Robust stability investigation of process control via Monte Carlo Method

The industrial process control systems usually encounter the time delay. Commonly, such the systems are controlled by the industrial PID controllers consisting of proportional-integral (P-I) elements existing in forward path for input tracking and load regulating proposes, and derivative (D) element existing in feedback path to reduce noises. Under harsh industrial environment, the process model is subjected to parameter variations. It is worthwhile to investigate the robustness of the controlled systems. This paper proposes robust stability and robust performance investigation of the process with time delay controlled by the industrial PID controller, designed by the adaptive tabu search (ATS). Based on the Monte Carlo method, it was found that the stability robustness of the controlled system is assured within plusmn30% of model parameter variations.