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Control System Professional (1995)

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The Nyquist PlotThe Singular-Value Plot

5.4 The Nichols Plot

NicholsPlot gives yet another way to depict frequency response information—by plotting the magnitude versus phase curve in the semilogarithmic scale.

Creating the Nichols plots.

Here is an open-loop transfer function for the spacecraft attitude control system, compensated with a PID controller from Franklin et al. (1991).

In[26]:=

Out[26]=

This is the Nichols plot for the system.

In[27]:=

NicholsPlot accepts the options PlotPoints, PlotSampling, and PhaseRange, as does BodePlot, as well as the options pertinent to ListPlot.

The Nyquist PlotThe Singular-Value Plot