Scientists have, for the first time, successfully developed a four-legged robot that can spontaneously change its gait when speed is varied.

The advance may lead to a wide range of applications such as adaptive legged robots working in disaster areas, user-friendly legged entertainment robots and automatic motion-creation algorithms for computer graphics animation.

Until now, the manner in which changing speeds cause quadrupeds to change their gaits – walking, trotting and galloping – was poorly understood.

Researchers from the Tohoku University in Japan successfully demonstrated the reproduction of the quadruped gait transition phenomena.

They achieved this via a decentralised control scheme, using a simple local rule in which a leg continues to support the body while sensing weight on the corresponding leg.

Moreover, they confirmed that the energy-efficiency profile of the robot's gait patterns matched those measured in horses.
The research is expected to lead to better understanding of the mechanism of how quadrupeds can flexibly and efficiently adjust their gait when their speed is changed, researchers said.

The result may constitute the basis of an unconventional approach to coordinating the many degrees of freedoms required for adaptive robot locomotion.