Fractional filter based internal model controller for non linear process

Abstract

Recently, fractional calculus found its applications in the field of process automation. Here the mathematical perspectives of fractional property are utilized to control the process. This article presents a design of fractional filter based internal model controller (IMC) for the nonlinear process. The process chosen is pH process plays significant role in the industrial applications. Control of pH process is highly challenging due to its severe nonlinear characteristics and process uncertainty as echoed in the titration curve. An attempt has been made to design the fractional filter based IMC controller for pH process based on desired phase margin and cross over frequency using MATLAB-SIMULINK. Here Oustaloup approximation technique is used to approximate the Fractional filter. Servo and regulatory performance of the process are analyzed and reflects that better control actions are achieved by the fractional filter based IMC through simulation and it is found to be satisfied.