  We consider tracking control for uncertain linear systems with known relative
degree which are possibly non-minimum phase, i.e., their zero dynamics may have
an unstable part. For a given sufficiently smooth reference signal we design a
low-complexity controller which achieves that the tracking error evolves within
a prescribed performance funnel. We present a novel approach where a new output
is constructed, with respect to which the system has a higher relative degree,
but the unstable part of the zero dynamics is eliminated. Using recent results
in funnel control, we then design a controller with respect to this new output,
which also incorporates a new reference signal. We prove that the original
output stays within a prescribed performance funnel around the original
reference trajectory and all signals in the closed-loop system are bounded. The
results are illustrated by some simulations.
