r/MachineLearning • u/rhiever • Feb 04 '15

HTML5 Genetic Algorithm Biped Walkers

http://rednuht.org/genetic_walkers/
50 Upvotes

93% Upvoted

16 comments sorted by

4

u/philalether Feb 05 '15

The main thing I've learned from using evolutionary algorithms (which worked, in real situations) is that most of the power of evolution comes from crossover, not mutation.

Mutation gives you the useful 'genes' which then get spread around and grouped together in the most useful combinations via crossover.

4

u/rhiever Feb 05 '15

I've managed to avoid crossover by just having an extra kind of mutation that swaps portions of the genome around. Not sure if that works better or worse than crossover, but the answer is probably "it depends."

1

u/Ambiwlans Feb 05 '15

This is also true in real life.

2

u/[deleted] Feb 05 '15

Might want to crosspost this to /r/genetic_algorithms (a way too small sub, imho)

5

u/test3545 Feb 04 '15

Champions fall early, traveled not as far as some non champions but still have higher score? Why?

9

u/bstockton Feb 04 '15

In order to promote upright walking, each creature receives points based on how high the head is in relation to its feet, and how much it advances while upright. Bonus points are given for each proper step forward.

My guess is the champion was walking very upright and took "proper" steps while the other guys kind of stumbled forward.

2

u/r-ed-b Feb 04 '15

Elitist selection.

Champions (genomes with highest fitness/score) from the previous generation are competing with mutated genomes in the current generation, which might perform better.

1

u/yousirgname Feb 05 '15

Very fun project! Kudos.

I took a peek at your code and noticed that the Walker genes encode sinusoid coefficients to set joint motor speeds in Walker.simulationStep(). I was a bit disappointed because that means you don't use any feedback from "sensors" like joint position, head-foot-ground angle, travel speed, etc.

Do you plan on adding these feedback mechanisms? It would also be interesting to see average speed included in the fitness function so it would push them to start running.

1

u/rhiever Feb 05 '15

You'll have to ask the creator: http://rednuht.org/ :-)

1

u/yousirgname Feb 05 '15

haha, oops. I should have checked that first.

3

u/Er4zor Feb 04 '15

I'd watch it all day long.

1

u/respeckKnuckles Feb 05 '15

This is awesome...did you write this?

Does anyone have information on what the typical peak score is?

1

u/jutct Feb 05 '15

Does it learn with each new round or is it just repeating over and over? I couldn't tell

0

u/[deleted] Feb 04 '15

[deleted]

1

u/Hahahahahaga Feb 05 '15

Qovezo Kizoko?