Iron Man-ASTHI Prototypes

Iron Man

Iron Man. Indians think of Sardar Vallabhai Patel. Music geeks mentally play the celebrated riff from the Black Sabbath song. But most people think of the Marvel Comic book character played by Robert Downey, Jr. in the movie Iron Man (2008). With the advent of the radical technology of powered exoskeletons as practical possibilities in the near future, Tony Stark in his suit may soon become a reality. Wait... what are powered exoskeletons? They are just what they suggest they are – an exoskeleton energized by a power supply. Exoskeletons have been around in nature for millions of years. Even humans have been using artificial exoskeletons in the form of armour for defence and combat. Now the technology of powered exoskeletons can take it further, to industrial applications and medicine.

Powered exoskeletons primarily do two things-

assist - help workers lift heavy loads, help rescuers lift and move debris, medically assist aged and incapacitated people; and

protect – protect soldiers, construction workers and other people working in hostile or unsafe environments.

These mobile machines can be considered to be ‘wearable robots’. They are usually mechatronic systems that are designed around the shape of the user. Accordingly, the joints and segments of the exoskeleton correspond to those on the user. The machines can have different power sources (finding a suitable power supply is actually one of the challenges involved in this technology).

Currently, there are already a few exoskeletons. For example, HULC™ manufactured by Lockheed Martin, Honda’s Exoskeleton Legs, M.I.T. Media Lab's Biomechatronics Group legs and Raytheon’s XOS.

But it was General Electric that had developed the first exoskeleton device in the ‘60s. Called the Hardiman, a hydraulic and electrical body suit, it was not very successful because itwas too heavy and bulky for military use. One of the first exoskeleton prototypes meant to aid in walking was created by Monty Reed, an army ranger who’d had a parachute accident in 1986, after being told that he would never be able to walk again. He was inspired by Starship Troopers (by science fiction author Robert Heinlein) and created LIFESUIT™1 (or LS1) in the broom closet of his basement while attending college. Monty is now Executive Director of THEY SHALL WALK™, a non-profit medical research organization. At present, prototype LS15 is being developed in their lab.

The HULC™, as explained by Lockheed Martin, its developers, is a completely un-tethered, hydraulic-powered anthropomorphic exoskeleton that provides users with the ability to carry loads over 90 kg for extended periods of time and over all terrains. An onboard micro-computer eliminates the need for a joy stick or other controllers. The HULC™ is capable of performing deep squats, crawls and upper-body lifting. It weighs around 27 kg including the two Lithium Polymer Batteries. The HULC™ exoskeleton transfers the heavy combat loads that soldiers have to carry to the ground through powered titanium legs without loss of mobility. Under a new exclusive licensing agreement between Lockheed Martin and Berkeley Bionics™, there will be further enhancement within the HULC system.

Scientists at M.I.T. Media Lab's Biomechatronics Group, with funding from the American Defense Advanced Research Projects Agency (DARPA), have developed an exoskeleton that promises to lessen the load of travelers and also advance research that will ultimately lead to robotic limbs for improving the strength and mobility of amputees. According to a report in the International Journal of Humanoid Robotics the M.I.T. exoskeleton is designed to be lighter and require lesser power than similar devices already under development. The wearer of the M.I.T. exoskeleton places his or her feet in boots attached to a series of tubes that run up the leg to a backpack. The exoskeleton, powered by a 48 V battery pack, uses an onboard computer, weighs 11.7 kg and requires 2 W of electrical power during loaded walking. The device fits parallel to the legs, transferring payload forces from the back of the wearer to the ground.

Last year, Honda Motor Company Limited introduced a supportive lower-body exoskeleton. This walking assist device is designed to reduce the load on leg muscles and joints (in the hip, knees, and ankles) by supporting a portion of the wearer's bodyweight. It acts as an exoskeleton in the sense that it straps over the wearer's clothes and provides two artificial legs that fit alongside the wearer's own legs. The exoskeleton, which comes in small, medium and large sizes, weighs about 6.5 kg. It is secured with a belt around the hip and thigh, then the user straps into a pair of shoes connected to it. A mini-saddle fits between the wearer's legs. The machine is powered by a lithium ion battery that lasts about two hours between charges, as long as the wearer isn't walking faster than 4.5 km/h.

The exoskeleton that has been most likened to Marvel Comics’ Iron Man himself, is the XOS. It is essentially a wearable robot that amplifies its wearer’s strength, endurance and agility. Built from a combination of sensors, actuators and controllers, the futuristic suit enables a user to easily carry a man on his back or lift 90 kg several hundreds of times without tiring. And yet, the suit is agile enough to let its wearer kick a football, punch a speed bag, or climb stairs and ramps with ease. In 2000, DARPA had requested for design proposals for a powered military exoskeleton. Of the fourteen designs submitted, DARPA had chosen the one submitted by Sarcos, an American engineering and robotics firm. The Sarcos design involved a suit powered by a single engine, including a tank holding 24 hours of fuel that sat near the wearer's buttocks. The suit gave the wearer increased strength and endurance through servo motors powered by the engine. The finished suit was named the XOS Exoskeleton and weighed 68 kg. Popular Science reported that the XOS gave wearers the ability to lift 91 kg "repeatedly with minimal strain". Nearly two years ago, American defense contractor Raytheon purchased Sarcos and is now developing this robot suit for the soldier of tomorrow. The lightweight aluminium XOS, senses the user’s every move and instantly moves with him or her, almost like a shadow or a second skin. It is designed for agility that can match a human's, but strength and endurance that far outweigh any human’s abilities. With the exoskeleton on and fully powered up, the user can easily pull down a weight of more than 90 kg. For the army the XOS could mean quicker supply lines, or fewer load-related injuries when soldiers need to lift heavy weights or move objects around repeatedly. The army hopes that later models can go into combat and carry heavier weapons or even wounded soldiers.

Exoskeletons could also be applied for rehabilitation of stroke or SCI patients. Such exoskeletons, sometimes called Step Rehabilitation Robots, could reduce the number of therapists needed by allowing even the most impaired patient to be trained by one therapist (as compared to the several needed now). Training could be more uniform and specifically customized for each patient. Presently there are several projects designing training aids for rehabilitations centers. For example, the LOPES exoskeleton and Cyberdyne’s gait trainer, HAL 5.

The LOPES project (LOwer-extremity Powered ExoSkeleton) is looking to design and implement a gait rehabilitation robot for treadmill training. The target group includes people who have suffered a stroke and have impaired motor control. The main goals of LOPES are reduction of the physical load on the therapist or patient, increased efficiency of gait training for stroke patients and selective support of gait functions.

Cyberdyne’s Robot Suit HAL (Hybrid Assistive Limb), as has been made public by the company, is a cyborg-type robot that can expand and improve physical capability. Through a sensor attached on the skin of the wearer, HAL catches very weak biosignals that can be detected on the surface of the user’s skin at the moment when the user moves (nerve signals are sent from the brain to the muscles via motoneuron, moving the musculoskeletal system as a consequence). HAL 5 is currently capable of allowing the operator to lift and carry about five times as much weight as they could lift and carry unaided. The full body machine weighs approximately 23 kg and is powered by a Battery Drive Charged battery (AC100V). It can operatecontinuously for about 2 h 40 min. Cyberdyne expects the HAL to be applied invarious fields such as rehabilitation support and physical training support in the medical field, ADL support for disabled people, heavy labour support in factories and rescue support at disaster sites.

Evidently, the powered exoskeleton has great potential, considering how many fields, and hence people, can benefit from the technology. Now there might be sceptics who call all this just blather and argue that it will not be feasible. We only have to remind them how it was with other path-breaking technologies like the computer and the cellphone. The rest, as they say, is (and will be) history. AsJohn Michael "Ozzy" Osbourne once sang, “Iron Man lives again!”