ElmoMC SimplIQ Software Manual - Manual (Page 224)

SimplIQ Software Manual The Controller
MAN-SIMSW (Ver. 1.4)
15-6
15.2.2 Position Controller Parameters
The position controller is implemented as a cascaded loop: The inner loop is a speed
controller and the outer loop is a simple gain. The simple gain operates on the position error
e
POS
(t):
) ( ) ( ) ( t k PosFeedbac t PosCommand t e
POS
− =
[counts]
to give [Internal speed units] ) ( ) ( t e K t CommandPI
POS
Out
P
⋅ = /
However, when the position error e
POS
(t) is too large, the gain is modified to avoid
instability and Out
P
K is replaced by:
)) ( ( ) )) ( ( 2 )), ( ( min( t e sign t e abs t e abs K
POS POS POS
Out
P
⋅ ⋅ ⋅ ⋅ α
.
where ] 9 [ 2 GS
= ⋅ α
.
This formula ensures that the speed controller is not required to decelerate beyond
 counts/second
2 . GS[9] must be calculated with  as 80% of the highest deceleration the
motor can produce with the current PL[1].
The inner loop is a speed controller, described previously in this chapter.
The parameters of the non-scheduled position controller are:
Parameter Description
KP[3] Proportional gain, Out
P
K .
GS[2] Controller gain selector.
GS[9] Acceleration limit.
VL[2], VH[2] Maximum speed command.
VL[3], VH[3] Maximum position command.
FF[2] Speed feed-forward.
UM For UM=4, the position feedback is taken from the auxiliary encoder.
For UM=5, the position feedback is taken from the main encoder.
… All parameters of the speed controller.
Table 15-4: Non-scheduled Position Controller Parameters