Researchers in South Korea have designed a wearable robot that can walk up to completely paralysed people so they can wear it right out of their wheelchairs without help from others.

The Korea Advanced Institute of Science & Technology (KAIST, www.kaist.ac.kr) researchers, led by Professor Kyoungchul Kong, designed the WalkOn Suit F1. Kong is CEO and founder of Angel Robotics.

The wearable robot is for people suffering with paraplegic disabilities that the team has been continuously researching since 2015. This robot targets persons with American Spinal Injury Association (ASIA) Impairment Scale A (complete paralysis) grade injury, the most severe level of paraplegia. Therefore, its development purpose is different from that of other rehabilitation therapy and muscle strength assisting robots being supplied nationally by Angel Robotics.

Kong’s research team first announced WalkOn Suit 1 in 2016, and then introduced WalkOn Suit 4 in 2020, increasing the walking speed to 3.2km/h, achieving the normal walking speed of people with no disabilities. In addition, it demonstrated the ability to pass through obstacles such as narrow passages, doors and stairs that can be encountered in daily life.

However, it had the same fundamental problem all wearable robots have, which is they require the help of others to wear the robot. While someone can walk without help from others once they are wearing the robot, they needed someone’s help to put it on.

The newly released WalkOn Suit F1 presented a technical solution to this problem. It applied a frontal-docking method instead of a rear-sitting method so users could wear the robot right away without getting out of the wheelchair and into the robot, which would require help from others mid-transition.

In addition, before wearing the robot, it can walk on its own like a humanoid robot and approaches the user. A function actively controls the centre of its weight against the pull of gravity so it maintains balance without falling over even if the user pushes the robot otherwise. The outer design, which crosses between a humanoid and a wearable robot, was done by Professor Hyunjoon Park of the department of industrial design at KAIST.

The original function of the wearable robot has also been improved. The performance of the balance control was improved to allow the free use of both hands in upright state, as well as the freedom to take several steps without a cane.

Through collaboration with Angel Robotics (www.angel-robotics.com), all core components of the robot, such as the motor, reducer, motor driver and main circuit, have been domestically produced. The output density of the motor and reducer modules has been improved by about two folds based on power per weight compared with the research team’s existing technology, and the control performance of the motor driver has been improved by about three times based on frequency response speed compared with the best overseas technology.

In particular, the embedded software technology of the motor driver has been improved so motion control algorithms can be stably implemented without using expensive higher-level controllers. In addition, a visual recognition system for obstacle detection and an AI board for neural network application have been installed.

“WalkOn Suit is the culmination of wearable robot technology for the disabled,” said Kong. “The numerous components, control and module technologies derived from WalkOn Suit are setting the standard for the entire wearable robot industry.”

A demonstration video of WalkOn Suit F1 can be seen at www.youtube.com/@KyoungchulKong_EXO-Lab.