Robustness Analysis of Multirate Control Systems in the Frequency Domain

This paper analyzes robustness of multirate control systems with fast control sampling rate and slow output measurement rate in the frequency domain. It is shown that the multirate control is characterized by manipulating the system frequency response in high frequency subbands and folding the high frequency subband response to the base frequency band. This amplifies the system loop gain in high frequency subbands leading to deterioration of system robustness stability under the uniform plant model perturbation.