Siemens SINAMICS RAILCTRL, Function Manual

Page: 38 / 106

5.3 Open-loop controlled operation
In open-loop controlled (encoderless) operation, the segment transition is specified by the
higher-level control system.
Function description
The following controlled variables are copied between the two SERVO drive objects for
coupling the segments:
● Commutation angle
commut_angle (r30486)
● Velocity setpoint
v_set (r0062)
The copy direction depends on the transferred control word (p30475).
The coupling of SERVO drive objects in open-loop controlled operation is shown in function
diagram "7365 – SERVO coupling in open-loop controlled mode, structure (Page 77)".
Oscillation damping
In open-loop controlled operation, the segment and the carrier form a system that is capable of
oscillation. To ensure an optically smooth traversal of the carriers, the open-loop controlled
operation also has an oscillation dampening, not only for traversing on a single segment, but
also at a segment transition.
For effective oscillation dampening at the segment transition, in addition to the listed controlled
variables, the following variables are copied between the SERVO drive objects:
● Induced voltage in the longitudinal direction
Ud_long_set (r1732)
● Induced voltage in the transverse direction
Uq_transv_set (r1733)
Function description
5.3 Open-loop controlled operation
RAILCTRL
36
Function Manual, 09/2019, A5E38120767B