姥姥精讀團(tuán)105第三節(jié)

姥姥精讀團(tuán)105正課第三LondonSwaying 每月兩期精5到7有語(yǔ)LondonSwayingAInSeptember1996,acompetitionwasorganizedbytheFinancialTimesinassociationwiththeLondonBoroughofSouthwarktodesignanewfootbridgeacrosstheThames.Thecompetitionattractedover200entriesandwaswonbyateamcomprisingArup(engineers),FosterandPartners(architects)andthesculptorSirAnthonyCaro.每每月兩期精5到7有語(yǔ)LondonSwayingBThebridgeopenedtothepublicon10June2000.Upto100,000peoplecrosseditthatdaywithupto2000peopleonthebridgeatanyonetime.Atfirst,thebridgewasstiIl.Thenitbegantosway,justslightly.Then,almostfromonemomenttothenext,whenlargegroupsofpeoplewerecrossing,thewobbleintensified.Thismovementbecamesufficientlylargeforpeopletostopwalkingtoretaintheirbalanceandsometimestoholdontothehandrailsforsupport.Itwasdecidedimmedia ytolimitthenumberofpeopleonthebridge,butevensothedeckmovementwassufficienttobefortableandtoraiseconcernforpublicsafetysothaton12Junethebridgewascloseduntiltheproblemcouldbesolved.每月兩期精5到7有語(yǔ)LondonSwayingCTheembarrassedengineersfoundthe tapethatdaywhichshowedthecenterspanswayingabout3inche etosideeverysecond.Theengineersfirstthoughtthatwindsmightbeexertingexcessiveforceonthemanylargeflagsandbannersbedeckingthebridgeforitsgalae.What'smore,theyalsodiscoveredthatthepedestriansalsoplayedakeyrole.Humanactivities,suchaswalking,running,jum swaying,etc.couldcausehorizontalforceswhichinturncouldcauseexcessivedynamicvibrationinthelateraldirectioninthebridge.Asthestructurebeganmoving,pedestriansadjustedtheirgaittothesamelateralrhythmasthebridge.每月兩期精5到7有語(yǔ)LondonSwayingC esmorecomfortableforthepedestrianstowalkinsynchronisationwiththebridgemovement(hence,`synchronousexcitationThisinstinctivebehaviourensuresthatthelateralforcesexertedbythepedestriansmatchtheresonantfrequencyofthebridgeandtheadjustedfootstepsmagnifiedthemotion一justlikewhenfourpeopleallstandupinasmallboatatthesametime.Asmorepedestrianslockedintothesamerhythmtheincreasingoscillationsledtothedramaticswayingcapturedon每每月兩期精5到7有語(yǔ)LondonSwayingDInordertodesignamethodofreducingthemovements,theforceexertedbythepedestrianshadtobe fiedandrelatedtothemotionofthebridge.Althoughtherearesomedescriptionsofthisphenomenoninexistingliterature,noneoftheseactually fiestheforce.Sotherewas yticalwaytodesignthebridgeagainstthiseffect.Animmediateresearchprogramwaslaunchedbythebridge'sengineeringdesignersOverArup,supportedbyanumberofuniversitiesandresearch每月兩期精5到7有語(yǔ)LondonSwayingEThetestsattheUniversityofSouthamptoninvolveda thespot'onasmallshaketable.ThetestsatImperialCollegeinvolvedswalkingalongaspeciallybuilt,7.2metre-longplatformwhichcouldbedrivenlaterallyatdifferentfrequenciesandamplitudes.EachtypeoftesthaditsIimitations.TheImperialCollegetestswereonlyabletocapture7-8footsteps,andthe`walkingonthespot'tests,althoughmonitoringmanyfootsteps,couldnotinvestigatenormalforwardwalking.Neithertestcouldinvestigateanyinfluenceofotherpeopleinacrowdthebehavioroftheindividualbeing每月兩期精5到7有語(yǔ)LondonSwayingFTheresultsofthelaboratorytestsprovidedinformationwhichenabledtheinitialdesignofaretro-fittobeprogressed.However,thelimitationsofthesetestswereclearanditwasfeltthattheonlywaytoreplicateproperlythepreciseconditionsoftheMillenniumBridgewastocarryoutcrowdtestsonthebridgedeckitself.ThesetestsdonebytheArupengineerscouldincorporatefactorsnotpossibleinthelaboratorytests.ThefirstofthesewascarriedoutwithI00peopleinJuly2000.Theresultsofthesetestswereusedtorefinetheloadmodelforthepedestrians.AsecondseriesofcrowdtestswascarriedoutonthebridgeinDecember2000.Thepurposeofthesetestswastofurthervalidatethedesignassumptionsandtoloadtestaprototypedamperinstallation.Thetestwascarriedoutwith275people.每每月兩期精5到7有語(yǔ)LondonSwayingGUnlesstheusageofthebridgewastobegreatlyrestricted,onlytwogenericoptionstoimproveitsperformancewereconsideredfeasible.Thefirstwastoincreasethestiffnessofthebridgetomoveallitslateralnaturalfrequenciesoutoftherangethatcouldbeexcitedbythelateralfootfallforces,andthesecondwastoincreasethedam ofthebridgetoreducetheresonantresponse.每月兩期精5到7有語(yǔ)WhichFOURofthefollowingsituationswerewitnessedontheopeningEeremonyofthebridge?ATheVibrationfrequencyofoscillationBAlltheengineerswenttoseetheceremonythatCOnlookersexpressedastonishmenttodesignofthisDLateralwagglehappenedontheEVisitorscanhardlymakeamoveonthebridgeFThebridgefelldownwhenpeopletriedtoretaintheirGThepedestrianscouldnoticethevibrationHTheopening-dayceremonywasheldonacloudyandrainy每月兩期精5到7有語(yǔ)UsingNOMORETHANTHREEWORDSforeachAftertheopeningceremony,theembarrassedengineerstriedtofindoutthereasonofthebridge'swobbling.Judgedfromthe theexcessiveforcecreatedby18 and19 mightbemainreason.Thedistributionof20 resultedfromhumanactivitiescouldgiveriseto21 throughoutthestructure.Thisconcussionpromptedpeopletostartadjustingthewaytheywalktokeepbalance,whichinturnreinforcedthe22 每月兩期精5到7有語(yǔ)ChooseNOMORETHANTHREEWORDSforeachResearchprogramslaunchedbyuniversityandThetrialat23 ‘Walkingonthespot’atSouthamptonCrowdtrialleadedby25 Limitedabilitytohave7-8footstepsNotenoughdataon24 Aimtomakeafurtherconfirm 每每月兩期精5到7有語(yǔ)Manor 每月兩期精5到7有語(yǔ)ManorDuringJuly2003,theMuseumofScienceinCambridge,MassachusettsexhibitedwhatHondacall`theworld'smostadvancedhumanoidrobot',ASIMO(theAdvancedStepinInnovativeMobility)Honda'sbrainchildisontourinNorthAmericaanddelightingaudienceswhereveritgoesAfter17yearsinthemaking,ASIMOstandsatfourfeettall,weighsaroundI15poundsandlookslikeachildinanastronaut'ssuit.ThoughitisdifficulttoseeASlMO'sfaceatadistance,oncloserinspectionithasas andtwolarge`eyes'thatconcealcameras.Therobotcannotworkautonomously一itsactionsareremotecontrolledbyscientiststhroughthecomputerinitsbackpack.YetwatchingASMlOperformatashowinMassachusetts,itseemeduncannilyhuman.每月兩期精5到7有語(yǔ)ManorTheaudiencecheeredasASIMOwalkedforwardsandbackwards,sidetosideandupanddownstairs.ASIMOcanpunchtheair(asiftosay,`Yes!'),mimicshruggingitsshoulders,clap,shakehandsandtakeabow.ItcanevendancetotheHawaiianHuIla.Aftertheshow,anumberofpeopletoldmethattheywouldlikerobotstoplaymoreofaroleindailylife一oneevensaidthattherobotwouldbelike`another '.Thesegesturesignalsaregoodtoentertaintheaudience一buttheyarealsopartofabroaderprogrammebyscientiststofacilitaterobots'entryintohumanculture.每月兩期精5到7有語(yǔ)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.每月兩期精5到7有語(yǔ)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.每月兩期精5到7有語(yǔ)ManorMITisgettingfurthestdowntheroadtocreatinghuman-likeandinteractiverobots.SomescientistsarguethatASIMOisagreatengineeringfeatbutnotanin ligentmachine一becauseitisunabletointeractautonomouslywithunpredictabilitiesini vironmentinmeaningfulways,andlearnfromexperience.RobotslikeCogandKismetandnewrobotsatMIT'sCSAILandmedialab,however,arebeginningtodothis.每月兩期精5到7有語(yǔ)ManorTheseareexcitingdevelopmentsCreatingamachinethatcanwalkmakegesturesandlearnfromi vironmentisanamazingachievement.Andwatchthisspace:theseachievementsarelikelyrapidlytobeimprovedupon.Humanoidrobotscouldhaveaplethoraofusesinsociety,hel freepeoplefromeverydaytasksInJapanforexample,thereisanaimtocreaterobotsthatcandothetaskssimilartoa agehuman,andalsoactinmoresophisticatedsituationsasfirefighters,astronautsormedicalassistantstotheelderlyintheworkplaceandinhomes一partlyinordertocounterbalancetheeffectsofanagingpopulation.每月兩期精5到7有語(yǔ)Manor每月兩期精5到7有語(yǔ)Soinadditiontothesepotentiallycreativeplans,thereliesacertaindehumanisation.Suchrobotssaymuchaboutthewayinwhichweviewhumanity,andtheybringoutthebestandworstofus.Thetensionbetweenthedehumanisedandcreativeaspectsofrobotshaslongbeenexploredinculture.Ononehand,thesedevelopmentsexpresshumancreativity一ourabilitytoinventexperiment,andtoextendourcontrolovertheword.Ontheotherhand,theaimtocreatearobotlikeahumanbeingisspurredonbydehumanizedid