A two machine Automated Fiber Placement (AFP) cell capable of
laying 1/2\mi and 1/4\mi tow at rates up to 1800\mi/min (45.7
m/min), including feeds and cuts, has been implemented for the
manufacture of large primary aircraft structures.
The control architecture of the cell is such that part programs
are machine independent and can run on either machine or
simultaneously on both machines at the same time. A Central Cell
Controller pushes part programs to each AFP machine and coordinates
the cell.
Volumetric accuracy of the two machines is under 0.008\mi (0.2
mm) radial error in the entire compensated envelop, which is
approximately 64' x 21' x 14' (19.5 m x 6.4 m x 4.3 m)
for each machine. This is accomplished through optimization of
volumetric kinematic compensation parameters using a linear
numerical solver. The machines reference a common coordinate system
which allows great flexibility in part programming.
A detachable head design was implemented which allows each
machine to swap between 1/4\mi and 1/2\mi tow widths in 120
seconds. The creel is contained on the head which provides very
short tow paths and isolates the AFP process to the detachable
tool. This allows creel re-fills, AFP head maintenance, repair, and
upgrade of AFP head to be performed off line without interrupting
production.
