Robust fault detection and isolation of limnimeters of barcelona´s sewer system using interval obeservers

In this paper, fault detection and isolation of limmimeters (water level sensors in the sewers) of Barcelona´s urban sewer systems is presented. The Barcelona urban drainage network has a telemetry network containing 22 rain gauges and inore than 100 limmimeters used for the conrrol system. In order to delect and isolate faulty instruments and to reconstruct ratllty mrasuruments from data fusion, a fault diagnosis system is necessary. The proposed fault diagnosis strategy is based on building an internal linear observer for every instrument [22]. Then, while the real measure is inside the inierval of predicted behaviour (or envelope) generated using its interval observer no fault can be indicated. However, when the measure is outside its envelope a fault can be indicated. Fault isolation is based on the matching of the real fault signature witti the theoretical fault signature using a bank of observers [18]. Measurements from faulty limimeeters are reconstructed using observers that are based on allernalive sensors thar are not in fault. Finally, the proposed fault diagnosis system is applied to several real scenarios providing promising results in order to be applied in a real-time implementation.