KCT-a-MATLAB-toolbox-for-motion-control-of-KUKA-ro

KCT:aMATLABtoolboxformotioncontrolofKUKArobotmanipulatorsFrancescoChinello,StefanoScheggi,FabioMorbidi,DomenicoPrattichizzoAbstract—TheKukaControlToolbox(KCT)isacollectionofMATLABfunctionsformotioncontrolofKUKArobotmanipulators,developedtoofferanintuitiveandhigh-levelprogramminginterfacetotheuser.Thetoolbox,whichiscompatiblewithall6DOFsmallandlowpayloadKUKArobotsthatusetheEth.RSIXML,runsonaremotecomputerconnectedwiththeKUKAcontrollerviaTCP/IP.KCTincludesmorethan30functions,spanningoperationssuchasforwardandinversekinematicscomputation,point-to-pointjointandCartesiancontrol,trajectorygeneration,graphicaldisplayanddiagnostics.Theflexibility,easeofuseandreliabilityofthetoolboxisdemonstratedthroughtwoapplicativeexamples.I.INTRODUCTIONMATLAB[1]isapowerfulandwidelyusedcommercialsoftwareenvironmentfornumericalcomputation,statisticanalysisandgraphicalpresentationavailableforalargenumberofplatforms.Specifictoolboxes(i.e.,collectionsofdedicatedMATLABfunctions)havebeendevelopedinthepastfewyearsforsupportinresearchandeduca-tion,inalmosteverybranchofengineering,suchas,e.g.,telecommunications,electronics,aerospace,mechanicsandcontrol.Asfarasroboticsisconcerned,severaltoolboxeshavebeenpresentedinthelastdecadeforthemodelingofrobotsystems[2]–[7].Thesesimulationtoolshavebeeninspiredbyvariousapplicativescenarios,suchasvision-basedrobotics[5],[6]andspacerobotics[3],andhaveaddresseddifferenttargetsrangingfromindustrial[4]toacademic/educational[2],[5]–[7].AmorechallengingproblemistodesignMATLABtoolkits,offeringversatileandhigh-levelprogrammingenvi-ronments,formotioncontrolofrealrobots.Someworkhasbeendoneinthisfieldforoneofthefirstindustrialrobots,thePuma560manipulator[8],[9]:howeverthisrobotisknowntohavesomeintrinsicsoftwarelimitations,especiallyinreal-timeapplications,whichhavebeenovercomebymorerecentmanipulators.InthispaperwewillfocusonthemanipulatorsproducedbyKUKA[10],oneoftheworld’sleadingmanufacturersofindustrialrobots.KUKAmanipulatorsaredesignedtocoveralargevarietyofapplicationsinindustrialsettings,suchas,e.g.,assembly,materialhandling,dispensing,palletizingandweldingtasks.AspecificC-likeprogramminglanguage,calledKRL(KUKARobotLanguage),hasbeendevelopedbyKUKAforrobotmotioncontrol.Thislanguageissim-pleandallowscomfortableprogramming.However,itisnotsuitedforcriticalreal-timeremotecontrolapplications,TheauthorsarewiththeDepartmentofInformationEngineering,UniversityofSiena,ViaRoma56,53100Siena,Italy.Listofe-mails:{chinello,scheggi,morbidi,prattichizzo}@dii.unisi.ititdoesnotsupportgraphicalinterfacesandadvancedmathe-maticaltools(suchas,matrixoperations,optimizationandfilteringtasks),anditdoesnotallowaneasyintegrationofexternalmodulesandhardware(suchas,e.g.,camerasorembeddeddevicesusingcommonprotocols:USB,Firewire,PCI,etc.).ApossiblewaytoovercomethesedrawbacksistobuildaMATLABabstractionlayerupontheKRL.AfirststeptowardsthisdirectionhasbeenrecentlytakenbyaMAT-LABtoolboxcalledKuka-KRL-tbx[11].Theauthorsin[11]useaserialinterfacetoconnecttheKUKARobotController(KRC)witharemotecomputerincludingMATLAB.AKRLinterpreterrunningontheKRC,establishesabi-directionalcommunicationbetweentherobotandtheremotecomputeranditisresponsiblefortheidentificationandexecutionofallinstructionsthataretransmittedviatheserialinterface.Kuka-KRL-tbxoffersahomogeneousenvironmentfromtheearlydesigntotheoperationphaseandaneasyintegrationofexternalhardwarecomponents.Inaddition,itpreservesthesecuritystandardsguaranteedbytheKRL(workspacesupervision,checkofthefinalpositionswitchesofeveryrobotaxis,etc.).However,Kuka-KRL-tbxsuffersfromsomelimitations:•TheMATLABcommandsofthetoolboxareone-to-onewiththeKRLfunctions:thislackofabstractionmayhindertheuserfromdesigningadvancedcontrolapplications.•Theserialinterfacemayrepresentalimitinreal-timecontrolapplications.•Thetoolboxdoesnotincludespecificroutinesforgraphicaldisplay.ThispaperpresentsanewMATLABtoolbox,calledKUKAControlToolbox(KCT),formotioncontrolofKUKArobotmanipulators.Thetoolbox,designedbothforaca-demic/educationalandindustrialpurposes,includesabroadsetoffunctionsdividedinto6categories,spanningopera-tionssuchas,forwardandinversekinematicscomputation,point-to-pointjointandCartesiancontrol,trajectorygenera-tion,graphicaldisplay,3-Danimationanddiagnostics.KCTshareswithKuka-KRL-tbxthesameadvantagesandimprovesitinseveraldirections:•ThefunctionsofKCTarenotaMATLABcounterpartofthecorrespondingKRLcommands.Thismakesthetoolboxextremelyflexibleandversatile.•KCTrunsonaremotecomputerconnectedwiththeKRCviaTCP/IP.Amulti-threadserverrunsontheKRCandcommunicatesviaEth.RSIXML(EthernetRobotSensorInterfaceXML)withaclient2010IEEEInternationalConferenceonRoboticsandAutomationAnchorageConventionDistrictMay3-8,2010,Anchorage,Alaska,USA978-1-4244-5040-4/10/$26.00©2010IEEE4603θ1z0≡z1θ2z2θ3z3θ4θ5z5z4θ6z6d21d32d43d54d65xo≡x1yo≡y1Fig.1.Referencerobot:6DOFelbowmanipulatorwithsphericalwrist.managingtheinformationexchangewiththemani-pulator.Thiscommunicationschemeguaranteeshightransmissionrates,thusenablingreal-timecontrolapplications.•KCThasseveraldedicatedfunctionsfo