Powered exoskeleton

A powered exoskeleton (also known as powered armor, power armor, exoframe, hardsuit, or exosuit) is a wearable mobile machine that is powered by a system of electric motors, pneumatics, levers, hydraulics, or a combination of technologies that allow for limb movement with increased strength and endurance.

The earliest exoskeleton-like device was a set of walking, jumping and running assisted apparatus developed in 1890 by a Russian named Nicholas Yagn. As a unit, the apparatus used compressed gas bags to store energy that would assist with movements, although it was passive in operation and required human power. In 1917, United States inventor Leslie C. Kelley developed what he called a pedomotor, which operated on steam power with artificial ligaments acting in parallel to the wearers movements. With the pedomotor, energy could be generated apart from the user.

The first true exoskeleton in the sense of being a mobile machine integrated with human movements was co-developed by General Electric and the United States Armed Forces in the 1960s. The suit was named Hardiman, and made lifting 110 kilograms (250 lb) feel like lifting 4.5 kilograms (10 lb). Powered by hydraulics and electricity, the suit allowed the wearer to amplify their strength by a factor of 25, so that lifting 25 kilograms was as easy as lifting one kilogram without the suit. A feature dubbed force feedback enabled the wearer to feel the forces and objects being manipulated.

While the general idea sounded somewhat promising, the actual Hardiman had major limitations. It was impractical, due to its 680-kilogram (1,500 lb) weight. Another issue was that it is a master-slave system, where the operator is in a master suit, which, in turn, is inside the slave suit that responds to the master and handles the workload. This multiple physical layer type of operation may work fine, but responds slower than a single physical layer. When the goal is physical enhancement, response time matters. Its slow walking speed of 0.76 metres per second (2.5 ft/s) further limited practical uses. The project was not successful. Any attempt to use the full exoskeleton resulted in a violent uncontrolled motion, and as a result it was never tested with a human inside. Further research concentrated on one arm. Although it could lift its specified load of 340 kg (750 lb), it weighed three quarters of a ton, just over twice the liftable load. Without getting all the components to work together, the practical uses for the Hardiman project were limited.

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Wikipedia