DARPA Puts $32M Toward Quadruped Robot Prototype

The Installer writes with this selection from GizMag: "Walking quadrupeds are being cast to play a major role in the rapidly unfolding age of robotics. The platform promises versatility far beyond that of wheeled-vehicles and will undoubtedly find applications in a wide variety of fields. Not surprisingly, the development of quadrupeds is being driven by the military and DARPA has recently boosted its efforts by awarding Boston Dynamics $32 million for the prototype phase of its Legged Squad Support System (LS3) program. ... LC3 is conceived as an autonomous support pack-robot for ground troops that can carry 400 pounds or more of payload, sustain itself for 24 hours and cover 20 miles in almost any kind of terrain."

Re:Why four legs?

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Well, was there a time when vertebrates ever had six limbs? I thought we'd just happened to pop out of the water that way; given that we vertebrates have all kept our basic layout since then, I wouldn't really say evolution ever had the opportunity to try six limbs on a large land creature.

Obviously more legs doesn't necessarily mean better. Why not eight, like the last guy said? There's an advantage to redundancy but like you said there are disadvantages as well. It just seems to me like six would be a happier medium between the two.

You need three points on the ground to remain relatively stable without getting into balance issues. Of course a good robot could balance itself on two - hell even a Segway can do it - but lets say in a complex situation like trying to climb a steep rocky hill in Afghanistan in a hurry you want as much stability as possible (note a person in that situation will be using their hands for additional stability too). To move while doing that requires at least one more limb, for a total of four. If there is have a failure in just one limb, you've reduced the robot's stability by quite a bit. I just seems to me like six would be worth it in varied terrain - I mean, if all you're going to do is bound across the plains all day like a gazelle the extra limbs may not be useful, but I'm imagining these things in more steep, mountainous areas as well, where extra footing could be a huge asset.