Abstract: A control system comprising an upstream nitrogen oxide (NOx) control module that increases an upstream NOx level based on an initial upstream NOx level in an exhaust system, and an ammonia (NH3) storage condition detection module that detects a NH3 storage condition based on a difference in a downstream NOx level before and after the upstream NOx level is increased. A method comprising increasing an upstream NOx level based on an initial upstream NOx level in an exhaust system, and detecting an NH3 storage condition based on a difference in a downstream NOx level before and after the upstream NOx level is increased.

Abstract: A method for controlling a malfunction catalyst diagnostic test that determines a malfunction status of a catalyst within a selective catalytic reduction device includes monitoring an exhaust gas flow within an aftertreatment system, estimating an effect of the exhaust gas flow on an estimated reductant storage on a catalyst within the selective catalytic reduction device, and selectively disabling the malfunction catalyst diagnostic test based upon the estimating the effect of the exhaust gas flow on the estimated reductant storage.

Abstract: A selective catalytic reduction (SCR) system includes an exhaust pipe for receiving an exhaust gas from an engine. A selective catalytic reduction (SCR) unit is provided downstream of the exhaust pipe. A first mixing element including a meshed body defines a first surface, a second surface, and a plurality of openings extending from the first surface to the second surface. The first surface and second surface are parallel to each other and define an angle relative to a flow direction of the exhaust flow. The angle is less than 90 degrees.

Abstract: A control system comprising an ammonia (NH3) storage level determination module that determines a NH3 storage level in an exhaust system, a desired NH3 storage level determination module that determines a desired NH3 storage level based on an exhaust temperature, and a nitrogen oxide (NOx) mass flow rate control module that controls a NOx mass flow rate based on a difference between the NH3 storage level and the desired NH3 storage level. A method comprising determining a NH3 storage level in an exhaust system, determining a desired NH3 storage level based on an exhaust temperature, and controlling a NOx mass flow rate based on a difference between the NH3 storage level and the desired NH3 storage level.

Abstract: A method of regulating an amount of NH3 stored in a catalyst of an exhaust after-treatment system includes determining a mass of NH3 into the catalyst based on a dosing rate of a dosing agent that is injected into an exhaust stream upstream of the catalyst and determining a mass of NH3 out of the catalyst. An accumulated mass of NH3 within the catalyst is calculated based on the mass of NH3 into the catalyst and the mass of NH3 out of the catalyst. The dosing rate is regulated based on the accumulated mass of NH3 within the catalyst.

Abstract: A control system includes a first module, a fuel determination module, a temperature error correction module, and a hydrocarbon injection control module. The first module determines a temperature difference between a desired inlet temperature of a particulate filter (PF) and an outlet temperature of a first catalyst. The fuel determination module determines an uncorrected desired fuel value based on the temperature difference, an ambient temperature, and a mass flow of exhaust gas. The temperature error correction module generates a desired fuel value based on the uncorrected desired fuel value. The hydrocarbon injection control module controls a hydrocarbon injector based on the desired fuel value.

Abstract: A powertrain includes an internal combustion engine and an aftertreatment system having an aftertreatment device utilizing a catalyst to convert NOx. A method for indicating a malfunctioning catalyst includes monitoring an actual NOx content exiting the aftertreatment system, monitoring factors affecting conversion efficiency of the aftertreatment device, determining a predicted threshold NOx content exiting the aftertreatment system for an exemplary malfunctioning catalyst based upon the factors affecting conversion efficiency, comparing the actual NOx content exiting the aftertreatment system to the predicted threshold NOx content exiting the aftertreatment system, and indicating a malfunctioning catalyst based upon the comparing.

Abstract: A method for indicating a malfunctioning catalyst in a powertrain including an internal combustion engine and an aftertreatment system including an aftertreatment device utilizing a catalyst to convert NOx includes monitoring a NOx content entering the aftertreatment system, monitoring a NOx content exiting the aftertreatment system, determining an actual conversion efficiency based upon the NOx content entering the aftertreatment system and the NOx content exiting the aftertreatment system, monitoring factors affecting conversion efficiency within the aftertreatment device, determining a malfunction conversion efficiency indicative of the malfunctioning catalyst based upon the factors affecting conversion efficiency within the aftertreatment device, and indicating the malfunctioning catalyst based upon comparing the actual conversion efficiency to the malfunction conversion efficiency.

Abstract: A method and system is disclosed for regenerating a particulate filter, desulfating a lean NOx trap, desulfating or regenerating a hydrocarbon-selective catalytic reduction catalyst, desulfating or regenerating a urea-selective catalytic reduction catalyst, or a combination thereof.

Abstract: A control system includes a temperature module that determines a temperature of a selective catalytic reduction (SCR) catalyst, a derivative module that determines a derivative of the temperature, and a dosing module that regulates a dosage of a reductant supplied to the SCR catalyst to regulate an engine out NOx level. A control module generates control signals based on the temperature derivative, wherein the control signals regulate an amount of reductant accumulated within the SCR catalyst to reduce reductant release from the SCR catalyst during thermal transients.

Abstract: A dosing module for a vehicle comprises a base dose module, a dose adjustment module, and a dose determination module. The base dose module generates a base dose signal that corresponds to a mass flow rate of a dosing agent. The dose adjustment module receives an ammonia (NH3) signal and determines a first dose adjustment based upon the NH3 signal. The NH3 signal indicates NH3 measured downstream of a catalyst. The dose determination module generates a dosing signal based upon the base dose signal and the first dose adjustment.

Abstract: A method of regulating an amount of NH3 stored in a catalyst of an exhaust after-treatment system includes determining a mass of NH3 into the catalyst based on a dosing rate of a dosing agent that is injected into an exhaust stream upstream of the catalyst and determining a mass of NH3 out of the catalyst. An accumulated mass of NH3 within the catalyst is calculated based on the mass of NH3 into the catalyst and the mass of NH3 out of the catalyst. The dosing rate is regulated based on the accumulated mass of NH3 within the catalyst.

Abstract: A reductant dosing control system, for use in a Selective Catalytic Reduction (SCR) system of a motor vehicle includes an input receiving a NOx feedback signal from an NOx sensor provided to the SCR system. A base dosing module calculates a required quantity of reductant to inject in front of a SCR catalyst of the SCR system based on the NOx feedback signal. The SCR catalyst has ammonia storage properties. An output signals a reductant metering mechanism to periodically or continuously inject excess reductant based on the required quantity of reductant.