Servo - December 2013

Two Steppin

My work with smaller bipeds has been helpful, but in many respects things are completely different with larger models. Some things do not scale well. For example, ants. If they were our size they could lift an elephant, but they don’t scale well. (Except in cheesy movies). Biped robots are the same.

With the small bipeds, I found it very easy to copy the sequence of the left leg step and reverse it for the right leg to complete a walk cycle. Small differences in the mechanical structure didn’t factor that much in the movement. Yet, that doesn’t work with larger structures.

We reversed the one-step sequence and found we had to tweak almost every frame. In one part of the step, we needed to add an intermediate frame to retain balance.

It is the Sunday after the qualifications were due, but we didn’t give up. WATSON took two full steps and returned to the frame from which we started.

The DARPA Robotics Challenge

So, what of the challenge? Are we out of the competition?

As it turns out, the short answer is ... yes and no.

This year’s DRC in December is mostly for Tracks A, B, and C. Since DARPA is footing their bill, the folks running the challenge mostly want to find out how well some of their sponsored teams are performing. So, if we were far enough along, we would have been invited to test WATSON along with Atlas and some other terrific works of engineering. However, Team Walk Like A Man is still entered in the challenge that takes place in December 2014.