Hypertracking beyond the Nyquist frequency
We study the problem of tracking or disturbance rejection for signals beyond the Nyquist frequency in the sampled-data context. Given the well-established sampling theorem, one is inclined to infer that it is possible to track or reject only those signals below the Nyquist frequency. However, such a high-frequency signal may be detected as an aliased signal, and this opens a new possibility in tra