Taking robotic exoskeletons a step further

Posted: December 2, 2019

Ayonga Hereid (right) works with the robotic exoskeleton in his lab, along with Graduate Research Associates Victor Paredes Cauna (left) and Guillermo Castillo Martinez (center).
A collaboration between Ohio State engineers and a robotic exoskeleton startup company could help restore the ability to walk for patients previously confined to a wheelchair.

Robotic exoskeletons are wearable devices that have been developed to enhance the physical performance of the wearer, including those suffering from paraplegia. Current commercially available models to help paraplegics walk require some type of additional support, such as crutches to provide balance. But researchers at Ohio State are working with Paris-based Wandercraft to take the technology a step further.

“The exoskeleton we’re developing can help the patient walk autonomously without any external support, freeing their hands to complete other tasks,” explained Ayonga Hereid, an assistant professor in the Department of Mechanical and Aerospace Engineering and principal investigator of the Cyberbotics Lab. “My main role in this project is to develop computationally efficient motion planning algorithms and robust feedback control for the entire human-exoskeleton system.”

Hereid came to Ohio State in January 2019, but has been working with Wandercraft for years. He first started collaborating on the project to advance the technology as a PhD student and later led the effort as a postdoctoral researcher. Not long after he arrived in Columbus, he purchased one of their robotic exoskeletons for his lab so that he could continue his research to achieve their shared vision of assisted mobility.

“Right now in our lab we’re working on making the walking algorithm more robust and dynamic so that patients can walk much faster, and we’re trying to develop control algorithms that can guarantee it won’t fall,” said Hereid. “While standing, it’s very stable. But when walking it may easily lose stability and fall even with small disturbances, for example when stepping from one type of flooring onto a thicker rug or mat.”

Hereid said the relationship with Wandercraft has been mutually beneficial—the company uses his algorithms in its product development and shares any programming updates with him and his research team. He and company officials will showcase the exoskeleton in March 2020 at the International Society of Physical and Rehabilitation Medicine World Congress in Orlando, Florida.

Beyond helping patients with spinal cord injury or disease, Hereid’s exoskeleton research could also stand to help elderly patients or those undergoing physical therapy. Whereas the current device is fully controlled, his long-term goal is to develop an assistive model that can sense human intention.

“This current version is basically like sitting in a car except you’re standing, but you can relax and the exoskeleton can take you where you want to go,” he said. “But in the near future we’re trying to develop an algorithm that can augment the human input so if you’re trying to take a step, the exoskeleton can sense that intention and assist you in achieving that motion.” The ratio of human versus machine input could be changed gradually to assist an injured person during the rehabilitation process, he added.

Hereid’s team is also working on developing a bi-pedal robot that can be used to complete tasks that are dangerous for humans, such as space exploration or disaster rescue.

by Meggie Biss, College of Engineering Communications | biss.11@osu.edu

Category: Faculty