This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Model-Based Fault Detection for Three-Way Automotive Catalyst Systems
Published April 19, 2004 by University of Salerno in Italy
A model-based, three-way automotive catalyst monitoring and fault detection strategy is presented in this work. A simplified oxygen storage and reversible catalyst deactivation model is employed to predict the measured post-catalyst air-fuel ratio. A fault is assumed to be present in the system when the current distribution of the post- catalyst air-fuel ratio prediction error differs from the base operating distribution. Changes in the post-catalyst air-fuel ratio prediction error distribution are indicative of both long-term catalyst poisoning effects and short-term emission control device failures. These changes are detected based on the results of a Kolmogorov-Smirnov test using sampled cumulative distribution functions. A moving horizon approach is used to determine the current error distribution.