  This paper presents the design of a diagnosis system for the detection,
identification and reconstruction of faults in pipelines. The design of such
diagnosis system is based on redundant relations and nonlinear observers,
taking into account faults in sensors, damages in pumps, and unknown
extractions. The proposed algorithm is developed based on a model described by
nonlinear equations of the fluid behavior in a pipeline, considering the
principles of conservation of mass and momentum. In order to distinguish among
different types of faults and to reconstruct their behavior, the diagnosis
system operates in stages. The first stage called detection & fault isolation
aims to isolate a fault symptom with a set of redundant relations deduced from
the analysis of the model in nominal conditions and assuming measurements of
the standard variables at the extremes of the pipeline. In the second stage
named fault reconstruction, nonlinear observation algorithms estimate the
temporal evolution of the isolated fault. The complete diagnosis system is
validated through a series of experiments in a hydraulic pilot pipeline of 200
[m].
