姥姥精读团105第三节

姥姥精读团105正课第三LondonSwaying 每月两期精5到7有语LondonSwayingAInSeptember1996,acompetitionwasorganizedbytheFinancialTimesinassociationwiththeLondonBoroughofSouthwarktodesignanewfootbridgeacrosstheThames.Thecompetitionattractedover200entriesandwaswonbyateamcomprisingArup(engineers),FosterandPartners(architects)andthesculptorSirAnthonyCaro.每每月两期精5到7有语LondonSwayingBThebridgeopenedtothepublicon10June2000.Upto100,000peoplecrosseditthatdaywithupto2000peopleonthebridgeatanyonetime.Atfirst,thebridgewasstiIl.Thenitbegantosway,justslightly.Then,almostfromonemomenttothenext,whenlargegroupsofpeoplewerecrossing,thewobbleintensified.Thismovementbecamesufficientlylargeforpeopletostopwalkingtoretaintheirbalanceandsometimestoholdontothehandrailsforsupport.Itwasdecidedimmedia ytolimitthenumberofpeopleonthebridge,butevensothedeckmovementwassufficienttobefortableandtoraiseconcernforpublicsafetysothaton12Junethebridgewascloseduntiltheproblemcouldbesolved.每月两期精5到7有语LondonSwayingCTheembarrassedengineersfoundthe tapethatdaywhichshowedthecenterspanswayingabout3inche etosideeverysecond.Theengineersfirstthoughtthatwindsmightbeexertingexcessiveforceonthemanylargeflagsandbannersbedeckingthebridgeforitsgalae.What'smore,theyalsodiscoveredthatthepedestriansalsoplayedakeyrole.Humanactivities,suchaswalking,running,jum swaying,etc.couldcausehorizontalforceswhichinturncouldcauseexcessivedynamicvibrationinthelateraldirectioninthebridge.Asthestructurebeganmoving,pedestriansadjustedtheirgaittothesamelateralrhythmasthebridge.每月两期精5到7有语LondonSwayingC esmorecomfortableforthepedestrianstowalkinsynchronisationwiththebridgemovement(hence,`synchronousexcitationThisinstinctivebehaviourensuresthatthelateralforcesexertedbythepedestriansmatchtheresonantfrequencyofthebridgeandtheadjustedfootstepsmagnifiedthemotion一justlikewhenfourpeopleallstandupinasmallboatatthesametime.Asmorepedestrianslockedintothesamerhythmtheincreasingoscillationsledtothedramaticswayingcapturedon每每月两期精5到7有语LondonSwayingDInordertodesignamethodofreducingthemovements,theforceexertedbythepedestrianshadtobe fiedandrelatedtothemotionofthebridge.Althoughtherearesomedescriptionsofthisphenomenoninexistingliterature,noneoftheseactually fiestheforce.Sotherewas yticalwaytodesignthebridgeagainstthiseffect.Animmediateresearchprogramwaslaunchedbythebridge'sengineeringdesignersOverArup,supportedbyanumberofuniversitiesandresearch每月两期精5到7有语LondonSwayingEThetestsattheUniversityofSouthamptoninvolveda thespot'onasmallshaketable.ThetestsatImperialCollegeinvolvedswalkingalongaspeciallybuilt,7.2metre-longplatformwhichcouldbedrivenlaterallyatdifferentfrequenciesandamplitudes.EachtypeoftesthaditsIimitations.TheImperialCollegetestswereonlyabletocapture7-8footsteps,andthe`walkingonthespot'tests,althoughmonitoringmanyfootsteps,couldnotinvestigatenormalforwardwalking.Neithertestcouldinvestigateanyinfluenceofotherpeopleinacrowdthebehavioroftheindividualbeing每月两期精5到7有语LondonSwayingFTheresultsofthelaboratorytestsprovidedinformationwhichenabledtheinitialdesignofaretro-fittobeprogressed.However,thelimitationsofthesetestswereclearanditwasfeltthattheonlywaytoreplicateproperlythepreciseconditionsoftheMillenniumBridgewastocarryoutcrowdtestsonthebridgedeckitself.ThesetestsdonebytheArupengineerscouldincorporatefactorsnotpossibleinthelaboratorytests.ThefirstofthesewascarriedoutwithI00peopleinJuly2000.Theresultsofthesetestswereusedtorefinetheloadmodelforthepedestrians.AsecondseriesofcrowdtestswascarriedoutonthebridgeinDecember2000.Thepurposeofthesetestswastofurthervalidatethedesignassumptionsandtoloadtestaprototypedamperinstallation.Thetestwascarriedoutwith275people.每每月两期精5到7有语LondonSwayingGUnlesstheusageofthebridgewastobegreatlyrestricted,onlytwogenericoptionstoimproveitsperformancewereconsideredfeasible.Thefirstwastoincreasethestiffnessofthebridgetomoveallitslateralnaturalfrequenciesoutoftherangethatcouldbeexcitedbythelateralfootfallforces,andthesecondwastoincreasethedam ofthebridgetoreducetheresonantresponse.每月两期精5到7有语WhichFOURofthefollowingsituationswerewitnessedontheopeningEeremonyofthebridge?ATheVibrationfrequencyofoscillationBAlltheengineerswenttoseetheceremonythatCOnlookersexpressedastonishmenttodesignofthisDLateralwagglehappenedontheEVisitorscanhardlymakeamoveonthebridgeFThebridgefelldownwhenpeopletriedtoretaintheirGThepedestrianscouldnoticethevibrationHTheopening-dayceremonywasheldonacloudyandrainy每月两期精5到7有语UsingNOMORETHANTHREEWORDSforeachAftertheopeningceremony,theembarrassedengineerstriedtofindoutthereasonofthebridge'swobbling.Judgedfromthe theexcessiveforcecreatedby18 and19 mightbemainreason.Thedistributionof20 resultedfromhumanactivitiescouldgiveriseto21 throughoutthestructure.Thisconcussionpromptedpeopletostartadjustingthewaytheywalktokeepbalance,whichinturnreinforcedthe22 每月两期精5到7有语ChooseNOMORETHANTHREEWORDSforeachResearchprogramslaunchedbyuniversityandThetrialat23 ‘Walkingonthespot’atSouthamptonCrowdtrialleadedby25 Limitedabilitytohave7-8footstepsNotenoughdataon24 Aimtomakeafurtherconfirm 每每月两期精5到7有语Manor 每月两期精5到7有语ManorDuringJuly2003,theMuseumofScienceinCambridge,MassachusettsexhibitedwhatHondacall`theworld'smostadvancedhumanoidrobot',ASIMO(theAdvancedStepinInnovativeMobility)Honda'sbrainchildisontourinNorthAmericaanddelightingaudienceswhereveritgoesAfter17yearsinthemaking,ASIMOstandsatfourfeettall,weighsaroundI15poundsandlookslikeachildinanastronaut'ssuit.ThoughitisdifficulttoseeASlMO'sfaceatadistance,oncloserinspectionithasas andtwolarge`eyes'thatconcealcameras.Therobotcannotworkautonomously一itsactionsareremotecontrolledbyscientiststhroughthecomputerinitsbackpack.YetwatchingASMlOperformatashowinMassachusetts,itseemeduncannilyhuman.每月两期精5到7有语ManorTheaudiencecheeredasASIMOwalkedforwardsandbackwards,sidetosideandupanddownstairs.ASIMOcanpunchtheair(asiftosay,`Yes!'),mimicshruggingitsshoulders,clap,shakehandsandtakeabow.ItcanevendancetotheHawaiianHuIla.Aftertheshow,anumberofpeopletoldmethattheywouldlikerobotstoplaymoreofaroleindailylife一oneevensaidthattherobotwouldbelike`another '.Thesegesturesignalsaregoodtoentertaintheaudience一buttheyarealsopartofabroaderprogrammebyscientiststofacilitaterobots'entryintohumanculture.每月两期精5到7有语ManorWhiletheJapanesehavemadehugestridesinsolvingsomeoftheengineeringproblemsofhumankineticsandbipedalmovementsforthepast10yearsscientistsatMIT'sformerArtificialIn ligence(AI)lab(recentlyrenamedtheComputerScienceandArtificialIn Laboratory,CSALL)havebeenmakingrobotsthatcanbehavelikehumansandinteractwithhumans.OneofMIT'srobots,Kismet,isananthropomorphicheadandhastwoeyes(completewitheyelids),ears,amouth,andeyebrows.Ithasseveralfacialexpressionsincludinghappy,sad,frightenedanddisgusted.Humaninterlocutorsareabletoreadsomeoftherobot'sfacialexpressions,andoftenchangetheirbehaviortowardsthemachineasaresult一forexampleplayingwithitwhenitappears`sad'.KismetisnowinMIT'smuseumbuttheideasdevelopedherecontinuetobeexploredinnewrobots.每月两期精5到7有语ManorCog(shortforCognition)isanotherpioneeringprojectfromMIT'SformerAllab.Coghasaheadeyestwoarmshandsandatorso一anditsproportionswereoriginallymeasuredfromthebodyofaresearcherintheIab.TheworkonCoghasbeenusedtotesttheoriesofembodimentviasensors,andtoimprove ligencethroughthesetypesofinteractions.ThisapproachtoAIwasthoughtupanddevelopedbyateamofstudentsandresearchersledbytheheadofMIT'sformerAllab,RodneyBrooks(nowheadofCSAIL),andrepresenteda ynewdevelopment.Anotherradicalapproach developedbyBrookswasbehaviour-basedrobotics.WhileconventionalapproachestoAIrobotsmightwanttomapalltheelementsthatareintherobo vironmentsothatitsbehaviourcouldbecomple ypre-plannedbeforehand,behaviour-basedroboticsfocusesinsteadongettingthemachinetoactautonomously.每月两期精5到7有语ManorMITisgettingfurthestdowntheroadtocreatinghuman-likeandinteractiverobots.SomescientistsarguethatASIMOisagreatengineeringfeatbutnotanin ligentmachine一becauseitisunabletointeractautonomouslywithunpredictabilitiesini vironmentinmeaningfulways,andlearnfromexperience.RobotslikeCogandKismetandnewrobotsatMIT'sCSAILandmedialab,however,arebeginningtodothis.每月两期精5到7有语ManorTheseareexcitingdevelopmentsCreatingamachinethatcanwalkmakegesturesandlearnfromi vironmentisanamazingachievement.Andwatchthisspace:theseachievementsarelikelyrapidlytobeimprovedupon.Humanoidrobotscouldhaveaplethoraofusesinsociety,hel freepeoplefromeverydaytasksInJapanforexample,thereisanaimtocreaterobotsthatcandothetaskssimilartoa agehuman,andalsoactinmoresophisticatedsituationsasfirefighters,astronautsormedicalassistantstotheelderlyintheworkplaceandinhomes一partlyinordertocounterbalancetheeffectsofanagingpopulation.每月两期精5到7有语Manor每月两期精5到7有语Soinadditiontothesepotentiallycreativeplans,thereliesacertaindehumanisation.Suchrobotssaymuchaboutthewayinwhichweviewhumanity,andtheybringoutthebestandworstofus.Thetensionbetweenthedehumanisedandcreativeaspectsofrobotshaslongbeenexploredinculture.Ononehand,thesedevelopmentsexpresshumancreativity一ourabilitytoinventexperiment,andtoextendourcontrolovertheword.Ontheotherhand,theaimtocreatearobotlikeahumanbeingisspurredonbydehumanizedid