Exoskeleton technology reduces soldier fatigue and injury

May 11, 2009
ORLANDO, Fla., 11 May 2009. Today's foot soldier is tasked with carrying more military electronics gear over rough terrain than any warfighter in history. The technology provides untold advantages over the enemy – but it is not by any means light.

By John McHale

ORLANDO, Fla., 11 May 2009. Today's foot soldier is tasked with carrying more military electronics gear over rough terrain than any warfighter in history. The technology provides untold advantages over the enemy – but it is not by any means light.

Creating a bionic soldier might solve that problem, but until that technology is feasible engineers at Lockheed Martin Missiles and Fire Control in Orlando, Fla., and Berkeley Bionics in Berkeley, Calif., are reducing warfighter fatigue and injuries through the Human Universal Load Carrier (HULC) exoskeleton.

Berkeley designed the electronics and bionics for the HULC exoskeleton, which include a custom single-board computer that controls the military system and keeps the exoskeleton's movements inline with the soldier's, says Adam Miller, director of new initiatives for business strategy and development at Lockheed Martin Missiles and Fire Control. The HULC system can withstand temperatures as hot as 125 degrees Fahrenheit.

"The HULC system is an un-tethered, hydraulic-powered anthropomorphic exoskeleton – where normal movement is not inhibited," Miller says. "It's about safety for the soldier," he adds.

"We saw utility of it and got into a discussion with Berkeley," Miller says. The provided the exoskeleton and Lockheed Martin provided ruggedization – "it is the perfect marriage of capabilities," he adds.

When in use soldiers can carry front and back loads weighing as much as 200 pounds – in addition to HULC's own weight of 53 pounds, says James Ni, program manager at Lockheed Martin Missiles and Fire Control. The HULC's load-carrying ability will also work without power, he adds.

The system essentially transfers the carried weight to the ground through powered titanium legs, Miller says. Operators can lift, crawl, and do deep squats.

The HULC is adjustable to fit soldiers between five feet four inches and six feet two inches, Ni says. Research showed that the majority of solders fall between those heights, he adds.

Miller and Ni declined to comment in specific detail on the computer specifications.

The HULC is powered by lithium polymer batteries – a 60-volt system that can draw peaks as high as 100 amps. The system runs at 250 watts, but powers down when the soldier is not moving, Ni says.

Each four-pound battery pack allows for a one-hour walk at three mph. The maximum speed is 7 mph for a long duration with a burst speed of 10 mph, Miller says.

"We have an exclusive licensing agreement with Berkeley Bionics on the HULC," Ni says. Berkeley originally developed the HULC system with funding from the Defense Advanced Research Projects Agency (DARPA) in Arlington, Va. to come up with an exoskeleton capability for soldiers, he adds.

According to Berkeley's web site the goal of that DARPA investment was to decrease the warfighter's "metabolic cost."

During early Berkeley evaluations the oxygen consumption of the users walking at a speed of 2 mph, was decreased by 5 percent to 12 percent when using their initial test unit without a payload, according to the Berkeley web site. "When the users carried a load, the effect was more pronounced. The oxygen consumption of these users carrying an 81 pound approach load at a speed of 2 mph was decreased by about 15 percent when using the prototype HULC."

The HULC is also a modular system, enabling warfighters to easily swap out attachments and components in the field, Miller says.

According to the Lockheed HULC data sheet the system has attachments for lifting heavy objects such as artillery shells, for a SWAT ballistic missile shield, and has a foldable kit to carry a combat casualty patient.

Currently the system is being demonstrated in a controlled environment, Miller says. The next step around the beginning of next year is to demonstrate a prototype in an operational environment, he continues.

Miller notes that they have also had talks with the U.S. Army's Natick Soldier Systems' Center in Natick, Mass, on how the HULC would work with the center's Future Force Warrior program. The discussions are in the early stages but there are some potential synergies, he adds.

The goal is to get the HULC to the Army quickly to "ride the wave of initial investment," Miller says.

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