Abstract:

A nonlinear dynamical system is proposed to formulate the microbial fedbatch fermentation process of 1, 3-propanediol (1, 3-PD) production. Taking the 1, 3-PD concentration at the terminal time as the performance index and the feed rates of glycerol and alkali as the control function, an optimal control problem subject to constraints of state and control is presented. A solution method is developed to seek the optimal feed rates based on control parameterization method and modified differential evolution algorithm. Numerical results show that the concentration of 1, 3-PD at the terminal time can be considerably increased compared with previous results.

Key words: nonlinear dynamical system; optimal control; control parameterization; modified differential evolution; fed-batch culture