IFAC Workshop on Lagrangian and Hamiltonian Methods for Nonlinear Control. Reprint. On Perturbation Methods for Mechanical Control Systems

In this note we investigate open-loop control of under-actuated mechanical systems and draw connections be-tween averaging and controllability theory. Two sets of results are presented: averaging under high-amplitude high-frequency forcing, and series expansions for the evo-lution of a forced mechanical system starting at rest