Archimedes Examples
The pattern wheel is a 13-part subassembly of a discriminator (see next
assembly, although a different design). The Archimedes planner reads in the
facetted models, finds all contacts, and determines a geometrically valid
part-level assembly sequence [79K] in a
few seconds. A plan that minimizes the number of subassembly reorientations
and robot tool changes is found in a total of a minute. The resulting plan
can then be simulated (excerpts: part
placement [87K], subassembly
reorientation [153K], and laser
welding [153K]). Translated to V+, the plan executes [469K] reliably in the
Archimedes workcell.
A discriminator is a mechanical safety device designed to prevent
accidental operation of a system. The discriminator has 42 parts, and
consists of approximately 4 Mbytes of CAD data. It is modeled in
Pro/ENGINEER, and translated to the ACIS solid modeling system for
internal processing. Reading in the models, finding all the contacts
between parts in the assembly, and determining a single geometrically
valid part-level assembly sequence for the discriminator currently
takes the Archimedes planner about 30 seconds. The assembly sequence
can then be animated
[534K]. When the tool module is used to model the tool constraints
for the discriminator, the resulting tool-level plans
[798K] are more detailed and more accurate than the part-level plans
above.
The Rockwell assembly is a circuit board in a case, a relatively
simple assembly mechanically, that is currently in low-volume
production at Rockwell. However, when assembly tools are considered,
a number of tight accessibility questions arise, requiring difficult
choices in assembly ordering. The assembly has 78 parts including all
fasteners and hardware, modeled by about 8 Mb of CAD data.
It was chosen as a vehicle to demonstrate Archimedes by the TEAM Virtual
Manufacturing Electromechanical Assembly group, in which Sandia
participates. Allied Signal modeled the assembly, then Archimedes
planned for its assembly, resulting in the following assembly sequence [1.1M].
This accelerometer is part of another safety device designed at
Sandia. The assembly has 79 parts, modeled by about 16 Mb of CAD
data. The customers were mainly interested in simply and quickly
visualizing possible assembly sequences, as well as easily generating
instructional video to train human assemblers. Archimedes
automatically found an assembly sequence for the accelerometer that
satisfies all user requirements in 4 minutes, resulting in this animation [3.5Mb].
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Last modified: 11/12/02
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