外文翻译--机器人技术简介

IntroductiontoroboticstechnologyInthemanufacturingfield,robotdevelopmenthasfocusedonengineeringroboticarmsthatperformmanufacturingprocesses.Inthespaceindustry,roboticsfocusesonhighlyspecialized,one-of-kindplanetaryrovers.Unlikeahighlyautomatedmanufacturingplant,aplanetaryroveroperatingonthedarksideofthemoon--withoutradiocommunication--mightrunintounexpectedsituations.Ataminimum,aplanetaryrovermusthavesomesourceofsensoryinput,somewayofinterpretingthatinput,andawayofmodifyingitsactionstorespondtoachangingworld.Furthermore,theneedtosenseandadapttoapartiallyunknownenvironmentrequiresintelligence(inotherwords,artificialintelligence).Mechanicalplatforms--thehardwarebaseArobotconsistsoftwomainparts:therobotbodyandsomeformofartificialintelligence(AI)system.Manydifferentbodypartscanbecalledarobot.Articulatedarmsareusedinweldingandpainting;gantryandconveyorsystemsmovepartsinfactories;andgiantroboticmachinesmoveearthdeepinsidemines.Oneofthemostinterestingaspectsofrobotsingeneralistheirbehavior,whichrequiresaformofintelligence.Thesimplestbehaviorofarobotislocomotion.Typically,wheelsareusedastheunderlyingmechanismtomakearobotmovefromonepointtothenext.Andsomeforcesuchaselectricityisrequiredtomakethewheelsturnundercommand.MotorsAvarietyofelectricmotorsprovidepowertorobots,allowingthemtomovematerial,parts,tools,orspecializeddeviceswithvariousprogrammedmotions.Theefficiencyratingofamotordescribeshowmuchoftheelectricityconsumedisconvertedtomechanicalenergy.Let'stakealookatsomeofthemechanicaldevicesthatarecurrentlybeingusedinmodernroboticstechnology.DrivingmechanismsGearsandchains:Gearsandchainsaremechanicalplatformsthatprovideastrongandaccuratewaytotransmitrotarymotionfromoneplacetoanother,possiblychangingitalongtheway.Thespeedchangebetweentwogearsdependsuponthenumberofteethoneachgear.Whenapoweredgeargoesthroughafullrotation,itpullsthechainbythenumberofteethonthatgear.Pulleysandbelts:Pulleysandbelts,twoothertypesofmechanicalplatformsusedinrobots,workthesamewayasgearsandchains.Pulleysarewheelswithagroovearoundtheedge,andbeltsaretherubberloopsthatfitinthatgroove.Gearboxes:Agearboxoperatesonthesameprinciplesasthegearandchain,withoutthechain.Gearboxesrequireclosertolerances,sinceinsteadofusingalargeloosechaintotransferforceandadjustformisalignments,thegearsmeshdirectlywitheachother.Examplesofgearboxescanbefoundonthetransmissioninacar,thetimingmechanisminagrandfatherclock,andthepaper-feedofyourprinter.PowersuppliesPowersuppliesaregenerallyprovidedbytwotypesofbattery.Primarybatteriesareusedonceandthendiscarded;secondarybatteriesoperatefroma(mostly)reversiblechemicalreactionandcanberechargedseveraltimes.Primarybatterieshavehigherdensityandalowerself-dischargerate.Secondary(rechargeable)batterieshavelessenergythanprimarybatteries,butcanberechargeduptoathousandtimesdependingontheirchemistryandenvironment.Typicallythefirstuseofarechargeablebatterygives4hoursofcontinuousoperationinanapplicationorrobot.SensorsRobotsreactaccordingtoabasictemporalmeasurement,requiringdifferentkindsofsensors.Inmostsystemsasenseoftimeisbuilt-inthroughthecircuitsandprogramming.Forthistobeproductiveinpractice,arobothastohaveperceptualhardwareandsoftware,whichupdatesquickly.Regardlessofsensorhardwareorsoftware,sensingandsensorscanbethoughtofasinteractingwithexternalevents(inotherwords,theoutsideworld).Thesensormeasuressomeattributeoftheworld.Thetermtransducerisoftenusedinterchangeablywithsensor.Atransduceristhemechanism,orelement,ofthesensorthattransformstheenergyassociatedwithwhatisbeingmeasuredintoanotherformofenergy.Asensorreceivesenergyandtransmitsasignaltoadisplayorcomputer.Sensorsusetransducerstochangetheinputsignal(sound,light,pressure,temperature,etc.)intoananalogordigitalformcapableofbeingusedbyarobot.MicrocontrollersystemsMicrocontrollers(MCUs)areintelligentelectronicdevicesusedinsiderobots.Theydeliverfunctionssimilartothoseperformedbyamicroprocessor(centralprocessingunit,orCPU)insideapersonalcomputer.MCUsareslowerandcanaddresslessmemorythanCPUs,butaredesignedforreal-worldcontrolproblems.OneofthemajordifferencesbetweenCPUsandMCUsisthenumberofexternalcomponentsneededtooperatethem.MCUscanoftenrunwithzeroexternalparts,andtypicallyneedonlyanexternalcrystaloroscillator.UtilitiesandtoolsROBOOP(AroboticsobjectorientedpackageinC++):Thispackageisanobject-orientedtoolboxinC++forroboticssimulation.TechnicalreferencesanddownloadsareprovidedintheResources.CORBA:Areal-timecommunicationsandobjectrequestbrokersoftwarepackageforembeddingdistributedsoftwareagents.EachindependentpieceofsoftwareregistersitselfanditscapabilitiestotheORB,bymeansofanIDL(InterfaceDefinitionLanguage).VisittheirWebsite(seeResources)fortechnicalinformation,downloads,anddocumentationforCORBA.TANGO/TACO:Thissoftwaremightbeusefulforcontrollingaroboticssystemwithmultipledevicesandtools.TANGOisanobjectorientedcontrolsystembasedonCORBA.DeviceserverscanbewritteninC++orJava.TACOisobjectorientedbecauseittreatsall(physicalandlogical)controlpointsinacontrolsystemasobjectsinadistributedenvironment.Allacti