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by aarongough 3006 days ago
I find Festo's work interesting, but the spider bot in particular looks really clunky overall in comparison to even some of the hobby level stuff that's out there. It would make sense to have a rolling robot if it was really fast (and could steer while rolling).

Here's an example of a hexapod from 6 years ago, I believe built from a kit but running customized motion control code:

https://www.youtube.com/watch?v=rAeQn5QnyXo

Skip to 0:45 to see it running. Still amazing to me and I haven't seen too many other legged robots that look this smooth.

2 comments

There are some more recent kits[1] which come close. I wouldn't think it would take a big change to hexapods like these to give the legs a rounder profile to roll on, if they curled their legs like the Festo.

1: https://youtu.be/-Dt2yVR3FJQ

I believe (please correct me if I'm wrong) that the kinematics for those two robots are pre-programmed, and will only work on flat surfaces with no obstacles. Yes, the main body does have an accelerometer which can sense its gross orientation, but if they're just using regular servos, there is no feedback from the legs to indicate height changes in the terrain or obstacles.

Pre-programmed kinematics makes for a cool-looking demo, but isn't going to be super-useful for making an all-terrain robot successful.

Compare that to what Ghost Robotics is doing:

https://www.youtube.com/watch?v=bnKOeMoibLg

In addition to the other capabilities shown, at the very end of the video it shows how quick and accurate the force feedback is.

That jump at 1:02 is spectacular!

And the quick reflexes on the ice are also pretty impressive.

Oh absolutely - but GR won't sell me a kit for $300 either... I wonder though if rolling doesn't make proper feedback less important - 'if the surface isn't level, start rolling!'
I'm hoping that GR will have development kits out in the not-too-distant future.

The hardware is "cheap", in the sense that each leg has two motors and that's it. All feedback is via position and torque sensing on the motors themselves. The mechanicals for the legs are also relatively simple and cheap.

It is the software which really makes the system perform.

It just rolls. It doesn't jump like the actual spider does.