Abstract: A method for reducing sensor noise in an automobile vehicle NOx sensor offset diagnostic includes: connecting an exhaust system to an engine of an automobile vehicle; sensing a condition of the exhaust system using at least one NOx sensor; identifying when the at least one NOx sensor is at a low noise condition; and running a diagnostic to identify conditions of the at least one NOx sensor. The method further includes selecting one of the low noise condition as the engine in an after-run condition or as the engine in an engine idle condition.

Abstract: A method for reducing sensor noise in an automobile vehicle NOx sensor offset diagnostic includes: connecting an exhaust system to an engine of an automobile vehicle; sensing a condition of the exhaust system using at least one NOx sensor; identifying when the at least one NOx sensor is at a low noise condition; and running a diagnostic to identify conditions of the at least one NOx sensor. The method further includes selecting one of the low noise condition as the engine in an after-run condition or as the engine in an engine idle condition.

Abstract: A diesel exhaust fluid (DEF) control system includes: a target module configured to determine a target rate of injection of a DEF by a DEF injector; an adjustment module configured to determine an adjustment based on a concentration of urea in the DEF; an adjusting module configured to adjust the target rate based on the adjustment to produce an adjusted rate of injection of the DEF by the DEF injector; and an injector control module configured to control injection of the DEF by the DEF injector based on the adjusted rate.

Abstract: A diesel exhaust fluid (DEF) control system includes: a target module configured to determine a target rate of injection of a DEF by a DEF injector; an adjustment module configured to determine an adjustment based on a concentration of urea in the DEF; an adjusting module configured to adjust the target rate based on the adjustment to produce an adjusted rate of injection of the DEF by the DEF injector; and an injector control module configured to control injection of the DEF by the DEF injector based on the adjusted rate.

Abstract: An emissions control system for treating exhaust gas containing NOx emissions from an internal combustion engine comprises a selective catalytic reduction (SCR) device that stores reductant that reacts with the NOx emissions, a reductant supply system configured to inject the reductant according to a reductant storage model; NOx module(s) configured to generate an NOx concentration signal indicating an NOx concentration, temperature module(s) configured to generate a temperature signal indicating an SCR temperature of the SCR device, and a control module operably connected to the reductant supply system, the NOx module, and the temperature module. The control module is configured to determine an amount of the reductant that is parasitically oxidized based on the NOx concentration signal and the temperature signal, and to determine a correction factor based on the amount of parasitically oxidized reductant to modify the reductant storage model.

Abstract: Systems and associated methods of treating diesel exhaust in a vehicle are disclosed. An example method includes providing an exhaust aftertreatment device in an exhaust tailpipe, and a first nitrogen oxide (NOx) sensor upstream of the exhaust aftertreatment device, with the exhaust aftertreatment device configured to reduce NOx present in an exhaust flow through the exhaust aftertreatment device with a treatment fluid applied to the exhaust flow. This example method may also include measuring a concentration of NOx in the exhaust flow with the first sensor, determining an error in the measurement of the NOx concentration, and applying a learning corrective adjustment in a subsequent measurement of the NOx concentration in the exhaust flow in response to that determination. A first magnitude of the learning corrective adjustment may be based at least in part upon a second magnitude of the error in the measurement.

Abstract: Selective catalytic reduction device (SCR) assessment methods include, while communicating exhaust to the SCR, determining a first temperature differential (dT) between a modeled exotherm phase temperature and a measured SCR exotherm outlet exhaust temperature, comparing the first dT to a first threshold, and determining that the SCR performance is suitable if the first dT is below the first threshold, or, if the first dT is above the first threshold, communicating exhaust gas to the SCR during a water endotherm phase, determining a second dT between a modeled endotherm phase temperature and a measured SCR endotherm phase outlet exhaust temperature, comparing the second dT to a second threshold, and determining that the SCR performance is suitable if the second dT is above the second threshold, or determining that the SCR performance is unsuitable if the second dT is below the second threshold. Performance can be SCR reductant storage capacity.

Abstract: Technical solutions are described for an emissions control system for a motor vehicle including an internal combustion engine. An example computer-implemented method for controlling an exhaust system of an internal combustion engine, includes detecting a high hydrocarbon region in the operation of the internal combustion engine. The method further includes responsively, measuring an upstream temperature of an oxidation device of the exhaust system. Further yet, the method includes in response to the upstream temperature being equal to or above a predetermined threshold, delaying an O2 diagnosis of the exhaust system for a signal rationality delay time.

Abstract: Technical solutions are described for an emissions control system for a motor vehicle including an internal combustion engine. The emissions control system includes a reductant injector device, a selective catalytic reduction (SCR) device, and a controller. The controller determines a reductant energizing time for the reductant injector device based on one or more operating conditions of the SCR device. The controller further computes a diagnostic adaptation factor for the reductant energizing time based on an on-board diagnostic signal. The controller further inputs an amount of reductant into the SCR device by adjusting a reductant energizing time of the reductant injector device according to the diagnostic adaptation factor.

Abstract: Technical solutions are described for an emissions control system for a motor vehicle including an internal combustion engine. The emissions control system includes a selective catalytic reduction (SCR) device, an NOx sensor, and a controller for ammonia slip detection. The ammonia slip detection includes comparing an NOx measurement from the NOx sensor with a predicted NOx value. In response to the NOx measurement exceeding the predicted NOx value by a threshold value, the threshold value being calibrated to a first predetermined value, the threshold value is calibrated to a second predetermined value, a timer is initiated to a predetermined duration, and during the predetermined duration of the timer, in response to a second NOx measurement from the NOx sensor exceeding the predicted NOx value by the threshold value set to the second predetermined value, a reductant dosing rate of the SCR device is adapted according to the second predetermined value.

Abstract: Technical solutions are described for limiting exposure of components of an emissions control system to rich exhaust conditions. An example an emissions control system includes an oxygen storage component; and a controller that limits exposure of the oxygen storage component to rich exhaust conditions. The limiting includes determining an air-to-fuel equivalence ratio in exhaust gas in response to an engine receiving a request to generate torque, the request including a displacement of a pedal; determining an amount of oxygen in the exhaust gas based on the air-to-fuel equivalence ratio; determining an oxygen level stored by the oxygen storage component; and if the oxygen level is above a predetermined threshold, lowering a torque generation rate of the engine, which specifies amount of torque generated per unit displacement of the pedal.

Abstract: A selective catalytic reduction device (SCR) system performs intrusive steady state dosing correction (SSDC) when a NOx error between a predicted and measured downstream NOx value exceeds a threshold. In SSDC, if NOx breakthrough or NH3 slip is detected above a SSDC threshold, a short term reductant dosing adaptation occurs. Optionally long term dosing adaptations occur if the magnitude of previous short term adaptations exceed a short term adaptation threshold. If SSDC is insufficiently improving SCR performance based on the number of intrusive events occurring within a period of time and the change in NOx error during the time period, a method includes modifying the SSDC protocol by one or more of increasing the duration of short term adaptations, decreasing the SSDC threshold, and reducing the short term adaptation threshold. The method further includes subsequently inhibiting intrusive events from occurring.

Abstract: A selective catalytic reduction device (SCR) system performs intrusive steady state dosing correction (SSDC) when a NOx error between a predicted and measured downstream NOx value exceeds a threshold. In SSDC, if NOx breakthrough or NH3 slip is detected above a SSDC threshold, a short term reductant dosing adaptation occurs. Optionally long term dosing adaptations occur if the magnitude of previous short term adaptations exceed a short term adaptation threshold. If SSDC is insufficiently improving SCR performance based on the number of intrusive events occurring within a period of time and the change in NOx error during the time period, a method includes modifying the SSDC protocol by one or more of increasing the duration of short term adaptations, decreasing the SSDC threshold, and reducing the short term adaptation threshold. The method further includes subsequently inhibiting intrusive events from occurring.

Abstract: Selective catalytic reduction device (SCR) assessment methods include, while communicating exhaust to the SCR, determining a first temperature differential (dT) between a modeled exotherm phase temperature and a measured SCR exotherm outlet exhaust temperature, comparing the first dT to a first threshold, and determining that the SCR performance is suitable if the first dT is below the first threshold, or, if the first dT is above the first threshold, communicating exhaust gas to the SCR during a water endotherm phase, determining a second dT between a modeled endotherm phase temperature and a measured SCR endotherm phase outlet exhaust temperature, comparing the second dT to a second threshold, and determining that the SCR performance is suitable if the second dT is above the second threshold, or determining that the SCR performance is unsuitable if the second dT is below the second threshold. Performance can be SCR reductant storage capacity.

Abstract: An emissions control system for treating exhaust gas containing NOx emissions from an internal combustion engine comprises a selective catalytic reduction (SCR) device that stores reductant that reacts with the NOx emissions, a reductant supply system configured to inject the reductant according to a reductant storage model; NOx module(s) configured to generate an NOx concentration signal indicating an NOx concentration, temperature module(s) configured to generate a temperature signal indicating an SCR temperature of the SCR device, and a control module operably connected to the reductant supply system, the NOx module, and the temperature module. The control module is configured to determine an amount of the reductant that is parasitically oxidized based on the NOx concentration signal and the temperature signal, and to determine a correction factor based on the amount of parasitically oxidized reductant to modify the reductant storage model.

Abstract: A vehicle includes an engine that combusts an air/fuel mixture to produce an exhaust gas stream containing oxides of nitrogen (NOx). A dosing system injects an amount of ammonia (NH3) into the exhaust gas stream based on an initial NH3 injection set point value. A selective catalyst reduction (SCR) device absorbs an amount of the NH3 contained in the exhaust gas stream and reduces an amount of NOx. An electronic hardware controller predicts an NH3 slip condition during which a portion the absorbed NH3 will slip from the SCR device, and modifies the initial NH3 injection set point value based on the predicted NH3 slip condition. The controller further generates a modified NH3 injection set point signal indicating an adjusted amount of the NH3 to inject during the predicted NH3 slip condition. The dosing system adjusts the amount of injected NH3 based on the modified NH3 injection set point signal.

Abstract: Technical solutions are described for limiting exposure of components of an emissions control system to rich exhaust conditions. An example an emissions control system includes an oxygen storage component; and a controller that limits exposure of the oxygen storage component to rich exhaust conditions. The limiting includes determining an air-to-fuel equivalence ratio in exhaust gas in response to an engine receiving a request to generate torque, the request including a displacement of a pedal; determining an amount of oxygen in the exhaust gas based on the air-to-fuel equivalence ratio; determining an oxygen level stored by the oxygen storage component; and if the oxygen level is above a predetermined threshold, lowering a torque generation rate of the engine, which specifies amount of torque generated per unit displacement of the pedal.

Abstract: An emissions control system includes a Selective Catalytic Reduction device adapted to reduce emissions, an injector adapted to inject a reductant into the device, a NOx sensor disposed downstream of the device, a controller, an iterative model, and a table. The controller is configured to perform short and long term control by confirming at least one short term criteria is met. Once confirmed, the controller calculates a normalized model error utilizing the model and a signal received from the sensor, and integrates the normalized model error. If the integrated normalized model error exceeds a threshold, the controller proceeds toward the long term control. If a long term criteria is met, a current long term factor and the integrated normalized model error is applied to the table to determine a new long term factor. The new long term factor is multiplied against an energization time of the injector.

Abstract: Method for controlling and detecting ammonium nitrate and/or ammonium nitrite poisoning within selective catalytic reduction (SCR) devices and systems incorporating the same are provided. Methods can include detecting a SCR inlet exhaust gas NO2:NOx ratio above a poisoning NOx flux threshold, detecting a SCR temperature below a poisoning temperature threshold, and determining SCR catalyst poisoning. Methods can further include performing a SCR catalyst cleaning strategy, wherein the SCR cleaning strategy comprises heating the SCR catalyst composition to a temperature above the poisoning temperature threshold. Cleaning strategies can including utilizing a heater, implementing a post-injection, after-injection, and/or auxiliary injection engine strategy wherein the engine is configured to supply exhaust gas to the SCR.

Abstract: Technical solutions are described for an emissions control system for a motor vehicle including an internal combustion engine. An example computer-implemented method for controlling an exhaust system of an internal combustion engine, includes detecting a high hydrocarbon region in the operation of the internal combustion engine. The method further includes responsively, measuring an upstream temperature of an oxidation device of the exhaust system. Further yet, the method includes in response to the upstream temperature being equal to or above a predetermined threshold, delaying an O2 diagnosis of the exhaust system for a signal rationality delay time.