US 12,247,508 B2
System and method for reduced nitrous oxide emissions using predictive urea dosing control
Venkata R. Chundru, San Antonio, TX (US); Sankar B. Rengarajan, San Antonio, TX (US); Jayant V. Sarlashkar, San Antonio, TX (US); and Scott Hotz, Pinckney, MI (US)
Assigned to SOUTHWEST RESEARCH INSTITUTE, San Antonio, TX (US)
Filed by Southwest Research Institute, San Antonio, TX (US)
Filed on May 3, 2022, as Appl. No. 17/661,863.
Prior Publication US 2023/0358157 A1, Nov. 9, 2023
Int. Cl. F01N 3/20 (2006.01); F01N 3/035 (2006.01); G01C 21/34 (2006.01); H04W 4/40 (2018.01)
CPC F01N 3/208 (2013.01) [F01N 3/035 (2013.01); G01C 21/3469 (2013.01); F01N 2610/02 (2013.01); F01N 2610/146 (2013.01); F01N 2900/0402 (2013.01); F01N 2900/08 (2013.01); F01N 2900/10 (2013.01); F01N 2900/1402 (2013.01); F01N 2900/1404 (2013.01); F01N 2900/1411 (2013.01); H04W 4/40 (2018.02)] 13 Claims
OG exemplary drawing
 
1. A system for reducing nitrous oxide (NOx) emissions in an aftertreatment system of a vehicle, the system comprising:
one or more computer processors;
one or more computer readable storage media; and
program instructions stored on the one or more computer readable storage media for execution by at least one of the one or more computer processors, the stored program instructions including instructions to:
determine a route for a trip for the vehicle;
determine a predicted power demand for the vehicle, for each step of a set of steps for the route, based on the determined route, predicted traffic density and predicted vehicle speed;
determine predicted vehicle dynamics that includes engine speed in revolutions per minute (RPM), torque and gear number for each step in the set of steps for the route based on the predicted power demand;
determine predicted exhaust flow rate, temperature, and NOx concentration for each step in the set of steps for the route based on the predicted vehicle dynamics;
determine, for each step in the set of steps for the route, predicted inlet conditions for a selective catalytic reduction (SCR) device associated with the aftertreatment system of the vehicle; the predicted inlet conditions includes a predicted NO2/NOx ratio, the predicted exhaust temperature, and the predicted exhaust flow rate;
determine a target coverage fraction of ammonia in the SCR for each step of a set of steps for the route, based on a predicted NOx flux and exhaust temperature; wherein the target coverage fraction of ammonia is determined prior to a start of the trip;
determine, during operation of the vehicle along the route, an actual coverage fraction of ammonia in the catalyst for each step of the set of steps for the route;
compare the actual coverage fraction of ammonia to the target coverage fraction of ammonia for each step of the set of steps;
determine a cost function based on maximizing an NOx conversion, reducing a consumption of urea, and maximizing a light-off SCR device for proper operation of a catalyzed particulate filter (CPF); wherein the cost function is determined according to:

OG Complex Work Unit Math
wherein

OG Complex Work Unit Math
 is a control horizon cost,

OG Complex Work Unit Math
 is a urea injection rate cost, and

OG Complex Work Unit Math
 is an NOx maximizing cost at the CPF inlet; and
adjust a urea injection rate based on the determined cost function.