SENSITIVITY OF FAILURE-DETECTION USING GENERALIZED OBSERVERS

The sensitivity-robustness problem in analytical redundancy based fault detection is considered. To overcome the limits on achievable sensitivity imposed by the structure of classical state space observers, a new General Observer structure is proposed, which provides additional degrees of freedom in shaping the observer sensitivity. This structure is particularly useful in applications where there exists uncertainty in the system dynamics and external disturbances. A parametrization of all stabilizing general observers is given and the design process is formulated as a minimum observer sensitivity problem which is the dual to the minimum sensitivity control problem. A synthesis procedure is formulated by applying the H infinity optimization theory.