PLC-controlled-elevator-system

Abstract--ThispaperpresentsthecontrolofelevatorsystemusingSiemensLOGOPLC.Thesystemisprogrammedtodriveadcmotorforforwardandbackwardmotoringmodewithsensorsateachfloor,emergencySTOPswitchformaintenancepurposeortopreventanyaccidentinsidethelift&doorswitchforsafetypurpose.Thesystemisalsoprogrammedtoconserveenergybyautomaticallyswitchofflightsandfansofcabinwhenmotorisinreststateforaspecifieddurationoftime.ThesoftwareusedinthiselevatorsystemisLOGO!SoftComfortV7.0.Thissystemcanbeusedforlearningthecontrolstrategiesinvolvedinelevatorsystemsforeducationalpurpose.IndexTerms—Automation,Energysaving,Elevator,LadderlogicandProgrammableLogicController(PLC).I.INTRODUCTIONNmoderntimeduetorapidpopulationgrowthintheurbanareas,inmulti-storedbuildingsneedforelevatorsisbeingincreased.Withrisinglifestandardsandattentiontowardssafetymeasuresandwiththedevelopmentinmoderntechnologic,elevatorsystemsaregettingbetter,fastandmorereliable.Inthepast,mostoftheelevatorsystemswerefocusedonthemountingofelevators,around1980stheneedforelevatormaintenanceandfaultstaffhadstartedtoincrease[1].Forexample,splashdoorshavebeenreplacedbyautomaticdoorssystem,cardswithrelayhavebeenreplacedbymicroprocessorelectroniccards,inmultistoragebuildingsingle-speedelevatorshavebeenreplacedbydouble-speedorspeed-controlledelevators.Suchdevelopmentsimprovethequalityofelevatorsystems,thereforeincreasethereliabilityofelevatorsystemcomparedtopreviousyears[2].Elevatorcontrolsystem[3-4],anditslogicanalysis[5-6]havebeencreatinginteresttoengineersanditscontextscheduling[7]isstillinresearch.GurmeetSinghiscurrentlypursuingM.Tech.(ElectricalEngineering)NITHamirpur,H.P.,India.Hecanbereachedat:[e-mail]tlythefacultyofElectricalEngineeringDepartment,NITHamirpur,H.P.,India.Hecanbereachedat:[e-mail]ltyofElectricalEngineeringDepartment,NITHamirpur,H.P.,India.Hecanbereachedat:[e-mail]tlythefacultyofElectricalEngineering,MNNIT,Allahabad,India.Shecanbereachedat:[e-mail].(ElectricalEngineering)NITHamirpur,H.P.,India.Hecanbereachedat:[e-mail]978-1-4673-5630-5//13/$31.00©2013IEEETheobjectiveofthispaperistocreatetheladderlogicprogrammingofaPLCcontrolledelevatorsystemandcontrolstrategiesinvolvedinanelevatorsystemscanalsobeusedforeducationalpurpose.ThetwofloorelevatorsystemladderlogicisdesignedusingSIEMENSLOGO!SoftComfortV7.0software.SIEMENSLOGO!SoftV7.0softwareprovidesimulationmodefortestingofyourladderlogicprogram.PLCcanmakeaconventionalelevatorsystemintoanautomatic,energysaving,safeandreliableelevatorsystembyusingvariousmathfunctions,timers,creatinginterlocksetc.intoitsprogram.Theinputsinformofsensors,pushbuttonsetcandoutputinformofmotor,light,fanetcareconnectedtothePLCinputandoutputterminals.II.PLCLAYOUTPLCisanelectronicdevicethatisusedtodesignthecontrolcircuitsofindustrialautomationsystems.Itcontrolsthesystemviainputs/outputsandisequippedwithcommunicationinterfaces.TheadvantageofusingPLCbasedsystemistoensurethehighreliability,smallspacerequirements,computingcapabilities,reducedcosts,abilitytowithstandharshenvironments,expandability,highpowerhandlingcapacityandreducesthehumanefforts.ThelayoutoftheSiemensLOGOSeriesPLCisshowninFig.1.Ithasdigital/analoginputanddigitaloutputs.Ithas4digitaland4analoginputsandalldigitaloutputsareshowninTable1.Thesecanbeusedaspertheuser’srequirementandalsocanbeextendedusingextensioncards[8].Fig.1:SiemensLogoPLC.PLCControlledElevatorSystemGurmeetSingh,AnshulAgarwal,Member,IEEE,R.K.Jarial,Member,IEEE,VineetaAgarwal,SeniorMember,IEEE,andMithunMondalITABLEISIEMENSLOGOPLCLABELINGAPLCisdividedintoparts,asshowninFig.2thesearethecentralprocessingunit(CPU),theinput/output(I/O)modules,powersupply,andprogrammingdevice.TheCPUisthecalledas“brain”ofPLC,memoryisalsorequiredfortheprogram(EPROMorEEPROMtypeplusRAM).TheI/Omodulesformtheinterfacebywhichfielddevicesareconnectedtothecontroller.Toenterthedesiredprogramintothememoryoftheprocessoraprogrammingdeviceisused.Theprogramisdoneinladderlogic,whichisoneofthemostpopularprogramminglanguages.PowersupplysectionalsosuppliesDCpowertotheI/Omodules.ForlargePLCsystems,thispowersupplysectiondoesnotnormallysupplypowertothefielddevices.Withlargersystems,powertofielddevicesisprovidedbyexternalalternatingcurrent(AC)ordirectcurrent(DC)sources.ForsomesmallmicroPLCsystems,thepowersupplymaybeusedtopowerfielddevices.Fig.2:PLCblockdiagram.III.ELEVATORSYSTEMSTRUCTUREThemotiveofanelevatorcontrolsystemistocontrolthemovementofanelevatoraccordingtotheuser’srequests.Itisclassifiedintotwoparts:A.ElectricpowerdrivingsystemItincludestheelevatorcabinorcar,DCmotorandbrakemechanism.B.ElevatorcontrolsystemTheelevator’scontrolsystemisgovernedbyPLC.Theinputsignalsare:car-calls,emergencystopsignal,dooropen/closesignalandlevelingsignal.PLCprogramcontainsalllogicalfunctionsoftheelevatorsystem,suchascallregistration,positionjudgmentofelevatorcar,chooselayer,prioritysetting.IV.I/OMODULESANDELECT