BigDog is a strange robotic pack mule that Boston Dynamics developed for the military. The .7 meters tall mechanical beast-of-burden is powered by a gasoline engine and, so far, has trotted at 3.3 mph and lugged around 120 lbs. The video is a hoot. From the Boston Dynamics site:
BigDog has an on-board computer that controls locomotion, servos the legs and handles a wide variety of sensors. BigDog's control system manages the dynamics of its behavior to keep it balanced, steer, navigate, and regulate energetics as conditions vary. Sensors for locomotion include joint position, joint force, ground contact, ground load, a laser gyroscope, and a stereo vision system. Other sensors focus on the internal state of BigDog, monitoring the hydraulic pressure, oil temperature, engine temperature, rpm, battery charge and others.
Link to Boston Dynamics, Link to New Scientist article (Thanks, Sean Ness!)
