Recall from Module 5, that the magnitude and phase of the harmonic response of a system can be obtained from its transfer function by substituting sjo Mo Glo ∠G(O There are two major representations of the frequency response: bode plot and Nyquist diagram M m▲ O=0 0=∞ q e G(O) Bode plot Nyquist diagram
The frequency response is a kind of model of system G()=G(s)= d Differential Equation Transfer Function System dt S=JO Frequency Response
• –– The frequency response is a kind of model of system: s j G j G s = = ( ) ( ) Differential Equation Transfer Function Frequency Response System dt d s = s = j dt d j =
12.2 Different forms of the Frequency Response Nyquist Diagram Section 8.2 Frequency Response Plots X(a) Negative w R( 0 Positive a
• Nyquist Diagram 12.2 Different forms of the Frequency Response
Bode Diagram M Fig. 12.3 Bode representation of frequency response
• Bode Diagram
Nichols Diagram 10 e 10 0 「o 30 40 270 225 180 135 Phase, degrees FIGURE Log-magnitude-phase curve for GH,(w)
• Nichols Diagram