Multisensor Data FusionMult isensor Data FusionMult isensor Data FusionMult isensor Data Fusionfor for for for the the the the Control System Control System Control System Control System of of of of an an an an

Dottorato di Ricerca in Ingegneria Elettronica,

Automatica e del Controllo dei Sistemi Complessi

for for for for the the the the Control System Control System Control System Control System of of of of an an an an Arc Arc Arc Arc Welding RobotWelding RobotWelding RobotWelding Robot

Filippo Bonaccorso Tutor Prof. G. Muscato

RAPOLAC clusters expertise and resources from 8participants, including 4 SMEs and 4 universities.The partners are drawn from member states of EU and oneother country, Argentina, and includes specialists in theareas of part manufacturing, microstructural analysis,modelling and control, and environmental specialists.

OUTLINEOUTLINEOUTLINEOUTLINE

• RAPOLACRAPOLACRAPOLACRAPOLAC• SMD PROCESSSMD PROCESSSMD PROCESSSMD PROCESS• WELDINGWELDINGWELDINGWELDING• WELDINGWELDINGWELDINGWELDING• EXPERIMENTAL TEST BEDEXPERIMENTAL TEST BEDEXPERIMENTAL TEST BEDEXPERIMENTAL TEST BED• USER INTERFACEUSER INTERFACEUSER INTERFACEUSER INTERFACE

INTRODUCTIONINTRODUCTIONINTRODUCTIONINTRODUCTION

RAPOLAC is focussed on the Shaped Metal Deposition (SMD)process which is ideal for use in prototype production as well as inmanufacturing, eliminating the need for tooling and shorteningmanufacturing, eliminating the need for tooling and shorteningdevelopment lead-times. It uses no tooling and has low to zeroharmful emissions.

RAPOLAC will carry out research on process automation and willconcentrate on documenting and controlling the material propertiesthrough the development of process models. Process parameters willbe developed for many materials and the cost and environmental

SMD PROCESSSMD PROCESSSMD PROCESSSMD PROCESSSMD PROCESSSMD PROCESSSMD PROCESSSMD PROCESS

SMD INTRODUCTIONSMD INTRODUCTIONSMD INTRODUCTIONSMD INTRODUCTION

Shaped Metal Deposition (SMD) is a near-net shape prototypingsystem patented by Rolls-Royce, licensed to the University ofSheffield and operated in collaboration with Footprint Tools.

• The process allows complex parts to be built directly from the CAD• The process allows complex parts to be built directly from the CADmodel with minimum finishing.• The system creates components from the base up in a layer-wise

fashion, depositing weld material without the need for tooling.• Complex parts can be made with improved material properties, and

it is possible for hybrid components to be created.• The main uses of SMD are one off parts, rapid prototyping, repair

and complex or hybrid components.

SMD INTRODUCTIONSMD INTRODUCTIONSMD INTRODUCTIONSMD INTRODUCTION

Real PartReal PartReal PartReal Part

Experimental Deposition ProcessExperimental Deposition ProcessExperimental Deposition ProcessExperimental Deposition Process

SMD INTRODUCTIONSMD INTRODUCTIONSMD INTRODUCTIONSMD INTRODUCTION

Arc Welding RobotArc Welding RobotArc Welding RobotArc Welding Robot

Layer by LayerLayer by LayerLayer by LayerLayer by LayerDepositionDepositionDepositionDeposition

Up toUp toUp toUp toDesired ShapeDesired ShapeDesired ShapeDesired Shape

SMD INTRODUCTIONSMD INTRODUCTIONSMD INTRODUCTIONSMD INTRODUCTION

The innovative aspect of the SMD process consists of reversing theproduction philosophy actuated up to now, by the traditionalmanufacturing methods, such as machining, where the material isremoved from the work piece to obtain a desired final shape.

DrawbacksDrawbacksDrawbacksDrawbacks::::DrawbacksDrawbacksDrawbacksDrawbacks::::• Large waste of material in scraps• Large prototyping time• High energy required.

All this costs increase depending of thematerial used.

SIMPLE DEPOSITIONSSIMPLE DEPOSITIONSSIMPLE DEPOSITIONSSIMPLE DEPOSITIONS

WELDINGWELDINGWELDINGWELDINGWELDINGWELDINGWELDINGWELDING

Vx

Z-axis

TIG WELDINGTIG WELDINGTIG WELDINGTIG WELDING

2D Heat Diffusion Equation2D Heat Diffusion Equation2D Heat Diffusion Equation2D Heat Diffusion Equation

Rosenthal’s (1938) Simplified SolutionRosenthal’s (1938) Simplified SolutionRosenthal’s (1938) Simplified SolutionRosenthal’s (1938) Simplified Solution

Decreasing Decreasing Decreasing Decreasing the the the the CurrentCurrentCurrentCurrent

Workpiece

Travel Travel Travel Travel Speed and CurrentSpeed and CurrentSpeed and CurrentSpeed and Currentaffects the

Welding pool widthWelding pool widthWelding pool widthWelding pool widthaffects the

Workpiece final thicknessWorkpiece final thicknessWorkpiece final thicknessWorkpiece final thickness

Increasing the Travel Increasing the Travel Increasing the Travel Increasing the Travel SpeedSpeedSpeedSpeed

TIG WELDINGTIG WELDINGTIG WELDINGTIG WELDING

TheTheTheThe layerlayerlayerlayer heightheightheightheight hhhh isisisis affectedaffectedaffectedaffected bybybyby thethethethe spatialspatialspatialspatialdistributiondistributiondistributiondistribution ofofofof thethethethe materialmaterialmaterialmaterial depositeddepositeddepositeddeposited....SoSoSoSo itititit dependsdependsdependsdepends onononon::::•TheTheTheThe TravelTravelTravelTravel speedspeedspeedspeed (TS)(TS)(TS)(TS)•TheTheTheThe amountamountamountamount ofofofof materialmaterialmaterialmaterial injectedinjectedinjectedinjected (WF(WF(WF(WF))))•TheTheTheThe ArcArcArcArc CurrentCurrentCurrentCurrent IIII•TheTheTheThe ArcArcArcArc LengthLengthLengthLength•TheTheTheThe ArcArcArcArc LengthLengthLengthLength

EXPERIMENTAL TEST BEDEXPERIMENTAL TEST BEDEXPERIMENTAL TEST BEDEXPERIMENTAL TEST BEDEXPERIMENTAL TEST BEDEXPERIMENTAL TEST BEDEXPERIMENTAL TEST BEDEXPERIMENTAL TEST BED

SM

DS

MD

SM

DS

MD

PR

OC

ES

SP

RO

CE

SS

PR

OC

ES

SP

RO

CE

SS

AmperageAmperageAmperageAmperage

Wire Feed RateWire Feed RateWire Feed RateWire Feed Rate1) Torch Height from the Bead1) Torch Height from the Bead1) Torch Height from the Bead1) Torch Height from the Bead

2) Bead width and height2) Bead width and height2) Bead width and height2) Bead width and heightC

ON

TR

OL

CO

NT

RO

LC

ON

TR

OL

CO

NT

RO

LDesired ShapeDesired ShapeDesired ShapeDesired Shape

Production TimeProduction TimeProduction TimeProduction Time

CONTROLLER KEY PARAMETERSCONTROLLER KEY PARAMETERSCONTROLLER KEY PARAMETERSCONTROLLER KEY PARAMETERS

SM

DS

MD

SM

DS

MD

PR

OC

ES

SP

RO

CE

SS

PR

OC

ES

SP

RO

CE

SS

Travel SpeedTravel SpeedTravel SpeedTravel Speed

Step Step Step Step HeightHeightHeightHeight

2) Bead width and height2) Bead width and height2) Bead width and height2) Bead width and height

3) Welding Pool Shape3) Welding Pool Shape3) Welding Pool Shape3) Welding Pool Shape

CO

NT

RO

LC

ON

TR

OL

CO

NT

RO

LC

ON

TR

OL

Desired ShapeDesired ShapeDesired ShapeDesired Shape

Desired Mechanical Desired Mechanical Desired Mechanical Desired Mechanical Properties of the Properties of the Properties of the Properties of the final work piecefinal work piecefinal work piecefinal work piece

PROCESS FEEDBACKPROCESS FEEDBACKPROCESS FEEDBACKPROCESS FEEDBACK

SOUNDSOUNDSOUNDSOUND

LIGHTLIGHTLIGHTLIGHT

VOLTAGEVOLTAGEVOLTAGEVOLTAGE

CCD CameraCCD CameraCCD CameraCCD Camera

WorkpieceWorkpieceWorkpieceWorkpiece

SOUNDSOUNDSOUNDSOUND

Thermal CameraThermal CameraThermal CameraThermal Camera

Torch Torch Torch Torch Height from the Height from the Height from the Height from the BeadBeadBeadBead====

Arc LengthArc LengthArc LengthArc Length

Weld pool geometryWeld pool geometryWeld pool geometryWeld pool geometry====

Bead Width and HeightBead Width and HeightBead Width and HeightBead Width and Height

Kuka Robot

Tig

Torch Torch Torch Torch HeightHeightHeightHeightfrom from from from the Beadthe Beadthe Beadthe Bead

Bead Bead Bead Bead widthwidthwidthwidthand and and and heightheightheightheight

RS RS RS RS 485485485485

EthernetEthernetEthernetEthernet

IR SensorsIR SensorsIR SensorsIR Sensors

MicrophoneMicrophoneMicrophoneMicrophone

CONTROLLER KEY PARAMETERSCONTROLLER KEY PARAMETERSCONTROLLER KEY PARAMETERSCONTROLLER KEY PARAMETERS

Tig

Welder NI NI NI NI LabVIEWLabVIEWLabVIEWLabVIEWRealRealRealReal TimeTimeTimeTime TargetTargetTargetTarget

Welding Welding Welding Welding Pool Pool Pool Pool DimensionsDimensionsDimensionsDimensions

Temperature Temperature Temperature Temperature ProfilesProfilesProfilesProfiles

DeviceNetDeviceNetDeviceNetDeviceNet Protocol Protocol Protocol Protocol

AmperageAmperageAmperageAmperageWire Feeder RateWire Feeder RateWire Feeder RateWire Feeder Rate

Travel SpeedTravel SpeedTravel SpeedTravel SpeedStep HeightStep HeightStep HeightStep Height

Arc Arc Arc Arc LengthLengthLengthLengthTorch positionTorch positionTorch positionTorch position

RS RS RS RS 485485485485

Sensors FeedbackSensors FeedbackSensors FeedbackSensors Feedback

RS 232 / RS 485 / Firewire / USB 2.0

Thermal CameraThermal CameraThermal CameraThermal Camera

CCD CameraCCD CameraCCD CameraCCD Camera

IR SensorsIR SensorsIR SensorsIR Sensors

USER INTERFACEUSER INTERFACEUSER INTERFACEUSER INTERFACEUSER INTERFACEUSER INTERFACEUSER INTERFACEUSER INTERFACE

USER INTERFACEUSER INTERFACEUSER INTERFACEUSER INTERFACE

STATUS MONITORSTATUS MONITORSTATUS MONITORSTATUS MONITOR

WELDING SETTINGSWELDING SETTINGSWELDING SETTINGSWELDING SETTINGS

SENSORS INTERFACESENSORS INTERFACESENSORS INTERFACESENSORS INTERFACE

INIT TABINIT TABINIT TABINIT TAB

POSITION TABPOSITION TABPOSITION TABPOSITION TAB

SOUND TABSOUND TABSOUND TABSOUND TAB

IRIRIRIR----SENSORS TABSENSORS TABSENSORS TABSENSORS TAB

L

IMAGE PROCESSINGIMAGE PROCESSINGIMAGE PROCESSINGIMAGE PROCESSINGArcArcArcArc----Length Length Length Length MasuringMasuringMasuringMasuring

TroughTroughTroughTroughImage ProcessingImage ProcessingImage ProcessingImage Processing

ZZ ZZ-- -- a

xis

axis

ax

is

axis

WorkpieceWorkpieceWorkpieceWorkpiece

WebcamWebcamWebcamWebcam

IMAGE PROCESSINGIMAGE PROCESSINGIMAGE PROCESSINGIMAGE PROCESSINGArcArcArcArc----Length Length Length Length MesuringMesuringMesuringMesuring

Trough Trough Trough Trough Image ProcessingImage ProcessingImage ProcessingImage Processing

IMAGE PROCESSINGIMAGE PROCESSINGIMAGE PROCESSINGIMAGE PROCESSINGWeldingWeldingWeldingWelding----pool Geometry Measuringpool Geometry Measuringpool Geometry Measuringpool Geometry Measuring

TroughTroughTroughTroughImage ProcessingImage ProcessingImage ProcessingImage Processing

Video CameraVideo CameraVideo CameraVideo Camera

IMAGE PROCESSINGIMAGE PROCESSINGIMAGE PROCESSINGIMAGE PROCESSING

Thermal CameraThermal CameraThermal CameraThermal Camera

PassBandPassBandPassBandPassBand filter, CWL : filter, CWL : filter, CWL : filter, CWL : 610nm610nm610nm610nm

CONCLUSIONCONCLUSIONCONCLUSIONCONCLUSION

•Each module is identified as an elementary unit or as avirtual machine that communicates with the other modulesto assure a good process control.• Several algorithms were designed and developed to obtain

this result.this result.•The proposed interface has been adopted in many different

trials to get the best working conditions and the tuningparameters for the controller.•The interface has been also really useful to monitor the

process during the experiments, allowing to check in realtime most of the parameters and to monitor the outputs.

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PUBLICATIONSPUBLICATIONSPUBLICATIONSPUBLICATIONS

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“Control“Control“Control“Control ofofofof WeldingWeldingWeldingWelding forforforfor RapidRapidRapidRapid ManufacturingManufacturingManufacturingManufacturing:::: TwoTwoTwoTwo CasesCasesCasesCases Study”Study”Study”Study”FFFF.... Bonaccorso,Bonaccorso,Bonaccorso,Bonaccorso, CCCC.... Bruno,Bruno,Bruno,Bruno, LLLL.... CantelliCantelliCantelliCantelli,,,, DDDD.... Longo,Longo,Longo,Longo, GGGG.... Muscato,Muscato,Muscato,Muscato, GGGG....SpampinatoSpampinatoSpampinatoSpampinato,,,, SIDRASIDRASIDRASIDRA08080808

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