PR-309-15209-R01 Evaluation of NSCR Specific Models for Use in CEPM

This 2015 NSCR project continues NSCR research started in 2009 and continued in 2011 under ERLE 2c and combines it with OBD research started in 2008 and continued in 2011. The 2009 NSCR research concluded that downstream measurement of lambda, O2 and NOx are useful for understanding performance of the entire package and evaluating compliance status and diagnosing system problems. However, that research also concluded that advanced signal conditioning and algorithms are required for unambiguous diagnostics. It also concluded system diagnostics was complex and beyond the capabilities of typical technicians. The 2011 OBD project demonstrated that a model-based diagnostics approach could precisely detect and diagnose typical combustion faults on lean burn engines. This 2015 project will specifically test and demonstrate the effectiveness of model based NSCR diagnostics using upstream and downstream exhaust sensors and other typical sensor inputs.