11 - Frequency Response
Completion requirements
9. AR and ф Various Systems for Sinusoidal Input
System | Transfer function | Amplitude ratio (AR) | Phase shift (\(\phi\)) |
---|---|---|---|
First order | \(\frac{K_p}{\tau_p s+1}\) | \(\frac{K_p}{\sqrt{\tau_p^2\omega^2+1}}\) | \(\tan^{-1}(-\omega \tau_p)\) |
Pure capacitive | \(\frac{K_p}{s}\) | \(\frac{K_p}{\omega}\) | \(-90^o\) |
Second order | \(\frac{K_p}{\tau^2s^2+2\zeta\tau s+1}\) | \(\frac{K_p}{\sqrt{(1-\tau^2\omega^2)^2+(2\zeta\tau\omega)^2}}\) | \(\tan^{-1}\left(-\frac{2\zeta\tau\omega}{1-\tau^2\omega^2}\right)\) |
Dead time | \(e^{-\tau_d s}\) | 1 | \(-\tau_d \omega\) |
Systems in series | \(G_1(s)G_2(s)\cdots G_N(s)\) | (AR)\(_1\)(AR)\(_2\cdots\)(AR)\(_N\) | \(\phi_1+\phi_2+\cdots+\phi_N\) |
System | Transfer function | Amplitude ratio (AR) | Phase shift (\(\phi\)) |
---|---|---|---|
Proportional controller | \(K_c\) | \(K_c\) | 0 |
PI controller | \(K_c\left(1+\frac{1}{\tau_I s}\right)\) | \(K_c\sqrt{1+\frac{1}{(\omega\tau_I)^2}}\) | \(\tan^{-1}\left(\frac{-1}{\omega\tau_I}\right)\) |
PD controller | \(K_c(1+\tau_Ds)\) | \(K_c\sqrt{1+\tau_D^2\omega^2}\) | \(\tan^{-1}(\tau_D\omega)\) |
PID controller | \(K_c\left(1+\frac{1}{\tau_Is}+\tau_Ds\right)\) | \(K_c\sqrt{\left(\tau_D\omega-\frac{1}{\tau_I\omega}\right)^2+1}\) | \( \tan^{-1}\left(\tau_D\omega-\frac{1}{\tau_I\omega}\right)\) |