4 ms·
What exactly is evolving? How is the genome represented, how does it control the walking?
by Houshalter 12y ago
What exactly is evolving? How is the genome represented, how does it control the walking?
- rednuht 12y agoThe genome is represented by a set of parameters that control the rotation speed on each joint, 3 parameters per joint. The rotation speed for each joint on each simulation step is given by: x * cos(y + z * simulation_steps); where x, y, and z are the parameters. I've experimented with more sophisticated models, but it was hard to get any kind of evolution in the attention span people give to a browser game. :D
- karpathy 12y agoI've worked on similar projects during my Master's degree. An important trick I learned was to make the controller a function of some kind of discrete feedback in the world (e.g. when the foot hits the ground). In your equation above for example, a simple way to incorporate this would be to reset simulation_steps to zero every time a foot hits the ground. This is also an important feature in the SIMBICON controller, which is arguably the simplest and most robust walker system. (http://www.cs.ubc.ca/~van/papers/Simbicon.htm http://www.cs.ubc.ca/~van/papers/Simbicon.htm) EDIT: and yes, Reinforcement Learning is much more effective way of attacking this type of problem (e.g. see some recent work from Sergey Levine http://www.eecs.berkeley.edu/~svlevine/ http://www.eecs.berkeley.edu/~svlevine/), but I also agree with the author that GA are fun :)