SLIDING MODE CONTROL DESIGN FOR CONTINUOUS YEAST FERMENTATION PROCESS

Fermentation is known to be highly nonlinear process. The problem of controlling them by using conventional controllers has been widely studied; in spite of the extensive work on self tunning controllers there are many problems in the processing industries for which current techniques are inadequate. This paper presents the application of sliding mode controller with First-Order-Plus-Dead-Time model approach to a continuous yeast fermentation process in wine making. Objective is to control the temperature of fermenter by controlling the jacket flow rate. The effect of change in the temperature on the concentration of yeast, concentration of glucose and concentration of alcohol are analyzed. This approach results in fixed structure controller with a set of tuning equations as a function of the characteristics parameter of the model. The simulation results of the SMCr are compared with the PI controller for setpoint changes and load disturbance changes and have shown that SMCr is better and more versatile.