--- In SeattleRobotics@yahoogroups.com
, Alan KM6VV <KM6VV@...> wrote:
> >Yeah, I think Rbt Full was mainly comparing the more common gaits,
> >biped walk/run with quadruped trot with hexapod tripod gait.
> >Hence the quote:
> >These measurements, plus the considerations mentioned above, have
led R.J. Full to conclude that, across the animal kingdom, legs and
> >locomotion work in an analogous fashion - namely, "... 1 human leg
> >works like 2 dog legs, 3 cockroach legs and 4 crab legs ...".
Raibert found a similar result relating quadruped gaits to a virtual
> >gait [Raib84].
> I like that observation! Although I see it the other way around, 4
crab work like 3 cockroach, which work like 2 dog, or 1 human.
BTW, this was all discussed several months ago before you got into
the conversations, but I have been working on a new quad, named Poco.
I **finally** built and operated the first leg yesterday, while
everyone else was celebrating college football bowl day. I've been
gathering parts and making plans for months. Doing mechanical stuff
is like getting root-canals for some of us.
In any case, I was looking at the Toejammer design for sometime, and
thought the hip rotator mechanism might be good on a quad. Peter has
talked about adding the fore-aft axis to aid turning, while I'm
trying the vertical rotation axis for this. It's similar to how
humans do most turns. While standing straight, rotate the foot into
the new direction, and step forward, etc.
So, I scrapped Toejammer [R.I.P.] to build the front end of Poco. The
idea is to attach regular 2-DOF legs to the frame with the hip
rotators. We'll see how this goes. Basically, the idea is to get
something similar to the dogs turning in these pictures.
To a large extent, the dog turns by angulating its entire body,
and "crossing-over" the front foot, while Poco will turn by rotating
the foot like a human, to produce approximately the same effect. The
trick will probably be to make sure the CoG stays inside the