Unsupervised neural networks

Mizipzor · 2005-09-01T15:58:07

I want to learn neural networks. I kinda understand how they work but I cant get my head around how they learn if there isnt a known "optimal" value, i.e. a techer. Exemple: I want a neural network to keep a helicopter in midair. The inputs are the helicopters weight or the gravitys pull (m*g) and the second is the vertical speed. The output is 1 or 0, should the engine be running or not. 1. vertival speed 0 >-w1-> | T | -- 0> engine 2. m * g 0 >-w2-> If I understand it right, the calculation goes as follows: First input (vertical speed) * first inputs weight (w1) + second input (m*g) * second inputs weight (w2). If that is bigger than the threshold (T) then the output fires (engine starts). Now after each execution the net is supposed to evolve (the weights change value). But how do they change? Since I dont know when I should go up or down I cant tell the net if it did the right or wrong thing. This is whats called a unsupervised neural network, right? I dont want to write anymore then no one cares to read. :P Please enlighten and/or correct me. Cheers.