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15MobileRobotsatWork15.1IntroductionRobotsofalltypesconstituteoneofthekeystohumansocialandeconomicdevelopment.Thefirstrobotsweredeviceswithoneormorearmsmakinghuman-likemotions.Inourdays,theshapeofrobotscoversaverylargerepertoryofformsincludingwheeledplatforms,mobilemanipulators,leggedbodies,animal-likerobots,andsoon.Alltheserobotscontributeinoneortheotherwaytohuman,industrial,agricultural,technical,andsociallifeimprovements.Thebenefitsofusingautonomousandintelligentmobilerobots(wheeledorlegged)inmedical,assistive,andserviceapplicationsarenumerous,andtheirpositiveimpactinmodernsocietyiscontinuouslyincreasing.Thepurposeofthepresentchapterispurelyencyclopedicandaimstoprovidethereaderasmallsetofmobilerobotsofvarioustypesthatareactuallyusedinmodernindustryandsociety[125].Specifically,thefollowingrobotcategoriesarediscussedwithrelevantphotosincluded:¡ñmobilerobotsandmanipulatorsinthefactoryandindustry,¡ñmobilerobotsinthesociety(rescue,guidance,hospital),¡ñmobilerobotsforhomeservices(cleaning,otherservices),¡ñassistivemobilerobots(autonomouswheelchairs,servicemobilemanipulatorsfortheimpaired),¡ñmobiletelerobotsandwebrobots,¡ñothermobilerobotapplications.Theaboveapplicationsillustratetheimportanceandvalueofmobilerobotsforachievingabetterqualityofhumanlifeinawidevarietyofdirections.15.2MobileRobotsintheFactoryandIndustryMobilerobotsusedonthefactoryshopflooraretypicallycalledautomatedorautonomousguidedvehicles(AGVs)andmovefollowingmarkersorwiresonthefloororemploysensorysystems(lasers,vision).AGVsareusedinfactoryformaterialhandling,producttransferfromoneplacetoanother,forinspectionandqualitycontrol,etc.TheyworkaroundtheclockcontributingtobettercontinuousIntroductiontoMobileRobotControl.DOI:(Northbrook,IL),actuallybeingatowtruckfollowingawireinthefloorinsteadofarail.Today,AGVsareprimarilylasernavigated,andcanbeprogrammedtocommunicatewithotherrobotstoassuresmoothproductmovementandstorageintheindustrialpremises.AllmodernflexiblemanufacturingsystemsuseAGVsforachievingtheirgoalsandassurefastandhigh-qualityproduction24haday.ThenavigationofAGVscanbeperformedinthefollowingways(Wikipediaarticle:Automated-Guided-Vehicles#Wired).¡ñWirednavigation¡ªAwiredsensorplacedonthebottomoftheplatform(facingtheground)detectstheradiofrequencywhichistransmittedfromawireplacedinaslotabout1in.belowtheground.TheAGVisthenmovedfollowingthewire.¡ñGuidetape-basednavigation¡ªThisnavigationtypeissuitableforautomatedguidedcarts(i.e.,light-dutyAGVs).Atapeisusedtoguidethevehicle,whichisequippedwithasuitableguidesensorenablingittofollowthepathofthetape.¡ñLaser-basednavigation¡ªThisisawirelessnavigationprocesswhichisperformedbymountingretroreflectivetapeonwalls,poles,andmachines.TheAGVhasarotatingturretcarryingalasertransmitterandreceiver.Thelaserissentoffandthenreceivedagainallowingthecomputationofthevehicle¡¯sorientation(andinsomecasesthedistance)automatically.TheAGVisequippedwithareflectormapstoredinmemory,andcancorrectitspositionbyafeedbackcontroltechnique(usingtheerrorbetweenthedesiredandreceivedmeasurement).¡ñGyroscope-basednavigation¡ªThisisaninertialguidancesystem.Transportersareembeddedintheflooroftheworkenvironment.TheAGVemploysthesetransporterstodetectthecorrectnessofitsroute,andagyroscopemeasuresthechangeinthedirectionofthevehicle.Thischange(error)isusedtocorrectthevehicle¡¯smotionandreturnitonthepath.¡ñNaturalfeatures-basednavigation¡ªThisallowstheAGVnavigationwithnoworkspaceretrofitting.Typically,oneormorerangefindersensors(laser,gyroscope,etc)areused,andtheextendedKalmanfilterorparticle/MonteCarlofiltersareusedforlocalizationandmapping.ThemostcommonsteeringtypeinfactoryAGVsisthedifferentialdrive.WhenthereareseveralAGVsworkingontheshopfloor,somekindoftrafficcontrolisrequired(forwardsensingcontrol,zonecontrol,etc.).TheapplicationsoffactoryandindustrialAGVsincludethefollowing:¡ñTrailerloading¡ªPickupofpalletsfromconveyors,orstaginglanesanddeliverintoatraileraccordingtoaloadingpattern.¡ñRawmaterialhandling¡ªTransportationofrawmaterials(metal,plastic,rubber,paper,etc.)receivedinthewarehouse,anddeliverytotheproperproductionline.¡ñFinishedproducthandling¡ªTransportationoffinishedgoodsfromtheproductionlinetostorageorshippingtocustomers.TheaboveapplicationsofAGVsareneededinmostmodernindustries¡ªautomotiveindustry,foodandbeverageindustry,paper-and-printindustry,chemical/pharmaceuticalindustry,manufacturingindustry,etc.Figures15.115.5showsomeAGVsusedinfactoriesandindustries,includingautonomousmobilemanipulators.636IntroductiontoMobileRobotControlFigure15.1TwoHitachiautonomouslyguidedvehiclesforthefactory.Source::TwomoreindustrialAGVs.(A)AdepthandlingAGV,(B)DTAVehiclesAGVpallettruck.Source: