MAKE • STORE • MOVE • COMPETE A Penton Publication

May 2012

www.mhlnews.com

AGVs Help Fighters Fly Off the Line

Transportation Strategy Session

p. 22

VLMs in the Each era

p. 26

Match Order to Picker

p. 30

Goods-to-Person Picking

p. 33

Total Cost to Ship

p. 38

A Special Breed of AGV Gives Wings to F-35s p. 18

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Cover Feature | AGVs in Manufacturing

AGVs Help Jet Fighters Fly Off the LineLockheed Martin

recruited a special

breed of guided

vehicle to enable

precision assembly

of a fighter plane a

day. The right stuff

means not only

being automated,

but autonomous.

By Tom Andel

The F-35 Joint Strike Fighter (JSF) owes a bit of its existence to Henry Ford. Lockheed Martin Aeronautics

(www.lockheedmartin.com) adapted his concepts of mass production and common parts to affordably produce this multirole aircraft for multiple branches of the U.S. military—Air Force, Navy and Marine Corps—as well as U.S. allies.

There’s not much that’s simple about this 5th generation fighter’s technology. It combines stealth, fully fused sensor in-formation and network-enabled opera-tions. A portion of Lockheed Martin’s facility in Marietta, Ga., is dedicated to

manufacturing the center wing section at a pace that accommodates a production rate of one aircraft a day. This production line replaces one that was first built at Lock-heed Martin’s facility in Fort Worth, Tex.

With accommodations for F-35 pro-duction in Fort Worth resulting in floor space challenges, a portion of the fighter’s production was moved to Marietta. This new production line presented a material handling challenge of its own—one that couldn’t be addressed with overhead han-dling. The automotive industry proved to be a role model with its use of automated guided vehicles.

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Why Guided Vehicles?

The Fort Worth facility’s use of overhead rail to move the wing assembly from station to station would not offer the time or space efficiency needed at the Marietta facility. The layout of the Marietta facility would require the kind of efficiency found in a car plant producing 20 to 40 vehicles an hour, so what better source to borrow material handling best practices from than the automotive industry?

“The aerospace industry has benefited from the experience of the automotive industry because its high production rates have pushed technology to be more automated,” says Peter Neumeier, of the aerospace engineer staff at Lockheed Martin. “We needed a production line to satisfy the rate of one aircraft a day for whatever variant was com-ing down the line. The Marietta facility had floor space constraints. So we performed a lean event and determined we needed to find a different so-lution to the transport of the center wing section. Fort Worth’s overhead rail system took up too much floor space and didn’t give us the flexibility we were looking for. We decided an AGV of some kind was a better solution.”

Lockheed selected Fori Automation (www.fori-auto.com) to provide the AGV system. According to Paul Meloche, vice president of sales for Fori, much of the AGV technology implemented at Lockheed that came from the automotive industry included the components that enable production capacity and accuracy. But Fori implemented some new technologies as well.

“Our drive steer mechanism provides the steer-ing and propulsion,” Meloche says. “It’s a sus-pended drive steer so it can articulate over rough concrete. We also developed a precision sensor measurement device for the magnetic field.”

No Tolerance for VariancePrecision is the key word here, since the compo-

nents of the center wing section have extremely tight tolerances. Many AGVs guided by a magnetic stripe wander left or right while following the path. Fori developed a 12-inch-wide precision magnetic measuring device that gauges the intensity of the magnetic field, enabling a vehicle to position itself at an assembly station to an accuracy within 4-5 mm.

Each AGV measures 67” wide, 181” long and 28” high, and supports tooling that, combined with the center wing section, weighs about 12,000 pounds.

The tooling is transported to 14 different process stations and each AGV must hold that tolerance every time it’s moved.

“We have these six pillars at each station that hold the tool in place and the tool doesn’t just sit on them, it mechanically clamps to the tool,” Neu-meier explains. “So the station and the tool be-come one once the tool is deposited at the station. These tools also have to interact with automatic drilling machines that drill somewhere between

With the tool used in the manufacture of the F-35

JSF’s center wing section measuring 20 ft tall,

Lockheed runs the risk of deflections resulting in

different tolerances at the top of the tool than at the

bottom. That meant the tool and the station designs

were critical, as was their interaction with the AGVs.

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Cover Feature | AGVs in Manufacturing

2000-3000 holes every time they sit in a station.”

With a tool measuring 20 ft tall, Lockheed runs

the risk of deflections resulting in different toler-

ances at the top of the tool than at the bottom.

That meant the tool and the station designs were

critical, as was their interaction with the AGVs.

An AGV comes in underneath the tool and picks

it up, then works through the associated safety

protocols before moving the tool out of the sta-

tion and into another. Each time an AGV slides

under the tooling, a cup and cone arrangement

clamps the AGV, which ensures a secure engage-

ment. Accomplishing this required synchronicity

among the navigation, guidance and propulsion

systems as well as with the servo motors in the lift-

ing mechanism.

Arranging Return of InvestmentThree AGVs interact autonomously with two

automatic drilling machine stations and 12 man-

ual operation stations in the production line. A

complete line move is accomplished on a third

shift in less than six hours. Lockheed needed

to ensure that by the next morning when the

Making AGVs Juicier

AIthough industrial batteries are the primary power

sources for the AGVs used at Lockheed Martin, the

drive toward lower cost and higher productivity is mak-

ing ultracapacitors an attractive option in many industries, accord-

ing to Chad Hall, vice president of sales at Ioxus (www.ioxus.com),

makers of these power devices. His company acquired Power

Systems (www.powersystems.co.jp/english), which specializes in

ultracapacitors for AGVs.

“A couple manufacturers of lift trucks use them and the payoff

time is 1-2 years, depending on how much the operator runs the

lift truck,” he says. “It makes the battery last longer per charge

and gives it a two to four times increase in life. Traditionally an

AGV using lead acid batteries operates six hours before a swap is

needed. That can take 20-30 minutes, plus the time of traveling to

the battery change

station. But with an

AGV you can put

inductive charging

in the fl oor under

spots where the ve-

hicle will be stopping.

The ultracapacitor

enables recharging

more frequently, using less energy each time you recharge.”

He adds that ultracapacitors are designed for higher cycle life

so could be active for 10 years before needing replacement. This

is particularly important in applications that handle heavy loads

over long distances. Hall claims ultracapacitors can provide hun-

dreds or thousands of amps, and thus increase lift capabilities

when used in tandem with lead acid batteries.

“For those applications a battery would perform some of the

work, but the ultracapacitor would handle the major current

portions of the cycle,” he explains. “You can thus increase your

payload capability and incorporate regeneration. Ultracapacitors

can accept a charge much faster than a battery can—seconds vs

hours.”

In one plastics manufacturing facility AGVs are used to position

and relocate materials throughout the plant. Ultracapacitors en-

able 24/7/365 operation, Hall says.

He adds that hybridization will open markets to ultracapacitor

applications, citing fuel cells as a natural fi t.

“The best application is to hybridize the energy store, where

you use a battery or fuel cell with the ultracapacitor,” he con-

cludes. “Fuel cells are great at producing energy but horrible at

producing power. You can’t change the current output from a fuel

cell without causing some damage to it.”

A portion of Lockheed Martin’s

facility in Marietta, Ga. is dedicated to

manufacturing the F-35’s center wing

section at a pace that accommodates a

production rate of one aircraft a day.

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mechanics and technicians arrive they were look-ing at a new assembly in order to meet the one-a-day production rate.

Each AGV is powered by four banks of batter-ies. For now the plan is for these vehicles to be used once a day on third shift so each can be fully charged during 1st and 2nd shifts in preparation for the next day’s set of moves.

Fori calls these AGVs MTAVs (fot MulTitask Autonomous Vehicles). The idea is that if you dedi-cate an AGV to only one task it’s harder to achieve an ROI, especially in manufacturing environments with lower production rates.

“In automotive you almost have to dedicate the

AGV to the application or to a specific piece of tooling,” Meloche says. “What we’ve come up with is the idea that the AGV has to do more than be dedicated to moving a single part down the line. We like to separate the part and the tooling from the AGV so maybe one or two can handle parts in multiple moves.”

For example, in a project Fori did for Bombar-dier (www.bombardier.com), another aerospace manufacturer, in addition to moving an aircraft through assembly, AGVs go to other areas of the plant to retrieve materials and components and bring them lineside.

“We build the AGV so you can kit it and add operator platforms and lifts around the periphery of the vehicle so it becomes a moving platform,” Meloche adds.

Fori is looking at the feasibility of AGVs equipped with robots to accomplish precision drilling. Other applications could include locking two AGVs together to create an extra long, extra high capacity synchronized AGV. In the meantime, Lockheed Martin is still learning all the ins and outs of what AGVs can do.

“At the beginning people expected we’d just drop an AGV in the flow line and everything would work,” he says. “They didn’t realize there’s a period of breaking in, teething pain and expe-rience gathering. We had Fori out a few times to modify the code to speed the process. We changed some of the safety zones to be slightly different in configuration because of potential interference.”

Lockheed finished factory acceptance testing of its AGV system in the last quarter of 2011 and has four months of production experience with the system as this is written. The transitioning of pro-duction from Fort Worth to Marietta is also in the completion phase, so Neumeier expects productiv-ity to only get better

Lockheed Martin’s new production line presented challenges

that couldn’t be addressed by overhead handling. The

automotive industry proved to be a role model with its use

of automated guided vehicles.

The F-35 Joint Strike Fighter’s technology

combines stealth, fully fused sensor

information and network-enabled operations.

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