ABSTRACT
Feed-forward control can be usefully applied whenever a process disturbance can be measured. Ratio control is a form of feed-forward control found in, for example, blending systems. Feed-forward control is used in a true form, since any increase or decrease in the distillate flow is passed on to the reflux flow. The advantage of the use of equations and in any practical application is that limit checks can be made before feed-forward and feedback incremental control signals are used. This is the necessary security checking part of any advanced control application. Also this form of implementation provides a simple way of incorporating feed-forward control in feedback loops that are dynamically compensated. Therefore the feed-forward paths will be modified to include dynamics in order to fully eliminate the impact of feed changes on concentration. The best way to tune the control scheme is online.
