PID - Ziegler-Nichols Ultimate Tuning

Contents

Classical Ziegler-Nichols PID gains from ultimate gain K_u and ultimate period T_u - an on-line tuning recipe for level, pressure and flow loops.

Formula

$$ K_p = 0.6 K_u,\ T_i = 0.5 T_u,\ T_d = 0.125 T_u $$

Symbol	Meaning	Unit	Source
$K_u$	Ultimate (critical) gain	-	P-only closed loop
$T_u$	Ultimate period of oscillation	s	P-only closed loop