  This paper presents a fault-tolerant control scheme for constrained linear
systems. First, a new variant of the Reference Governor (RG) called At Once
Reference Governor (AORG) is introduced. The AORG is distinguished from the
conventional RG by computing the Auxiliary Reference (AR) sequence so that to
optimize performance over a prescribed time interval instead of only at the
current time instant; this enables the integration of the AORG with fault
detection schemes. In particular, it is shown that, when the AORG is combined
with a Multi-Model Adaptive Estimator (MMAE), the AR sequence can be determined
such that the tracking properties are guaranteed and constraints are satisfied
at all times, while the detection performance is optimized, i.e., faults can be
detected with a high probability of correctness. In addition a reconfiguration
scheme is presented that ensures system viability despite the presence of
faults based on recoverable sets. Simulations on a Boeing 747-100 aircraft
model are carried out to evaluate the effectiveness of the AORG scheme in
enforcing constraints and tracking the desired roll and side-slip angles. The
effectiveness of the presented fault-tolerant control scheme in maintaining the
airplane viability in the presence of damaged vertical stabilizer is also
demonstrated.
