Robust stabilizing simple multi-period repetitive controllers for multiple-input/ multiple-output time-delay plants

The simple multi-period repetitive control system proposed by Yamada and Takenaga is a type of servomechanism for a periodic reference input. That is, the simple multi-period repetitive control system follows the periodic reference input with a small steady state error, even if a periodic disturbance or uncertainty exists in the plant. In addition, simple multi-period repetitive control systems ensure that the transfer functions from the periodic reference input to the output and from the disturbance to the output have a finite number of poles. Yamada et al. clarified the parameterization of all stabilizing simple multiperiod repetitive controllers. Recently, Sakanushi et al. proposed the parameterization of all robust stabilizing simple multi-period repetitive controllers for multiple-input/multiple-output plants with uncertainty. However, their method cannot be applied to time-delay plants. In this paper, we propose the parameterization of all robust stabilizing simple multi-period repetitive controllers for multiple-input/multiple-output time-delay plants.