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. BigDog is described by its developers Boston Dynamics as -the most advanced quadruped robot on Earth-. Raibert says the latest version of BigDog can handle slopes of 35 degrees - 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 percent of its bodyweight. The robot can follow a simple path on its own or can be remotely controlled. The legs on the next version of BigDog-V3- will each have an additional powered joint and will be able to take on even steeper slopes and rougher terrain at higher speed - its makers say. Contributed by ZN. Show Less >>