PH control using sliding mode Observer design and Comparison with the PI and GSPI

In this paper, the pH control solution is considered in a laboratory reactor. A prototype of an acid and an open stream is continuously coupled to the reactor tank in an appropriate proportions is used for PH process control then, according to the PEM table, the equation of the pH state is obtained after that with Optimizing the PI coefficients, the PI controller is designed. The classic PI controller was not able to control this process, so the state-of-the-art observer was used, which was able to control with high precision. The proposed observer estimates state variables with extreme precision due to linear design. In the design of non-linear observation, sliding mode control is used. This method is suitable for estimating the state variables of the non-linear nonlinear systems, but due to the occurrence of chattering, its efficiency is greatly reduced. In order to prevent chattering and also to increase the accuracy, the second-order slip-off theory of the flicker is used to design non-linear observation. Finally, a nonlinear viewer is designed and simulated by using of modeling theory.