This video shows how a neural network can learn to navigate a track. There is a generation counter in the upper right. Each car that sets out to learn receives the same input signals to be able to make decisions. For each new generation, ten cars become modeled after the best performing car of the prior generation. What constitutes "best performing" can be dialed in and modified, but for the most part, it is based on how long a car survives without crashing and how far it has gotten along the track.
It isn't until the 30th generation that the AI learns to navigate the first right turn successfully. In the 33rd generation, the AI learns how to navigate the second turn. By the 46th generation, the AI is able to navigate multiple turns but the driving is quite slow with noticeable speed differences between the right and left turns. From this point forward, it gradually learns to go faster and faster.
The light green color car represents the best performing car from the prior generation. In many cases, this car will be the fastest of the current generation, but when you see an orange car beat the green car, it is because some randomness has resulted in a better performing car that allows it to outpace the best car from a prior generation.
Once the car learns to navigate a track, we change tracks to see if the trained cars are able to navigate a never-before-seen track.
There is a recap at the end of the video that shows key milestones of learning and performance improvement in the 70 generations captured in this video.
This program was developed by my son, Nathan, during his junior year of high school for fun.
0:00 - Generation 1 - learning begins but no cars survive first turn
1:13 - Generation 30 - successfully navigates first turn
1:20 - Generation 33 - successfully navigates second turn
2:15 - Generation 46 - multiple turns made successfully but car is SLOW.
Best Lap Time 160.9s
7:41 - Generation 48
Best Lap Time: 107.49
9:29 - Generation 49 - new orange car is faster initially but loses to green car.
11:11 - Generation 50
Best Lap Time: 93.9s
12:45 - Generation 51
Best Lap Time: 88.4s
15:44 - Generation 53
Best Lap Time: 86.5s
17:12 - Generation 54
Best Lap Time: 78.0s
23:45 - Generation 59
TRACK CHANGE
Best Lap Time: 76.6s
27:41 - Generation 62
TRACK CHANGE
28:58 - Generation 63
TRACK CHANGE
Best Lap Time: 75.4s
31:30 - Generation 65
TRACK CHANGE
Best Lap Time: 73.7s
34:00 - Generation 67
Best Lap Time: 70.7s
35:11 - Generation 68
Best Lap Time: 70.6s
36:23 - Generation 69
Best Lap Time: 70.6s