Power and endurance for comfortable wearable robotics

The augmentation of human power and endurance by way of a power assisted exoskeleton could revolutionize rehabilitation, industry and the battlefield. The use of servo motors placed near limb joints results in a rotary motion of the human limb which adapts well to attaching the exoskeleton to the limb and to integrate limb movement. Air muscles or pneumatics offers advantages over DC motors for instantaneous high thrust limb motion using light weight components and even soft and malleable exoskeletons. However these implementations mimic human muscle and apply forces longitudinally resulting in high compression forces on the longitudinal exoskeleton. In the rotary approach forces are applied perpendicularly so as to flex adjoining limbs. In this rotary case the device can be designed to be more easily attached and worn. The work reported here describes the progress with a new type of exoskeleton and air muscle design based on a new approach to exoskeleton and air muscle layout that combines contractive actuation with rotary motion. The aim is to reduce the need for bulky exoskeleton members, share out forces over larger areas and thereby demonstrate strapless, comfortable and easy fitting footwear. The developed prototype is tested for augmenting a test subject´s explosive power and significantly reducing the metabolic cost of walking while carrying a heavy load.