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WELDING

AUTOMATION

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The aim of automation is

to minimize the humaninvolvement and bring asmany welding functions as

possible under the controlof the machine, which inturn results in higher

quality, consistency andproductivity.

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Limitations of Manual Welding

High fatigue factor on the welder dueto bright light, heat, smoke and sparksstub is to be discarded, reducing theArc-On Time

Quality of the weld is a function ofwelders expertise, his mood andfatigue levellonger beads: inconsistent bead shape

and sizelow productivity due to its low arc-ontime of 30%.

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over eighty percent of allsuch welding is done by

manual means.arc welding is one of thelargest job category

average arc-on-time is lessthan 30%huge application area andlow manual productivity

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arc welding is one of the most

potential fields for automation

and application ofrobots

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Tasks Involved in Arc Welding

1. Starting and Maintaining the Arc2. Feeding the Filler Electrode into theArc3. Controlling the Heat input for proper

penetration4. Moving the Arc along the joint at aproper velocity5. Guiding the arc along the joint

6. Manipulating and moving the torch toobtain proper joint fill7. Correcting the Arc characteristics toovercome deviations

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LEVELS OF AUTOMATION - AWS

1. MANUAL WELDING

2. SEMI AUTOMATIC WELDING

3. MECHANIZED WELDING4. AUTOMATIC WELDING

5. ROBOTIC WELDING

6. ADAPTIVE CONTROL WELDING

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Manual Welding

The welder starts and maintains

the arc, feeds the electrode intothe arc, obtains properpenetration and controls the weld

pool, moves the arc with a propervelocity and guides it along thejoint profile, manipulates theelectrode or the gun for correct

placement of the weld metal toobtain a quality weldIS CALLED A CLOSED LOOP SYSTEM

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Semi-Automatic Welding

The welding gun is held by the welder and

the electrode wire is continuously fedthrough the gun in to the arc. It is notrequired for the welder to maintain the arc,discard the stub or change the electrode.

Slag removal is largely eliminated and theamount of fumes and smoke is reduced.

Frequently applied to GMAW and FCAW

CLOSED LOOP SYSTEM

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Mechanized Welding

the machine maintains the arc, feedsthe electrode, moves the torch alongthe joint at proper speed

most popularly applied to SubmergedArc Welding (SAW) and is also popularwith GMAW, FCAW.

Low fatigue factor, higher productivityWelder supervises the processClosed loop system

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Automatic Welding

Welding machines are built to provide aset of required motion patterns andpreset welding parameters.

The welders duty is to set the work piecesand choose a motion pattern and asuitable set of welding parameters.

repeated jobs

frequently applied to GMAW,GTAW, FCAWand SAW processes.

open loop system

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Robotic Welding

robot with a controller provides the

motion path of the arc and the weldingparameters for making the weld.

The degrees of freedom of the welding

torch or the number of axes along whichthe torch can move in space is much higherin case of robotic welding whencompared to automatic welding

employed for simple welds with a complexwelding path. Paths which are intermittent

Open loop system

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Adaptive Control Welding

aims at making the automatic and roboticwelding processes closed loop systems byproviding power to sense the processparameters and make necessary corrections

controlled by a computer controller

closed loop system where human presenceis replaced by sensors and computercontrols

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MASTER CONTROLLER WELDING

SYSTEM(CELL CONTROLLER)

ADAPTIVE

CONTROL

IMAGE

PROCESSOR

IMAGE

DISPLAY

ARC IMAGE

PICKUP

THE WELDING ARC

ARC

MANIPULATOR

ARTIFICIAL

INTELLIGENCE

DATABANK

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LASER/ VIDEO

SCANNER

POSITION

CONTROLLE

R

NEURAL NETWORK

TORCH

SCANNER

TACK WELD

SEAM

Neural Network based seam tracking system

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Equipment Used for Welding Automation

welding power sources, electrode wirefeeders, specially designed torches, wirestraighteners

arc and work motion devices :Turntables, Pipe rotator units, Driving vehicles,Tripod units & column and boom, Control units,Wire feeder units, Clamping benches, Oscillationunits, Seam searching / tracking systems,

Camera systems, Orbital welding systems,System controllers, power sources and software,Wire feeder units, Orbital driving vehicles,

Tube-to-tubesheet weld heads, Purging gas-systems,

W ldi P S

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Welding Power Sources

Constant Power (CP): MMAW

Constant Voltage (CV): GMAW, FCAWConstant Current (CC) : GTAW, PAW

inverter welding machines:

MIG/MAG, MIG/MAG pulse, AC-DC TIG,TIG pulse .

Digitized Power Sources :

all operating and control jobs areperformed via a central micro-controller

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The Inverter Technology :Power sources are made smaller

100,000 Hz (or 100 kHz)instead of the 50 Hz

70 kg to 3 kg.

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Digitized Power Sources

*all operating and control jobs areperformed via a central micro-controller

*Same machine can be used for differentwelding processes ex: AC/DC TIG,DCTIG/MIG/Pulsed MIG etc.

*Out put of any designed wave form

*process control is carried out via software

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Electrode Wire Dispensing Systems

to carry large reels of electrode wire(100 500 kg)

motorized dereelers

motorized dispensing systemsFully enclosed electronic control modulehigh torque motors

Replaceable motor brushes

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arc motion devices

1. Tractors for flat position welding2. Carriages for all position welding3. Side beam carriages4. Manipulators, Boom and Mast

assemblies5. Gantry and Straddle carriages

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Welding tractor

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Side beam carriage

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Boom and Mast assemblies

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Boom and Mast assemblies

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Work Motion Devices

1. Universal or tilt-top positioners

2. Turning Rolls3. Head and tail stock positioners

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Universal Positioner

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Pipe Rotator

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Head and Tail Stock Positioner

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Automatic Dedicated Welding Machines

Heat exchanger welding machineswelding automobile torque converters truck wheels automobile axles bicycle frames vertical welding in ships

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robotic welding work-cell

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Robot and Universal Positioner