[ODE] Community page

Ian Munro I.Munro at herts.ac.uk
Thu Oct 10 02:32:02 2002


Mattias wrote:
> If anyone wants to see some more evolved life, check out 
> http://www.cambrianlabs.com/Mattias/Evolved/ , where I use Genetic 
> Programming to evolve a hopper. Russel, if you want to, you could add 
> that also.

Pretty interesting stuff.
I'm doing similar things with a two legged runner and using Mathew Wall's
GALIB.

Sorry, I haven't got any details online at the moment, but have a look at
http://www.bunnyburgers.com/tigger.jpg  for a picture of the beast in
action.

I'd previously used the sort of control systems described by Railbert, but
am now trying a sort of limit cycle based approach, where just once per a
hop I measure the creatures attitude in space, apply (genetic algorithm
generated) weights to all these values, sum them together and the use the
resulting number to set the leg velocity for flight. For stance I use the
same process but a different set of weights.
My reasoning was that the railbert approach might be producing a control
system that was fighting against the natural dynamics, whilst a
non-prescriptive approach might work in harmony with the dynamics. The
down-side is that the system is so non-prescriptive that a lot of time is
wasted simulating completely unfeasible control weightings.
The creature evolves to hops ok if I use both legs in sync, but I've only
just started on the bipedal running strategies, so it's a bit hit and miss
at the moment.

Cheers
Ian