Abstract

Truly wearable robotic systems pose great engineering challenges because the device must be lightweight, safe, compliant, and powerful, but also energy efficient. Designers and robotic engineers have struggled to meet these functional requirements; the ankle poses very difficult design parameters with very large power requirements, 250 W.

Direct drive ankle systems have been proposed, but they are heavy. A direct drive 250 W DC Motor gearbox combination weighs 7kg (about 15 lbs) but more importantly the powerful motor/gearbox can cause injury if the power is applied during an incorrect time in the gait cycle. Other powerful, high-pressure oil systems have also been investigated as well.