuseadynamicmodeltogeneratefeedforward andfeedbacksignals.Thisisreferredtoasmodel-basedcontrol.
ThenumberofODEsusedinconventionalmodel-basedshipcontrolsystemsisusuallylessthan20.APIDcontrollertypicallyrequirestwostates:onefortheintegratorandoneforthelow-passfilterusedtolimitnoiseamplification.Consequently,setpoint regulationin6DOFcanbeimplementedbyusing12ODEs.However,trajectory-trackingcontrollersrequireadditionalstatesforfeedforwardaswellasfilteringsohigher-ordercontrollawsarenotuncommon.
Observer Design Model: Theobservermodelwillingeneralbedifferentfromthemodelusedinthecontrollersincethepurposeistocapturetheadditionaldynamicsassociatedwiththesensorsandnavigationsystemsaswellasdisturbances.Itisasimplifiedversionofthesimulationmodelwhereattentionisgiventoaccuratemodelingofmeasurementnoise,failuresituationsincludingdead-reckoningcapabilities,filteringandmotionprediction.
Formarinecraft,themodel-basedobserveroftenincludesadisturbancemodelwherethegoalistoestimatewave,windandoceancurrentforcesbytreatingtheseascolorednoise.FormarinecraftthenumberofODEsinthestateestimatorwilltypicallybe20foraDPsystemwhileabasicheadingautopilotisimplementedwithlessthan5states.
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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The Classical Models in Naval Architecture
m!u! ! vr " wq ! xg"q2 " r2# " yg"pq ! r!# " zg"pr " q! #$ # Xm!v! ! wp " ur ! yg"r2 " p2# " zg"qr ! p! # " xg"qp " r!#$ # Ym!w! ! uq " vp ! zg"p2 " q2# " xg"rp ! q! # " yg"rq " p! #$ # ZIxp! " "Iz ! Iy#qr ! "r! " pq#Ixz " "r2 ! q2#Iyz " "pr ! q! #Ixy
" m!yg"w! ! uq " vp# ! zg"v! ! wp " ur#$ # KIyq! " "Ix ! Iz#rp ! "p! " qr#Ixy " "p2 ! r2#Izx " "qp ! r!#Iyz
" m!zg"u! ! vr " wq# ! xg"w! ! uq " vp#$ # MIzr! " "Iy ! Ix#pq ! "q! " rp#Iyz " "q2 ! p2#Ixy " "rq ! p! #Izx
" m!xg"v! ! wp " ur# ! yg"u! ! vr " wq#$ # N
Themotionsofamarinecraftexposedtowind,wavesandoceancurrentsareusuallymodeledin6DOFbyapplyingNewton's2ndlaw:
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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The Classical Models in Naval ArchitectureTheexternalforcesandmomentsX,Y,Z,K,M andN actingonamarinecraftareusuallymodeledbyusing:
ManeuveringTheory: ThestudyofashipmovingatconstantpositivespeedUincalmwater withintheframeworkofmaneuveringtheoryisbasedontheassumptionthatthehydrodynamiccoefficientsarefrequencyindependent(nowaveexcitation).Themaneuveringmodelwillinitssimplestrepresentationbelinearwhilenonlinearrepresentationscanbederivedusingmethodslikecross-flowdrag,quadraticdampingorTaylor-seriesexpansions.
SeakeepingTheory:Themotionsofshipsatzeroorconstantspeed inwavescanbeanalyzedusingseakeepingtheorywherethehydrodynamiccoefficientsandwaveforcesarecomputedasafunctionofthewaveexcitationfrequencyusingthehullgeometry.Thefrequency-dependentmodelsareusuallyderivedwithinalinearframeworkwhileextensionstononlineartheoryisanimportantfieldofresearch.
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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Maneuvering TheoryAssumesthattheshipismovinginrestrictedcalmwater.Hence,themaneuveringmodelisderivedforashipmovingatpositivespeedUunderazero-frequencywaveexcitationassumptionsuchthataddedmassanddampingcanberepresentedbyusinghydrodynamicderivatives(constantparameters).
Thezero-frequencyassumptionisonlyvalidfor surge,sway andyaw sincethenaturalperiodofaPDcontrolledshipwillbeintherangeof100-150s.For150s thisresultin:
!n ! 2"T
! 0.04 rad/s #
Thenaturalfrequenciesinheave,rollandpitcharemuchhighersoitisnotstraightforwardtoremovethefrequencydependenceinthesechannels.
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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Maneuvering TheoryItiscommontoformulatetheshipmaneuveringmodelasacoupledsurge-sway-yawmodelandthusneglectheave,rollandpitchmotions:
• Hydrodynamicaddedmasspotentialdampingduetowaveradiationandviscousdamping• Hydrostaticforces(springstiffness)• Windforces• Waveforces(1st- and2nd-order)• Controlandpropulsionforces
m!u! ! vr ! xgr2 ! ygr! " " Xm!v! # ur ! ygr2 # xgr! " " YIzr! # m!xg#v! # ur$ ! yg#u! ! vr$" " N
#
MRB!" ! CRB!!"! " #RB #
!RB ! !hyd " !hs hydrodynamic andhydrostatic forces
" !wind " !waveenvironmental forces
" !control #
!i ! !Xi,Yi,Zi,Ki,Mi,Ni"!, i ! #hyd, hs, wind, wave, control$ #
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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Linearized Maneuvering ModelsInthelinear6-DOF casetherewillbeatotalof36massand36dampingelements proportionaltovelocityandacceleration.Inadditiontothis,therewillberestoringforces,propulsionforcesandenvironmentalloads.Ifthegeneralizedforce iswrittenincomponent,thelinearaddedmassanddampingforcesbecome:
where Xu,Xv , . . . ,Nr are the linear damping coefficientsand Xu! ,Xv! , . . . ,Nr! represent hydrodynamic added mass.
!hyd
X1 ! Xuu " Xvv " Xww " Xpp " Xqq " Xrr" Xu# u# " Xv# v# " Xw# w# " Xp# p# " Xq# q# " Xr#r#!
N1 ! Nuu " Nvv " Nww " Npp " Nqq " Nrr" Nu# u# " Nv# v# " Nw# w# " Np# p# " Nq# q# " Nr#r#
#
#
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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Nonlinear Maneuvering ModelsApplicationofnonlineartheoryimpliesthatmanyelementsmustbeincludedinadditiontothe36linearelements.
TruncatedTaylor-seriesexpansionsusingoddterms(1st- and3rd-order)whicharefittedtoexperimentaldata(Abkowitch 1964)or2nd-ordermodulusterms(Fedyaevsky 1963)
Theequationsbecomerelativelycomplicatedduetothelargenumberofhydrodynamiccoefficientsontheright-handsideneededtorepresentthehydrodynamicforces.
Taylor-seriesexpansionsarefrequentlyusedincommercialplanarmotionmechanism(PMM)testswherethepurposeistoderivethemaneuveringcoeffs.experimentally.
X1 ! Xu" u" # Xuu # Xuuuu3 # Xv" v" # Xvv # Xvvvv3 # !
"
N1 ! Nu" u" # Nuu # Nuuuu3 # Nv" v" # Nvv # Nvvvv3 # !
#
#
X1 ! Xu" u" # Xuu # X |u|u|u|u # Xv" v" # Xvv # X |v|v |v|v # !
"
N1 ! Nu" u" # Nuu # N |u|u|u|u # Nv" v" # Nvv # N |v|v |v|v # !
#
#
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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Seakeeping,isthestudyofmotionwhenthereiswaveexcitationandthecraftkeepsitscourseanditsspeedconstant(whichincludesthecaseofzerospeed).Thisintroducesadissipativeforceknownasfluidmemoryeffects(Cummins1962).
Thegoverningmodelisformulatedinthetimedomain(Cumminsequation):
Seakeeping Theory
!MRB ! A"!#$!" ! B total"!#!# ! "0
tK"t # !#!#"!#d! ! C! " $wind ! $wave ! "$ #
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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- body-fixedvelocities:- positionandEulerangles:-M,CandDdenotethesysteminertia,Coriolisanddampingmatrices- gisavectorofgravitationalandbuoyancyforcesandmoments
- q isavectorofjointangels- isavectoroftorque-M andC arethesysteminertiaandCoriolismatrices
InFossen(1991)therobotmodel:
M!q"q! " C!q,q# "q $ %
wasusedasfoundationtowritethe6-DOFmarinecraftequationsofmotioninacompactvectorial setting.
Matrix-VectorRepresentation
Therobotmodelwasmodifiedtodescribemarinecraftaccordingto:
!
! ! !u,v,w,p, q, r"T! ! !x,y, z,!, ",#"T
Fossen's Robot-Like Vectorial Model for Marine Craft
M!" ! C!!"! ! D!!"! ! g!#" ! g0 " $ ! $wind ! $wave
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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Itisadvantageoustoexpresstheequationsofmotioninmatrix-vectorform:
sincenonlinearsystempropertiessuchas:
§ symmetry ofmatrices§ skew-symmetryofmatrices§ positiveness ofmatrices
canbeexploitedinthepassivity/stabilityanalysis.Thesepropertiesrelatestopassivity ofthemodel.NoticethThese propertiesaredestroyedbylinearization.
Thesepropertiesalsorepresentsphysicalpropertiesofthesystemwhichshouldbeexploitedwhendesigningnonlinearcontrollersandobservers formarinecraft.
Thematrix-vectornotationmakesitveryeasytosimulatethemodel(inMatlab andC++)
Why use Matrix-Vector Form?
M!" ! C!!"! ! D!!"! ! g!#" ! g0 " $ ! $wind ! $wave
Lecture Notes TTK 4190 Guidance and Control of Vehicles (T. I. Fossen)
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forces and linear and positions and
DOF moments angular velocities Euler angles
1 motions in the x-direction (surge) X u x2 motions in the y-direction (sway) Y v y3 motions in the z-direction (heave) Z w z4 rotation about the x-axis (roll, heel) K p !
5 rotation about the y-axis (pitch, trim) M q "
6 rotation about the z-axis (yaw) N r #
xb
yb
zb
u ( )surge
r ( )yaw
v ( )sway
( )heavew
( )rollp
( )pitchq
ThenotationisadoptedfromSNAME(1950).
Foramarinecraft,DOFisthesetofindependentdisplacementsandrotationsthatcompletelyspecifythedisplacedpositionandorientationofthecraft.Acraftthatcanmovefreelyinthe3-Dspacehasmaximum6DOFs—threetranslationalandthreerotationalcomponents.
Consequently,afullyactuatedmarinecraftoperatingin6DOFmustbeequippedwithactuatorsthatcanproduceindependentforcesandmomentsinalldirections.
Degrees of Freedom (DOF)
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Whendesigningfeedbackcontrolsystemsformarinecraft,reduced-ordermodelsareoftenusedsincemostvehiclesdonothaveactuationinallDOF.Thisisusuallydonebydecouplingthemotionsofthevesselaccordingto:
1-DOFmodelscanbeusedtodesignforwardspeedcontrollers(surge),headingautopilots(yaw)androlldampingsystems(roll).
3-DOFmodelsareusuallyhorizontal-planemodels(surge,swayandyaw)forships,semi-submersiblesandunderwatervehiclesthatareusedinDPsystems,trajectory-trackingcontrolsystemsandpath-followingsystems.Forslenderbodiessuchastorpedo-shapedAUVsandsubmarines,itisalsocommontoassumethatthemotionscanbedecoupledintolongitudinalandlateralmotions.
·Longitudinalmodels(surge,heaveandpitch)forforwardspeed,divingandpitchcontrol.·Lateralmodel(sway,rollandyaw)forturningandheadingcontrol.
4-DOFmodels (surge,sway,rollandyaw)areusuallyformedbyaddingtherollequationtothe3-DOFhorizontal-planemodel.Thesemodelsareusedinmaneuveringsituationswherethepurposeistoreducerollbyactivecontroloffins,ruddersorstabilizingliquidtanks.
6-DOFmodels (surge,sway,heave,roll,pitchandyaw)arefullycoupledequationsofmotionusedforsimulationandpredictionofcoupledvesselmotions.Thesemodelscanalsobeusedinadvancedcontrolsystemsforunderwatervehicles,whichareactuatedinallDOF.
Degrees of Freedom (DOF)