Abstract: Technical solutions described herein include an emissions control system for treating exhaust gas in a motor vehicle including an internal combustion engine. The emissions control system includes a model-based controller to control reductant injections into the exhaust gas. Controlling the reductant injections includes determining an amount of NOx and an amount of NH3 at an outlet of the first SCR device, and at an outlet of the second SCR device. The controlling further includes computing an amount of reductants to inject to maintain a first predetermined ratio between the amount of NH3 and the amount of NOx at the outlet of the first SCR device and to maintain a second predetermined ratio between the amount of NH3 and the amount of NOx at the outlet of the second SCR device. Further, the controlling includes sending a command for receipt by the reductant injectors to inject the computed amount of reductants.

Abstract: Technical solutions described herein include an emissions control system for treating exhaust gas in a motor vehicle including an internal combustion engine. The emissions control system includes a model-based controller to control reductant injections into the exhaust gas. Controlling the reductant injections includes determining an amount of NOx and an amount of NH3 at an outlet of the first SCR device, and at an outlet of the second SCR device. The controlling further includes computing an amount of reductants to inject to maintain a first predetermined ratio between the amount of NH3 and the amount of NOx at the outlet of the first SCR device and to maintain a second predetermined ratio between the amount of NH3 and the amount of NOx at the outlet of the second SCR device. Further, the controlling includes sending a command for receipt by the reductant injectors to inject the computed amount of reductants.

Abstract: An exhaust gas after-treatment system for an internal combustion engine includes a selective catalyst reduction on filter (SCRF) exhaust gas after-treatment device in communication with exhaust gases from the internal combustion engine and having treated exhaust gas output. An oxides of nitrogen (NOx) sensor is coupled to treated exhaust gases and has a NOx sensor output signal that is NOx and ammonia (NH3) cross-sensitive. A closed loop observer (CLO) is operatively coupled to receive the NOx sensor output signal and provides a NOx concentration signal to an electronic control unit operatively associated with the exhaust gas after-treatment system and the internal combustion engine. CLO output at least includes an exhaust gas NOx concentration estimate and the ECU is arranged to be operable upon the NOx concentration estimate to control exhaust gas after-treatment system and internal combustion engine to effect an overall reduction in actual NOx concentration with the exhaust gases.

Abstract: An emissions control system for a motor vehicle that includes an internal combustion engine includes a first selective catalytic reduction (SCR) device and a reductant injector, The system further includes a model-based controller that is configured to calculate a target amount of reductant to inject to maintain a predetermined ratio between an amount of NH3 and an amount of NOx at the outlet of the first SCR device, and to send a command for receipt by the reductant injector to inject the calculated amount of reductant. The model-based controller is further configured to send a command for receipt by an engine controller to influence NOx production by the engine by modifying an engine operating parameter, based on a calculated target amount of NOx at the inlet of the first SCR device.

Abstract: An emissions control system for a motor vehicle that includes an internal combustion engine includes a first selective catalytic reduction (SCR) device and a reductant injector, The system further includes a model-based controller that is configured to calculate a target amount of reductant to inject to maintain a predetermined ratio between an amount of NH3 and an amount of NOx at the outlet of the first SCR device, and to send a command for receipt by the reductant injector to inject the calculated amount of reductant. The model-based controller is further configured to send a command for receipt by an engine controller to influence NOx production by the engine by modifying an engine operating parameter, based on a calculated target amount of NOx at the inlet of the first SCR device.

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: An after-treatment system includes a selective catalyst reduction on filter (SCRF) device in communication with exhaust gases from an engine yielding treated exhaust gases. A nitrogen oxides (NOx) sensor is configured to measure the treated exhaust gases and has an output signal that is NOx and ammonia (NH3) cross-sensitive. A NOx sensor model is coupled to receive the output signal and mass flow data for the treated exhaust gases and provides a NOx model signal to an electronic control unit (ECU) that is operatively associated with the after-treatment system and the engine. The NOx model signal represents an exhaust gas NOx concentration estimate based upon an actual NOx concentration and an actual NH3 concentration of the exhaust gas. The ECU is operable upon the NOx concentration estimate to control the after-treatment system and the engine to effect an overall reduction in actual NOx concentration of the treated exhaust gases.

Abstract: An exhaust gas after-treatment system for an internal combustion engine that includes a selective catalyst reduction on filter (SCRF) exhaust gas after-treatment device in communication with exhaust gases from the internal combustion engine and having a treated exhaust gas output. An oxides of nitrogen (NOx) sensor is coupled to the treated exhaust gases and has a NOx sensor output signal that is NOx and ammonia (NH3) cross-sensitive. A closed loop observer (CLO) is operatively coupled to receive the NOx sensor output signal and provides a NOx concentration signal to an electronic control unit that is operatively associated with the exhaust gas after-treatment system and the internal combustion engine.

Abstract: Technical solutions described herein include an emissions control system for treating exhaust gas in a motor vehicle including an internal combustion engine. The emissions control system includes a model-based controller to control reductant injection into the exhaust gas. Controlling the reductant injection includes determining an amount of NOx and an amount of NH3 at an outlet of the first SCR device, and at an outlet of the second SCR device. The controlling further includes computing an amount of reductant to inject to maintain a first predetermined ratio between the amount of NH3 and the amount of NOx at the outlet of the first SCR device and to maintain a second predetermined ratio between the amount of NH3 and the amount of NOx at the outlet of the second SCR device. Further, the controlling includes sending a command for receipt by the reductant injector to inject the computed amount of reductant.

Abstract: Technical solutions are described for selective catalytic reduction diagnosis in an emissions control system or an exhaust system used for treating exhaust gas, such as in a motor vehicle including an internal combustion engine. An example emissions control system includes a selective catalytic reduction (SCR) device. The emissions control system further includes a controller that is performs SCR fault diagnosis. The SCR fault diagnosis includes computing a plurality of estimated NH3 storage capacity values (?) of an SCR catalyst of the SCR device. The diagnosis further includes determining a diagnostic parameter of the SCR device using the plurality of estimated NH3 storage capacity values.

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 selective catalytic reduction diagnosis in an emissions control system or an exhaust system used for treating exhaust gas, such as in a motor vehicle including an internal combustion engine. An example emissions control system includes a selective catalytic reduction (SCR) device. The emissions control system further includes a controller that is performs SCR fault diagnosis. The SCR fault diagnosis includes computing a plurality of estimated NH3 storage capacity values (?) of an SCR catalyst of the SCR device. The diagnosis further includes determining a diagnostic parameter of the SCR device using the plurality of estimated NH3 storage capacity values.

Abstract: A method of controlling a particulate filter of an internal combustion engine is disclosed. A regeneration cycle of the particulate filter is initiated. During the regeneration, a value of an exhaust gas temperature at an outlet of the particulate filter is determined and a value of a residual soot quantity stored into the particulate filter is estimated on the basis of the measured value of the exhaust gas temperature at the outlet of the particulate filter. The regeneration cycle may be started and stopped based on the estimated residual soot quantity.

Abstract: A method, control system, and vehicle system configured to control a selective catalyst reduction (SCR) system subtracts an amount of NOx present in a tailpipe upstream of the SCR system from an amount of NOx present in the tailpipe downstream of the SCR injector. A cumulative difference may be determined based on integrating the subtracted NOx value. The method, control system, and vehicle system are configured to determine whether the cumulative difference exceeds a control threshold, and to set a selected upstream NOx value as a predetermined model upstream NOx amount if the cumulative difference exceeds the control threshold, but to set the selected upstream NOx value as the determined upstream NOx amount if the cumulative difference does not exceed the control threshold. Thus, the system is reset to the model when downstream NOx values exceed upstream NOx values above a threshold, to bring the system back within control.

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: A method, control system, and vehicle system configured to control a selective catalyst reduction (SCR) system subtracts an amount of NOx present in a tailpipe upstream of the SCR system from an amount of NOx present in the tailpipe downstream of the SCR injector. A cumulative difference may be determined based on integrating the subtracted NOx value. The method, control system, and vehicle system are configured to determine whether the cumulative difference exceeds a control threshold, and to set a selected upstream NOx value as a predetermined model upstream NOx amount if the cumulative difference exceeds the control threshold, but to set the selected upstream NOx value as the determined upstream NOx amount if the cumulative difference does not exceed the control threshold. Thus, the system is reset to the model when downstream NOx values exceed upstream NOx values above a threshold, to bring the system back within control.

Abstract: A method is disclosed for controlling an injector for injecting a reductant into a selective catalytic reduction system of an internal combustion engine. A value of a concentration of nitrogen-oxides in the exhaust gas aftertreatment system downstream of the selective catalytic reduction system is measured, and a first difference is calculated between the measured value of the nitrogen-oxides concentration and a predetermined reference value thereof. A value of a concentration of ammonia in the exhaust gas aftertreatment system downstream of the selective catalytic reduction system is measured, and a second difference is calculated between the measured value of the ammonia concentration and a predetermined reference value thereof. A quantity of reductant to be injected by the injector is calculated as a function of the calculated first difference and second difference, and the injector is operated to inject the calculated quantity of reductant.

Abstract: Disclosed are model predictive control (MPC) systems, methods for using such MPC systems, and motor vehicles with selective catalytic reduction (SCR) employing MPC control. An SCR-regulating MPC control system is disclosed that includes an NOx sensor for detecting nitrogen oxide (NOx) input received by the SCR system, catalyst NOx sensors for detecting NOx output for two SCR catalysts, and catalyst NH3 sensors for detecting ammonia (NH3) slip for each SCR catalyst. The MPC system also includes a control unit programmed to: receive desired can conversion efficiencies for the SCR catalysts; determine desired can NOx outputs for the SCR catalysts; determine maximum NH3 storage capacities for the SCR catalyst; calculate the current can conversion efficiency for each SCR catalyst; calculate an optimized reductant pulse-width and/or volume from the current can conversion efficiencies; and, command an SCR dosing injector to inject a reductant into an SCR conduit based on the calculated pulse-width/volume.

Abstract: A method of operating a Selective Catalytic Reduction on Diesel Particulate Filter or SDPF is disclosed. During a SDPF regeneration; temperature values are obtained for the SDPF inlet and SDPF outlet. The temperature values are used to calculate a rate of increase of SDPF outlet temperature and a rate of increase of SDPF inlet temperature. A ratio between the rate of increase of SDPF outlet temperature values and the rate of increase of SDPF inlet temperature values is calculated, and if the ratio is greater than a threshold thereof, the exhaust gas composition is modified in some manner.

Abstract: An automotive vehicle includes an internal combustion engine and an exhaust system. The exhaust treatment system includes a dosing system that injects NH3 into an exhaust gas stream generated by the engine. An SCR device stores an amount of the NH3 and converts NOx into diatomic nitrogen (N2) and water (H2O) based on the stored amount of the NH3. The vehicle further includes an SCR status estimator device and a controller. The SCR status estimator device determines an NH3 coverage ratio (R), which indicates a stored amount of NH3 with respect to a maximum NH3 storage capacity of the SCR device. The controller determines a target NOx reduction efficiency (?NOx) of the SCR device, and an NH3 coverage ratio set point (Rsp) based on the ?NOx. The controller also generates an NH3 control signal (u) that controls the dosing system based on a comparison between the R and the Rsp.