Here is an attempt of tracking using 4 PID:

2 PID are for eyes tracking

2 PID are for head : the head moves in order to reduce the angle of eyes from the center (90 degrees)

• The next step is to know what is angle range for eye's servos
• how faster eyes movement should be, respect to the head movement : in the script i made head less responsive than eyes

[[4PID.Tracking.py]]