自动化专业英语翻译-(2)

-1-ControlPanelsTheeffectivenessofacarefullyengineeredprocesscontrolsystemcanbereducedifinadequateattentionisgiventothedesignandconstructionofthecontrol.Thecontrolpanel,whetherasinglepanelofsimplifieddesignforlocalmountingorpartofanextensivecontrolcenter,literallyistheinterfacebetweentheoperatorandtheprocess.Controlpaneldesignembracesseveralobjectives:1)tosimplifytheoperator/processinterfacesothat:a.Thecritical,mostimportantprocessconditionsareimmediatelyavailabletotheoperatorwithoutconsciouseffort.b.Lessimportantinformationcanbecalleduponbytheoperatorinaccordancewithoperatingschedulesinaroutinefashion,butnotinanywayinterferewithsupervisionofkeyvariables.Thepanelshouldbedesignedtoeffectivelysortoutandseparateinformationelementssothattheoperator’sattentionduringanytimeofemergencyorspecialsituationswillnotbedivertedtotheinformationoflesserimportance,orworse,ofcompleteirrelevance.2)Toaccommodatethespecialcontrolsituationswhichariseperiodically,suchasprocessstart-up,shutdown,andmajormaintenanceeitherofprocessorcontrolequipmentandinstrumentation.3)Toprovideinformationforcostaccountingandotherfactorsofmanagerialimportancethatmaynotbereflectedimmediatelyintheday-to-dayadjustmentsofoperatingconditions.4)Toallowforexpansionandmodernizationoftheprocesswithtime,includinglatertieswithcomputerizedsupervisionordirectcomputercontrol,butconsideringcarefullythecostofprovidingforsuchalterationsversustheprobabilityoftheirneed.5)Topermitconvenienceofinstallationandcaseofmaintenanceofallpanel-associatedequipment.6)Toprovideanaestheticallypleasingappearance(particularlyinthecaseofcentralpanels)becausethecontrolroomessentiallyisthe“windowtotheprocess”andusuallyisthecenterofvisitsbyVIPs.Further,anattractivecontrolcenter,welllightedandair-conditioned,contributestotheefficiencyoftheoperatorsandprotectionoftheequipment.Alltheforegoingobjectivesandmorearesubject,ofcourse,totrade-offswhereincostmustbeweighedagainstprojectedgains.Oncemade,thesetrade-offdecisionsresultinsuchpracticalfactorsas:-2-1)Selectionofinstrumentsintermsoftheirdisplayandcontrollabilityfeaturesaswellassizeandmaintainability.2)Functionalarrangementsoftheinstruments,includingannunciatorsandalltheotheraccessories.Forexample,pilotlightsandselectorswitchesmustbelocatedinaccordancewiththeanthropomorphicprinciplesdevelopedinthestudyofhumanengineeringtominimizementalandphysicalfatigue.3)Lightingofthepanelandcontrolroomandotherenvironmentalfactors,includingairconditioning.4)Mosteffectivemeansforbringinginandoutalltheconnectinghardware-piping,cabling,andsoon-involvedintheroutingofinformationandenergytoandpromthecontrolpanel.Controlpaneldesign,withsomanyobjectivestobeachieved,includingtheeconomicobjectives,thusinvolvesscoresoftrade-offdecision.In1960’s,paneldesignwaslargelydeterminedbywhatwasavailableinstandardinstrumentation.Usually,theinstrumentswerecontainedinverylargecasesandnotparticularlydesignedforremotelycontrollingacomplexprocessfromacontrolpanel.Earlierinstrumentsessentiallywerenotdesignedwiththeirmountingonapanelasafactorofultimateimportance.Thesituationhadreversedinthelate1970’s,butnotwithouthavinghadtogothroughseveralstepsinapaneldesignrevolution,includingfull-graphicandsemigraphicpaneldesign.Numerouspaneldesignexperimentshavesucceededandarenowcommonplace;otherfailedandweredropped.Amajorstepintheimproveddesignofpanelswasthedirectresultofminiaturizedelectrical,mechanicalinstrumentcomponentsandespeciallythecomputertechniquewhich,inturn,enabledthedesignofpractical,miniatureinstruments.Inthemoderndesignofcontrolpanel,therearesomerulesaccordingtothepaneldesignphilosophy:①controllersaremountedateyelevelwiththeirmanualadjustmentswithinafewdegreesoftheshoulderarmarc;②instrumentsaregroupedintologicaloperationalsectionwithspacesbetweenprocessentities;③thevisuals;opeofthesemigraphicallowsanincreaseinheighttopermitplacementofthealarmwindowclosetoeyelevel;④selectorswitches,pushbuttons,andpilotlightsaremountedlessconveniently,astheyareutilizedonlyduringabnormalunitoperation;⑤recorders,belowtheirassociatedcontroller,areataheightwhereprocesstrendsmaybereadilynoticed,andyetdonotusevaluableoperatingspace;⑥although-3-openedforthepurposeofthephotograph,therearofthepanelmaybelockedtodenyaccesstounauthorizedpersonnel.Asmentionedbefore,theanthropomorphicprinciplesifhumanengineeringareappliedintheinstrumentpaneldesigninordertoobtaintheeffectiveandoptimumoperation.Inaddition,thegroupingofprocessentitiesassiststheoperatorinlocatingthedesiredinstrument.控制盘如果控制盘的设计和结构没有给予足够的重视，那么不论是作为局部安装简化设计的单快屏，还是作为大范围控制中心的一部分，控制盘实际上就是。控制盘设计包括几个目的：1）为简化操作人员与控制过程之间的界面，因此：a、操作者可无意识的即刻使用紧急的、最重要的过程条件。b、根据常规的操作方式，而不是关键变量监管的任何方式，一些不太重要信息应能被操作者访问。控制盘应被设计为能够有效挑选和分离信息成分，以便在紧急事件或特殊情况下，操作者的注意力不被更不重要的、或更坏的、或完全不相干的信息转移。2)为适应周期性出现的特殊控制情况，例如过程启动、停止、过程或控制装备和仪器的大维修。3)为了提供花费数目和管理价值的其它因素的信息，此信息可能不会立即反映到每日的调整上。4)为了考虑时间控制过程的扩展和现代化，包括近期与电脑管理的联系或计算机直接管理，但也应仔细考虑一下对于如此改进的应用可能性的费用问题。5)为了所有与控制盘有关设备的安装方便和维护问题。6)为了提供一个在美学观点上令人满意的外形（特别是在中心板的情况下），因为控制室基本上是“过程的窗口”，并且通常是贵宾参观的中心。此外，具有吸引力、良好采光和空调的控制中心对于操作者的工作效率和设备保护均有帮助。所有前面提到的目标和其它问题当然要经过比