Sensor Fault Detection of a CSTR Plant Using an Unknown Input Observer

In this paper, unknown input observers (UIO) are used to detect sensor faults of a chemical plant. The basic principle of unknown input observers is to decouple disturbances from the state estimation error. A single full-order observer is designed to detect sensor faults in the presence of unknown inputs (disturbances). By doing so, we generate a residual, a weighted output of the state estimation error, decoupled from disturbances. The resulting robust (in the sense of disturbances) residual can be used for fault detection and isolation. In order to evaluate its ability, the presented method is applied to a highly nonlinear dynamic system describing the behavior of a jacketed continuous stirred tank reactor (CSTR). The faulty behavior of output sensors in the chemical reactor is investigated. Simulation results show the efficiency and performance of the presented method.

Sensor Fault Detection of a CSTR Plant Using an Unknown Input Observer Keywords:

Unknown Input Observer , Robust Fault detection , Disturbance decoupling