ElmoMC SimplIQ Digital Servo Drives-Bell Command Reference - Manual (Page 220)

The speed command, multiplied by the gain FF[2], is fed as reference to the speed
controller in addition to position correction. Setting FF[2] exactly to the gear ratio
between the position sensor and the speed sensor minimizes the tracking errors.
3.6. Unit Mode 5: Single Feedback Mode
Single feedback mode is used when the same sensor is used for speed, commutation and
position. This setup is quite common and it is used whenever a separate load sensor is
not required.
Σ
Position
command
position
feedback
-
Σ
Speed
estimator
Speed
controller
Position
Controller
DV[2]
Speed
feedback
-
DV[1]
[2]
d
FF
dt
Σ Σ
[1]
d
FF
dt
Figure 3-8: Single Feedback Mode (UM=5)
The Position Reference Generator
The Position controller
The Speed controller
The speed command, multiplied by the gain FF[2], is fed as reference to the speed
controller in addition to position correction. Setting FF[2] = 1 minimizes the tracking
errors.
SimplIQ for Steppers Application Note Unit Modes
MAN-STECR (Ver. 1.1)
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