A New Repetitive Control Strategy in a Liquid Level System

摘要

In this research work, a new attempt is made to implement a Repetitive Control Strategy (RCS) in a Liquid Level System (LLS). First, the liquid level system is approximated into a First Order Plus Time Delay (FOPTD) model by step testing method. RCS is incorporated in the conventional level control loop of proportional (P) mode. Ziegler-Nichols Tuning Rule (ZNTR) based proportional controller parameter is considered in the loop. A periodic signal of sine wave in inflow to the level system is generated and real time runs of the LLS are carried out for the periodic input tracking with RCS based P mode control loop. The performance analysis of periodic input tracking is done. A similar run is carried out with the system having conventional P-mode structure in the control loop. A comparison in the performance analysis clearly indicates that the incorporation of RCS in the control loop in LLS provides a better tracking performance than the conventional P mode. The robustness of RCS incorporation in control loop is also justified with another tuning rule.