Washington: Scientists claim to have invented the world’s most advanced pair of robotic legs that accurately mimic human walking, a feat they say has brought the goal of developing human-friendly household robots a step closer.
Created by a team from the Department of Electrical and Computer Engineering at the University of Arizona, the legs are the first to mimic walking in a biologically accurate and energy-efficient manner.
The biological accuracy of this robot, which has been detailed in the Journal of Neural Engineering, has allowed the researchers to investigate the processes underlying walking in humans and may bolster theories of how babies learn to walk.
It could also help understand how patients with spinal cord injury can recover the ability to walk, the team said.
According to the researchers, a key component of human walking is the central pattern generator (CPG), which is a neural network in the lumbar region of the spinal cord that generates rhythmic muscle signals.
The CPG produces, and then controls, these signals by gathering information from different parts of the body that are responding to the environment. This is what allows people to walk without needing to think about it. The simplest form of a CPG is a half-centre, which consists of just two neurons that fire signals alternatively, producing a rhythm.
The robot contains an artificial half-centre as well as sensors that deliver information back to the half-centre, including load sensors that sense force in the limb when the leg is pressed against a stepping surface.
“Interestingly, we were able to produce a walking gait, without balance, which mimicked human walking with only a simple half-centre controlling the hips and a set of reflex responses controlling the lower limb.” Dr Theresa Klein, who worked on the invention with Anthony Lewis, said in a release.
The researchers hypothesise that babies start off with a simple half-centre, similar to the one developed in this robot, and over time they ‘learn’ a network for a more complex walking pattern.
This could explain why babies have been seen to exhibit a simple walking pattern when placed on a treadmill even before they have learnt to walk — a simple half-centre is already in place.
“This underlying network may also form the core of the CPG and may explain how people with spinal cord injuries can regain walking ability if properly stimulated in the months after the injury,” Dr Klein added.
