Global output regulation of uncertain feedback linearizable systems

A global robust output regulation problem via state feedback is addressed for a family of single input-single output uncertain nonlinear systems in strict feedback form. Assuming that the regulator equations are solvable in a suitable compact set, closed loop L₂ and Linfin robustness properties and global asymptotic output regulation to a reference signal generated by a known exosystem are guaranteed despite bounded time-varying (definitively constant) model parameter perturbations. Robust adaptive output tracking for feedback linearizable systems which may have unbounded uncertain tracking dynamics or may not have a well defined relative degree is achieved.