FUZZY CONTROL OF BAKERS-YEAST FED-BATCH BIOPROCESS - A ROBUSTNESS STUDY

The purpose of the investigation was to determine if, based on the monitoring of the residual substrate concentration, fuzzy control is an effective way of controlling a fermentation process. Various simulations were made using a knowledge model, first to evaluate the performance of the control for the biomass concentration, and then to analyze how it reacted in the presence of disturbances. Results showed high final productivity and biomass concentration. Despite different disturbances, as the feeding glucose concentration changed or the temporary substrate feed-rate increased, the fuzzy controller provided process stability and robustness near the set-point. Moreover, these properties were maintained in the case of noisy measurements.