BigDog is funded by the Defense Advanced Research Projects Agency in the hopes that it will be able to serve as a robotic pack mule to accompany soldiers in terrain too rough for conventional vehicles. Instead of wheels or treads, BigDog uses four legs for movement, allowing it to move across surfaces that would defeat wheels. The legs contain a variety of sensors, including joint position and ground contact. BigDog also features a laser gyroscope and a stereo vision system.
The robot is pretty cool, especially when the guy tries to kick it and make it fall over, then the robot corrects itself. Im sure this would require some pretty sophisticated programming – combined with the quick reactions of its legs.. Not an easy feat to achieve.