Page 369 - Modern Control Systems

Section 5.9 Design Examples 343

FIGURE 5.33
An upper-torso
humanoid robot
named Domo helps
researchers
investigate robot
manipulation in
unstructured
environments.
(Photo courtesy of
Aaron Edsinger, MIT
Humanoid Robotics
Group.)

at the control design problem. Here we consider a complex fourth-order model of
the lateral dynamics of the aircraft motion that is approximated by a second-order
model using the approximation methods of Section 5.8. The simplified model can be
used to gain insight into the controller design and the impact of key controller para-
meters on the transient performance.

EXAMPLE 5.10 Hubble space telescope control
The orbiting Hubble space telescope is the most complex and expensive scientific in-
strument that has ever been built. Launched to 380 miles above the earth on April 24,
1990, the telescope has pushed technology to new limits. The telescope's 2.4 meter
(94.5-inch) mirror has the smoothest surface of any mirror made, and its pointing sys-
tem can center it on a dime 400 miles away [18]. The telescope had a spherical aber-
ration that was largely corrected during space missions in 1993 and 1997 [21],
Consider the model of the telescope-pointing system shown in Figure 5.34.