User`s guide

9 Design Case Studies
9-30
The command produces t he plot shown below.
This design is robust and can tolerate a 11 dB gain increase or a 40 degree
phase lag in the open-loop system without going unstable. By continuing this
design process, you may be able to find a compensator that stabilizes the
open-loop system and allows you to reduce the seek time.
Frequency (rad/sec)
Phase (deg); Magnitude (dB)
Bode Diagrams
−100
−50
0
50
100
Gm=11.6 dB (Wcg=296.1); Pm=43.1 deg. (Wcp=106.5)
10
0
10
1
10
2
10
3
−300
−200
−100
0
100