ElmoMC SimplIQ Digital Servo Drives-Bell Command Reference - Manual (Page 286)

The discrete equivalent form is:
2 1
2
0
a z a z
z b
+ +
where:
2
2
2
2
1 4 4
8
2
ω
ω
ω
+ +
−
=
T T
d
T
a
2
2
2
2
2 4 4
4 4
ω
ω
ω
ω
+ +
− +
=
T T
d
T
d
T
a
2
2
2
2 1 0 4 4
4
1
ω
ω
ω
+ +
= + + =
T T
d
a a b
7.2.2 Notch Filter Element
(Represented by Second-order Block)
The basic continuous-time notch filter element is:
2
2 2 2
2
2
1 1 1
2
2
1
2
2
2
2
ω ω
ω ω
ω
ω
+ ⋅ ⋅ ⋅ +
+ ⋅ ⋅ ⋅ +
s d s
s d s
where:
ω
1
= 2 π · f
1
, and f
1
[Hz] is the notch frequency.
ω
2
= 2 π · f
2
, and f
2
[Hz] is the notch frequency.
d
1
is the notch damping.
d
2
is the double-pole damping.
The discrete equivalent form is:
2 1
2
2 1
2
0
a z a z
b z b z b
+ +
+ +
where:
q
c p
b
1
1 1
0
+ +
= ,
q
p
b
) 1 ( 2
1
1
−
= ,
q
c p
b
1
1 1
2
+ −
= ,
q
c p
a
1
2 2
2
+ −
=
q
p
a b b b a
) 1 ( 2
1 2
2 2 1 0 1
−
= − − + + =
assuming:
SimplIQ for Steppers Application Note Filters
MAN-STECR (Ver. 1.1)
87