User`s guide

Hard-Disk Read/Write Head Controller
9-25
The corresponding open-loop model
is obtained by the series connection
D = zpk(0.85,0,1,Ts)
oloop = Hd * D
Now see how this compensator modifies the open-loop frequency response.
bode(Hd,'--',oloop,'-')
y
Dz()
Plant
u
H
d
z()
Compensator