Monthly Archives: November 2014

A throwback to Big Dog

OK, this isn’t going to be a blog with a lot of puns, I promise you, but sometimes, I can’t resist a layup like this one.  I just noticed this video; found it in an aggregated video, which is not the sort of thing I watch (unless it involves my daughter and I watching cats do stupid things).  Not sure how I missed it when it first came out, but it shows what appears to be a design between Big Dog and Alpha Dog in the evolutionary progression, given the angle of the knees and the thinner trunk, so it is out of the chronological order I’m attempting to portray in this series, thus the “punny” title.

The engineering is definitely impressive in terms of the machine’s ability to remain balanced while heaving a cinder block, but also seems more like a curiosity than a viable prototype; I can’t imagine what use this would be put to, other than clearing out moderately heavy debris as part of a pack of disaster recovery robots.  Perhaps is was related to preparations for the DARPA robotics challenge?  To sum things up here, I guess the best thing to say is, just like a horse, it might not be a good idea to stand directly behind this version of big dog:

 

Son of Big Dog: Alpha Dog/LS3 (part 3)

More field work with LS3 in this video from the DARPA youtube channel (as opposed to the Boston Dynamics channel, where I generally prefer to get them).  This one demonstrates the LS3’s “follow tight” mode which allows it to follow a human operator.

Right off the bat, it seemed like the robot took longer than I would expect to power up; maybe they need to replace those spinning drives with SSDs :).  On the plus side, voice control is nice and I was very impressed by how quiet the machine is, especially compared with Big Dog; it didn’t sound too much louder than the noise made by the operator walking through leaves at a normal pace.

In the dry stream bed, it seemed like the stance should have been much wider for more stability, but I expect that there is a good reason for the design choices that were made.  The little tumble that the machine takes into the stream is amusing, but there was something that I didn’t notice on my first viewing: the robot rolls right onto a barely visible stationary camera that looked like it was placed slightly downstream to catch a different angle of the crossing; you can even briefly see a team member hop to safety on the right side of the frame.  This also explains the way that the scene was cut the way it was: they extricated the camera and moved the robot upstream a bit before filming the “standing up” behavior.  I originally thought that there must have been some problem on the first standup attempt that caused them to decide to reshoot, but now I bet that the machine could have stood up and kept going much more quickly.  The rest of the video after that is fairly unremarkable, although I found it amusing that the stop sign appeared to be in English and Arabic; check it out for yourself:

Son of Big Dog: Alpha Dog/LS3 (part 2)

Now the LS3 is headed out into the field, exhibiting the following behaviors in this video: climbing a typically rocky forested New England hill, playing “follow the leader” with a human subject through high grass and an open field, double timing it down a dirt road,  standing up, and a brief bit of operation with multiple LS3 units.  The robot body is more robust than the Alpha Dog prototype from the previous video, with clear evolutionary progression on the side “ribs” that help the robot roll onto its “stomach” when standing up; also, the execution of the “standing up” behavior is smoother and more polished: