  We consider control systems governed by nonlinear O.D.E.'s that are affine in
the time-derivative du/dt of the control u. The latter is allowed to be an
integrable, possibly of unbounded variation function, which gives the system an
impulsive character. As is well-known, the corresponding Cauchy problem cannot
be interpreted in terms of Schwartz distributions, even in the commutative
case. A robust notion of solution already proposed in the literature is here
adopted and slightly generalized to the case where an ordinary, bounded,
control is present in the dynamics as well. For a problem in the Mayer form we
then investigate the question whether this notion of solution provides a
"proper extension" of the standard problem with absolutely continuous controls
u. Furthermore, we show that this impulsive problem is a variational limit of
problems corresponding to controls u with bounded variation.
