Unifying the Parity-Space and GLR Approach to Fault Detection with an IMU Application
2008 (English)Report (Other academic)
Using the parity-space approach, a residual is formed by applying a projection to a batch of observed data and this is a well established approach to fault detection. Based on a stochastic state space model, the parity-space residual can be put into a stochastic framework where conventional hypothesis tests apply. In an on-line application, the batch of data corresponds to a sliding window and in this contribution we develop an improved on-line algorithm that extends the parity-space approach by taking prior information from previous observations into account. For detection of faults, the Generalized Likelihood Ratio (GLR) test is used. This framework allows for including prior information about the initial state, yielding a test statistic with a significantly higher sensitivity to faults. Another key advantage with this approach is that it can be extended to nonlinear systems using an arbitrary nonlinear filter for state estimation, and a linearized model around a nominal state trajectory in the sliding window. We demonstrate the algorithm on data from an Inertial Measurement Unit (IMU), where small and incipient magnetic disturbances are detected using a nonlinear system model.
Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2008. , 13 p.
LiTH-ISY-R, ISSN 1400-3902 ; 2862
Fault detection, Parity space sensor fusion, Inertial sensors, Magnetometer
National CategoryControl Engineering
IdentifiersURN: urn:nbn:se:liu:diva-56185ISRN: LiTH-ISY-R-2862OAI: oai:DiVA.org:liu-56185DiVA: diva2:316984