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簡介:中文中文6512字出處出處INTERNATIONALJOURNALOFPRECISIONENGINEERINGANDMANUFACTURING,2010,1113947DEVELOPMENTOFA3AXISDESKTOPMILLINGMACHINEANDACNCSYSTEMUSINGADVANCEDMODERNCONTROLALGORITHMSKIMBS,ROSK,PARKJK1INTRODUCTIONASNEWFIELDSSUCHASITINFORMATIONTECHNOLOGY,BTBIOTECHNOLOGYANDNTNANOTECHNOLOGYEMERGEASADRIVINGFORCEINTHEINDUSTRY,THEINTERESTSINMICROFACTORYSYSTEMHAVEBEENGROWINGTHEMICROFACTORYISAMINIATURIZEDFLEXIBLEMANUFACTURINGSYSTEMWHICHCONSUMESMINIMALSPACEANDENERGYCOMPAREDTOTHECONVENTIONALONE,ANDITISDESIREDTOPRODUCEMICRO/MESOSIZEMECHANICALCOMPONENTSNECESSARYFORIT,BTANDNTAPPLICATIONSMAJORTECHNICALUNITSCONTRIBUTINGTOMICROMECHANICALMACHININGSYSTEMSARE,TONAMEAFEW,HIGHSPEEDSPINDLESYSTEMS,MICROHIGHPRECISIONFEEDINGSYSTEMS,CONTROLSYSTEMSTOGENERATECOORDINATEDMOTIONS,TOOLINGANDCHUCKINGSYSTEMS,FRAMEDESIGNANDMODULEALLOCATIONSCHEMESBASEDUPONOPTIMIZATIONFORHIGHSTIFFNESSRESEARCHERSHAVEBEENTRYINGTOPUTMICROTECHNOLOGIESTOGETHERTOBUILDMICROFACTORYSYSTEMSWHICHMAKEMICRO/MESOSIZEPRECISIONPARTSTOMEETTHENEEDSFROMTHEMANUFACTURINGINDUSTRY1INTHISPAPER,WEPRESENTAMINIATURIZED3AXISMILLINGMACHINEANDADEDICATEDCNCSYSTEMFORTHEMACHINETHE3AXISMILLINGMACHINEISCONSTRUCTEDASONEOFMICROFACTORYMODULEANDDESIGNEDTOPRODUCEHIGHPRECISIONMICROPARTSITHASADESKTOPSIZEOF200300200MM3ANDISSERVINGASOURTESTBEDMACHINEFROMFINITEELEMENTANALYSISANDANIMPACTHAMMERTEST,WEHAVEVERIFIEDTHATITHASAGOODSTRUCTURALSTIFFNESSANDHIGHNATURALFREQUENCIESAHIGHSPEEDAIRTURBINESPINDLEONTHEHORIZONTALZAXISCANRUNATUPTO160,000RPMTHIS3AXISMILLINGMACHINEWASPUTUNDERREALMACHININGTESTSANDITSUCCESSFULLYDEMONSTRATEDITSMACHININGCAPABILITIESACNCSYSTEMWASDEVELOPEDFOROPERATIONOFTHE3AXISDESKTOPMILLINGMACHINETHECNCSYSTEMINCLUDESAGCODEINTERPRETERWHICHCANPROCESSABASICSETOFGCODESANDMCODESINREALTIMETHECNCSYSTEMCONSISTSOFTWOPARTSTHEONEISAGRAPHICALUSERINTERFACEWHICHRUNSUNDERMICROSOFTWINDOWS,ANDTHEOTHERISADSPPROGRAMWHICHINTERPOLATESCOMMANDSANDEXECUTESAREALTIMESERVOCONTROLTWOPARTSCOMMUNICATEEACHOTHERTHROUGHADUALPORTRAMRANDOMACCESSMEMORYJOBASSIGNMENTSFORTHETWOPARTSAREDISCUSSEDINDETAILINTHISPAPERTOIMPROVETHEPERFORMANCEOFTHECNCSYSTEMFORTHE3AXISMILLINGMACHINEBEYONDTHETRADITIONALPIDTYPECONTROL,DIFFERENTCONTROLSCHEMESHAVEBEENTESTEDINCLUDINGH∞CONTROL,INPUTSHAPINGCONTROL,DISTURBANCEOBSERVERANDCROSSCOUPLEDCONTROLONTHE321STATICANDDYNAMICANALYSISFINITEELEMENTANALYSISWASDONETOINVESTIGATETHESTATICANDDYNAMICCHARACTERISTICSOFTHEDESIGNED3AXISMILLINGMACHINEUSINGAFINITEELEMENTMODELASSHOWNINFIG3THECOMPUTATIONALRESULTSSHOWEDTHATTHEDEFLECTIONDUETOITSOWNWEIGHTWASNEGLIGIBLEWHENA10NFORCEWASLOCATEDATTHEMACHININGPOSITIONINZDIRECTION,THENUMERICALRESULTSSHOWEDTHATTHEDISPLACEMENTCHANGEATTHEWORKTABLEWOULDBEABOUT007,ANDTHEBACKFAMEWOULDUNDERGOLESSTHAN002DEFLECTIONINZDIRECTIONITSEEMSTHATTHE3AXISMILLINGMACHINEHASGOODSTIFFNESSDUETOGOODFRAMEDESIGNANDAPAIROFSMALLLMGUIDESSUPPORTINGEACHXANDYDIRECTIONTHEMODALANALYSISREVEALEDMANYIMPORTANTDYNAMICMODESOFTHE3AXISMILLINGMACHINEWEUSEDTHEIMPACTHAMMERTESTTOVERIFYTHECOMPUTEDNATURALFREQUENCIESTHEMEASUREDNATURALFREQUENCIESDONOTEXACTLYMATCHTHECOMPUTEDONES,BUTTHEINDICATEDFREQUENCYRANGEFROMTHEFINITEELEMENTMODALANALYSISWASSIMILARTOTHATFROMTHEIMPACTHAMMERTESTFIG4ANDTABLE1SHOWTHEMEASUREDNATURALFREQUENCIESANDCORRESPONDINGFREQUENCYRESPONSEFUNCTIONOFTHE3AXISMILLINGMACHINEITCANBESEENTHATTHENATURALFREQUENCIESOFZAXISSTAGE,WHICHISSUPPOSEDTOBELOWINSTIFFNESSDUETOITSAIRBEARING,LOCATEATARANGEOF250390HZTHENATURALFREQUENCYOFTHEXYSTAGESHOWSATABOUT400AND710HZAND,FORTHEBACKFRAME,ITISAROUND440AND640HZITSEEMSTHATTHEDESIGNEDMINIATURIZED3AXISMILLINGMACHINEHASHIGHERNATURALFREQUENCIESTHANCONVENTIONALMACHINETOOLS
下載積分: 10 賞幣
上傳時間:2024-03-16
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大?。?0.98(MB)
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簡介:中文中文6420字,字,4000單詞,單詞,2萬英文字符萬英文字符出處出處OSSWALDD,WRNHMECHANICALSYSTEMANDCONTROLSYSTEMOFADEXTEROUSROBOTHANDC//2004機械手的機械和控制系統(tǒng)DOSSWALD,HWRN摘要最近,全球內(nèi)帶有多指夾子或手的機械人系統(tǒng)已經(jīng)發(fā)展起來了,多種方法應(yīng)用其上,有擬人化的和非擬人化的。不僅調(diào)查了這些系統(tǒng)的機械結(jié)構(gòu),而且還包括其必要的控制系統(tǒng)。如同人手一樣,這些機械人系統(tǒng)可以用它們的手去抓不同的物體,而不用改換夾子。這些機械手具備特殊的運動能力(比如小質(zhì)量和小慣性),這使被抓物體在機械手的工作范圍內(nèi)做更復(fù)雜、更精確的操作變得可能。這些復(fù)雜的操作被抓物體繞任意角度和軸旋轉(zhuǎn)。本文概述了這種機械手的一般設(shè)計方法,同時給出了此類機械手的一個示例,如卡爾斯魯厄靈巧手Ⅱ。本文末介紹了一些新的構(gòu)想,如利用液體驅(qū)動器為類人型機器人設(shè)計一個全新的機械手。關(guān)鍵詞多指機械手;機器人手;精操作;機械系統(tǒng);控制系統(tǒng)11引言引言2001年6月在德國卡爾斯魯厄開展的“人形機器人”特別研究,是為了開發(fā)在正常環(huán)境(如廚房或客廳)下能夠和人類合作和互動的機器人系統(tǒng)。設(shè)計這些機器人系統(tǒng)是為了能夠在非專業(yè)、非工業(yè)的條件下(如身處多物之中),幫我們抓取不同尺寸、形狀和重量的物體。同時,它們必須能夠很好的操縱被抓物體。這種極強的靈活性只能通過一個適應(yīng)性極強的機械人手抓系統(tǒng)來獲得,即所謂的多指機械手或機器人手。上文提到的研究項目,就是要制造一個人形機器人,此機器人將裝備這種機器人手系統(tǒng)。這個新手將由兩個機構(gòu)合作制造,它們是卡爾斯魯厄大學(xué)的IPR(過程控制和機器人技術(shù)研究院)和C(計算機應(yīng)用科學(xué)研究院)。這兩個組織都有制造此種系統(tǒng)的相關(guān)經(jīng)驗,但是稍有不同的觀點。IPR制造的卡爾斯魯厄靈巧手Ⅱ(如圖1所示),是一個四指相互獨立的手爪,我要確定手指的尺寸和安置位置,可以采用兩種方法擬人化和非擬人化。然后將取決與被操作的物體以及選擇何種期望的操作類型。擬人化的安置方式很容易從人手到機器人手轉(zhuǎn)移抓取意圖。但是每個手指不同的尺寸和不對稱的安置位置將增加加工費用,并且是其控制系統(tǒng)變得更加復(fù)雜,因為每個手指都必須分別加以控制。對于相同手指的對稱布置,常采用非擬人化方法。因為只需加工和構(gòu)建單一的“手指模塊”,因此可減少加工費用,同時也可是控制系統(tǒng)簡化。32驅(qū)動系統(tǒng)指關(guān)節(jié)的驅(qū)動器對手的靈活度也有很大的影響,因為它決定潛在的力量、精度及關(guān)節(jié)運動的速度。機械運動的兩個方面需加以考慮運動來源和運動方向。在這方面,文獻(xiàn)里描述了有幾種不同的方法,如文獻(xiàn)3中說可由液壓缸或氣壓缸產(chǎn)生運動,或者,正如大部分情況一樣使用電動機。在多數(shù)情況下,運動驅(qū)動器(如電機)太大而不能直接與相應(yīng)的指關(guān)節(jié)結(jié)合在一起,因此,這個運動必須由驅(qū)動器(一般位于機器臂最后的連接點處)轉(zhuǎn)移過來。有幾種不同的方法可實現(xiàn)這種運動方式,如使用鍵、傳動帶以及活動軸。使用這種間接驅(qū)動指關(guān)節(jié)的方法,或多或少地降低了整個系統(tǒng)的強度和精度,同時也使控制系統(tǒng)復(fù)雜化,因為每根手指的不同關(guān)節(jié)常常是機械地連在一起,但是在控制系統(tǒng)的軟件里卻要將它們分別獨立控制。由于具有這些缺點,因此小型化的運動驅(qū)動器與指關(guān)節(jié)的直接融合就顯得相當(dāng)必要。33傳感系統(tǒng)機器手的傳感系統(tǒng)可將反饋信息從硬件傳給控制軟件。對手指或被抓物體建立一個閉環(huán)控制是很必要的。在機器手中使用了3種類型的傳感器1手爪狀態(tài)傳感器確定指關(guān)節(jié)和指尖的位置以及手指上的作用力情況。知道了指尖的精確位置將使精確控制變得可能。另外,知道手指作用在被抓物體上的力,就可以抓取易碎物件而不會打破它。2抓取狀態(tài)傳感器提供手指與被抓物體之間的接觸狀態(tài)信息。這種觸覺信息可在抓取過程中及時確定與物體第一次接觸的位置點,同時也可避免不正確的抓取,如抓到物體的邊緣和尖端。另外還能察覺到已抓物體是否滑落,從而避免物體因跌落而損壞。3物體狀態(tài)或姿態(tài)傳感器用于確定手指內(nèi)物體的形狀、位置和方向。如果在抓取物體之前并不清楚這些信息的情況下,這種傳感器是非常必要的。如果此傳感器還能作用
下載積分: 4 賞幣
上傳時間:2024-05-21
頁數(shù): 11
大小: 3.02(MB)
子文件數(shù):
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簡介:1SOUTHWESTPETROLEUMUNIVERSITYGRADUATIONTHESISCONTACTELIMINATIONINMECHANICALFACESEALSUSINGACTIVECONTROLGRADENAMESPECIALITYPROCESSEQUIPMENTANDCONTROLINSTRUCTORSOUTHWESTPETROLEUMUNIVERSITY201062們的位置并不在接觸的位置一定的權(quán)利。熱慣量也必須考慮到事件發(fā)生的預(yù)測和控制之間的時間延遲激活。整體而言,溫度測量是不是直接測量間隙,因此,這種方式才是最重要的它可能無法檢測到破壞,即情況下,接觸密封操作。在本研究中,減少偏差和相對減少了密封面接觸的可能性各種方式進(jìn)行了介紹和審議。第一次接觸是監(jiān)測從使用渦流探頭密封的動態(tài)行為。這些提供適當(dāng)或不當(dāng)行為密封瞬時信息。然后,控制策略以及控制系統(tǒng)的開發(fā)和實施,以保持盡可能清除,相對偏差小,以保證非接觸式的FMR機械端面密封操作。22間歇面對面接觸間歇面對面接觸一個基本的描述和命名富達(dá)機械密封給出了圖1(見本運動學(xué)模型的細(xì)節(jié)5)。大壩是密封的轉(zhuǎn)子之間的傾斜面和固定定子(也都顯示在圖2)面積。為了減少磨損,其中之一的面孔通常是由較軟的材料,例如,碳石墨。在操作過程中面臨升空到一定中心線間隙,C,而較軟的材料也歪曲因為機械和熱變形,由錐角,Β代表注意,這兩個C和Β非常小(一微米的和弧度,分別順序),因此,圖1不是比例顯示這些尺寸參數(shù)。腦脊液漏由于在密封的壓力降產(chǎn)生的情況將通過Β(如圖1。流從中心向周邊地區(qū)發(fā)生)造成的流體流動匯流的差距。理想情況下,密封面垂直排列軸和相互平行。正如其名稱所暗示的,不應(yīng)該有任何的接觸過程中的非接觸式機械密封操作。然而,在現(xiàn)實中,在操作過程中接觸可能會出現(xiàn)由于大相對密封面之間的錯位。相對偏差之間的密封面,Γ(見圖1),是制造和裝配公差,機械惡化,或在工藝操作,彎曲軸,密封面接觸等干擾的結(jié)果,不僅會產(chǎn)生影響力量,是不容易預(yù)測,但同時也增加了摩擦和磨損的端面和產(chǎn)生熱量的延長。
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上傳時間:2024-03-16
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大?。?0.65(MB)
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下載積分: 10 賞幣
上傳時間:2024-03-15
頁數(shù): 18
大?。?4.29(MB)
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簡介:鄭州航空工業(yè)管理學(xué)院英文翻譯2012屆機械設(shè)計制造及其在自動化專業(yè)1006962班級姓名郝振興學(xué)號100696208指導(dǎo)教師賀紅霞職稱教授二О一二年三月十二日21THETIMEBACKGROUNDOFMATERIALPROCESSINGMACHINEINTHELONGSPANOFHISTORYOFHUMANPROGRESS,MANYTOOLS,MACHINESANDMETHODSWERECREATEDANDAVARIETYOFMATERIALSWITHDIFFERENTPROPERTIESWEREPROCESSEDMATERIALSANDITSPROCESSINGHAVEBECOMEONEOFPILLARANDDRIVINGFORCEOFMANKINDPROGRESSINPACEWITHMULTIPOLARCOMPETITIONINCURRENTWORLDANDPEOPLE’SSTRIVINGPERSEVERINGLYFORHAPPIERLIFE,MATERIALFUNCTIONGOESBEYONDUNCEASINGLYMEN’SKNOWLEDGEANDIMAGINATION,FOREXAMPLE,CRYPTICFUNCTIONMATERIAL,SEMICONDUCTORMATERIAL,ENERGYMATERIAL,VIBRATIONABSORPTIVEMATERIAL,SUPERSTRENGTHALUMINUMALLOYACCOUNTINGFOR70PERCENTOFAPPLICATIONOFAERONAUTICSANDSPACE,METALFOILOF4~5ΜM,DEEPDRAWINGPLATEWITHANISOTROPYBELOW1PERCENT,ELECTRONICALUMINUMFOILWITHMICROORIENTATIONUPTO95PERCENT,HEATRESISTINGALUMINUMALLOYWITHSUPERSTRONGSPECIFICSTRENGTHUSEDINAERONAUTICS,SPACEANDDEEPSEA,ETCTHUSSEVERALIMPORTANTDEVELOPMENTTRENDSWITHDISTINCTTIMEFEATURESINMATERIALPROCESSINGDOMAINARESHAPEDUPASFOLLOWS1CREATINGMATERIALPROCESSINGMACHINEWITHEXTRAORDINARYPHYSICALFIELDFORPROCESSINGMATERIALWITHSPECIALTEXTURESTRUCTURESANDFUNCTIONSFOREXAMPLE,APPLICATIONSOFTHERMALENERGYANDMECHANICALENERGYAREBREAKINGTHROUGHUNCEASINGLYTECHNOLOGYLIMIT,ANDSOMENONTRADITIONENERGY,SUCHASMICROWAVE,CHEMICALENERGY,BIOENERGY,ETC,AREINTRODUCEDINTOMATERIALPROCESSINGPROCEDUREONEAFTERANOTHER,SOTHATSOMEMATERIALPROCESSINGMACHINESWITHEXTRAORDINARYENERGYCIRCUMSTANCEAREPRODUCED2BREAKINGTHROUGHTRADITIONALPHYSICALLIMITSANDINTEGRATINGMELTING,SOLIDIFYING,PLASTICDEFORMATIONANDHEATTREATMENTTOOBTAINSPECIALFUNCTIONOFMATERIALANDCUTDOWNEXPENSES3FOREXAMPLE,NEARNETSHAPINGMATERIALPROCESSINGTECHNOLOGY,SUCHASFASTROLLING,SPRAYINGDEPOSITION,OVERPLASTICMOLDING,INJECTIONMOLDING,HIGHENERGYBEAM,ETC,ISAPPLIED3MATERIALPROCESSINGPROCESSISFORGEDAHEADINTHEDIRECTIONOFHIGHSPEED,HEAVYDUTYANDHIGHACCURACYONLINECONTROL,FORINSTANCE,THEROLLINGSPEEDGOESUPTO130MS1,THEDEFORMATIONPRESSURERISESUPTO300MPA,ACCURACYOFDIMENSIONUPTO01ΜM,ACCURACYOFSHAPEUPTO01I,STRENGTHACCURACYCOMESUPTO01MPAFORTHESEREASONS,ITISNECESSARYFORMATERIALPROCESSINGMACHINEDESIGNTHEORYTOINTEGRATEANDCOALESCEINGENIOUSLYCORRELATIVEFRONTIERSCIENCEANDTECHNOLOGYTOCREATEANDPRODUCESOMENEWCONCEPTMATERIALPROCESSINGMACHINEWITHFOLLOWINGFUNCTIONS
下載積分: 10 賞幣
上傳時間:2024-03-12
頁數(shù): 19
大?。?0.09(MB)
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簡介:4570漢字,漢字,3380單詞,單詞,16萬英文字符萬英文字符出處出處RESEARCHJOURNALOFAPPLIEDSCIENCES,ENGINEERINGANDTECHNOLOGY5413021308,2013本科畢業(yè)論文外文文獻(xiàn)及譯文文獻(xiàn)、資料題目ANEXPERIMENTALANALYSISOFBRAKEEFFICIENCYUSINGFOURFLUIDSINADISCBRAKESYSTEM文獻(xiàn)、資料來源RESEARCHJOURNALOFAPPLIEDSCIENCES文獻(xiàn)、資料發(fā)表日期20120808院(部)機電工程學(xué)院專業(yè)班級姓名學(xué)號指導(dǎo)教師完成日期2AGAINSTTHERESISTANCESTHATOPPOSETHEVEHICLE’SMOTIONRELYINGONTHESERESISTANCESTOSLOWDOWNAVEHICLECOULDCAUSEMANYPROBLEMS,SOANADDITIONALRESISTANCECALLEDABRAKEISNEEDEDTOCONVERTTHEKINETICENERGYTOHEATENERGYATAFASTERRATEINORDERTOREDUCETHESPEEDOFTHEVEHICLEMCPHEEANDJOHNSON2007THISREDUCESTHESPEEDOFTHEVEHICLEATAFASTERRATEANDBRINGSTHEVEHICLETORESTWITHINTHESHORTESTPOSSIBLETIMEWHENTHEBRAKESAREAPPLIEDFROMTHEPOINTOFVIEWOFJOHNSONETAL2003MOSTAUTOMOTIVESYSTEMSINUSETODAYUTILIZEFRONTDISCBRAKES,BUTFOURWHEELDISCSYSTEMSAREALSOCOMMONINDISCBRAKES,THEROTORROTATESWITHTHEWHEELANDTHEPADSMOVEOUTTORUBTHEROTORWHENTHEBRAKESAREAPPLIEDMOSTDISCBRAKESUSEFLOATINGCALIPERSTHECALIPERSLIDESINANDOUTASTHEBRAKESAREAPPLIEDANDRELEASEDTHEPISTONMOVESTHEINSIDEPADOUTANDPUSHESTHEOUTSIDEPADINTOTHEROTORBYSLIDINGTHECALIPERBACKTOWARDTHEROTORTHEUSEOFDISCBRAKESTOREDUCESPEEDORBRINGTHEVEHICLETORESTWHENINMOTIONCANNOTBEOVEREMPHASIZEDIFTHESAFETYOFTHEOCCUPANTISTOBEGUARANTEEDHEINZ1999TOBRINGAVEHICLETOASTOP,THEDISCBRAKESHAVETOABSORBALLTHEENERGYGIVENTOTHEVEHICLEBYTHEENGINEANDTHATDUETOTHEMOMENTUMOFTHEVEHICLETHISENERGYMUSTTHENBEDISSIPATEDINMOSTVEHICLEDISCBRAKES,THEENERGYISABSORBEDBYFRICTION,CONVERTEDINTOHEATANDTHEHEATDISSIPATEDTOTHESURROUNDINGAIRTHOMS,1988ASTHEENERGYISABSORBED,THEVEHICLEISSLOWEDDOWNINOTHERWORDS,ITSMOTIONISRETARDEDTHEBRAKESMUSTALSOPULLUPTHEVEHICLESMOOTHLYANDINASTRAIGHTLINETOBRINGTHEVEHICLETOASTOPPOSITIONITISTHEREFOREVERYIMPORTANTTHATTHEDISCBRAKESOFVEHICLESOPERATEWITHTHEHIGHESTEFFICIENCYTHISCOULDREDUCETHERATEOFACCIDENTSDUETOBRAKEFAILURESOTHATLIFEANDPROPERTYCOULDBEPRESERVEDANDALSOTOENSURETHATOCCUPANTSOFTHESECOMMERCIALVEHICLESGOABOUTTHEIRNORMALLIVESWITHOUTANYFEAROFBEINGINVOLVEDINANACCIDENTAVAILABLECRASHDATAINGHANASUGGESTSTHATABOUT1,900PERSONSAREKILLEDANNUALLYINROADTRAFFICCRASHESAFUKAARETAL,2008ANDTHATMORETHAN40OFTHEROADTRAFFICFATALITIESAREOCCUPANTSOFCARS,BUSESANDTRUCKSMOSTOFTENTHANNOT,SOMEOFTHEROADACCIDENTSINVOLVINGCOMMERCIALVEHICLES,SUCHASTHEMINIBUSESHAVEBEENATTRIBUTEDTOTHEFAILUREOFTHEDISCBRAKESTHEREASONFORTESTINGTHEVISCOSITYOFTHESEBRAKEFLUIDS,ESPECIALLYTHATOFTHE
下載積分: 10 賞幣
上傳時間:2024-03-16
頁數(shù): 21
大?。?0.82(MB)
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上傳時間:2024-03-16
頁數(shù): 12
大小: 1.34(MB)
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簡介:ZZZZZZZ大學(xué)畢業(yè)設(shè)計(論文)外文文獻(xiàn)學(xué)院XXXXXXXX專業(yè)班級XXXXXX學(xué)生姓名XXXXX指導(dǎo)教師XXXXXXTHEMOUNTEDGRINDINGTOOLSWHEELSHAVEBEENWIDELYUSEDINCONVENTIONALMOLDANDDIEFINISHINGINDUSTRIESTHEGEOMETRICMODELOFMOUNTEDGRINDINGTOOLSFORAUTOMATEDSURFACEFINISHINGPROCESSESWASINTRODUCEDINAFINISHINGPROCESSMODEOFSPHERICALGRINDINGTOOLSFORAUTOMATEDSURFACEFINISHINGSYSTEMSWASDEVELOPEDINGRINDINGSPEED,DEPTHOFCUT,FEEDRATE,ANDWHEELPROPERTIESSUCHASABRASIVEMATERIALANDABRASIVEGRAINSIZE,ARETHEDOMINANTPARAMETERSFORTHESPHERICALGRINDINGPROCESS,ASSHOWNINFIG1THEOPTIMALSPHERICALGRINDINGPARAMETERSFORTHEINJECTIONMOLDSTEELHAVENOTYETBEENINVESTIGATEDBASEDINTHELITERATUREFIG1SCHEMATICDIAGRAMOFTHESPHERICALGRINDINGPROCESSINRECENTYEARS,SOMERESEARCHHASBEENCARRIEDOUTINDETERMININGTHEOPTIMALPARAMETERSOFTHEBALLBURNISHINGPROCESSFIG2FORINSTANCE,ITHASBEENFOUNDTHATPLASTICDEFORMATIONONTHEWORKPIECESURFACECANBEREDUCEDBYUSINGATUNGSTENCARBIDEBALLORAROLLER,THUSIMPROVINGTHESURFACEROUGHNESS,SURFACEHARDNESS,ANDFATIGUERESISTANCETHEBURNISHINGPROCESSISACCOMPLISHEDBYMACHININGCENTERSANDLATHESTHEMAINBURNISHINGPARAMETERSHAVINGSIGNIFICANTEFFECTSONTHESURFACEROUGHNESSAREBALLORROLLERMATERIAL,BURNISHINGFORCE,FEEDRATE,BURNISHINGSPEED,LUBRICATION,ANDNUMBEROFBURNISHINGPASSES,AMONGOTHERSTHEOPTIMALSURFACEBURNISHINGPARAMETERSFORTHEPLASTICINJECTIONMOLDSTEELPDS5WEREACOMBINATIONOFGREASELUBRICANT,THE
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上傳時間:2024-05-21
頁數(shù): 22
大?。?0.92(MB)
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簡介:中文中文4240字出處出處CHENW,LUOX,SUH,ETALANINTEGRATEDSYSTEMFORULTRAPRECISIONMACHINETOOLDESIGNINCONCEPTUALANDFUNDAMENTALDESIGNSTAGEJINTERNATIONALJOURNALOFADVANCEDMANUFACTURINGTECHNOLOGY,201517畢業(yè)設(shè)計畢業(yè)設(shè)計論文論文外文資料翻譯外文資料翻譯原文題目目超精密機床設(shè)計的概念和基本設(shè)計階段的綜合系統(tǒng)原文來源源施普林格出版社倫敦2015學(xué)生姓名名學(xué)號號所在院所在院系部部機械工程學(xué)院專業(yè)名稱稱機械設(shè)計制造及其自動化(機械設(shè)計)具體的功能模塊,包括結(jié)構(gòu)設(shè)計與分析、結(jié)構(gòu)設(shè)計、結(jié)構(gòu)分析和支持模塊。該系統(tǒng)快速、方便地進(jìn)行機床結(jié)構(gòu)設(shè)計。WOONG等人利用設(shè)計知識開發(fā)了一種高效、系統(tǒng)的機床設(shè)計智能化軟件系統(tǒng)。CHEN等人使用集成的設(shè)計方法開發(fā)了一種超精密飛切機床三種配置(水平,龍門,塔式)是從配置庫中選擇的候選配置的設(shè)計階段,根據(jù)機床的功能要求,考慮動態(tài)性能的最佳配置選擇。而在以往的研究中,對精密機床的研究主要集中在機床的詳細(xì)設(shè)計和性能分析方面,系統(tǒng)的概念和基本設(shè)計方法很少有報道。在本文中,闡述了對概念和基本設(shè)計階段用于縮短設(shè)計時間、提高精密機床的可靠性超精密機床設(shè)計的集成系統(tǒng)重要性。22超精密機床設(shè)計集成系統(tǒng)超精密機床設(shè)計集成系統(tǒng)21機床的概念和基本設(shè)計過程精密機床是一種高標(biāo)準(zhǔn)的精密系統(tǒng),以維持所需的精度,生產(chǎn)率和可重復(fù)性。一個機器的精度相對于工件表面和相對的結(jié)構(gòu)和動態(tài)循環(huán)的精密切削工具的定位精度的影響,是基本也是重要的機械設(shè)計。因此,機床的結(jié)構(gòu)設(shè)計階段必須考慮機床的剛度循環(huán)和機床運動誤差的問題。此外,機床振動的動態(tài)特性和熱性能是高精度加工的關(guān)鍵問題之一。由于動態(tài)和熱性能的機器受機器的配置影響較大,所以,評估應(yīng)該在設(shè)計階段的早期。然而,只有少數(shù)制造商使用評估工具,以檢查配置的合格性??傊?,在概念和基本設(shè)計階段,必須考慮精密機床設(shè)計的主要因素有以下幾點機床的剛度預(yù)算,動態(tài)性能,熱性能和機床的誤差預(yù)算。機床結(jié)構(gòu)的概念和基本設(shè)計過程分為四個步驟,即,目標(biāo),建模,分析和選擇如圖1所示,提出了幾種配置提出了幾種配置。
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上傳時間:2024-03-16
頁數(shù): 14
大?。?0.43(MB)
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下載積分: 10 賞幣
上傳時間:2024-03-16
頁數(shù): 13
大?。?3.63(MB)
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簡介:1附錄附錄1英文原文SELECTIONOFOPTIMUMTOOLGEOMETRYANDCUTTINGCONDITIONSUSINGASURFACEROUGHNESSPREDICTIONMODELFORENDMILLINGABSTRACTINFLUENCEOFTOOLGEOMETRYONTHEQUALITYOFSURFACEPRODUCEDISWELLKNOWNANDHENCEANYATTEMPTTOASSESSTHEPERFORMANCEOFENDMILLINGSHOULDINCLUDETHETOOLGEOMETRYINTHEPRESENTWORK,EXPERIMENTALSTUDIESHAVEBEENCONDUCTEDTOSEETHEEFFECTOFTOOLGEOMETRYRADIALRAKEANGLEANDNOSERADIUSANDCUTTINGCONDITIONSCUTTINGSPEEDANDFEEDRATEONTHEMACHININGPERFORMANCEDURINGENDMILLINGOFMEDIUMCARBONSTEELTHEFIRSTANDSECONDORDERMATHEMATICALMODELS,INTERMSOFMACHININGPARAMETERS,WEREDEVELOPEDFORSURFACEROUGHNESSPREDICTIONUSINGRESPONSESURFACEMETHODOLOGYRSMONTHEBASISOFEXPERIMENTALRESULTSTHEMODELSELECTEDFOROPTIMIZATIONHASBEENVALIDATEDWITHTHECHISQUARETESTTHESIGNIFICANCEOFTHESEPARAMETERSONSURFACEROUGHNESSHASBEENESTABLISHEDWITHANALYSISOFVARIANCEANATTEMPTHASALSOBEENMADETOOPTIMIZETHESURFACEROUGHNESSPREDICTIONMODELUSINGGENETICALGORITHMSGATHEGAPROGRAMGIVESMINIMUMVALUESOFSURFACEROUGHNESSANDTHEIRRESPECTIVEOPTIMALCONDITIONS1INTRODUCTIONENDMILLINGISONEOFTHEMOSTCOMMONLYUSEDMETALREMOVALOPERATIONSININDUSTRYBECAUSEOFITSABILITYTOREMOVEMATERIALFASTERGIVINGREASONABLYGOODSURFACEQUALITYITISUSEDINAVARIETYOFMANUFACTURINGINDUSTRIESINCLUDINGAEROSPACEANDAUTOMOTIVESECTORS,WHEREQUALITYISANIMPORTANTFACTORINTHEPRODUCTIONOFSLOTS,POCKETS,PRECISIONMOULDSANDDIESGREATERATTENTIONISGIVENTODIMENSIONALACCURACYANDSURFACEROUGHNESSOFPRODUCTSBYTHEINDUSTRYTHESEDAYSMOREOVER,SURFACEFINISHINFLUENCESMECHANICALPROPERTIESSUCHASFATIGUEBEHAVIOUR,WEAR,CORROSION,LUBRICATIONANDELECTRICALCONDUCTIVITYTHUS,MEASURINGANDCHARACTERIZINGSURFACEFINISHCANBECONSIDEREDFORPREDICTINGMACHININGPERFORMANCESURFACEFINISHRESULTINGFROMTURNINGOPERATIONSHASTRADITIONALLYRECEIVEDCONSIDERABLERESEARCHATTENTION,WHEREASTHATOFMACHININGPROCESSESUSINGMULTIPOINTCUTTERS,REQUIRESATTENTIONBYRESEARCHERSASTHESEPROCESSESINVOLVELARGENUMBEROFPARAMETERS,ITWOULDBEDIFFICULTTOCORRELATESURFACEFINISHWITHOTHERPARAMETERSJUSTBYCONDUCTINGEXPERIMENTSMODELLINGHELPSTOUNDERSTANDTHISKINDOFPROCESSBETTERTHOUGHSOMEAMOUNTOFWORKHASBEENCARRIEDOUTTODEVELOPSURFACEFINISHPREDICTIONMODELSINTHEPAST,THEEFFECTOFTOOLGEOMETRYHASRECEIVEDLITTLEATTENTIONHOWEVER,THERADIALRAKEANGLEHASAMAJORAFFECTONTHE3ALTHOUGHTHEDIFFERENCEBETWEENTHEMREGARDINGTHESURFACEROUGHNESSWASLARGEBAYOUMIETAL4HAVESTUDIEDTHEAFFECTOFTHETOOLROTATIONANGLE,FEEDRATEANDCUTTINGSPEEDONTHEMECHANISTICPROCESSPARAMETERSPRESSURE,FRICTIONPARAMETERFORENDMILLINGOPERATIONWITHTHREECOMMERCIALLYAVAILABLEWORKPIECEMATERIALS,11L17FREEMACHININGSTEEL,62353FREEMACHININGBRASSAND2024ALUMINIUMUSINGASINGLEFLUTEDHSSMILLINGCUTTERITHASBEENFOUNDTHATPRESSUREANDFRICTIONACTONTHECHIP–TOOLINTERFACEDECREASEWITHTHEINCREASEOFFEEDRATEANDWITHTHEDECREASEOFTHEFLOWANGLE,WHILETHECUTTINGSPEEDHASANEGLIGIBLEEFFECTONSOMEOFTHEMATERIALDEPENDENTPARAMETERSPROCESSPARAMETERSARESUMMARIZEDINTOEMPIRICALEQUATIONSASFUNCTIONSOFFEEDRATEANDTOOLROTATIONANGLEFOREACHWORKMATERIALHOWEVER,RESEARCHERSHAVENOTTAKENINTOACCOUNTTHEEFFECTSOFCUTTINGCONDITIONSANDTOOLGEOMETRYSIMULTANEOUSLYBESIDESTHESESTUDIESHAVENOTCONSIDEREDTHEOPTIMIZATIONOFTHECUTTINGPROCESSASENDMILLINGISAPROCESSWHICHINVOLVESALARGENUMBERFPARAMETERS,COMBINEDINFLUENCEOFTHESIGNIFICANTPARAMETERSANONLYBEOBTAINEDBYMODELLINGMANSOURANDABDALLAETAL5HAVEDEVELOPEDASURFACEROUGHNESSMODELFORTHEENDMILLINGOFEN32MASEMIFREECUTTINGCARBONCASEHARDENINGSTEELWITHIMPROVEDMERCHANTABILITYTHEMATHEMATICALMODELHASBEENDEVELOPEDINTERMSOFCUTTINGSPEED,FEEDRATEANDAXIALDEPTHOFCUTTHEAFFECTOFTHESEPARAMETERSONTHESURFACEROUGHNESSHASBEENCARRIEDOUTUSINGRESPONSESURFACEMETHODOLOGYRSMAFIRSTORDEREQUATIONCOVERINGTHESPEEDRANGEOF30–35M/MINANDASECONDORDEREQUATIONCOVERINGTHESPEEDRANGEOF24–38M/MINWEREDEVELOPEDUNDERDRYMACHININGCONDITIONSALAUDDINETAL6DEVELOPEDASURFACEROUGHNESSMODELUSINGRSMFORTHEENDMILLINGOF190BHNSTEELFIRSTANDSECONDORDERMODELSWERECONSTRUCTEDALONGWITHCONTOURGRAPHSFORTHESELECTIONOFTHEPROPERCOMBINATIONOFCUTTINGSPEEDANDFEEDTOINCREASETHEMETALREMOVALRATEWITHOUTSACRIFICINGSURFACEQUALITYHASMIETAL7ALSOUSEDTHERSMMODELFORASSESSINGTHEINFLUENCEOFTHEWORKPIECEMATERIALONTHESURFACEROUGHNESSOFTHEMACHINEDSURFACESTHEMODELWASDEVELOPEDFORMILLINGOPERATIONBYCONDUCTINGEXPERIMENTSONSTEELSPECIMENSTHEEXPRESSIONSHOWS,THERELATIONSHIPBETWEENTHESURFACEROUGHNESSANDTHEVARIOUSPARAMETERSNAMELY,THECUTTINGSPEED,FEEDANDDEPTHOFCUTTHEABOVEMODELSHAVENOTCONSIDEREDTHEAFFECTOFTOOLGEOMETRYONSURFACEROUGHNESSSINCETHETURNOFTHECENTURYQUITEALARGENUMBEROFATTEMPTSHAVEBEENMADETOFINDOPTIMUMVALUESOFMACHININGPARAMETERSUSESOFMANYMETHODSHAVEBEENREPORTEDINTHELITERATURETOSOLVEOPTIMIZATIONPROBLEMSFORMACHININGPARAMETERSJAINANDJAIN8HAVEUSEDNEURALNETWORKSFORMODELINGANDOPTIMIZINGTHEMACHININGCONDITIONSTHERESULTSHAVEBEENVALIDATEDBYCOMPARINGTHEOPTIMIZEDMACHININGCONDITIONSOBTAINEDUSINGGENETICALGORITHMSSURESHETAL9HAVEDEVELOPEDASURFACEROUGHNESSPREDICTIONMODELFORTURNINGMILDSTEELUSINGARESPONSESURFACEMETHODOLOGYTOPRODUCETHEFACTORAFFECTSOFTHEINDIVIDUALPROCESS
下載積分: 10 賞幣
上傳時間:2024-03-16
頁數(shù): 17
大?。?0.08(MB)
子文件數(shù):
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簡介:畢業(yè)設(shè)計(論文)報告紙共頁第1頁┊┊┊┊┊┊┊┊┊┊┊┊┊裝┊┊┊┊┊訂┊┊┊┊┊線┊┊┊┊┊┊┊┊┊┊┊┊┊MULTIDOMAINSIMULATIONMECHANICSANDHYDRAULICSOFANEXCAVATORABSTRACTITISDEMONSTRATEDHOWTOMODELANDSIMULATEANEXCAVATORWITHMODELICAANDDYMOLABYUSINGMODELICALIBRARIESFORMULTIBODYANDFORHYDRAULICSYSTEMSTHEHYDRAULICSYSTEMISCONTROLLEDBYA“LOADSENSING”CONTROLLERUSUALLY,MODELSCONTAINING3DIMENSIONALMECHANICALANDHYDRAULICCOMPONENTSAREDIFFICULTTOSIMULATEATHANDOFTHEEXCAVATORITISSHOWNTHATMODELICAISWELLSUITEDFORSUCHKINDSOFSYSTEMSIMULATIONS1INTRODUCTIONTHEDESIGNOFANEWPRODUCTREQUIRESANUMBEROFDECISIONSINTHEINITIALPHASETHATSEVERELYAFFECTTHESUCCESSOFTHEFINISHEDMACHINETODAY,DIGITALSIMULATIONISTHEREFOREUSEDINEARLYSTAGESTOLOOKATDIFFERENTCONCEPTSTHEVIEWOFTHISPAPERISTHATANEWEXCAVATORISTOBEDESIGNEDANDSEVERALCANDIDATESOFHYDRAULICCONTROLSYSTEMSHAVETOBEEVALUATEDSYSTEMSTHATCONSISTOF3DIMENSIONALMECHANICALANDOFHYDRAULICCOMPONENTS–LIKEEXCAVATORS–AREDIFFICULTTOSIMULATEUSUALLY,TWODIFFERENTSIMULATIONENVIRONMENTSHAVETOBECOUPLEDTHISISOFTENINCONVENIENT,LEADSTOUNNECESSARYNUMERICALPROBLEMSANDHASFRAGILEINTERFACESINTHISARTICLEITISDEMONSTRATEDATHANDOFTHEMODELOFANEXCAVATORTHATMODELICAISWELLSUITEDFORTHESETYPESOFSYSTEMSTHE3DIMENSIONALCOMPONENTSOFTHEEXCAVATORAREMODELEDWITHTHENEW,FREEMODELICAMULTIBODYLIBRARYTHISALLOWSESPECIALLYTOUSEANANALYTICSOLUTIONOFTHEKINEMATICLOOPATTHEBUCKETANDTOTAKETHEMASSESOFTHEHYDRAULICCYLINDERS,IE,THE“FORCEELEMENTS”,DIRECTLYINTOACCOUNTTHEHYDRAULICPARTISMODELEDINADETAILEDWAY,UTILIZINGPUMP,VALVESANDCYLINDERSFROMHYLIB,AHYDRAULICSLIBRARYFORMODELICAFORTHECONTROLPARTAGENERIC“LOADSENSING”CONTROLSYSTEMISUSED,MODELEDBYASETOFSIMPLEEQUATIONSTHISAPPROACHGIVESTHEREQUIREDRESULTSANDKEEPSTHETIMENEEDEDFORANALYZINGTHEPROBLEMONAREASONABLELEVEL2MODELINGCHOICESTHEREARESEVERALAPPROACHESWHENSIMULATINGASYSTEMDEPENDINGONTHETASKITMAYBENECESSARYTOBUILDAVERYPRECISEMODEL,CONTAININGEVERYDETAILOFTHESYSTEMANDNEEDINGALOTOFINFORMATION,EG,MODELPARAMETERSTHISKINDOFMODELSISEXPENSIVETOBUILDUPBUTONTHEOTHERHANDVERYUSEFULIFPARAMETERSOFAWELLDEFINEDSYSTEMHAVETOBEMODIFIEDATYPICALEXAMPLEISTHEOPTIMIZATIONOFPARAMETERSOFACOUNTERBALANCEVALVEINANEXCAVATORKRAFT1996THEOTHERKINDOFMODELISNEEDEDFORAFIRSTSTUDYOFASYSTEMINTHISCASESOMEPROPERTIESOFTHEPUMP,CYLINDERSANDLOADSARESPECIFIEDREQUIREDISINFORMATIONABOUTTHEPERFORMANCEOFTHATSYSTEM,EG,THESPEEDOFTHEPISTONSORTHENECESSARYINPUTPOWERATTHEPUMPSHAFT,TOMAKEADECISIONWHETHERTHISDESIGNCANBEUSEDINPRINCIPLEFORTHETASKATHANDTHISMODELHASTHEREFORETOBE“CHEAP”,IE,ITMUSTBEPOSSIBLETOBUILDITINASHORTTIMEWITHOUTDETAILEDKNOWLEDGEOFPARTICULARCOMPONENTSTHEAUTHORSINTENDEDTOBUILDUPAMODELOFTHESECONDTYPE,RUNITANDHAVEFIRSTRESULTSWITHAMINIMUMAMOUNTOFTIMESPENTTOACHIEVETHISGOALTHEMODELINGLANGUAGEMODELICAMODELICA2002,THEMODELICASIMULATIONENVIRONMENTDYMOLADYMOLA2003,THENEWMODELICALIBRARYFOR3DIMENSIONALMECHANICALSYSTEMS“MULTIBODY”O(jiān)TTERETAL2003ANDTHEMODELICALIBRARYOFHYDRAULICCOMPONENTSHYLIBBEATER2000WASUSEDTHEMODELCONSISTSOFTHE3DIMENSIONALMECHANICALCONSTRUCTIONOFTHEEXCAVATOR,ADETAILEDDESCRIPTIONOFTHEPOWERHYDRAULICSANDAGENERIC“LOADSENSING”CONTROLLERTHISMODELWILLBEAVAILABLEASADEMOINTHENEXTVERSIONOFHYLIB3CONSTRUCTIONOFEXCAVATORSINFIGURE1ASCHEMATICDRAWINGOFATYPICALEXCAVATORUNDERCONSIDERATIONISSHOWNITCONSISTSOFACHAINTRACKANDTHEHYDRAULICPROPELDRIVEWHICHISUSEDTOMANOEUVRETHEMACHINEBUTUSUALLYNOTDURINGAWORKCYCLEONTOPOFTHATISACARRIAGEWHERETHEOPERATORISSITTINGITCANROTATEAROUNDAVERTICALAXISWITHRESPECTTOTHECHAINTRACKITALSOHOLDSTHEDIESELENGINE,THEHYDRAULICPUMPSANDCONTROLSYSTEMFURTHERMORE,THEREISABOOM,ANARMANDATTHEENDABUCKETWHICHISATTACHEDVIAAPLANARKINEMATICLOOPTOTHEARMBOOM,ARMANDBUCKETCANBEROTATEDBYTHEAPPROPRIATECYLINDERS畢業(yè)設(shè)計(論文)報告紙共頁第3頁┊┊┊┊┊┊┊┊┊┊┊┊┊裝┊┊┊┊┊訂┊┊┊┊┊線┊┊┊┊┊┊┊┊┊┊┊┊┊ORIENTATIONOFTHEATTACHMENTPOINTSOFTHE“LEFT”AND“RIGHT”REVOLUTEJOINTSOFTHEJOINTRRRCOMPONENTAREKNOWNTHEREISANONLINEARALGEBRAICLOOPINTHEJOINTRRRCOMPONENTTOCOMPUTETHEANGLESOFITSTHREEREVOLUTEJOINTSGIVENTHEMOVEMENTOFTHESEATTACHMENTPOINTSTHISNONLINEARSYSTEMOFEQUATIONSISSOLVEDANALYTICALLYINTHEJOINTRRROBJECT,IE,INAROBUSTANDEFFICIENTWAYFORDETAILSSEEINAFIRSTSTEP,THEMECHANICALPARTOFTHEEXCAVATORISSIMULATEDWITHOUTTHEHYDRAULICSYSTEMTOTESTTHISPARTSEPARATLYTHISISPERFORMEDBYATTACHINGTRANSLATIONALSPRINGSWITHAPPROPRIATESPRINGCONSTANTSINSTEADOFTHEHYDRAULICCYLINDERSAFTERTHEANIMATIONLOOKSFINEANDTHEFORCESANDTORQUESINTHEJOINTSHAVETHEEXPECTEDSIZE,THESPRINGSAREREPLACEDBYTHEHYDRAULICSYSTEMDESCRIBEDINTHENEXTSECTIONSALLCOMPONENTSOFTHENEWMULTIBODYLIBRARYHAVE“BUILTIN”ANIMATIONDEFINITIONS,IE,ANIMATIONPROPERTIESAREMOSTLYDEDUCEDBYDEFAULTFROMTHEGIVENDEFINITIONOFTHEMULTIBODYSYSTEMFOREXAMPLE,ARODCONNECTINGTWOREVOLUTEJOINTSISBYDEFAULTVISUALIZEDASCYLINDERWHERETHEDIAMETERDISAFRACTIONOFTHECYLINDERLENGTHLDL/40WHICHISINTURNGIVENBYTHEDISTANCEOFTHETWOREVOLUTEJOINTSAREVOLUTEJOINTISBYDEFAULTVISUALIZEDBYAREDCYLINDERDIRECTEDALONGTHEAXISOFROTATIONOFTHEJOINTTHEDEFAULTANIMATIONWITHONLYAFEWMINORADAPTATIONSOFTHEEXCAVATORISSHOWNIFFIGURE8THELIGHTBLUESPHERESCHARACTERIZETHECENTEROFMASSOFBODIESTHELINEFORCEELEMENTSTHATVISUALIZETHEHYDRAULICCYLINDERSAREDEFINEDBYTWOCYLINDERSYELLOWANDGREYCOLORTHATAREMOVINGINE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簡介:1本科生畢業(yè)設(shè)計外文資料翻譯題目社區(qū)民意調(diào)查平臺設(shè)計與實現(xiàn)專業(yè)計算機科學(xué)與技術(shù)班級XXX姓名XXX指導(dǎo)教師指導(dǎo)教師XXX(高級實驗師)所在學(xué)院所在學(xué)院信息學(xué)院附件1外文資料翻譯譯文2外文原文3ACCORDINGTOTHESAMPLINGMETHODSFORANALYZINGTHEQUESTIONNAIREDATA,RESEARCHERSCANUSENOTONLYDESCRIPTIVESTATISTICSMETHODSTODESCRIBETHEBASICDISTRIBUTIONOFTHESAMPLES,BUTALSOINFERENTIALSTATISTICSMETHODSTOINFERTHEREALHUMANBEHAVIORANDSOCIALPHENOMENONSIGNIFICANCEOFGROUPDIFFERENCESISONEOFTHEFOURTYPESOFTHERESEARCHQUESTIONSTABACHNICKFIDELL,1996FOREXAMPLE,INAQUESTIONNAIRESURVEYFORELEMENTARYSCHOOLSTUDENTS,“ISTHEREASIGNIFICANTDIFFERENCEBETWEENBOYSANDGIRLSABOUTTHEHOURSTHEYACCESSTHEINTERNETEVERYWEEK”ISANINTERESTINGPHENOMENONTHATRESEARCHERSWANTTOKNOWINTHEQUESTIONNAIREANALYSIS,HOWTOFINDASTATISTICALLYSIGNIFICANTDIFFERENCEBETWEENTWOORMOREGROUPSINACONTINUOUSMEASUREISONEOFTHEMAJORRESEARCHISSUESINTHETRADITIONALQUANTITATIVERESEARCH,THERESEARCHERSWILLFIRSTLYPROPOSESEVERALHYPOTHESESOFTHESUBJECTACCORDINGTOTHEIREXPERIENCES,ANDTHENDETERMINEWHETHERTHEREEXISTSASTATISTICALSIGNIFICANCEINSOMEHYPOTHESISINATRYANDERRORMANNERTHEQUALITYOFTHERESULTUSINGTHEMANNER,OFCOURSE,ISINACCORDANCEWITHTHEQUALITYOFTHEHYPOTHESES,ANDTHEPROCESSOFFINDINGTHESTATISTICALLYSIGNIFICANTDIFFERENCESISHIGHLYDEPENDENTONRESEARCHERSINTUITIONANDEXPERIENCEFOREXAMPLE,INAQUESTIONNAIRESURVEYOFELEMENTARYSCHOOLSTUDENTS’INTERNETUSAGEBEHAVIOR,ARESEARCHERMIGHTMAKEAHYPOTHESIS,“THEREISASTATISTICALLYSIGNIFICANTDIFFERENCEBETWEENDIFFERENTGENDERSABOUTTHEHOURSTHEYACCESSTHEINTERNETEVERYWEEK,“ANDTHENUSEAPPROPRIATEINFERENTIALSTATISTICSMETHODACCORDINGTOHIS/HERKNOWLEDGEOFSTATISTICSTOTESTTHISHYPOTHESISWITHOUTMAKINGTHEHYPOTHESIS,THEDIFFERENCECANNOTBEFOUNDEVENIFITREALLYEXISTSTHEREFORE,HOWTOACQUIRETHEKNOWLEDGEANDEXPERIENCEOFSENIORRESEARCHERSMIGHTBEHELPFULFORTHEJUNIORRESEARCHERSBESIDES,GRANULARITYOFORIGINALQUESTIONNAIREDATAMAYNOTBEGOODENOUGHTOFINDTHESTATISTICALLYSIGNIFICANTDIFFERENCESFOREXAMPLE,INAQUESTIONNAIRESURVEYOFELEMENTARYSCHOOLSTUDENTSINTERNETUSAGEBEHAVIOR,IFTHEREISNOSIGNIFICANTDIFFERENCEBETWEENDIFFERENTRESIDENTREGIONSABOUTTHEHOURSSTUDENTSACCESSTHEINTERNETEVERYWEEK,THERESEARCHERMIGHTCONCLUDETHEREISNOSIGNIFICANTDIFFERENCEBETWEENDIFFERENTRESIDENTREGIONSHOWEVER,EACHREGIONMAYCONTAINSEVERALCOUNTIESINGEOGRAPHYBYDRILLINGDOWNTHESTUDENTSRESIDENTDIMENSIONTOLOWERLEVELSOFGRANULARITY,ITISSTILLPOSSIBLETOFINDASIGNIFICANTDIFFERENCEBETWEENDIFFERENTCOUNTIESWHENRESEARCHERSANALYZEAQUESTIONNAIREDATA,THEYHAVETOMAKESOMEHYPOTHESESOFTHEPOSSIBLESTATISTICALLYSIGNIFICANTDIFFERENCESFROMTHEDATAANDUSETHEIRKNOWLEDGELIKERULESTOSELECTTHE
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簡介:本科畢業(yè)生畢業(yè)設(shè)計(論文)外文翻譯1WALLWALKERPROPOSALOFLOCOMOTIONMECHANISMCLEANINGEVENATTHECORNERTMIYAKE12ANDHISHIHARA11KAGAWAUNIVJAPAN2MIRAIKIKAIINC,JAPANABSTRACTTHEPURPOSEOFTHISRESEARCHISTODEVELOPTHEWINDOWCLEANINGROBOTFORCLEANINGASINGLELARGEWINDOWPANESUCHASASHOWWINDOWITREQUIRESTHEFOLLOWINGDEMANDSTOAPPLYTHEWINDOWCLEANINGROBOTFORTHEPRACTICALUSE1CLEANTHECORNEROFWINDOWBECAUSEFOULINGISLEFTTHEREOFTEN2SWEEPTHEWINDOWPANECONTINUOUSLYTOPREVENTMAKINGSTRIPEDPATTERNSONAWINDOWPANETHEKEYSOFMECHANISMSARETHEROTATABILITYOFTHEMOBILEPARTAROUNDTHEOTHERPARTSANDTHECONTINUOUSLOCOMOTIONINORDERTOACHIEVETHEABOVEPOINTSTHEFORMERENABLESTHEROBOTTOCHANGETHEDIRECTIONWITHKEEPINGITSPOSITIONANDATTITUDEATTHECORNEROFWINDOWTHELATTERISNECESSARYFORPREVENTINGLEAVINGTHESTRIPEDPATTERNONAWINDOWPANEWEDESIGNEDTHECONTINUOUSMOTIONUSINGTWOWHEELLOCOMOTIONWITHADHERINGONTHEWINDOWPANEUSINGASUCTIONCUPTHESIZEOFPROTOTYPEISABOUT300MM300MM100MMANDITSWEIGHTISABOUT2KGWITHOUTBATTERIESASTHERESULTSOFBASICEXPERIMENTSOFTHEPROTOTYPEONAVERTICALSMOOTHWINDOWGLASS,TRAVELINGVELOCITYOFGOINGUPDIRECTIONWAS008M/S,ONEOFGOINGDOWNDIRECTIONWAS014M/SANDHORIZONTALDIRECTIONWAS011M/SINTHISPAPERTHE1STCHAPTERMENTIONSBACKGROUNDANDOBJECTIVESOFTHISRESEARCH,ANDALSOINTRODUCESTHECONCEPTOFWALLWALKERTHE2NDCHAPTERDISCUSSESTHEADHERINGANDMOVINGMECHANISMTHE3RDCHAPTERILLUSTRATESITSBASICPROPERTIESBASEDONTHEEXPERIMENTSFINALLY,PROBLEMSANDFUTUREWORKSAREDISCUSSEDINTHE4THCHAPTER本科畢業(yè)生畢業(yè)設(shè)計(論文)外文翻譯3–SIZE300MM300MM100MMTHESEAREALSODEFINEDBYTHERESULTSOFSURVEYINGTHEDEMANDSFROMTHECLEANINGCOMPANIESTHISPAPERPROPOSESTHESMALL,LIGHTANDPORTABLEWINDOWCLEANINGROBOTNAMEDWALLWALKER,WHICHAREDESIGNEDTOSATISFYTHEMARKETDEMANDSASMENTIONEDABOVEFIGURE1ISTHERENDERINGATASCENEOFPRACTICALUSEOFWALLWALKERTHEWALLWALKERISADHERINGONAWINDOWPANEANDCLEANINGASMOVINGONLARGEWINDOWSTHISPAPERDISCUSSESTHEEFFECTIVENESSOFPROPOSEDLOCOMOTIONMECHANISMTHE2NDCHAPTERDISCUSSESTHELOCOMOTIONMECHANISMSANDILLUSTRATESTHEPROTOTYPEFORTESTINGTHEPROPOSEDLOCOMOTIONMECHANISMTHE3RDCHAPTERILLUSTRATESITSBASICPROPERTIESBASEDONTHEEXPERIMENTSFIG1SMALLSIZEWINDOWCLEANINGROBOTONAWINDOW2LOCOMOTIONMECHANISMVARIOUSRESEARCHESOFLOCOMOTIONMECHANISMSONTHEWINDOWCLEANINGROBOTSHAVEBEENREPORTEDHOWEVERTHEYDONOTMEETOURSPECIFICATIONSDEFINEDBASEDONTHEMARKETDEMANDSABOVEMENTIONEDFOREXAMPLE,CLIMBINGROBOTBYLEGGEDWALKCANNOTREALIZETHECONTINUOUSMOVEMENT,ANDALSOITSTURNABILITYISLOW6CLIMBINGROBOTUSINGCRAWLERMECHANISMALLOWSCONTINUOUSMOVEMENT,BUTTHEROTATABILITYISASLOWASORLOWERTHANTHELEGGEDWALK7WINDOWCLEANINGROBOTBYCRAWLERMECHANISMHADBEENDEVELOPEDSIZE440400180MMWEIGHT65KGMAXIMUMSPEED2CM/SECBYSHRAFT
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簡介:1中文中文7600字出處出處RENEWABLEANDSUSTAINABLEENERGYREVIEWS1320092175–2180RENEWABLEANDSUSTAINABLEENERGYREVIEWSHIGHBRIGHTNESSLEDSENERGYEFFICIENTLIGHTINGSOURCESANDTHEIRPOTENTIALININDOORPLANTCULTIVATIONNAICHIAYEHA,JENPINGCHUNGABSTRACTTHERAPIDDEVELOPMENTOFOPTOELECTRONICTECHNOLOGYSINCEMID1980HASSIGNIFICANTLYENHANCEDTHEBRIGHTNESSANDEFFICIENCYOFLIGHTEMITTINGDIODESLEDSLEDSHAVELONGBEENPROPOSEDASAPRIMARYLIGHTSOURCEFORSPACEBASEDPLANTRESEARCHCHAMBERORBIOREGENERATIVELIFESUPPORTSYSTEMSTHERAISINGCOSTOFENERGYALSOMAKESTHEUSEOFLEDSINCOMMERCIALCROPCULTUREIMMINENTWITHTHEIRENERGYEFFICIENCY,LEDSHAVEOPENEDNEWPERSPECTIVESFOROPTIMIZINGTHEENERGYCONVERSIONANDTHENUTRIENTSUPPLYBOTHONANDOFFEARTHTHEPOTENTIALSOFLEDASANEFFECTIVELIGHTSOURCEFORINDOORAGRICULTURALPRODUCTIONHAVEBEENEXPLOREDTOAGREATEXTENTTHEREAREMANYRESEARCHESTHATUSELEDSTOSUPPORTPLANTGROWTHINCONTROLLEDENVIRONMENTSSUCHASPLANTTISSUECULTUREROOMANDGROWTHCHAMBERTHISPAPERPROVIDESABRIEFDEVELOPMENTHISTORYOFLEDSANDABROADBASEREVIEWONLEDAPPLICATIONSININDOORPLANTCULTIVATIONSINCE1990CONTENTS1INTRODUCTION2LEDDEVELOPMENT3COLORRATIOSANDPHOTOSYNTHESIS4LEDSANDINDOORPLANTCULTIVATION41PLANTTISSUECULTUREANDGROWTH42SPACEAGRICULTURE843ALGACULTURE44PLANTDISEASEREDUCTION5INTERMITTENTANDPHOTOPERIODLIGHTINGANDENERGYSAVING6CONCLUSION1INTRODUCTIONWITHIMPACTSOFCLIMATECHANGE,ISSUESSUCHASMOREFREQUENTANDSERIOUSDROUGHTS,FLOODS,ANDSTORMSASWELLASPESTANDDISEASESAREBECOMINGMORESERIOUSTHREATSTOAGRICULTURETHESETHREATSALONGWITHSHORTAGEOFFOODSUPPLYMAKEPEOPLETURNTOINDOORANDURBANFARMINGSUCHASVERTICALFARMINGFORHELPWITHPROPERLIGHTING,INDOORAGRICULTUREELIMINATESWEATHERRELATEDCROPFAILURESDUETODROUGHTSANDFLOODSTOPROVIDEYEARROUNDCROPPRODUCTION,WHICHASSISTINSUPPLYINGFOODINCITIESWITHSURGINGPOPULATIONSANDINAREASOFSEVEREENVIRONMENTALCONDITIONS3FIG1LEDDEVELOPMENTBEGANWITHINFRAREDANDREDDEVICESMADEWITHGALLIUMARSENIDEADVANCESINMATERIALSSCIENCEHAVEMADEPOSSIBLETHEPRODUCTIONOFDEVICESWITHEVERSHORTERWAVELENGTHS,PRODUCINGLIGHTINAVARIETYOFCOLORSJMARGOLINREPORTEDTHATTHEFIRSTKNOWNLIGHTEMITTINGSOLIDSTATEDIODEWASMADEIN1907BYHJROUNDNOPRACTICALUSEOFROUND’SDIODEWASMADEFORSEVERALDECADESUNTILTHEINVENTIONOFTHEFIRSTPRACTICALLEDBYNICKHOLONYAK,JRIN1962HISLEDSBECAMECOMMERCIALLYAVAILABLEINLATE1960STHESEGAASPLEDSCOMBINETHREEPRIMARYELEMENTSGALLIUM,ARSENICANDPHOSPHORUSTOPROVIDEA655NMREDLIGHTWITHBRIGHTNESSLEVELSOFAPPROXIMATELY1–10MCDAT20MAASTHELUMINOUSINTENSITYWASLOW,THESELEDSWEREONLYUSEDINAFEWAPPLICATIONS,PRIMARILYASINDICATORSFOLLOWINGGAASP,GAPGALLIUMPHOSPHIDEREDLEDSWEREDEVELOPEDTHESEDEVICESEXHIBITVERYHIGHQUANTUMEFFICIENCIESATLOWCURRENTSASLEDTECHNOLOGYPROGRESSEDTHROUGHTHE1970S,ADDITIONALCOLORSANDWAVELENGTHSBECAMEAVAILABLETHEMOSTCOMMONMATERIALSWEREGAPGREENANDRED,GAASPORANGE,ANDHIGHEFFICIENCYREDANDGAASPYELLOWTHETRENDTOWARDSMOREPRACTICALAPPLICATIONSSUCHASINCALCULATORS,DIGITALWATCHES,ANDTESTEQUIPMENTALSOBEGANTODEVELOPASTHELEDMATERIALSTECHNOLOGYBECAMEMOREADVANCED,THELIGHTOUTPUTWASINCREASED,ANDLEDSBECAMEBRIGHTENOUGHTOBEUSEDFORILLUMINATIONIN1980SANEWMATERIAL,GAALASGALLIUMALUMINUMARSENIDEWASDEVELOPEDFOLLOWEDBYARAPIDGROWTHINTHEUSEOFLEDSGAALASTECHNOLOGYPROVIDESSUPERIOR
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