Hardware Reference
In-Depth Information
r:u_v, g:u_m
0.5
0.4
0.3
0.2
0.1
0
−0.1
−0.2
−0.3
−0.4
−0.5
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0.016
0.018
Figure 3.78: Control input of micro-actuator (solid line) and VCM (dashed
line) corresponding to Figure 3.77.
r:y, g:y_v,b:y_m
1.2
1
0.8
0.6
0.4
0.2
0
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
x 10
−3
time in sec
Figure 3.79: Response of dual-actuator model with 1 µm step input. Solid
line: y
p
, dash-dot line: y
v
, dotted line: y
m
.
the sensitivity transfer function and complementary sensitivity transfer func-
tion shown in Figure 3.81 reveal that, although the closed loop bandwidth is
fairly high, the error rejection capability is not very good for the chosen con-
troller and observer gains. The performance index of equation 3.155 does not
explicitely include the frequency domain objectives. However, the frequency
domain properties of the closed loop system can be manipulated indirectly by
changing the weight matrices R
1
, R
2
, V
1
and V
2
. These weight matrices should
be reselected such that the frequency domain responses better suit the desired
performance.
