Abstract
This paper is concerned with continuous repetitive control systems for plants with delay. The stabilization of modified repetitive control systems with a low-pass filter in the servocompensator is considered on the basis of frequency response method. It is shown that a series compensation with small gain for repetitive control of delay-free systems is directly applicable to delay systems without any predictors, whereas the conversion speed is very slow. It is also shown that for giving good responses in the case of delay plants, a predictor is required for repetitive control systems with one degree of freedom in the presence of delay, and two predictors for the systems with two degrees of freedom. A scheme for repetitive control systems with predictors is presented. The steady state characteristics of the control system ard similar to those of delay-free case except that the output follows the periodic refrence input with delay.
