The Big Dog

Currently, Defense Advanced Research Projects Agency (DARPA) made the Big Dog robots which are hoped to serve as a robotic pack mule to accompany soldiers in terrain too rough for conventional vehicles. Instead of wheels or treads, Big Dog uses four legs for movement, allowing it to move across surfaces that would defeat wheels. Big Dog has a variety of locomotion behaviors. It can stand up, squat down, walk with a crawling gait that lifts just one leg at a time, and walk with a trotting gait that lifts diagonal legs in pairs, trot with a running gait that includes a flight phase, and bound in a special gallop gait. It looks ugly; DARPA did not do any aesthetic design on Big Dog, because the military is not very much concerned with the aesthetics either. What they want is a tireless animal that can do the job of an animal as well as an animal without the need to feed it, care for it, house it and train it. 

You may already know about the Big Dog from DARPA and Boston Dynamics from eight years ago. At that time, the Big Dog could wobbly walk up to 5 mph.  But now it has some bestial competition: the DARPA Cheetah. Its legs are so frightening. DARPA made a great change of the Big Dog which is called Cheetah now. It could run up to 23 mph in laboratory’s running machine. (Biddle, 2013)The robot's movements are designed to mimic those of fast-running animals in nature. The robot increases its stride and running speed by flexing and un-flexing back on each step, much as an actual cheetah does. The improvement of the Big Dog is not only running faster, but it also has added an arm, which can throw a cinder block weighing 35 pounds 17 feet while walking. In this case, the Big Dog can walk on the battlefield smoothly. Even there is something on its way; the Big Dog can easily clean up the way with its arm. That is really helpful.