Automatic Tuning Methodology for Automotive Lean NOx Trap Catalyst Using Response Data

Abstract

This article provides an overview of the Lean NOx trap (LNT) catalysts' operating mechanism and proposes a method for auto-tuning the LNT model using response data. LNT catalysts are used in automotive applications to reduce NOx emissions from diesel engines, or lean-burn engines in general. The LNT catalyst is a complex nonlinear chemical system designed for cyclic operations, which can be very difficult to model in detail. Therefore, a simplified model was used which is based on the main chemical and physical processes typical to LNT. To tune the model, the method of choice of temperature for the lookup tables associated with multi-objective optimization and different input data sources was used: both steady state tests performed on a synthetic gas bench and more dynamic enginedynamometer tests.