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论文类型：期刊论文
发表时间：2013-02-01
发表刊物：APPLIED MATHEMATICAL MODELLING
收录刊物：SCIE、EI
卷号：37
期号：3
页面范围：695-706
ISSN号：0307-904X
关键字：Nonlinear dynamical system; Optimal control; Control parametrization enhancing transform; Constraint transcription; Fed-batch fermentation
摘要：The main control goal in fed-batch fermentation is to get a high concentration of production. In this paper, a new nonlinear dynamical system, in which the feed rate of glycerol is the control function and the switching instants between the batch and feed processes are the variables, is proposed to formulate the fed-batch fermentation process of glycerol bio-conversion to 1,3-propanediol (1,3-PD). To maximize the concentration of 1.3-PD at the terminal time, an optimal control model involving the nonlinear system and subject to the continuous state constraints and the control constraint is presented. To seek the optimal solution of the constrained optimal control problem, the control parametrization enhancing transform together with the constraint transcription technique is first used to convert the constrained optimal control problem into a sequence of mathematical programming problems. An improved Particle Swarm Optimization is subsequently constructed to solve the resultant mathematical programming problem. Numerical results show that, by employing the obtained optimal strategy, 1,3-PD concentration at the terminal time can be increased considerably. (C) 2012 Elsevier Inc. All rights reserved.