Thaaaaaaaaank you for bringing that to my attention Ynot, that was remarkable! And that's exactly the sort of behavior I want to see these kinds of machines express. I remember a good few years ago I had seen the segment where this same robot was kicked in the side (and in the meantime had forgotten about it), which together with the way it slipped around on the icy ground made it look alive. I'm going to spend a bit of time poking around for more information on Big Dog, it's bloody inspiring.

@ DD: To convert that into mechanical sensors would be fantastic to use in conjunction with the robot's perceived 3D environment. I'm not sure what we'd use though for artificial semicircular canals. Perhaps we can use a ferro-fluid to fill makeshift hollow rings wrapped in wire, but I don't think the fluid would produce an outward magnetic field if it's taking the shape of a ring... It would act kind of like a magnet bent around and connected to itself, which wouldn't do much good. I'll have to think about it more.

Timothy Paradox, that Virginia Tech tripod is quite novel. It demonstrates a form of locomotion I've never seen before, although that wasn't what I was aiming for... I see how it represents bipedal movement though. I think, if a unit could be placed on top that would remain upright without having to be flipped above and beneath the hull of the robot, I could see more use for it. I'll think on that too.

And what do you think about using pneumatic artificial muscles for joint movement? I'm thinking this would be a nice option for very long legs, right next to hydraulics.