Disturbance compensation in continuous time by sampled data control

This paper points out that whenever a class of disturbances can be compensated in continuous time, then it can also be compensated in continuous time by means of sampled data control with a suitably defined hold function. Sampling patterns can then be chosen essentially independent of the disturbances to be compensated so that, in principle, high-frequency disturbances can be compensated with low-frequency sampling.