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论文类型：期刊论文
发表时间：2016-12-01
发表刊物：JAPAN JOURNAL OF INDUSTRIAL AND APPLIED MATHEMATICS
收录刊物：SCIE、EI、Scopus
卷号：33
期号：3
页面范围：683-700
ISSN号：0916-7005
关键字：Continuous fermentation; 1, 3-propanediol; Sensitivity functions; Nonlinear switched system; Switching optimal control
摘要：Considering both extracellular and intracellular environments, we propose a nonlinear switched system composed of 16 modes based on the different metabolic mechanism to model the microbial continuous fermentation process of glycerol to 1,3-propanediol (1,3-PD). The existence and continuity of sensitivities of the system states with respect to the decision variables and unknown parameters are discussed. Taking the dilution rate and the feeding glycerol concentration as control variables, the sensitivity functions as constraints, an optimal control problem is presented with the concentration of 1,3-PD at the terminal time as performance index. According to sensitivity analysis, we obtain the gradient formulas of performance index and constraints with respect to the decision variables and the parameters to be identified. The sequential quadratic programming algorithm is adopted to seek a numerical solution. Numerical results indicate that under the obtained optimal dilution rate and feeding glycerol concentration, the productivity of 1,3-PD at the terminal time is increased significantly.