ProtoLink developed a control system to optimally route potato chips through
the conveyor network of a large food processing plant. The goal of the project
was to send exactly the right amount of product to two "seasoned" loops without
concern for what was "left-over" for a third "plain" loop.
We implemented a mass balance control strategy to balance the amount of product
being directed to each seasoned loop with the amount of product capable of
being consumed or "pulled" by the packaging machines drawing from each loop.
Control was accomplished by manipulating product diverters located at key
positions in the conveyor network.
Our role in this project involved project management, design, implementation,
testing, and training. We developed a C++ application to retrieve packaging
machine information from our Ishida32 DDE Server and
an Oracle database. This application computes the desired product pull for each
packaging line using ProtoLink-developed algorithms and writes that information
to an Allen-Bradley PLC at a configurable interval. We programmed the PLC to
perform the following functions:
- serve as the central data repository for the system
- manipulate I/O data
- compute total pull for each seasoned loop
- set up parameters for an adaptive process control (APC) application
- route APC results to a diverter control panel
- implement manual diverter control
- monitor the health of other system components
We configured the APC application which provides the closed-loop control
functionality. Finally, we implemented a Wonderware InTouch application to
provide a graphical view of the process and serve as the operator interface to
the system.
This successful project resulted in improved plant productivity and reduced
customer stale complaints.
