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 \(\omega_n t\) for various values of \(\zeta\) (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 \(\omega/p\)

Bode diagram of a first order zero plotted against normalised frequency

Figure 17 Bode diagram of a first order zero plotted against normalised frequency \(\omega/z\)

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 \(\omega/\omega_n\) for various values of \(\zeta\)

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

Figure 19 Effect of an extra pole at \(s = -­p_r\) on a second order system

a) % overshoot \(M_P\) vs \(p_r/\zeta \omega_n\)

b) normalised rise time \(\omega_n t_r\) vs \(p_r/\zeta \omega_n\)

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

Figure 20 Effect of an extra zero at \(s = -­z_r\) on a second order system

a) % overshoot \(M_P\) vs \(z_r/\zeta \omega_n\)

b) normalised rise time \(\omega_n t_r\) vs \(z_r/\zeta \omega_n\)

Maximum phase lead v alpha for a phase-lead compensator

Figure 21 Maximum phase lead v \(\alpha\) 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 \(M_P\) and frequency response resonant peak vs phase margin for a second order system (note \(M_r = M_\max\))