A COMPUTER CONTROL ALGORITHM FOR FEEDBACK COMPOSITION CONTROL USING OFF-LINE ANALYSIS

A tunable feedback control algorithm is developed for a first-order pl us dead time process which has a variable sample interval and a variab le dead time. This variable sample interval, variable dead time (VSIVD T) controller is applied to controlling the product composition of a b lender using off-line composition analysis. The blender and controller s are simulated using the IBM Real-Time Process Management System/Adva nced Control System (RTPMS/ACS). The VSIVDT controller performed bette r than an alternative controller based on the Dahlin algorithm which u ses off-line analysis. When compared to controllers using on-line anal ysis, it performed as well as a PI controller but not as well as a con troller using the Dahlin algorithm.