Model predictive control algorithms and their application to a continuous fermenter

Abstract

In many continuous fermentation processes, the control objective is to maximize productivity per unit time. The optimum operational point in the steady state can be obtained by maximizing the productivity rate using feed substrate concentration as the independent variable with the equations of the static model as constraints. In the present study, three model-based control schemes have been developed and implemented for a continuous fermenter. The first method modifies the well-known dynamic matrix control (DMC) algorithm by making it adaptive. The other two use nonlinear model predictive control algorithms (NMPC, nonlinear model predictive control) for calculation of control actions. The NMPC1 algorithm, which uses orthogonal collocation in finite elements, acted similar to NMPC2, which uses equidistant collocation. These algorithms are compared with DMC. The results obtained show the good performance of nonlinear algorithms

Discrete Time Nonlinear Controller Design with Guaranteed Asymptotic Stability and Shorter Horizon Lengths

“…Efficacy of the proposed approach for the terminal set characterization and its applicability to NMPC discrete time simulations is demonstrated using the benchmark fermenter system, which is used by several researchers. 26,28,30,33 Choice of Tuning Matrices. To simplify the numerical computation of the terminal set using the LQR based approach, following parametrization is carried out:…”

“…Efficacy of the proposed approach for the terminal set characterization and its applicability to NMPC discrete time simulations is demonstrated using the benchmark fermenter system, which is used by several researchers. ,,, …”

“…Efficacy of the novel LQR based approach is demonstrated using the benchmark fermenter system. Various researchers use this system with identical parameter values for demonstrating their controller performance and stability results (for example, refs − ). However, the literature on the application of QIH-NMPC formulation on the fermenter system with assured asymptotic stability is minimal, and it becomes another novelty of the current work.…”

Dynamics and Control Strategies for a Butanol Fermentation Process

“…The control algorithm used was the dynamic matrix control (DMC), which was able to control substrate and product concentrations. Other examples of successful use of DMC in continuous fermentations include the studies reported by Goochee et al [7], Silva et al [8], and Lunelli et al [9].…”