The Rider Roll Control System
ensures highly accurate control
RRS microPOS, announced by Nobel Systems Ltd., is a digital,
closed-loop system for controlling nip pressure applied by the
rider roll on paper manufacturing and processing machines.
This system provides uniform hardness and even tension distribution
throughout the reel, thus ensuring consistent quality. Highly accurate
control also reduces the number of web breaks as well as reducing wrinkling.
Prior to applying to the reel to be wound, the rider roll is positioned in
displacement mode to ensure a parallel and rapid switchover. The roll
application is carried out very gently at a reduced speed to eliminate the
risk of damage to the reel. After applying, the system reverts to force control
and will then also monitor any vibrations and counteract reel ejection tendencies.
In the RRS microPOS system, there are six freely programmable force
control curves. The force control curves can also be generated in the PLC
and transferred to the RRS microPOS in analogue form or via Modbus.
The main part of the parameters are entered prior to delivery and the
entire parameter set-up can be stored on a disk.
The RRS microPOS is programmed with a Windows programme on a
standard PC via RS232. The parameters are shown in a menu system
for simple and clear handling.
The servo system comprises servo valves and servo cylinders,
position transducers for position control and load cells supporting the
rider roll to control the line force.
One or two parallel control position transducers continuously measure
the position of the rider roll. The rider roll is moved at maximum speed
until it approaches close to the paper core when its speed is reduced.
The force control mode then commences using the rider roll force
measuring load cells as feedback. The programme also contains six
different core diameters. During the reeling phase, required line force
(nip loading) is controlled by one of six selectable force curves or by an
externally generated desired value from the PC/PLC. The curves are a
function of the roll diameter and the parameters already entered and
can be selected on the basis of paper quality and other factors.
The closed force control means that the load cells measure the actual
roll force and any deviations from the force curves are continually corrected.
After reeling is completed, the system switches to position control and
goes to the waiting mode and remains in position control while waiting
for the next command.
Options available include combinations of one or two axle force and
positioning control.
The system is supplied complete in an integral 1P65 waterproof
enclosure with internal screw terminal connections.
_____________________________________________
For more information, please contact:-
Nobel Systems - Murdock Road, Bedford MK41 7PQ. United Kingdom
Tel: +44(0) 1234 220800 Fax: +44(0) 1234 325387
January 2000 - Ref: MicroPOS/N2322
