DWT based repetitive controller for tracking of periodic reference signal

The objective of this work is to apply repetitive control strategy in an existing laboratory based Liquid Level System for tracking of periodic trajectories applied in the set point or rejecting periodic disturbances with known period. This paper deals with different conventional control techniques and repetitive control strategy for the Liquid Level System (LLS). The main objective of this paper is to demonstrates in steps the ways of design and implementation of Repetitive Control System (RCS) for the plant and in advance an attempt have been taken to reduce the memory size of the repetitive controller by the application of Discrete Wavelet Transform and Inverse Discrete Wavelet Transform in the repetitive control loop i.e. Discrete Wavelet Repetitive Control System (DWRCS) is experimented. Comparisons in terms of performances in both time & frequency (using bode plot) domain are done to show the effectiveness of the DWRCS over the traditional ideas.