A Linear Matric Inequality based Multi-loop PI control Design for Coupled Multivariable Liquid Level System

Abstract This paper presents design and development of a optimal robust PI controller design based on a linear matrix inequalities for a typical industrial process control system.In this method, the design problem has been transformed into a state feedback controller design problem for an augmented uncertainty MIMO system and further, the control problem can be solved by employing constraint optimization problem by satisfying defined LQ cost objective function. To illustrate robust stability, the study incorporates multiplicative input and output uncertainty. Simulation results verify the efficacy of the proposed controller , presenting its effectiveness in achieving both set-point accuracy and disturbance attenuation. Furthermore, the study employs disk margin analysis to ascertain safe ranges for gain and phase margin.