Advanced Welding Processes: Technologies and Process Control

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Advanced welding processes
SCARA
Cartesian
11.5 Typical welding robot configurations.
Articulated arm
ability to reach difficult access areas (it may be no coincidence that it has a
similar configuration to the human arm).
The SCARA (Selective Compliance Assembly Robot Arm) configuration
has traditionally been employed for assembly operations and has limited
positional capabilities; it has, however, been used by some manufacturers as
the basis of a simple, easily taught four to five axis machine for small batch
production. A SCARA robot system has also been employed for refurbishment
of worn crusher hammers. This is not a traditional application of robots due
to the unpredictable wear profile. In this case, the variations in wear were
accommodated by using the tolerance of the FCAW process combined with
the manual selection of one of three preprogrammed ‘jobs’ based on visual
assessment of the wear. Other applications of robotic wear replacement have
relied on pre-machining the worn part to a known profile before robotic
build-up.
Cartesian or gantry robots have been developed for very small high-precision
applications and when very large operating envelopes are required. These
standard configurations may be adapted to particular applications; for example,
it is common to suspend articulated arm robots from overhead gantries for
improved access and it is possible to construct special robot configurations
by rearrangement of the axes. Whilst the latter system may not appear to be