NIF gets a lift through high-tech transporters
If the Enterprise, Voyager and Defiant are moving about you and you’re
not lost in space on the set of a "Star Trek" television show,
you must be in the laser bay of the National Ignition Facility (NIF).
That’s where three vehicles carry ultra clean canisters used to transport
phone-booth-sized optical assemblies (the Line Replaceable Units, LRUs)
and install them in the NIF laser system.
Made by AGV Products Inc. of Charlotte, N.C., these transporters are high-tech
and highly intelligent forklifts. Guided by a computer-controlled laser,
they each weigh 29,000 pounds and can carry a canister LRUs weighing as
much as 8,000 pounds. The transporters position the canisters, docking
them within one millimeter and one-tenth of a degree rotation, very tight
tolerances. The laser-guided transporters are able to move their forks
front and back, side to side, and to rotate them on an angle, allowing
them to insert the canisters into the Beampath Infrastructure System in
the NIF.
The most complex automated guided vehicles ever built are bright yellow
with red trim. The battery powered transporters maneuver about NIF like
graceful sea lions gliding among the coral reefs. "They can also
move sideways, much like a land crab," says Ray Abounader, lead Engineering
Technician for the transporters.
Another special feature of each laser-guided transporter is that it can
supply AC (alternating current) power to the canisters it carries. The
vehicles are completely electric because electrical actuators are cleaner
than hydraulics. The vehicles also carry their own utilities — compressed
air, vacuum system, and "clean air" gas. The latter is used
to purge the environment in these mini clean room canisters being transported
and to drive some of the pneumatics in the canisters.
The transporters also need power to open their lids and insert their LRUs
into NIF. "There is constant communication between the transporter’s
computer control system and the canister’s computer control system,"
says Steve Yakuma, lead engineer for NIF’s Transport and Handling
Group. One Traffic Management Computer controls the motion of all three
transporters in the high bay to maximize efficiency.
The transporters carry canisters used to install the LRUs that are a variety
of shapes and sizes. Inside the canisters are amplifier glass slab assemblies,
flashlamp assemblies, mirrors, and other optical assemblies.
The Transport & Handling Group designed and oversaw the fabrication
of the transporters and canisters and now they’re conducting tests
on the NIF site intended to demonstrate that the systems are meeting their
functional and cleanliness requirements prior to installing LRU’s
next year.
"Our goal is to put the equipment, as well as the installation team,
through its paces and show that we’re ready to go " says Gina
Bonanno, associate project manager for NIF Assembly, Installation and
Refurbishment.
"By testing in the field we are encountering things that might not
be identified in a test environment. This gives us the opportunity to
address issues early, prior to beginning the installation process. The
results to date are very encouraging, we’re demonstrating that the
systems are working as designed," says Bonanno.
The LRUs are built in the Optics Assembly Building, a Class 100 clean
room (no more than 100 particles greater in size than five microns per
cubic foot of air). "Once the LRUs are installed in the clean canister,
they can be transported and inserted into the clean NIF beamlines,"
says Bonanno.
How it all began
Three years ago, AGV Products won the bid to create the unique forklifts
and began working with LLNL engineers to custom design the biggest, cleanest
robots necessary to transport and install the LRUs that comprise NIF.
The first transporter, Enterprise, was built and tested and resulted in
a few improvements in the second and third transporters, Voyager and Defiant.
AGV Products, Inc. builds automated guide vehicles (AGVs) for a range
of applications and is the only supplier of three guidance systems —
laser, inertial and wire — according to Matt Herrstromer, president
of AGV Products, Inc. Automated guide vehicles are used by General Motors
to build trucks and by Boeing to build airplane wings.
A sign in the high bay of Bldg. 432, where the laser-guided transporters
are tested, proclaims, "NIF Operations, to Ignite and Beyond."
The laser-guided transporters may not reach "to infinity and beyond,"
as the character Buzz Lightyear proclaims in the children’s movie
"Toy Story." However, the transporters are playing a key role
in cleanly installing the optics that comprise NIF, and this powerful
laser system is designed to ignite its targets and provide scientists
with knowledge beyond what we know today regarding the evolution of our
sun and the stars.