2017 International Forest Industries Magazines June July 2017 | Page 40

LUMBER PROCESSING
SAWLINES – DELTA COMPUTER SYSTEMS
Delta Computer Systems’ new RMC200 motion controller can perform
closed loop control of up to 32 axes simultaneously
A smooth operation
and limited
interruptions can
trump the pursuit
of pure speed in the
sawline
M
ill operators and
equipment suppliers alike
are finding that smoothing
out the production process can
lead to an increase in productivity
and a reduction in waste material
generated by the processing line.
Smoother processing happens
when the line is tightly integrated
such that material proceeds in lock
step, i.e., ‘just in time’ between
process stages. In an integrated
sawline, the process of producing
finished lumber begins with log
infeed scanning, log turning and
positioning, then primary and
secondary breakdown, with the
processing sequence assisted by
motion controllers to maximize
productivity.
In an integrated veneer
processing plant, multiple motion
axes must be controlled precisely
to peel the logs and guide the
sheet output from the lathe
smoothly into the clipper and on
to the grading system and sorting/
stacking hardware.
By matching the speeds of
all the process steps, gaps in
production and material overruns
don’t occur. The most productive
and most efficient machines don’t
necessarily need to run at full
speed. Smoothing the process
flow can save energy and reduce
maintenance costs by minimizing
shock on the systems, and it can
also reduce the stress put on
machine operators.
Getting all the moving parts of
an integrated processing line to
move in synchrony is often not a
trivial task for system integrators,
34 International Forest Industries | JUNE / JULY 2017
New 32-axis
motion controller
enables
integrated
processing lines
however. It starts with setting
up closed-loop control of all the
motion elements. Then, a means
must be provided for the motion
control system in each stage of
the process to communicate with
processing stages up and down
the line.
A PLC is often used to
coordinate the motion, but time
delays will occur as process status
information and commands are
passed up and down the control
system hierarchy and inefficiencies
in processing can result. Such
delays can be eliminated if the
motion stages can communicate
directly with one another.
A fleet of motion control units
could be employed to automate
the whole process, and many
integrated processing lines do
this, however the economics of
implementing a large number of
motion axes suggests that the
lowest system cost can be obtained
by employing motion controllers
that can support a large number of
axes with a single controller.
To meet the growing motion
control needs of multi-axis forest
products applications, Delta
Computer Systems of Battle
Ground, Washington, has built on
its history of best-in-class electro-
hydraulic motion control products
to develop the New RMC200
motion controller (See Figure 1).
The RMC200 allows up to
32 axes to be controlled and
synchronized simultaneously by
a single controller, making the
Delta RMC200 the most capable
electro-hydraulic motion controller
available today.
RMC200 uses the same
software and firmware as the
company’sRMC75 (1 or 2 axes)
and RMC150 (up to 8 axes)
motion controllers to synchronize
multiple axes, for use in machines
demanding smooth motion and
scalable performance.
Also like Delta’s other
controllers, RMC200 provides
built-in support for controlling
We developed the RMC200 to deliver the
capabilities and ease-of-use of our motion
controllers to customers that increasingly
need more axes than we have offered in one
controller in the past
Steve Nylund, Delta Computer Systems, Inc.