| Baumüller
makes essential machine functions available
as software modules in the form of the existing
eleven technology modules: From synchronization
and positioning to the cam controller. Together
with Baumüller intelligent drives,
the technology modules provide future-proof,
flexible systems and machines.
The advantages of decentralized
drive systems.
Decentralized drives replace the mechanical
line shaft in complicated mechanical engineering
systems. This structure is more meaningful,
more efficient and generally cheaper, because
individual mechanical modules can be separated
or added and the complexity of the overall
controller is simplified by relocating functionality
into the modules.
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Each mechanical module has
its own automation module consisting of
a controller, a drive amplifier and a motor.
Individual modules can be commissioned separately.
The control system is specific to the respective
mechanical function and is optimized. When
converting to
different product sizes it is therefore
not necessary to change gearwheels and modify
the mechanical system. The adaptation is
taken care of by the software.
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The basic idea for all technology modules
Baumüller presents its technology modules
as an expanding library of software
modules for machine functions. This contains all
of Baumüller’s experience in
high-capacity machinery in the printing, plastics,
packaging and textile industries.
Each technology module is tailored to elementary,
important machine functions
and optimally adapted.
Each technology module records and evaluates
all of the local encoders and sensors of the mechanical
system module and is in fullcontrol of functionality.
An inter-modular bus links numerous mechanical
modules and the b maXX-PLC open and closed loop
control system, acting as the master. This can
be done using standard field bus systems such
as CANopen, Profibus-DP and SERCOS. EtherCAT or
CANsync are the most suitable for a modular
machine with synchronous movements in the individual
modules.
Virtual master axis
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In distributed
machines without a mechanical line shaft
the individual drives are synchronized on
a virtual master, because the movements
are performed more accurately than with
a real master.
The virtual master generates setpoints
without any deviation from the theoretically
ideal shape. There are no signs of the undesirable
velocity fluctuations that always occur
with real axes.
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When operating
with a virtual master, all slaves are synchronized
by a clock signal from the master at the
same sampling point. |
Synchronization
| The
slave axes move at synchronous angles in
relation to a master axis. The position
of the real master axis is recorded by a
resolver, an incremental encoder or a SINCOS
encoder. The maximum resolution is 2,097,152
increments per revolution.
Thanks to the short cycle time, the slave
in the Baumüller synchronization
module tracks master movement changes much
more quickly and accurately than the majority
of other servo controllers. The master axis
for each slave can also be a virtual master.
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The synchronization
function can be dynamically coupled in the
process. |
Elektronic gear unit
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The electronic
gear unit adds gear ratio adjustment to
the functionality of the synchronization.
The gear ratio from 32,767 : 1 to 1 : 65,535
is specified as a quotient from two natural
numbers.
Compared to mechanical gearboxes, the gear
ratio can be changed quickly and finely
tuned.The following are particularly useful
for technology gearbox applications:
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- Rapid gear ratio adjustments
- Switching to a virtual master
- Rapid changeover to another virtual
or real master.
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Dancer controller
The dancer controller extends
the scope of functionality of the „electronic
gear unit“ module. A dancer shaft
that has constant force applied to it keeps
the tensile force in the web constant. The
position of the dancer shaft is recorded
as an actual value.
The dancer shaft is kept within the permitted
position range by correcting the gear ratio
in the “Gear unit” module.
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Cam disk
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The cam disk
links the cyclic movements of a real or
virtual master with the cyclic movements
of a slave via a cam function. The master
and slave cycles can also be of different
durations, but must always be in an integer
ratio to each other.
Each master angle position has a slave
position assigned to it via a table. This
table contains the movement profile (cam)
for the slave axis.
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This table contains
a maximum of 16,384 entries, each with 32-bit
resolution. Several cams can be stored at
the same time. You can switch between cams
with the same number of interpolation points
in the process. Switching over takes place:
- Via an external signal,
- At a preselected angle position,
- Within a certain master angle range.
Switching over can be defined for a certain
movement direction. A special positioning
algorithm subsequently compensates for setpoint
jumps or unsteadiness during a cam change
or when the clutch is being engaged/ disengaged.
The master position can also be specified
via a virtual master. |
Winder
| The winder
operates as a core winder. The tensile force
of the web can have open or closed loop
control. The current diameter is calculated
from the web velocity and the angle shaft
velocities compared with the parameterizable
monitoring thresholds and signaled.
Externally measured values can also be
evaluated.
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The winder can be
set to different winding characteristics:
- Constant tensile force
- Constant torque
- Externally specified tensile force
- Storable winding curve
In controlled operation the following
compensation is possible:
- Compensation for friction loss in dependence
on the velocity (this curve
is either parameterized or recorded in
a self-learning teach-in procedure)
- Compensation for the mass inertia of
the winder when accelerating
and braking
Web breaks are detected by continuously
comparing calculated and measured velocity
values or via an external signal. If a break
occurs the winder is
immediately slowed down to a standstill. |
Positioning
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Static Positioning
Positioning is a basic controller function.
In combination with the PLC, several thousand
positions can be stored or different acceleration
ramps specified, depending on the amount
of memory in the PLC.
Dynamic Positioning
Dynamic positioning contains all of the
functionality of static positioning. A new
setpoint can also be specified during an
active movement process. The drive takes
over the new setpoint immediately.
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A special algorithm
ensures that the transition from the old
setpoint to the new setpoint is continuous
and smooth. |
Register control
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most well-known application for register
control is multi-color printing: All colors
must be accurately printed on top of each
other in successive printing groups.
In order to do this, a mark is printed
at the edge of each copy in the first printing
group. As soon as sensors in the downstream
printing groups detect the mark, the angle
position of the respective printing roller
is stored (Web/cylinder comparison).
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Alternatively,
the register error can also be recorded
in each printing group as
the difference between the reference mark
and the printing groups “own”
mark
(web/web comparison). If the angle position
of the printing group cannot be correctly
aligned, the difference is corrected.Register
control is not just suitable for rotating
systems, but also flat-bed systems that
use linear movements. Instead of aligning
the processing station on the material,
the material itself can be aligned in relation
to the processing station
using the infeed drives (insetting).
Any number of drives can be interlinked
using the register control technology module
in a decentralized system. During operation,
a drive can be removed from the register
control system and put back in again later.
The drive synchronizes itself again automatically
and maintains the register. Register control
is basically suitable for all machines where
a workpiece is distributed over several
stations that move synchronously in relation
to each other and have to process the workpiece
in-register, such as bag forming, filling
and sealing machines and deep-drawing machines.
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Cam controller
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Certain actions
must be triggered depending on a certain
master axis, particularly on machines with
high chopping rates. In a cam controller,
signals are triggered depending on the current
position of the master. The on/off switching
points are freely selectable. Switching
off can also be timer-controlled.
The cam controller also has idle time compensation.
This makes it possible to switch valves
that close slowly at the correct point in
time, for example.
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number of cams is only limited by the amount
of memory in the drive PLC, and can be of
the magnitude of several hundreds. |
Cross-cutter/rotating cutter
The cross-cutter consists
of a synchronous drive with compensation
positioning of a slave axis in relation
to a master axis. The slave axis for the
cross-cutter is linked to the virtual master
via CANsync or can be read in via a real
master in the form of a shaft encoder. The
number of cutters per cylinder circumference
varies between 1 and n.
The cross-cutter can be combined with register
control. This makes it possible to make
variable run-time format changes.
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Flying cut/flying saw
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EiA master
axis moves a product that is moving
toward a certain target point. A slave axis
should
catch up with the master at this target
point, whereby the slave reaches the same
velocity and therefore becomes synchronous.
The slave can be nearer to or further from
the target point than the master. After
the synchronous movement the slave is reset
again or immediately
synchronized to the next target point.
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