Types of Controllers,Fee-dba-ck control configuration,Inferential control configuration,Feedforward control configuration

Fee-dba-ck control configuration:

Uses direct measurements of the controlled variables to adjust the values of the manipulated variables. The objective is to keep the controlled variables at desired levels

Inferential control configuration:

Uses secondary measurements, because the controlled variables are not measured, to adjust the values of the manipulated variablesThe objective here is to keep the (unmeasured) controlled variables at desired levels.

The estimator uses the values of the available measured outputs, along with the material and energy balances that govern the process, to compute mathematically (estimate) the values of the unmeasured controlled variables.

These estimates in turn are used by the controller to adjust the values of the manipulated variables.

Feedforward control configuration

Uses direct measurements of the disturbances to adjust the values of the manipulated variablesThe objective here is to keep the values of the controlled output variables at desired levels.