Section 4.1 Traditional Design Methods When 2.25 Kn<15 and 0.16<0n<0.57,for a 10%overshoot: B= 15-K 15+K ,4=1 and for a 20%overshoot: 36 B= 27+5K,:4=1 If1.5<Kn<2.25and0.57<0n<0.96, B=吕（信+）u=音k Z-N/RZN usually gives very bad response for the plant with large time delay.Hence,some designers believe that PID cannot be used for the plant with large time delay.Actually,with proper design methods PID can be applied to such systems Zhang.W.D..CRC Press.2011 Version 1.0 7/71Section 4.1 Traditional Design Methods When 2.25 < Kn < 15 and 0.16 < θn < 0.57, for a 10% overshoot: β = 15 − Kn 15 + Kn , µ = 1 and for a 20% overshoot: β = 36 27 + 5Kn , µ = 1 If 1.5 < Kn < 2.25 and 0.57 < θn < 0.96, β = 8 17  4 9 Kn + 1 , µ = 4 9 Kn Z-N/RZN usually gives very bad response for the plant with large time delay. Hence, some designers believe that PID cannot be used for the plant with large time delay. Actually, with proper design methods PID can be applied to such systems Zhang, W.D., CRC Press, 2011 Version 1.0 7/71