NO_x estimation using local state-space models

摘要

Implementations described herein relate to utilizing discrete transient local state space models to modify an output from a steady state NO_x estimation model to provide a final estimated NO_x value. An engine operating space, defined by a speed and injection quantity map, is subdivided into several discrete local state spaces and a transient model is developed for each discrete state space to output a NO_x estimation correction value. The transient models may be a regression model or the transient model may be an empirical map of data values. The NO_x estimation correction value modifies a steady state NO_x value to calculate the final NO_x estimated value. The final NO_x estimated value is then output to another component, such as a controller as an input for controlling one or more components of an engine, an aftertreatment system, and/or a diagnostic system.