
Video.A nimble, four-legged robot is so surefooted it can recover its balance even after being given a hefty kick. The machine, which moves like a cross between a goat and a pantomime horse, is being developed as a robotic pack mule for the US military.
"Internal force sensors detect the ground variations and compensate for them," says company president and project manager Marc Raibert. "And BigDog's active balance allows it to maintain stability when we disturb it."
Raibert says the latest version of BigDog can handle slopes of 35° -- a steeper gradient than one in two. The hydraulics are driven by a two-stroke single-cylinder petrol engine, and it can carry over 40 kg, about 30% of its bodyweight. The robot can follow a simple path on its own, or can be remotely controlled.