Robust Control of a Laboratory Process

The paper presents robust control of a laboratory transport delay process using the industrial control system SIMATIC. Due to varying transport delay the laboratory process is modeled as a system with interval parametric uncertainty. The process is identified in the form of a transfer function. The Taylor expansion of the transport delay term leads to interval polynomials. Robust PI controllers are designed for the laboratory process. The robust synthesis method is based on plotting the stability boundary locus in the (kp, ki) – plane and the subsequent choice of a stabilizing PI controller using the pole-placement method so that the prescribed quality of control is achieved.