The Robustness of Pi & Pid Controllers in the Presence of Sampling Jitter

Variations in sampling time, or sampling jitter, is a common industrial control problem. This paper investigates the performance of industrial PI and PID controllers in the presence of sampling jitter. The commonly employed controller performance assessment (CPA) benchmark index is used on a wide variety of industrial plant models to show that while the PI control is relatively immune to jitter, the derivative component of the PID controller causes the PID controller to exhibit excessive sensitivity to sampling jitter, although this can be partially compensated by appropriate filtering.