Environmental Engineering Reference
In-Depth Information
From: a
Tfa
(m/s
2
)
From: e
wg
(rad/s)
-10
-30
-20
-40
-30
-50
-40
-50
-60
-60
-70
-70
-80
-80
10
0
10
0
Frequency (Hz)
Frequency (Hz)
Fig. 5.9
Bode diagram of the collective pitch H
?
control
100
50
W
11
(s)
W
12
(s)
Unc
add13
Unc
add25
1/U(s)
W
2
(s)
0
-50
-100
10
-3
10
-2
10
-1
10
0
10
1
10
2
10
3
Frequency (Hz)
Fig. 5.10 Weight functions, uncertainties and control sensitivity function in the design of the
collective pitch H
?
control
After obtaining the pitch controller, the stability robustness of the closed loop
for all plant in the family of linear models has to be analyzed. As it is proved in the
small gain theorem [
29
], the inverse of the control sensitivity function has to be an
upper limit of the modeled additive uncertainties (Fig.
5.10
) to guarantee the
robustness of the control in all operating points in the above rated zone.
