  The paper is concerned with the stability of the set of trajectories of a
vector field, in the presence of impulsive perturbations. Patchy vector fields
are discontinuous, piecewise smooth vector fields that were introduced in AB to
study feedback stabilization problems. For patchy vector fields in the plane,
with polygonal patches in generic position, we show that the distance between a
perturbed trajectory and an unperturbed one is of the same order of magnitude
as the impulsive forcing term.
