ElmoMC SimplIQ Digital Servo Drives-Bell Command Reference User Manual
Page 287
=
2
tan
2
T
d
c
k
k
k
ω
,
2
2
tan
1
=
T
p
k
k
ω
, (
2
,
1
=
k
)
1
2
2
+
+
=
c
p
q
7.2.3 Double-lead Element
(Represented by Second-order Block)
The basic continuous-time double lead-lag element is:
2
+
+
⋅
b
s
a
s
a
b
The frequency a / (2
π) [Hz] is the lead corner frequency. The frequency b / (2π) [Hz] is
the lag corner frequency.
The discrete equivalent form is:
2
-
z
)
-
z(1
G)
-
(1
G
+
β
β
Order Parameter
1
k
1
= (1 - β)
2
2
k
2
= Gβ · (Gβ + 2 · (1 - β))
3
k
3
= - (Gβ)
2
4
k
4
= β
2
The DC gain of this block is unity.
β is selected as β = e
-bt
.
G is selected by
a
b
G
=
, with 0 < β < 1 and 1 < G < 3.
7.2.4 First-order Element
(Represented by Second-order Block)
The basic continuous-time single lead-lag element is:
b
s
a
s
a
b
+
+
⋅
The discrete equivalent form is:
−
−
⋅
−
−
β
α
α
β
z
z
1
1
SimplIQ for Steppers Application Note
Filters
MAN-STECR (Ver. 1.1)
88