Bosch rexroth MCL, Project Planning Manual

Page: 191 / 206

Velocity loop integral action time
(integral part)
For velocity loop integral action time (integral part), the following possibilities
must be taken into consideration:
Possibility 1 Possibility 2 Possibility 3 Possibility 4
Alignment of length
measuring systems
and guides
ideal not ideal not ideal not ideal
Integral part in both axes in both axes in one axis only in no axis
Behavior of the axes Tensioning of the me‐
chanical system is not
realized as both mo‐
tors ideally follow the
position command val‐
ue
Both axes work
against each other un‐
til compensation via
the mechanical cou‐
pling or until the maxi‐
mum current is
reached at one or both
drive controllers and
no more control effect
can be achieved
The axis without inte‐
gral part allow continu‐
ous position offset.
The position offset de‐
pends on the stiffness
of the mechanical cou‐
pling of both axes as
well as the proportional
gains in the position
and velocity control
loop
Both axes allow contin‐
uous position offset.
The position offset de‐
pends on the propor‐
tional gains in the posi‐
tion and velocity con‐
trol loop
Tab. 14-7: Parametrization of the velocity loop integral action time S-0-0101 at
Gantry axes.
Optimization
For optimization of velocity and position control loop, the above-described
procedure must be observed.
Parameter changes during optimization of Gantry axes must al‐
ways be carried out at both axes. If this is not possible, the pa‐
rameter changes during optimization should be carried out subse‐
quently in small steps at both axes.
14.7.3 Estimating the moved mass using a velocity ramp
The moving weight of a machine slide is often not precisely known. This may
be obstructed by subsequently installed attachments, moving components,
etc.
The procedure described below enables estimation of the moved axis mass
according to recording of a velocity ramp. For example, this enables estima‐
tion of the acceleration capacity of the axis.
Preparation
Precondition for positioning is oscillographical representation of the following
parameters:
●
S-0-0040, Velocity actual value
● S-0-0080, Torque/force command value
For this purpose, an oscilloscope or the oscilloscope function of the drive can
be used in combination with IndraWorks or NC.
MCL Ironless Linear Motors 183/197
Commissioning, operation and maintenance
R911330592_Edition 06 Bosch Rexroth AG