Nonlinear Control of a Batch Reactive Rectifier

This article considers the issue of designing a nonlinear control strategy for a batch reactive rectifier. The hybrid control strategy consists of a state estimator, namely Luenberger-like nonlinear estimator (LNE) and the feedback linearizing controller (FLC). The LNE observation scheme aims to estimate the imprecisely known parameter (augmented state) along with the unmeasured state using the available state information. The state predictor includes only two ordinary differential equations and is formulated based on the component continuity equation around the condenser-reflux drum envelope. It implies that the predictor model is not a perfect representation of the actual process. For effective handling of this structural discrepancy, the corrector model is coupled with the predictor in the LNE estimator. The next part of this article synthesizes the FLC controller for the example system. A comparison is made in terms of closed-loop performance between the FLC-LNE scheme and gain-scheduled proportional integral (GSPI) controller. Extensive simulation results reveal that the proposed structure appears to be a promising approach to the control of the batch distillation column.