…And we’re back after a long holiday to continue delving into the video record of the evolution of Big Dog and its progeny.  This video is a PR piece generated by a meet and greet event whose details are already slipping from my memory, but it does provide some interesting close up views of some of the sensor hardware as well as a snippet of an operator (looks like the “Follow Tight” guy) commanding the robot from a manual controller while walking behind it.  This last bit was interesting as an insight on how the robot could be used in a combat situation even if it is not armed; the body itself is heavy enough to absorb incoming small arms and automatic weapons fire, so it might make a good shield for infantry assaulting a defended position, similarly to the way in which soldiers will currently advance behind tanks.  Check it out and see what you think:

This is a short video that focuses on an interesting part of the LS3 sensing systems: the use of a “shoe tracker” device which is strapped around a soldier’s foot and helps the machine to follow.  Apparently, this is not required but approves tracking performance.  Also, the sound of the motor seems much louder in this video than in previous ones, although it has a much deeper note than the whiny buzz of 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:

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:

One evolutionary branch of the Big Dog family is Alpha Dog, which eventually becomes LS3 (AKA Legged Squad Support System).  Here we start to see the transition from a very rough research prototype to a more polished prototype that is capable of participating in field trials with end users.

First we start in the lab, with a video of Alpha Dog being put through its paces.  One subtle but informative aspect of this video is the safety features associated with the test area: caution tape to warn humans that they are entering a potentially dangerous area, flashing lights on the robot to indicate that it is in operation and may move unexpectedly, and a heavy gantry to prevent the robot from falling over or exiting the test area in the event of a severe malfunction.  Other interesting points to note here are (obviously) the robot’s ability to traverse rough terrain, its impressive “standing up” behavior, and the looting of the Boston Dynamics fitness center (presumably not just to simulate the added weight of a payload but also to adjust the center of mass to correct for asymmetry in the weight distribution of drive components):