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 a ProtoLink-developed 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.