The cultivation of microalgae in photobioreactors (PBRs) is important in various sectors such as food, bioenergy, pigments, and cosmetics. Productivity optimization can be achieved without the need for a dynamic process model using model-free extremum seeking control (ESC). This article explores the use of ESC to drive the productivity of a continuous PBR to optimal or suboptimal setpoints. The latter can be achieved by estimating on-line the gradient of a measurable performance index using a recursive least squares estimator and by regulating this gradient to a specific value (zero corresponding to the optimum) using the dilution rate as a manipulated variable. Experimental results for the cultivation of the microalgae Scenedesmus obliquus in a lab-scale flat-panel PBR are discussed. They show the fast convergence of ESC and its robustness towards environmental perturbations, such as changes in the incident light intensity.

中文翻译：

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极值控制在连续光生物反应器中斜栅藻微藻培养中的实验应用

在光生物反应器 (PBR) 中培养微藻在食品、生物能源、颜料和化妆品等各个领域都很重要。无需使用无模型极值搜索控制 (ESC) 的动态过程模型即可实现生产率优化。本文探讨了如何使用 ESC 将连续 PBR 的生产力提高到最佳或次优设定点。后者可以通过使用递归最小二乘估计器在线估计可测量性能指标的梯度并使用稀释率作为操纵变量将该梯度调节到特定值（零对应于最佳值）来实现。斜栅藻微藻培养试验结果在实验室规模的平板 PBR 中进行了讨论。它们显示了 ESC 的快速收敛及其对环境扰动的鲁棒性，例如入射光强度的变化。