Design of robust PID controller for a CSTR plant with interval parametric uncertainty using Kharitonov theorem

A parameter-plane method based on Kharitonov theorem for the design of a robust proportional integral derivative (PID) controller for the control of a chemical continuous stirred tank reactor (CSTR), which is an example for a plant with interval parametric uncertainty, has been presented in this paper. A locus of the stability boundary is plotted for each of the four Kharitonov vortex polynomials in the K
_P
versus K
_I
parameter plane. An intersecting stability region is identified in the KP-KI plane from which the parameters of the stabilizing PID controller are obtained. Simulation results show that the designed controller successfully stabilizes and improves the performance of the uncertain system under consideration.