Extremum Seeking Control For A Class Of Non Hammerstein-wienner Nonlinear Plants
Alessandro Jacoud Peixoto1; Guido José Valenzano Tocaimasa2; Diego Pereira-Dias3; Alessandro Rosa Lopes Zachi4
1 DEL/Poli/UFRJ; 2 PPEEL/CEFET-RJ; 3 LNDC/COPPE/UFRJ; 4 PPEEL/CETEF-RJ
Resumo
This work addresses an extension to the classical design of a perturbation-based extremum seeking control (ESC) method applied to a class of non Hammerstein-Wienner (HW) plants. The original ESC, when applied to a non HW system, requires a strong reduction of the perturbation frequency which can make the ESC be impractical. Two approaches for ESC application are presented: a gradient-reconstruction ESC (GR-ESC) and a pre-compensated ESC (PC-ESC). The first technique is used when some parameters of the plant are known \emph{a priori} or can be estimated by proving the system, while the second one allows to deal with uncertain higher order plants. Based on previous results, the considered class of plants captures the essential dynamic of the Eikrem's model for gas lifted oil wells. In this sense, the application of the proposed ESC schemes to the optimization of oil production in gas lifted oil wells is also addressed. The proposed ESC techniques applied in this context, indicating that it is possible to maintain the oil production around the optimum point of the well-performance curve in gas lifted oil wells without reducing the frequency of the perturbation to forbidden practical values. The closed loop control performance is evaluated via numerical simulations.
Palavras-chave: Extremum Seeking Control; Non Hammerstein-Wienner; Phase-lock-loop; Gas lifted Wells