ElmoMC SimplIQ Digital Servo Drives-Bell Getting Started - Manual (Page 71)

The SimplIQ for Steppers Getting Started & Tuning and Commissioning Guide
MAN-BELGS (Ver. 1.1)
71
Figure 63: An example of unacceptable controller – KI is too large
Guideline 3: The final response should have an overshoot of about 25%, no
undershoot and non-saturating current demand.
0 0.01 0.02 0.03 0.04 0.05
-2
-1.2
-0.4
0.4
1.2
2
x 10
4
Tim e (sec.)
C
o
u
n
ts
/sec.
S peed
Reference
0 0.01 0.02 0.03 0.04 0.05
-4
-2.4
-0.8
0.8
2.4
4
Am
p
e
re
Tim e (sec.)
Figure 64: A small signal step response characterization of a good PI controller. It
should have an overshoot of about 20-30% and a very small or zero undershoot
0.1 0.12 0.14 0.16 0.18 0.2
-1.5
-0.6
0.3
1.2
2.1
3
x 10
4
C
o
u
n
ts
/sec.
Tim e (sec.)
K I=20000,K P =30
K I=16000,K P =30
Reference
0.1 0.12 0.14 0.16 0.18 0.2
-2
-1.2
-0.4
0.4
1.2
2
Am
p
e
re
Tim e (sec.)
K I=20000,K P =30
K I=16000,K P =30