I am pretty new to evolutionary Computation and thus not experienced. So
forgive me, if my questions are dull..
I am trying to set up a GP-System that can create a PID-controller
Thus for doing that, I need
a) a node, that can sum up the value another node holds and
b) a node, that contains the value another node had in the cycle before.
The solution my GP System should find is:
y = Kp * e + Ki * Ta * esum + Kd * (e – ealt)/Ta
where Kp, Ki, Ta, Kd are constants
and e is calculated out of values changing each timestep. ( so practically
"e" isn't a terminal symbol, but rather a subtree which result is the value
so, plainly speaking I have a subtree which returns the value of "e". I then
need a node "e_sum" and a node "e_old".
Any hints on how to implement those nodes? Do you need additional information?