System and methods for in-use NOx robustness emission control

A method for a controller of a vehicle, the method comprising:

• measuring an amount of tailpipe NOx emitted by the vehicle, at regular intervals, over a staggered set of current moving average windows (MAWs) of a fixed duration;
• for each MAW of the staggered set of current MAWs, predicting a total cumulative amount of tailpipe NOx emitted by the vehicle over the MAW, based on tailpipe NOx measurements from an elapsed portion of the MAW;
• and
• in response to the predicted total cumulative amount of tailpipe NOx exceeding a threshold amount of NOx, adjusting one or more operating parameters of the vehicle to reduce the predicted total cumulative amount of tailpipe NOx;
• wherein adjusting the one or more operating parameters of the vehicle to reduce the predicted total cumulative amount of tailpipe NOx further comprises at least one of:
• during a motored negative acceleration of the vehicle, opening a throttle disposed at an intake passage of an engine of the vehicle, and closing an exhaust gas regeneration (EGR) valve of an EGR system of the engine;
• restricting a tip-in response of the vehicle to reduce increases in engine-out NOx;
• increasing an EGR flow rate of the engine to reduce engine-out NOx;
• increasing a heat transfer from engine-out exhaust gases to a coolant at a charge air cooler and/or EGR cooler of the vehicle to reduce catalyst temperatures;
• increasing transmission shift speed points to reduce brake-specific NOx emissions and/or reduce catalyst temperatures;
• adjusting a torque derating curve to degrade a performance of the engine;
• and
• switching to an engine operation mode (EOM) that reduces engine-out NOx.

An engine system of a vehicle, comprising:

• a controller including a processor and instructions stored in a memory of the controller, that when executed, cause the controller to:
• via a tailpipe NOx sensor of the vehicle, measure an amount of tailpipe NOx emitted by the vehicle, at regular intervals over a staggered set of current moving average windows (MAWs) of a fixed duration;
• predict a probability of the amount of tailpipe NOx emissions exceeding a threshold amount of tailpipe NOx emissions by comparing a cumulative amount of tailpipe NOx generated during an elapsed portion of each MAW of the staggered set of current MAWs to a time-based cumulative NOx emissions allowance for the MAW;
• and
• in response to the probability increasing above a first threshold probability, perform a first adjustment to one or more operating parameters of the vehicle to decrease the amount of tailpipe NOx emissions;
• in response to the amount of tailpipe NOx emissions not decreasing as a result of the first adjustment:
• predict the probability of the amount of tailpipe NOx emissions exceeding the threshold amount of tailpipe NOx emissions based on whether a margin between an average amount of tailpipe NOx emitted over a MAW of the staggered set of current MAWs and a threshold MAW tailpipe NOx decreases below a predicted threshold tailpipe NOx margin, the threshold tailpipe NOx margin predicted based on expected engine-out NOx emissions of the vehicle, current NOx emissions sensitivities, and/or a predicted catalyst conversion efficiency in relation to the expected engine-out NOx emissions;
• and
• in response to the probability increasing above a second threshold probability, perform a second adjustment to one or more operating parameters of the vehicle to decrease the amount of tailpipe NOx emissions.