Robust PID Controller Design for Unstable Processes with Parametric Uncertainty

AbstractThe paper presents a method for robust PI controller design for system affected by parametric uncertainty. The proposed method is based on plotting the stability boundary locus in the plane of controller parameters that is called (kp, ki) - plane. The design approach is verified using simulations of control of the continuous stirred tank reactor (CSTR) with hydrolysis of propylen oxide to propylene glycol. The reactor which has three uncertain parameters is controlled into its unstable steady-state