—In this note we deal with a new observer for nonlinear systems of dimension n in canonical observability form. We follow the standard high-gain paradigm, but instead of having an observer of dimension n with a gain that grows up to power n, we design an observer of dimension 2n − 2 with a gain that grows up only to power 2.
The paper deals with the problem of output regulation for the class of multi-input multi-output square nonlinear systems satisfying a minimum-phase assumption and a " positivity " condition on the high-frequency gain matrix. By following a design paradigm proposed in  for single-input single-output nonlinear systems, it is shown how an internal… (More)
—We address a particular problem of output regulation for multi-input multi-output nonlinear systems. Specifically, we are interested in making the stability of an equilibrium point and the regulation to zero of an output, robust to (small) un-modelled discrepancies between design model and actual system in particular those introducing an offset. We propose… (More)