Ultimate frequency method recommended control constants
From Letherman
Type of controller | Kp | Kp/Ki | Kd/Kp |
P | 0.5 K'p | - | - |
P + I | 0.45 K'p | 0.8 T' | - |
P + I + D | 0.6 K'p | 0.5 T' | 0.125 T' |
where K'p is the proportional gain value resulting in steady oscillations of controlled system and T' is the period of the steady oscillation.