ABSTRACT
Emerson Process Management (Delta-V Fuzzy), Gensym, Invensys, (Connoisseur), MATLAB®, Matrikon (Control Performance Optimizer), Modicon PLC (Concept), Yokogawa.
SUMMARY
We often use “IF-THEN” statements in automation. For example, “IF the discharge receiver is full, THEN switch to the next tank.” Or, “IF the ¶ow rate is in the 300-500 kg/h range, THEN use 5%/kg/h for the controller gain.” Or, “IF the temperature is near the safety limit, THEN switch to the auxiliary controller.” However, such logical moves abruptly switch from one condition to another. Smooth transitions are desirable. For example, in stopping a car, we progressively increase breaking force and then progressively lighten up when approaching the stop point. We do not instantly switch breaks to full-on and then full-off. Fuzzy logic (FL) permits the automation of smooth transitions.
