This paper is concerned with the structure of
asymptotically
stabilizing feedbacks for a nonlinear control system
on $\mathbb{R}^n$.
We first introduce a family of discontinuous, piecewise smooth vector fields
and derive a number of properties enjoyed by
solutions of the corresponding O.D.E's.
We then define a class of “patchy feedbacks”
which are obtained by patching together a locally finite
family of smooth controls.
Our main result shows that,
if a system is asymptotically controllable at the origin, then
it can be stabilized by a piecewise constant
patchy feedback control.