
Saunder January 22, 2014 10:43 K15053˙Book
Disturbance Rejection for Ball Mill Grinding Circuits 181
Y
1
(s)
Y
2
(s)
Y
1r
(s) Y
2r
(s)
C
1
(s)
C
2
(s)
U
1
(s) U
2
(s)
D
ˆ
f 2
(s)
D
ˆ
f 1
(s)
Disturbance
observer I
Disturbance
observer II
Feedforward-feedback DOB-MPC controller
Model predictive
controller
+
–
+
–
Figure 11.5 Internal structure of the feedforward-feedback DOB-MPC controller.
11.4 Performance Analysis and Comparisons
For controlstudy, planttesthas beenconstructed to developthe input-output transfer
function model of grinding circuit as follows:
Y
1
(s )
Y
2
(s )
=
G
11
(s ) G
12
(s )
G
21
(s ) G
22
(s )
U
1
(s )
U
2
(s )
, (11.22)
where
G
11
(s ) = g
11
(s )e
−τ
11n
s
=
−0.58
2.5s +1
e
−0.68s
, (11.23) ...