Optimal immune PI tuning rules for networked control systems with long time delays

This work presents a novel method for Networked Control Systems (NCS) with long time delays based on proportional-integral (PI) control with an immune feedback algorithm. Moreover, a simple set of tuning rules is presented so that the method can be applied to the simpler and more flexible structure of the PI, which already exists on many of the industrial control systems, and improves its performance while taking advantage of the present architecture. A first-order plus dead time (FOPDT) model is considered due to its simple and sufficiently accurate approximation for industrial applications. Hence, the controller has been optimized for several types of first- order processes, subjected to disturbances and changes of the reference. Experiments using the TrueTime network simulator are provided and, the results comparing the proposed method against the existing one, demonstrate the effectiveness of the proposed PI immune approach in compensating for long time delays while providing disturbances rejection, good performance, and robustness.