I want to understand why Sqrt controller is used in Position controller in Arducopter-
Specifically , correction factor = sqrt( 2*acc_f *(error - acc_f/P^2 )) ; this code is used to calculate velocity target ,if error > acc_f/P^2 , here default acc_f = 2.5 m/sec2, default P = 1 (although not sure)
else , if error is < acc_f/P^2 , then simple P control is used , correction factor = P* error,
Can someone pls tell me what is this term acc_f/P^2 signify
I want to understand what utility sqrt controller serves here and any reference of its derivation, so that i can understand the full physics of sqrt controller better and what it helps in.