Page 22 - Welding Robots Technology, System Issues, and Applications

Welding Robots
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Welding Institute – UK [26]. In these databases the input data is generally the type
of weld (butt weld or fillet weld), the welding position (flat, horizontal, vertical or
overhead), wire diameter and the plate thickness or eventually the leg length in the
case of fillet welds. The output data is usually the welding parameters (namely,
current, voltage, welding speed and number of weld beads/layers). Using databases
of this type with a computer, the selection of the welding parameters may be
performed automatically. Even the selection of the wire diameter may be carried
out automatically as a function of the thickness of the components, or stay for free
user selection being an input parameter.

It might be expected that with this information in the computer, having a CAD
model of the component to be welded, the system would be able to select the
welding data for each weld and send these data to the robotic welding system.
Though it seems easy to achieve this goal in the case of single welds, some data are
missing in the available databases for the case of welds with multiple layers. In
fact, in this case the position of the torch in each layer needs to be indicated to the
robot.

Since for the majority of the companies that produce multi-layer welds there is
only a small number of distinct welds, then it is not hard to fill up the database for
their particular case. Consequently, using this method it is easy to carry out the off-
line programming of the components to be welded, it being only necessary to
adjust the coordinates of the process points in the first specimen to be welded.

1.2 Historical Perspective

Welding is a skill used to manufacture, produce, construct and repair metal objects.
In fact this skill can also be used to join other type of materials, but this book
focuses only on welding processes used to join metal objects, where this skill is
critical for several areas of activity like defense, aerospace, shipbuilding,
transportation, building and bridge construction, industrial apparatus and consumer
products.

The word “robot” comes from the Czech “robota” that means tireless work, and
was used for the first time in 1921 by the novelist Karel Capek in his novel
“Rossum’s Universal Robots”. But robotics was in the head of the most brilliant
minds of our common history, since most of them took time to imagine, design and
build machines that could mimic some of the human capabilities. It is one of the
biggest dreams of man, to build obedient and tireless machines, capable of
substituting man doing their boring and repetitive work. An idea very well
explained by Nicola Tesla in his diary [4]:

“… I conceived the idea of constructing an automaton which would
mechanically represent me, and which would respond, as I do myself, but,
of course, in a much more primitive manner, to external influences. Such an