周期循环控制

《周期循环控制》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、CycletoCycleManufacturingProcessControlDavidE.Hardt*andTsz-Sin-Siu*Abstract--Mostmanufacturingprocessesproduceparts·Highbandwidthcontrolofmachinestatevariablessuchthatcanonlybecorrectlymeasuredaftertheprocesscyclehasasdisplacement,force,pressureortemperature.(ma-beencompl

2、eted.Evenifin-processmeasurementandcontrolchinestatecontrol)ispossible,itisoftentooexpensiveorcomplextopractically·Outputsamplingwithprocessdiagnosticsbasedonimplement.Inthispaper,asimplecontrolschemebasedonmeasuredprocessstatistics.StatisticalProcessControloutputmeasurem

3、entandinputchangeaftereachprocessing(SPC)cycleisproposed.Itisshowntoreducetheprocessdynamicstoasimplegainwithadelay,andreducethecontrolproblemExamplesofintermediatelevelsofcontrolsuchastoaSISOdiscretetimeproblem.Thegoalofthecontrolleristobothreducemeanoutputerrorsandreduc

4、etheirvariance.materialstatecontrol(e.g.directfeedbackofmaterialInsodoingtheprocesscapability(e.g.Cpk)canbeincreasedstress,strainortemperature)areveryunusual.Evenlesswithoutadditionalinvestmentincontrolhardwareorin-commonareexamplesofdirectprocessoutputfeedback,processsen

5、sors.Thiscontrolsystemisanalyzedfortwotypessuchasin-processpartgeometryfeedback.ofdisturbanceprocesses:independent(uncorrelated)andde-Asimpleblockdiagramofaprocess(seeFig.1)em-pendent(correlated).Fortheformertheclosed-loopcontrolphasizesthesedistinctions.Italsoshowsclearl

6、ythatanyincreasedtheoutputvariance,whereasforthelatteritcancontrolotherthanoutputfeedbackneglectstheinfluenceofdecreaseitsignificantly.Inbothcases,propercontrollerde-ubiquitousprocessdisturbances.Themostcommonofsigncanreducethemeanerrortozerowithoutintroducingtheseisthehi

7、ghlikelihoodofmaterialpropertyvariations.poortransientperformance.Thesefindingweredemon-stratedbyimplementingCycletoCycle(CtC)controlonasimplebendingprocess(uncorrelateddisturbance)andonanCONTR.EQUIPMENTMATERIALinjectionmoldingprocess(correlateddisturbance).There-sultsfol

8、lowedcloselythosepredictedbytheanalysis.EquipmentloopIndexTerms--ManufacturingProcessControl,SPC