In this paper, we propose a novel distributed fault
detection method to monitor the state of a linear system, partitioned
into interconnected subsystems. The approach hinges
on the definition of a partition-based distributed Luenberger
estimator, based on the local model of the subsystems and
that takes into account the dynamic coupling terms between
the subsystems. The proposed methodology computes – in a
distributed way – a bound on the variance of a properly defined
residual signal, considering the uncertainty related to the
state estimates performed by the neighboring subsystems. This
bound allows the computation of suitable local thresholds with
guaranteed maximum false-alarms rate. The implementation
of the proposed estimation and fault detection method is
scalable, allowing Plug & Play operations and the possibility
to disconnect the faulty subsystem after fault detection. Theoretical
conditions guaranteeing the convergence of the estimates
and of the bounds are provided. Simulation results show the
effectiveness of the proposed method.
