ABB ACSM1 Series, Manual

Page: 64 / 510

Drive control and features
64
Position profile generator
The position profile generator moves the position reference to the selected target
position, taking the positioning speed acceleration/deceleration into account. The
generator continuously calculates the speed from which the drive can decelerate to
a stop within the target distance using the defined deceleration reference.
Acceleration reference is used at start of positioning to increase the positioning
speed until reference speed or calculated speed is reached. The calculated speed is
used to generate the optimised position reference, which guides the drive to its
target position. The filtering is performed by a moving average filter, a Finite Impulse
Response (FIR).
The following figure shows how the position profile generator generates a position
reference.
The position profile generator is also used to compensate for synchronisation errors
in synchron control and for position correction errors in position control. Errors can
be caused by
• dynamic limitation of position reference change, or
• cyclic correction of position difference measured by external latches.
PGG
FIR
Pos. reference
Pos. speed
Acceleration
Deceleration
Pos. filtering time
t
t
t
65.06 PROF ACC 1 / 65.14 PROF ACC 2
65.07 PROF DEC 1 / 65.15 PROF DEC 2
4.13 POS REF IPO
4.20 SPEED FEED FWD
Target position reference
Position speed reference