An academic applies his background in control systems to helping the disabled walk again, using two different approaches.
Soon after returning to South Korea’s Sogang University following a PhD at University of California, Berkeley in 2009, Professor Kyoungchul Kong took on the challenge of developing wearable robots for people with partial impairments. Using real-time control to recreate natural movements, he made his first prototype of Angelegs in 2011.
The core technology for Angelegs, according to one interview with Kong, is “zero impedance actuation” based on his control algorithm and series elastic actuators, of which there are four (hips and knee joints).
“I wanted to make a really special actuation module. I wanted to make very special shoes that measured the ground reaction force very accurately,” he said, adding that successfully commercialising the device would be a satisfying outcome from solving numerous engineering problems over all those years.
“My study in Korea, my studentship and professorship and now CEO [role are] all about making some part of human assistive robot, especially Angelegs.”
His second approach, named WalkON, is designed for complete paraplegics, and was developed after being inspired by a lecture by Cybathlon organiser Robert Reiner in 2015.
The machine and its human driver achieved a bronze medal in the powered exoskeleton competition the following year, completing six tasks simulating challenges faced by paraplegics.
Kong said he had to completely disregard numerous innovations he’d made in complex adaptive control, using information from an inclination sensor to adjust gait, and adopt a completely different mindset for the project, which he is also currently commercialising through SG Robotics.
He also abandoned attempts with EEG and voice control. The wearer controls the robot’s movement by buttons, as this proved the most reliable option. Anything less than 100 per cent reliability could frustrate a user.