WHL - 11 Humanoid Project at Waseda University.
In 1980, Waseda University developed WL-9DR, the world's first robot to exhibit quasi-dynamic walking. Five years later, Waseda University's Humanoid Research Laboratory teamed with Hitachi Ltd. to develop the WHL-11 (Waseda Hitachi Leg-11) biped, walking robot. Using the earlier WL series robot as a model, they added an onboard computer and a hydraulic pump that allowed the robot to walk on a flat surface at 13 seconds a step. In one exhibition, WHL-11 walked over 64km. The drawback to such approaches was that WHL-11 had no ability to climb up inclines or over obstacles. Since then, much work has gone into control systems that can adjust gaits, and balance the body in real time to allow more versatile walking.
Legged locomotion is much easier to accomplish (and much safer to develop and test) on smaller humanoids. The SDR-4X was recently developed by Sony as a domestic robot capable of handling uneven surfaces and stairs on the fly. While other approaches have demonstrated hard-coded walking behavior, the Sony project attempted to create a truly useful robot that can sense depth and distance of objects sufficiently well to be able to walk over obstacles and adjust its gaits on the fly to cope with changing surface heights. The project is also remarkable for the flexibility of the robot, which allows it to dance and contort itself much more freely than most humanoid systems.
The SDR-4X uses vision to adapt its walking behavior to cope with stairs and other features typical of a home.
Honda's P3 humanoid.
Perhaps the most impressive walking behavior to date has been demonstrated by Honda's life-sized androids. In 1996, Honda revealed P2, the 6-foot-tall, 460-pound result of a secret, 10-year project that cost Honda some $100 million. Honda now has another smaller and lighter android known as P3. Finished in September 1997, P3 is slightly over 5 feet tall and weighs only 286 lbs. The high flexibility of P3's joints coupled with sophisticated balance control mechanisms allow it to perform complex actions such as walking sideways and kicking, despite the fact that P3 has, unlike humans, a rigid back. P3's balance control allows it to climb up stairs and to cope with uneven surfaces. Although P3 can quickly and independently compensate for uneven or sloping floors, it is unable to autonomously gauge the height of stairs and thus still requires input from a human engineer. Future work will be necessary before robots can adjust to rough terrain on the fly.
P3 walks up a flight of steps. Honda Motor Co.