Usually when you talk about material handling muscle you're talking about lift trucks or cranes. But now that I've just finished writing a feature for MH&L's May issue on the making of Lockheed-Martin's F-35 fighter jet, I have a new respect for the power of automated guided vehicles.
At this Lockheed plant, AGVs move tooling that, combined with the center wing section of the jet, weighs about 12,000 pounds. The tooling is transported to 14 different process stations and each AGV must not only support that load, but position it to within a tight tolerance for drilling accuracy.
Each AGV is powered by four banks of industrial batteries. 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.
After learning about this, I wondered how such power could be sustained if they ever had to use the AGVs on more than one shift. Coincidentally, while writing this story I heard about a company called Ioxus, which makes ultracapacitors. I've written about companies that have used capacitors to improve their company's power factor, but now ultracapacitors are being applied in lift trucks and AGVs to improve their power factors.
Chad Hall, vice president of sales at Ioxus, told me ultracapacitors are designed for higher cycle life so they can add power and life to battery applications. This is particularly important in applications that handle heavy loads over long distances. Hall claims ultracapacitors can provide hundreds 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.”
He says a plastics manufacturing facility is using AGVs to position and relocate materials throughout the plant, and that ultracapacitors enable the potential for 24/7/365 operation.
He adds that hybridization will open markets to ultracapacitor applications, citing fuel cells as a natural fit.
“The best application is to hybridize the energy store, where you use a battery or fuel cell with the ultracapacitor,” he said. “Fuel cells actually require an ultracapacitor to have a long life. 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.”
Hall's company recently acquired Power Systems, which specializes in ultracapacitors for AGVs, so he expects to see such applications multiply.
“Traditionally an AGV using lead acid batteries operates six hours before a swap is needed,” he concluded. “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 floor under spots where the vehicle will be stopping. The ultracapacitor enables recharging more frequently, using less energy each time you recharge.”
Now all we need are more plants that operate 24/7/365.