ElmoMC SimplIQ Software Manual - Manual (Page 223)

SimplIQ Software Manual The Controller
MAN-SIMSW (Ver. 1.4)
15-5
15.2 The Position Controller
15.2.1 Block Diagram
The position controller comprises a proportional gain, cascaded over the speed controller.
The block diagram is given in the following figure.
DV[3]
Σ Position
com m and
-
Speed com m and
(DV[2], Am p) Position
Controller
KP[3],GS[9]
Σ
FF[2] d/dt
Autom atic
Controller
Selector
0
Fixed if
GS[2]=0
Main Position
sensor
Auxiliary Position
Sensor
Position feedback
UM=4
UM=5
Com m andPi ePos
Figure 15-2: Position Controller Block Diagram
The reference to the speed controller is composed of the derivative of the position command
(speed) and of the output of the auxiliary position controller. The derivative of the position
command is multiplied by the FF[2] factor in order to eliminate tracking errors at steady
speed.
The gain scheduler can be used or the gains of the controller can be fixed, setting GS[2]=0.
The high-order filter can be used or not. To avoid the use of the high-order filter, set
KV[0]=0.
The same controller is used for single-feedback mode (UM=5) and for the dual-feedback
mode (UM=4). Use the single feedback mode when there system includes only one sensor,
for commutation, speed and position sensing. Use dual-feedback mode when the load is
driven through a gear, and where a separate load sensor enables precise load positioning
despite backlash and gear compliance.