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Control upgrade downgrades variances |
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By: Carl Kirkland
A structural foam molder reduced a 7-second variation in cycle time to less than 50 msec by adding a closed loop hydraulic motion controller to an open loop machine.
A Model RMC100 motion controller from Delta Computer Systems Inc. (Vancouver, WA) was interfaced with the machine’s open loop Maco 8000 machine control to provide closed loop control over the injection unit’s hydraulic cylinders.
Maintenance Solutions Inc. (Kendallville, IN) performed the upgrade for DeKalb Molded Plastics Inc. (Butler, IN). Maintenance Solutions programmed the RMC100 to interface directly with all of the transducers and the proportional valve. It also designed and wrote the software for the RMC100’s ability to interface with the GUI, using Delta’s RMCWin configuration software package.
The GUI displays actual vs. target injection position, speed profiles, and valve-drive commands as an X-Y graph plot. Process control loop parameters, such as integral loop gains, other setpoint values, and storage by name can be created, edited, and retrieved in Microsoft Access. Officials at DeKalb say they hope to upgrade their other machines in a similar manner in the near future.
IMM - September 2004
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