
H
∞
˙x = Ax +
ˆ
B
1
ˆv + B
2
u
ˆz =
ˆ
C
1
x +
ˆ
D
11
ˆv +
ˆ
D
12
u
y = C
2
x +
ˆ
D
21
ˆv
ˆv ˆz
ˆ
B
1
= (B
∆
B
1
)L
1
,
ˆ
C
1
= L
2
C
∆
C
1
,
ˆ
D
11
= L
2
D
∆∆
D
∆1
D
1∆
D
11
L
1
,
ˆ
D
12
= L
2
D
∆2
D
12
,
ˆ
D
21
= (D
2∆
D
21
)L
1
,
L
1
=
γηS
−1/2
0
0 I
, L
2
=
S
1/2
0
0 I
,
S = S
T
> 0
S = (S
1
, . . . , S
r
, s
1
I
m
1
, . . . , s
f
I
m
f
) ,
r
k
1
, . . . , k
r
k
1
+ ··· + k
r
+ m
1
+ ··· + m
f
= n
∆
H
∞
kˆzk < γkˆvk , ∀ˆv 6≡ 0 ,
k · k L
2
ˆv = L
−1
1
v
∆
v
!
, ˆz = L
2
z
∆
z
!
kzk
2
− γ
2
kvk
2
< −(kS
1/2
z
∆
k
2
− η
−2
kS
1/2
v
∆
k
2
) .