Pid Controller Tuning for Integrating Processes: Analysis and New Design Approach

This paper discusses PID controller tuning for integrating processes with time-delay and first order lag. Most of the existing tuning rules for this kind of processes have the same general structure, and the properties of these rules are discussed especially in connection with varying time-delay systems. The paper proposes a novel tuning method that optimizes the closed-loop performance with respect to certain robustness constraint while considering the delay variance via jitter margin maximization. Further, we develop new PID controller tuning rules based on the tuning method. The paper discusses the new tuning rules in detail and compares them with some of the recently published results. The work was originally motivated by the need for robust but simultaneously well performing PID controller tuning parameters in an agricultural machine case process. We also demonstrate the superiority of the proposed tuning rules with this case process.