Certainty equivalence in nonlinear output regulation with unmeasured error

In this article, we consider a nonlinear output regulation problem in which the controlled output and the measured output are not the same. It is assumed that the controlled plant has a single control input, and that it can be transformed into Gauthier-Kupka's observability canonical form. Then, it is shown that a design based on certainty equivalence is effective for determining a controller that solves the given problem.