Robust Fault Diagnosis of Nonlinear Systems Based on an Unknown Input Extended Kalman Observer
| Authors: | Li Linglai, Tsinghua University, China
Zhou D.H., Tsinghua University, China
Liu K.D., Hebei Engineering Univeristy, China |
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| Topic: | 6.4 Safeprocess |
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| Session: | Fault Diagnosis and Fault Tolerant Control: Theory |
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| Keywords: | Fault diagnosis, Kalman filters, Disturbance rejection, Convergence analysis, Lyapunov methods. |
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Abstract
Unknown input observer is one of the most important strategies for robust fault diagnosis of linear systems. Inspired by the unknown input Kalman filter, we extend it to nonlinear cases as the EKF does. Using this as a nonlinear observer, we prove its convergence under some mild conditions. As a result, a robust FDI strategy for nonlinear systems is obtained. Simulation studies on a three-tank system “DTS200” demonstrate the effectiveness of the proposed approach.
