Walk this way

摘要

In recent years robots have gone through a rapid evolution: like their human creators, they have gone from crawling on the ground to walking upright on two legs. Indeed, the latest humanoid robots, such as Honda's Asimo and Sony's QRIO, can climb stairs, dance, run and jump. Even the most advanced robots, however, still cannot move with the grace, agility and flexibility of a human. The problem with current robots is the "zero-moment point" (ZMP) algorithm that controls them, says Jessy Grizzle of the University of Michigan in Ann Arbor. Although ZMP can produce some impressive results, its design requires a low centre of gravity and flat feet, making it unable to emulate the speed and agility of a human gait or to cope with uneven surfaces. Both QRIO and Asimo walk in a crouched position, with their knees permanently bent in an awkward, consti-pated-looking manner. Their ability to climb stairs is the result of careful choreography and laborious mapping of the environment, says Dr Grizzle.