For nonlinear systems affine in the input with state x ∈ R n , input u ∈ R and output y ∈ R, it is a well-known fact that, if the function mapping (n−1)) is an injective immersion, then the system can be locally transformed into an observability normal form with a triangular structure appropriate for a high-gain observer. In this technical note we extend… (More)
—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.
—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)
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)