Stabilization of instable periodic orbits of nonlinear dynamical systems has
been a widely explored field theoretically and in applications. The techniques
can be grouped in time-continuous control schemes based on Pyragas, and the two
Poincar\'e-based chaos control schemes, Ott-Gebogi-Yorke (OGY) and difference
control. Here a new stability analysis of these two Poincar\'e-based chaos
control schemes is given by means of Floquet theory. This approach allows to
calculate exactly the stability restrictions occuring for small measurement
delays and for an impulse length shorter than the length of the orbit. This is
of practical experimental relevance; to avoid a selection of the relative
impulse length by trial and error, it is advised to investigate whether the
used control scheme itself shows systematic limitations on the choice of the
impulse length. To investigate this point, a Floquet analysis is performed. For
OGY control the influence of the impulse length is marginal. As an unexpected
result, difference control fails when the impulse length is taken longer than a
maximal value that is approximately one half of the orbit length for small
Ljapunov numbers and decreases with the Ljapunov number.Comment: 13 pages. To appear in New Journal of Physic