Application of Fuzzy Logic Control

In the polymer extrusion process the product quality §can be achieved by controlling the melt viscosity §within a narrow fluctuation range. On the demand of §using viscosity-measuring instruments as sensors to §control the quality of the products, we developed an §empirical off-line viscosity model, which is used to §derive the extrusion viscosity models in the control §process without in-line rheometer. The objective of §this study is to develop extrusion viscosity models §together with collected data from several §experimental tests and template rule-base to build a §Multi-Input Multi-Output fuzzy logic closed-§loop controller for the plastics extrusion control. §The objective of this controller is to eliminate §process variations and to produce the polymer of §consistent quality. The fuzzy logic is provided for §designing the MIMO closed-loop controller because it §is suitable for applying to the polymer extrusion §process control with such advantages as handling §complex problems like non-linear and poor quality §measurements,etc. An off-line simulation and the §closed-loop tests are performed on the extruder to §test the effectiveness of the MIMO FLC.