Army tests AI-enabled, power-enhancing exoskeleton

The Army is testing an exoskeleton technology which uses AI to analyze and replicate individual walk patterns, provide additional torque, power and mobility for combat infantry and enable heavier load-carrying, industry officials said.

Army evaluators have been assessing a Lockheed-built FORTIS knee-stress-release-device exoskeleton with soldiers at Fort A.P. Hill as part of a focus on fielding new performance enhancing soldier technologies.

Using independent actuators, motors and lightweight conformal structures, lithium ion battery powered FORTIS allows soldiers to carry 180 pounds up five flights of stairs while expending less energy.

 “We’ve had this on some of the Army’s elite forces, and they were able to run with high agility carrying full loads,” Maxwell said.

Lockheed engineers say FORTIS could prove particularly impactful in close-quarters urban combat because it  enhances soldier mobility, speed and power.

It is built with a conformal upper structure that works on a belt attached to the waist. The belt connects with flexible hip sensors throughout the systems. These sensors tell the computer where the soldier is in space along with the speed and velocity of the movements.

“We were showing a decrease in the metabolic cost of transport, the measure of how much energy is required to climb uphill,” said Keith Maxwell, senior program manager, exoskeleton technology, Lockheed Martin..

FORTIS uses a three-pound, rechargeable BB-2590 lithium ion battery.

Developed by Lockheed with internal research and development funds, FORTIS is designed to help soldiers run, maneuver, carry injured comrades and perform a wide range of combat tasks while preventing hyperextension of the knee.

Engineers report that FORTIS reduces the amount of energy required to perform a task by nine percent, using on-board AI to learn the gait of an individual soldier. The system integrates an actuator, motor and transmission all into one device, intended to provide 60 Newton Meters of additional torque, Maxwell explained.

“It knows what you are trying to do when you are trying to do it,” Maxwell said.

“It locks and gives you a forward torque-twist that causes the lower leg to move toward the back, then it reverses direction to bring your leg forward,” he explained.

FORTIS is a next-generation effort intended to move beyond Lockheed’s previously designed HULC exoskeleton which weighs 85 pounds and restricts soldier mobility, developers said.

A recent, independently-funded University of Michigan study found that FORTIS does substantially enhance soldier mobility.