Controller transfers materials

Most of today's material-transfer controllers are microprocessor based and use similar logic. However, when the material-transfer controller includes processing "horsepower" to also perform a real-time predictive adaptive control (PAC) algorithm, the controller can hit material transfer targets and do it in the least amount of time.

By Staff January 1, 2003

A 2002 EDITORS’ CHOICE AWARDS WINNER

PROCESS & ADVANCED CONTROL

Most of today’s material-transfer controllers are microprocessor based and use similar logic. However, when the material-transfer controller includes processing ”horsepower” to also perform a real-time predictive adaptive control (PAC) algorithm, the controller can hit material transfer targets and do it in the least amount of time.

That’s exactly what Mettler Toledo (Columbus, OH) is doing with its recently released Q.impact material-transfer controller-adding intelligence to make precise, repeatable material transfers in the least possible time.

Working with Procter & Gamble (P&G, Cincinnati, OH), Mettler Toledo has obtained exclusive rights to the PAC algorithm developed and widely used by P&G to minimize cycle-times, while achieving precise, repeatable material transfers.

P&G’s real-time PAC technology accounts for instrument reading lags; material-in-suspension; valve let-through; material kinetic forces; and uses data to predict the exact moment of cut-off for optimum accuracy. To meet varying application requirements, the Q.impact controller includes:

Spill-only algorithm to control material movements that have very low flow rates;

K1 algorithm to control material movements that have moderate flow rates; and

K2 algorithm to control high flow rates.

Because the PAC algorithm uses real-time adaptive technology, no models need to be developed, and PAC technology automatically tunes the algorithm to compensate for normal variations that occur in each material transfer. Among the variables PAC automatically compensates for are: material density; flow rate; valve characteristics (speed/let-through); and pump performance.

In a PLC or DCS architecture, Mettler Toledo’s Q.impact controller serves as a slave, getting material transfer recipe instructions from the ”master” control system. I/O devices directly involved in material transfers, such as weigh-cells, flowmeters, valves and pumps, are wired directly to the appropriate Q.impact controllers, and a communication handshake is established between the master and the slaves it manages.

www.mt.com

Added intelligence to make precise, repeatable material transfers quickly

Uses Procter & Gamble’s real-time PAC technology

Serves as a slave in PLC or DCS architectures

Click here to view the full list of 2002 Editors’ Choice Awards winners Click here to return to the article introduction