On-Board Diagnostic and Fault Detection Strategies for an Automotive Three-Way Catalyst

摘要

This work presents model-based strategies for on-board catalyst monitoring and fault detection using a simplified catalyst oxygen storage and reversible deactivation model. The performance of the catalyst is inferred from the error between the post-catalyst exhaust gas oxygen sensor measurement and the model predicted value. Each of these strategies is based on the use of some test statistic that is computed from a window of post-catalyst prediction error data updated in real-time. A fault is reported when the value of this statistic exceeds a threshold that is determined from some specified confidence level. We conclude with an evaluation of these strategies.