An Equivalent Control Based Observer for Biomass in a Batch Process

Abstract

In this paper a sliding-mode observer for a batch bioprocess, the d-endotoxins production of bacillus thuringiensis (BT), is presented. The proposed observer is based on the equivalent control method and a class of second-order sliding mode operators. The use of these operators in the observer design allows the fixed-time convergence of the measured variables, while the unmeasured variables converge exponentially. This structure allows to estimate the biomass in the d-endotoxins production of BT, even, under noisy measurement conditions. Simulations show the feasibility of the proposed observer. Convergence proofs are also presented