Patent ID: 11879367
Assignee: PACCAR INC
Field: Environmental technology (Chemistry)
Classification: CPC F  Y | IPC F

Claim 0:
1. A method, comprising:
operating a diesel engine of a heavy-duty truck such that the diesel engine generates an exhaust gas flow and the exhaust gas flow flows into an exhaust after-treatment system of the heavy-duty truck, the exhaust after-treatment system including a close-coupled selective catalytic reduction system and an underbody selective catalytic reduction system downstream of the close-coupled selective catalytic reduction system with respect to the exhaust gas flow;
controlling a first DEF injector upstream of the close-coupled selective catalytic reduction system to increase a first rate at which the DEF injector injects DEF into the exhaust gas flow;
measuring a first level of NOx gases with a first NOx sensor upstream of the close-coupled selective catalytic reduction system and a second level of NOx gases with a second NOx sensor downstream of the close-coupled selective catalytic reduction system as the first rate at which the first DEF injector injects DEF increases;
using the measurements to determine a level of error in measurements provided by the first NOx sensor;
adjusting a subsequent measurement provided by the first NOx sensor based on the determined level of error in measurements provided by the first NOx sensor; and
controlling the first DEF injector to inject DEF at a first adjusted rate based on the adjusted measurement provided by the first NOx sensor;
controlling a second DEF injector downstream of the close-coupled selective catalytic reduction system and upstream of the underbody selective catalytic reduction system to increase a second rate at which the second DEF injector injects DEF into the exhaust gas flow;
measuring a third level of NOx gases with the second NOx sensor downstream of the close-coupled selective catalytic reduction system and upstream of the underbody selective catalytic reduction system and a fourth level of NOx gases with a third NOx sensor downstream of the underbody selective catalytic reduction system as the second rate at which the second DEF injector injects DEF increases;
using the measurements of the third and fourth levels of NOx gases to determine a level of error in measurements provided by the second NOx sensor;
adjusting a subsequent measurement provided by the second NOx sensor based on the determined level of error in measurements provided by the second NOx sensor; and
controlling the second DEF injector to inject DEF at a second adjusted rate based on the adjusted measurement provided by the second NOx sensor.