Cyberdyne HAL-5 – exoskeleton robot

Robotic exoskeletons can be helpful in many ways as assisting the disabled and elderly in their daily tasks, or easing of any physically demanding task such as disaster rescue or construction. The HAL 5 exoskeleton helps the wearer to carry out a variety of everyday tasks, including standing up from a chair, walking, climbing up and down stairs, and lifting heavy objects. The developer of HAL, Yoshiyuki Sankai, a professor at the University of Tsukuba, started the development of HAL (short for Hybrid Assistive Limb) 15 years ago in order to aid people who have degenerated muscles or those paralyzed by brain or spinal injuries.

Sankai and his team developed two control systems that work together to command HAL-5′s limbs. The first control system, bio-cybernic system (a term coined by Sankai), monitors electric currents known as electromyogram, or EMG, signals on the wearer’s body. These signals flow along muscle fibers when a person intends to move. Coin-size sensors attached to the wearer’s skin near the shoulders, hips, knees, and elbows pick up the signals and feed them to the control computer, which then triggers the actuators to put the robotic arms and legs into action.

The job of the second control system is to let the wearer and suit move together more smoothly. It stores walking patterns–generated the first time the person tries out the suit–that are used to keep the suit’s limbs always in sync with those of the wearer. This system can be fine-tuned so the exoskeleton matches each wearer’s distinct gait, which is especially important if, say, the person has one leg less capable than the other. Senkai says it takes two months to calibrate the control systems so that they work optimally for each individual.

It also allows certain disabled people, whose EMG signals aren’t detectable, to use the suit. “If the user has trouble in the spinal cord or in the brain, we can’t use the bioelectric signals,” Sankai says. “In this case, the robotic autonomous control system activates itself automatically once the user starts moving.”

Cyberdyne HAL 5 comes in three sizes – small, medium and large and weighs in at 23kg. The whole suit is powered by a 100-volt battery attached to the operator’s waist. The suit can operate for almost five hours before it needs recharging, and exoskeletons developers are working on even longer operation time. Depending on the type of HAL you wear, it can multiply the original strength by a factor of 2 to 10. HAL-5′s structure consists of a frame made of nickel molybdenum and extra-super-duralumin, an aluminum alloy used in the wings of Japan’s famous World War II Zero fighter planes. Further strengthened by plastic casing, the metal frame is strapped to the body and supports the wearer externally.

If the brain/machine interfaces (BMI) become more efficient we could expect exoskeletons to become controlled even by the persons paralyzed from the neck down. Since it has robotic limbs, it could provide much better mobility and operation. Unfortunately, the HAL 5 is currently rentable only in Japan and it is available only in Japan and Europe (they have a branch office established in Amsterdam).