Simulation of L/A control in fed-batch culture of baker's yeast

L/A controllers have extended their use from continuous to fed-batch fermentation where the control is applied from the start of an initial batch phase. As opposed to proportional integral derivative (PID) controllers where even a startup procedure is recommended prior to fed-batch, the L/A controller is not upset by an early connection. It is easily retuned continuously by means of ethanol measurements and can cope with a large range of output conditions. The performance of an L/A algorithm, which uses biomass concentration as the controlled variable, is assessed through simulation. The self-contained algorithm is relatively simple with no greater intrinsic complexity than modern PID stand alone controllers.