5. Some useful design curves

Unit step response vs normalised time for various values of zeta (2nd order)

Figure 15 Unit step response vs normalised time ωnt for various values of ζ (2nd order)

Bode diagram of a first order pole plotted against normalised frequency

Figure 16 Bode diagram of a first order pole plotted against normalised frequency ω/p

Bode diagram of a first order zero plotted against normalised frequency

Figure 17 Bode diagram of a first order zero plotted against normalised frequency ω/z

Bode diagram of a second order complex pair of poles plotted against normalised frequency for various values of zeta

Figure 18 Bode diagram of a second order complex pair of poles plotted against normalised frequency ω/ωn for various values of ζ

Figure 19 Effect of an extra pole at on a second order system

Figure 19 Effect of an extra pole at s=­pr on a second order system

a) % overshoot MP vs pr/ζωn

b) normalised rise time ωntr vs pr/ζωn

Figure 19 Effect of an extra zero at on a second order system

Figure 20 Effect of an extra zero at s=­zr on a second order system

a) % overshoot MP vs zr/ζωn

b) normalised rise time ωntr vs zr/ζωn

Maximum phase lead v alpha for a phase-lead compensator

Figure 21 Maximum phase lead v α for a phase-lead compensator

Transient response overshoot and frequency response resonant peak vs phase margin for a second order system

Figure 22 Transient response overshoot MP and frequency response resonant peak vs phase margin for a second order system (note Mr=Mmax)