PLC与机器人控制的英文文献

cePLCCo~~rol~~~~~e~~e~MotorinRobotManipulatorA.S.ZEINELDINElectricalEngineeringDept.,FacultyofEngineering,ShebinEl-Kom,MenoufiaUniversity,Egypt.e-mail:IN%”[e-mail]’,Tel.XX(048)212549,Fax.XX(048)23695Abstract-11.1recentyears,acompletedigitalcontrolofmulti-axis-systemhasbeendeveloped.ThispaperdescribesanIndustrialProgrammableLogicControlPLC)usedforcontrollingfive-axisrotorposition,directionandspeed,therebyreducingthenumberofcircuitcomponentsloweringthecostandenhancingreliability.Someexperimentalresultsindicatingcontroller’shighperformanceandfunctionalityaregivenKeywordsPLC,Robot,andsteppermotor.IINTRODUCTIONTheprincipalaimofmotioncontrolisthedesignofcontrolsystemsabletomaketrueautomaticallythemovementofamachine.Thisperformancemustbereachedoptimizingtheproductivityofthemachinery,i.e.achievinghigherworkingspeed,minimizingtheenergyrequired,reducingthewearofthemechanicalelement[l].Toprovidehighperformanceservocontrolwithmaximumapplicationflexibilityforbus-basedcontrolsystcms,acompletelydigitalarchitectureisrequired.Inmostcases,thePECisasolid-statedevice,designedtooperateinnoisyindustrialenvironmentsandperformallthelogicfunctionspreviouslyachievedusingelectromechanicalrelays,drumswitches,mechanicaltimersandcounters[21.Stepmotors,whicharegenerallyusedinmicrocomputer,arenowvcidelyusedinrobotics[3].Inthispaper,IproposedaspeedcontroloffiveaxisroboteachaxiscontainsonestepmotorbyusingPLC(SLC150).ILTHEPROGRAMMABLELOGICCONTROLLERThePLC,likeacomputer,employsamicroprocessorchiptodotheprocessingandmemorychipstostoretheprogram.ThebasicPLCstructureisshowninFigure1,theinputdevicesaresensorsthatmonitorthemachineorprocessbeingcontrolled.Thestatusofthesesensors(ONorOFF)isfedtothePLCcontroller.DependingupontheinputstatusofthesesensorstheoutputsofthePLCmaybeswitchedontoenergizemotors,relays,valvesetc....,tocontrolthemachineorprocess.ThePLG[2]oftypeSLC150has10inputsnumberedfrom1to10,andthenafurther10inputsnumberedfromIO1to1IO.Thesearecalledinpitinterfacethethrustbearingtothemountandturretclampaddresses.TheSLCI50has12outputsnumberedfrom11assembly(theyareplacedoneithersideofthethrustto16,and11Ito116.Thesearecalledoutputaddressesbearing),Turretgear(therearetwoone254~0thandone40-tooth),steppermotors(fivemotors),digitalencoder,Armlinks,andGripperisarobothandthatprovidesjawpositionanddynamicsqueezeforceinformationtotheRI:QmiokasicPLCArchitectureFigure2showsatypicalrobot141.Itconsistsofbaseplatehas8-32threadedholesonone-inch(thesizeofthebaseplateis12inchesby14inches),Turretisarotatingplatformequippedwithabeltaroundillscircumference(Ithas8-32threadedholesonone-inchcenters.Theseholesaccommodatemountingtherobotarmandwristmotorsatvariouslocationsrelativetoiil’scenter),Tunetclampwhichattachestheturrettotlheturretshaft,Turretmountwhichattacheslipthebaseplaileandhousestheturretmotorandsupportstheturretsh&andturret.Turretshallisusedtoretaintheturretwithinthemountassembly,turretbearing(Therearctwo)aresecuredwithunthemounttoholdtheturretshaft,Thni.jtbearingmountsareontheturretshafttoaccommodaretheweightoftherobotandtoprovidesmoothrotationofthcturret,Thrustwashersmountontheturretshaftlocontroller.-Pig.2ATYPICALROBOTThesteppermotorsuppliedwiththeroboticssystelmprovideprecisemovementinresponsetopulsesofelectricalcurrent.Themotorsincrement1.8degreespercommandedstepandrequireatotalof200st’eps(orincrements)torotatethemotorshaftonecompleterevolution.Thesteppermotorisafour-phasepermanentmagnetmotor(labeledasA,B,CandD.AschematicdiagramofthemotorisshowninFig.3a.Thereisonewindingperphase,andthereforeoneconnectorpinperphase.EachwindinghasaresistanceofSohm,andinductanceof8m.h.,eachwindingoperatesof5volt.andrequires1Ampereofcurrent.ThetimingofthedrivesignaltoeachphaseisshowninFig.3b.9754I5I976Table1Controlofmotordirection'rerrnlnalorElccbbmktmltchsInputsOlr-Fig.4ProposedcontrolsystemV.RESULTSWehaveadjustedthesequencer(SQO)inPLCsoftwareprogramtoachievethetimingofthedrivesigndtoeachphaseofsteppermotorasthesequenceshowninFig.3bforstepperiodequalsto78m.sec.,thenswitchonPLCinputswitches01,02,03,04,05,101,102,103,IO4and105.TheFourinputsignalstothemotornumber1or2or3OH4or5isshowninFig.6,whilethecorrespondingmotorenderspeedisshowninFig.7.AnotherexampleofmotorspeedisshowninFig.8,thePLCcontrolthedirectionofsteppermotor,foracertaincycler;,themotorrotatesinclockwisedirectionthenreversesitsdirection(anti-clockwise).W.CONCLUSIONTheresultsofthisworkshowtheadvantagesofaPLCforcontrollingthefiveaxisrobotics(Itcontaiinsof5steppermotor).therobustnessofthePLCcontrollierhasbeenachievedbyrotatingthemotorinclockwisedirectionthenreverseitsdirectioninanti-clmhse.977Consequently,thePLCcontrollerseemstobeasimpletoolforcontrollingrobotbyextremelysimplealgorithm.REFERENCES[I]P.L.G.Malapelle,“Newmicroprocessorsystemeasiercustomcontrolsbuilding-up”,IFAC,Peerugla,Italy,October27-29,1992.[2]‘‘AnintroductiontoIndustrialProgranunableControllers”,LjtechnicalsystemsInc.,USA,1994,PP26.[3]F.Bttin,M.Deloizy,@.Godel,“Application~fhuuylogicinthespeedcontrolofastepmotor”,ACEW’95,5-7June,Turkey,19