A team of researchers at the Southern University of Science and Technology in Shenzhen, China, has built a wearable robot that adds two mechanical legs positioned behind a human to help to alleviate heavy loads on the wearer while reducing the energy required to walk.
The system, which creates a human-robot hybrid that travels like a four-legged centaur, is designed to walk in sync with a human while supporting part of the load typically carried in a backpack.
Source: SUSTech
Rather than functioning like traditional exoskeletons, which attach to human legs, the centaur-like system serves as a separate robotic pair of limbs connected to the wearer via an elastic interface on the back.
This design reportedly enables the robot to perform much of the load-bearing task as the human wearer maintains responsibility for both balance and navigation.
During trials, the exoskeleton significantly reduced physical strain. Specifically, when wearers carried a 44.09 lb load, metabolic energy use dropped by roughly 35%. Meanwhile, foot pressure was reduced by approximately 52% compared to walking without assistance.
Further, the robot’s legs coordinated with the wearer’s speed and direction using motion planning, trajectory planning and model predictive control, thus enabling stable movement across assorted walking conditions.
The team also found that the system demonstrated stable movement while carrying heavy loads and that the robotic legs could support more than half of the carried weight while maintaining natural walking patterns.
Possible applications for the exoskeletons include military logistics, disaster rescue operations and industrial transport tasks.
The study, “Design, modeling, control, and evaluation of a wearable Centaur robot for load-carriage walking assistance,” appears in The International Journal of Robotics Research.
