Hopping Robot Legs Use Fiberglass Tendons
September 7th, 2008
A team at Oregon State University has taken another step forward toward making walking robots more human-like and energy efficient by equipping them with artificial tendons. Current robotic limbs struggle to recover energy through their springy gait, but the Oregon team introduced steel cable tendons and fibreglass springs made from the same material as archers’ bows, which allows smaller motors to be used.
In humans, 40-percent of energy expended during walking and running is stored in the tendons; robots can be programmed to adopt a similar gait, but that requires a lot of energy and even then the results are poor. The new system uses the motors to store energy in the springs. Each can store a kilojoule of energy per kilogram. A motor providing the same power on its own would weigh 30 times as much as the spring does. Walking better means walking faster. Walking faster means you can’t run away. Somebody should tell the Oregon State team to slow down. Or at least equip their bots with a chip that gives humans a ten second head start.
