Fuzzy Sliding Mode Control for a pH process

Abstract

Tuning of a pH process is a challenging problem due to the strong on-line non-linearity and extreme sensitivity to disturbances of the process. Hence, a nonlinear control strategy based on sliding mode, which is a standard approach to tackle the parametric and modeling uncertainties of a nonlinear system, is chosen for tuning a pH process. Fuzzy Sliding Mode Control (FSMC) as a robust and intelligent nonlinear control technique is proposed to control processes with severe nonlinearity and unknown models. The proportional and integral constants are adjusted by new tuning rule of fuzzy to adapt with the extreme condition of process. Sliding mode control is introduced into classical model free Fuzzy Logic Control(FLC) for discrete time nonlinear systems with uncertainty to design a novel fuzzy sliding mode control to meet the requirement of necessary and sufficient reaching conditions of tuning a pH process. The simulation results show that the proposed controller outperforms the classical fuzzy logic controller in stability, convergence and robustness. Here Sliding Fuzzy logic control for obtaining the optimal design of the pH process is explained. The performance of the algorithm in obtaining the optimal tuning values has been analyzed in pH process through computer simulation.