3.7. STRUCTURED SINGULAR VALUE(ยต) ANALYSIS AND SYNTHESIS 115
plant = 1/makepoly([1,0,-0.01],"s")
Wm = makepoly([1,20],"s")/makepoly([1,200],"s")
omega = logspace(0.01,100,25)
plantg = freq(plant,omega)
Wmg = freq(Wm,omega)
g1 = ctrlplot(plantg,{logmagplot});
g1 = ctrlplot(Wmg,g1,{logmagplot,linestyle=4});
g1 = plot(g1,{!grid,legend=["Open loop plant";...
"multiplicative perturbation weight"]})?
Frequency
0.1 1 100.01 100
Magnitude
1e-05
0.0001
0.001
0.01
0.1
1
10
1e-06
100
Open loop plant
multiplicative perturbation weight
The open-loop system under consideration is illustrated in Figure 3.10.
Figure 3.10: Open loop perturbation model
# Now include some weights for performance: