  We investigate theoretically the possibility for robust and fast cooling of a
trapped atomic ion by transient interaction with a pre-cooled ion. The
transient coupling is achieved through dynamical control of the ions'
equilibrium positions. To achieve short cooling times we make use of shortcuts
to adiabaticity by applying invariant-based engineering. We design these to
take account of imperfections such as stray fields, and trap frequency offsets.
For settings appropriate to a currently operational trap in our laboratory, we
find that robust performance could be achieved down to $6.3$ motional cycles,
comprising $14.2\ \mathrm{\mu s}$ for ions with a $0.44\ \mathrm{MHz}$ trap
frequency. This is considerably faster than can be achieved using laser cooling
in the weak coupling regime, which makes this an attractive scheme in the
context of quantum computing.
