Jump to content

  • Log In with Google      Sign In   
  • Create Account

evolving the stability of a body


Old topic!
Guest, the last post of this topic is over 60 days old and at this point you may not reply in this topic. If you wish to continue this conversation start a new topic.

  • You cannot reply to this topic
6 replies to this topic

#1 bollµ   Members   -  Reputation: 354

Like
0Likes
Like

Posted 13 January 2013 - 04:59 AM

Hi all!

 

I've been trying to "evolve" some creatures that are built up of circles and joints, and can also have a "booster" that propels them in a certain direction.

 

I've been using genetic algorithms to try and do this but I'm not really able to define what "stability" is. As in, I'm not able to identify if a structure is stable or not

 

As of now, I'm checking if it's able to stand on it's own for 20 seconds. If it can, then it's considered stable. But I'm finding it *really* hard to integrate movement into it. the AI isn't able to place the motors in effective positions so that they move :/

 

any ideas?

Thanks

Bollu


a WIP 2d game engine: https://code.google.com/p/modulusengine/

English is not my first language, so do feel free to correct me :)


Sponsor:

#2 h4tt3n   Members   -  Reputation: 1286

Like
0Likes
Like

Posted 13 January 2013 - 02:59 PM

Hi there,

 

It's a bit hard to comment on your post without atleast seeing a demo program or a video clip that exemplify your problem.

 

Cheers,

Mike



#3 0r0d   Members   -  Reputation: 819

Like
0Likes
Like

Posted 14 January 2013 - 11:31 PM

Not a trivial problem.



#4 h4tt3n   Members   -  Reputation: 1286

Like
0Likes
Like

Posted 15 January 2013 - 01:41 AM

Could you perhaps describe for us precisely and in detail what these unstable bodies do, that you find undesireable. I believe that if you can answer this question you are already halfway at the solution.

 

Cheers,

Mike



#5 rip-off   Moderators   -  Reputation: 8727

Like
0Likes
Like

Posted 15 January 2013 - 05:43 AM

Something like this? (caveat: I don't have flash installed, so I'm working from memory of a couple of years ago). This is a simpler case, but the essential idea might work for you.



#6 Selenaut   Members   -  Reputation: 102

Like
0Likes
Like

Posted 28 January 2013 - 07:35 PM

If by "unstable" you mean "wobbling around and it may be able to stand up but it won't stay still," then you can use a few reference points on the creature's main polygon (or body or whatever you want to call it) and check for movement deltas. If the averae is above a set threshold, then it can be deemed unstable.

 

Additionally, you can use this as a more refined fitness amount (for your GA).

 

Good luck,

 

Selenaut


Edited by Selenaut, 28 January 2013 - 07:36 PM.


#7 LorenzoGatti   Crossbones+   -  Reputation: 2764

Like
0Likes
Like

Posted 29 January 2013 - 02:53 AM

If you want to evolve walking "legs", you can split the problem into three stages: first legs with a decent shape and position, then an assignment of motors that can move the legs arbitrarily enough, then a motor activation schedule that causes walking.

 

To make legs, you could probably graft standard pieces to the "body": for example you can start with a rather short outer edge facing down and triangulate the trapezoid between it and its projection on the ground plane with close to equilateral triangles with edge lengths in a certain range; motors that contract or extend struts (SODA Constructor style) can be placed in the almost vertical front and back edges to bend, shorten or lengthen the "leg".

 

How to move legs might allow a direct solution (deformed leg shape -> altered strut lengths -> forces), while making the whole model walk can be approached with genetic algorithms or the like.


Produci, consuma, crepa




Old topic!
Guest, the last post of this topic is over 60 days old and at this point you may not reply in this topic. If you wish to continue this conversation start a new topic.



PARTNERS