  We study adaptive fault tolerant tracking control for uncertain linear
systems. Based on recent results in funnel control and the time-varying
Byrnes-Isidori form, we develop a low-complexity model-free controller which
achieves prescribed performance of the tracking error for any given
sufficiently smooth reference signal. Within the considered system class, we
allow for more inputs than outputs as long as a certain redundancy of the
actuators is satisfied. An important role in the controller design is played by
the controller weight matrix. This is a rectangular input transformation chosen
such that in the resulting system the zero dynamics, which are assumed to be
uniformly exponentially stable, are independent of the new input. We illustrate
the fault tolerant funnel controller by an example of a linearized model for
the lateral motion of a Boeing 737 aircraft.
