ElmoMC SimplIQ Digital Servo Drives-Bell Command Reference - 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
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