seam-tracked laser beam remote welding with automated … · seam-tracked laser beam remote welding...

Seam-tracked Laser Beam Remote Welding

with Automated Gap Bridging

Dr.-Ing. Florian Albert

Scansonic MI GmbHApplication CenterBerlin, Germany

INDUSTRIAL LASER APPLICATIONS Munich, 24.06.2015

Outline

1. Company profile

2. Initial situation and challenges for laser remote welding

3. Solution RLW-A

a) Seam tracking

b) Bridging gaps

4. Conclusion and Acknowledgement

Scansonic MI GmbH Seam Tracked Laser Remote Welding with Automated Gap Bridging

1 Company Profile – SCANSONIC

� Founding of the company: 2000

� Market leader in seam tracked laser brazing/welding at bodywork

� Prime market: automotive industry and suppliers for automotive engineering

� Number of employees: app. 200 (permanent staff) + 20 (interns/students)

� 2015: > 2.000 laser optics in use worldwide

� DIN EN ISO 9001 certified

� Own application center with 5 lasers (diode and disk lasers up to 8 kW) and 8 robots


1 Company Profile – Scansonic Optics in Europe

Audi, VWBratislava

PSARennes

Magna SteyrAlbersdorf

Seat, AudiMartorell

SkodaKvasiny

NTO IRE-PolusMoskwa

RenaultNovo Mesto

VolvoOlofström

FiatTurin

Deutschland: Audi, Bombardier, BMW, Daimler, KWD, MTU, Opel, Photon, Porsche, Viessmann, VW

BMW MiniOxford

VolvoUmeå

PSASochaux

PSAPoissy

PSAMulhouse

AudiBrüssel

RenaultDouai

PSATrnava

AudiGyőr

VWPoznań

SkodaMladá Boleslav

Laser CenterSankt Petersburg

GAZNischni Nowgorod

DaimlerKecskemét

BMW MiniSwindon

DaimlerVitoria

VW AutoeuropaPalmela

PSAMadrid

PSAVigo

GMEllesmere Port

GMLuton

VWPamplona

voestalpine Polynorm B.V.Bunschoten

Valmet Automotive Inc.Uusikaupunki


2 Initial Situation

� Laser Remote Welding is gaining more and more attention (e.g. in BIW production)

� No wire costs

� Short cycle time because of a reduced auxiliary process time

� But: component tolerances are a major challenge for the usage of remote welding

� Difference between programmed beam position and the actual componentlocation must be compensated bycomplex and thus costly design measures

� A changing gap situation makes itdifficult to choose suitable processparameters to reach a bridged weldseam

Door Audi A8 *)

welding withScansonic ALO3

*) Latzl., M.: Die leichte und funktionale Tür des neuen Audi A8. In: Proceedings of Türen und Klappen, 2010


2 Challenges


� Laser Remote Welding of fillet or sq. butt welds

� with seam tracking

� with gap bridging

Stampingfailures(simulated)

� Challenge:Following the edge

Stampingfailures(simulated)

� Challenge:Following the edge

Gap between the sheets

� Challenge:Bridging the gap withoutfiller wire

Gap between the sheets

� Challenge:Bridging the gap withoutfiller wire

� Remote Welding Optic RLW-A

Welding with Scansonic RLW-A

+ No wire costs

+ High efficiency

- How to find theseam?

- How to bridgegaps?

new optic for high precision Remote-Welding with opticalseam tracking and beam oscillation

Scansonic MI GmbH

3 Solution RLW-A

Seam Tracked Laser Remote Welding with Automated Gap Bridging

3a Seam Tracking


� Forerun 10 mm

� System gets time to react

� Robot program strategy must be considered (Fixture, Shadows, Orientation), like tactile head

� Advantages of 3 linens (6D):

� Cartesian and angular positions are known (how is the head positioned in reference to the part)

� More redundancy and stable seam recognition (more measurement data)

� Important:

� Seam tacking lines cover complete y scan range (±16.5 mm)

� Seam tracking lines are fixed in position

� But special On-The-Fly function still possible (moving x-scanner)

x

laserspot

seam-trackinglines

Process direction

y

y travelrange

for run

3a Seam Tracking


Deliberately caused edge faults (cutting tool):

RLW

Lower Sheet

Upper Sheet

RLW

Gap

Melt Pool

Oxide Skin

RLW

Initial Situation

� Gap beetween upper and lower sheet can not be bridged with standard parameter for zero gap situation

� Adjustments of process parameters are necessary

Problem

� Oxide skin around the melt pool leads to high surface tension and joining failures

� Increasing of melt pool by using bigger beam diameters is not sufficient due to loss of beam intensity � instable keyhole

Solution

� Increasing the melt pool by beam oscillation � high beam intensity + large melt pool

� High beam velocity leads to a good material deposition from upper to lower sheet

Bridged Gap

3b Bridging Gaps


Oscillationin y or x&y

upper sheet

lower sheet

� By seam tracking the correct position of the laser beam and the gap between the sheets are known

� A geometrical model and the necessary S-Value give information about:

� Y-Offset of the beam

� Amplitude of beam oscillation

� Laser power

� (Frequency of beam oscillation)S-Value = 0.7 x t

Scansonic MI GmbH

3b Bridging Gaps

Seam Tracked Laser Remote Welding with Automated Gap Bridging

3b Bridging Gaps

Gap: 0 mm

Gap: 0.7 – 0.8 mm

� Automated seam tracking in Y

� Bridging of a varying gap by an adjustment of laser power, beam offset and oscillation amplitude in Y

� Bridging of a hs = 0 … 0.8 mm gap at two t = 0.8 mm zinc coated steel sheets

� S-Value at every position > 0.7 x t


Gap height

to 0.05mm 0.05 mm –0.2 mm

0.2 mm –0.4 mm

0.4 mm –0.6 mm

0.6 mm –0.7 mm

Oscillationstrategy

Non-oscillated Transversal (Y)

Transversal (Y)

Transversal (Y)

Transversal (Y)

Front andback sideof steelsheets

Cross sectionview

[VS 2.5m/min;H260LAD]

Reproducible, proper welds

3b Bridging Gaps


Beam Oscillation in Y-Direction

Gap 0mmGap 0,6 mm Gap 0 mm

No full penetration, uniform heating

Backside

3b Bridging Gaps

Seam Tracked Laser Remote Welding with Automated Gap BridgingScansonic MI GmbH

Material: AW 6082; t=1,5

Gap 0,5 mm

Micro Sections

Material: AW 5182; t=1,5Gap 0 mm

1,5 mm

0,4 mm

0,5 mm

Beam Oscillation in Y-Direction

3b Bridging Gaps

Seam Tracked Laser Remote Welding with Automated Gap BridgingScansonic MI GmbH

� At remote welding seam tracking is necessary to realize fillet welds or butt welds at the correct position

� At remote welding gap bridging is possible by a controlled change of parameter

� The measurement of the gap allows to control the process parameter(laser power, beam offset, amplitude and frequency of oscillation)

� The necessary S-value leads to correct parameter based on a developed model

Thank you for your attention!

The author would like to thank the German Federal Ministry of Education and Research(BMBF) for the support of parts of the carried out work within the “Brightlas ResearchProject”.

Conclusion and Acknowledgement

Scansonic MI GmbH concl.Seam Tracked Laser Remote Welding with Automated Gap Bridging

seam-tracked laser beam remote welding with automated … · seam-tracked laser beam remote welding...

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