Centaur-style wearable robot adds 2 legs to cut walking effort by 35%

Researchers at Southern University of Science and Technology in Shenzhen, China, have developed a novel wearable robot that adds two mechanical legs behind a human user, effectively creating a centaur-like hybrid to assist with carrying heavy loads. Unlike traditional exoskeletons that attach directly to the human legs, this system connects via an elastic interface on the back, allowing the robotic legs to share the weight and provide propulsion while the human maintains balance and navigation. Tests demonstrated that carrying a 44-pound load with the robot reduced the user's metabolic energy expenditure by about 35% and foot pressure by roughly 52%, indicating a significant reduction in physical strain. The design features an elastic coupling with nonlinear stiffness that adapts to load conditions, remaining firm under lighter loads for coordination and becoming more compliant under heavier loads to absorb forces. This separation of roles enables efficient collaboration: the human steers and balances, while the robot handles most mechanical work. Advanced motion planning and model predictive control allow the robotic legs to synchronize with the user's walking