Abstract: A method of monitoring a particulate filter of an exhaust aftertreatment device includes sensing a first pressure drop across the particulate filter at a first instant in time, and sensing a second pressure drop across the particulate filter at a second instant in time. A controller may then calculate a rate-of-change of the pressure drop between the first instant in time and the second instant in time while sensing a flow rate of an exhaust gas flowing through the exhaust aftertreatment device. Using the sensed exhaust flow rate, the controller may determine a rate-of-change threshold, and subsequently compare the calculated rate-of-change to the rate-of-change threshold. The method further includes updating a soot model using the sensed second pressure drop if the calculated rate-of-change is less than the rate-of-change threshold.

Abstract: A method of correcting a soot mass estimate in a vehicle exhaust after-treatment device includes monitoring an exhaust gas pressure drop across a particulate filter included with the vehicle exhaust after-treatment device; determining an initial soot mass estimate from a monitored exhaust gas pressure drop; revising the initial soot mass estimate in view of a monitored engine speed, engine load, exhaust gas temperature, and NOx gas flow rate; and generating a particulate filter regeneration request if the revised soot mass estimate exceeds a threshold.

Abstract: An internal combustion engine includes an intake air compressor system and is fluidly coupled to an exhaust aftertreatment system having a particulate filter. A method for operating the internal combustion engine includes determining a total engine-out soot generation based upon a summation of a steady-state engine-out soot generation rate and an engine-out soot generation rate correction. The engine-out soot generation rate correction is either zero when the intake air compressor system is closed-loop controlled or a rate based upon a deviation between an actual boost pressure and an expected boost pressure from the intake air compressor system. The particulate filter is regenerated when the total engine-out soot generation exceeds a predetermined threshold.

Abstract: A method for controlling regeneration within an after-treatment component of an engine includes receiving a signal that is responsive to a change in pressure across an after-treatment component and calculating an estimate of accumulated particulate matter in the after-treatment component using a soot accumulation model calibrated to simulate operation of the engine at a reference condition. A soot model correction factor is based at least in part on an environmental temperature correction and is applied to the estimate of accumulated particulate matter in the after-treatment component to produce a temperature-compensated estimate of accumulated particulate matter in the after-treatment component.

Abstract: A particulate estimation system is configured for estimating a mass of particulate matter accumulated in a particulate filter of an exhaust system. The system includes a memory device, an interface, and a controller. The memory device stores a plurality of modules. Each of the plurality of modules is configured to uniquely estimate an amount of the particulate matter accumulated within the particulate filter over a period of time. The interface receives a plurality of input signals. The plurality of input signals correspond to a plurality of modules that are stored in the memory device. The controller derives a hybrid model based on the input signals. The hybrid model is configured to provide an output that is an estimation of the amount of particulate matter accumulated within the particulate filter over the period of time as a function of the plurality of input signals.

Abstract: A method for controlling regeneration within an after-treatment component of a compression-ignition engine includes receiving a value of a parameter associated with an exhaust stream passing through the after-treatment component and determining a rate of change of the parameter. A filtered parameter value is calculated based on the value of the parameter, the rate of change of the parameter, and a predetermined filtering relationship for the parameter. Accumulated particulate matter in the after-treatment component is estimated based, at least, on a soot accumulation model and the filtered parameter value. The estimate of accumulated particulate matter in the after-treatment component is compared to a predetermined threshold associated with the after-treatment component, and a remedial action is initiated when the estimate of accumulated particulate matter in the after-treatment component exceeds the predetermined threshold.

Abstract: A method for controlling regeneration within an after-treatment component of an engine comprises receiving an upstream temperature signal representing a temperature of an exhaust stream upstream from the after-treatment component and calculating an expected downstream temperature based on the upstream temperature signal and a model for calculating the expected downstream temperature. A temperature index is calculated based on the upstream temperature signal and the expected downstream temperature, and an estimate of accumulated particulate matter in the after-treatment component is calculated based, at least in part, on the temperature index. The estimate of accumulated particulate matter in the after-treatment component is compared to a predetermined threshold associated with the after-treatment component, and a remedial action is initiated when the estimate of accumulated particulate matter in the after-treatment component exceeds the predetermined threshold.

Abstract: Method for controlling regeneration within an after-treatment component of an engine comprises receiving an upstream temperature signal, receiving a downstream temperature signal, and calculating a temperature difference based on a difference between the upstream temperature signal and the downstream temperature signal. The temperature difference is compared to a predetermined temperature change limit to determine whether the temperature difference is less than or greater than the predetermined temperature change limit. If the temperature difference is less than the predetermined temperature change limit, an estimate of accumulated particulate matter in the after-treatment component is calculated using a primary soot accumulation model. If the temperature difference is greater than the predetermined temperature change limit, an estimate of accumulated particulate matter in the after-treatment component is calculated using a secondary soot accumulation model.

Abstract: An amount of particulate matter accumulated in a particulate filter of an exhaust system is estimated by preloading a memory location with a plurality of hybrid models. Each hybrid model estimates an amount of particulate matter accumulated in the particulate filter between a pair of operating points. An estimated amount of particulate matter accumulated in the particulate filter is stored in the memory location for each hybrid model. Each hybrid model is ranked based on estimation accuracy during operating conditions and the highest ranked hybrid model is selected. The estimated amount of particulate matter accumulated in the particulate filter corresponding to the highest ranked hybrid model is added to the soot estimation value stored in the memory location that corresponds to a ranked hybrid model to provide a soot estimation value of a cumulative estimated amount of particulate matter contained in the particulate filter for the ranked hybrid model.

Abstract: A method of controlling the regeneration of a particulate filter includes defining a regeneration trigger limit for at least one operating parameter of the vehicle, modifying the regeneration trigger limit based upon a sensed ambient operating condition and a sensed vehicle operating condition to define a modified regeneration trigger limit, and regenerating the particulate filter when the modified regeneration trigger limit for the operating parameter is reached.

Abstract: In one exemplary embodiment of the invention, a method of regenerating a particulate filter includes flowing an exhaust gas from an internal combustion engine into a particulate filter and determining a particulate level in the particulate filter. The method also includes performing a primary regeneration when the particulate level is below a first value, the primary regeneration including flowing exhaust gas with a selected amount of hydrocarbons in the exhaust gas into the particulate filter, and performing a secondary regeneration when the particulate level is above the first value, the secondary regeneration including flowing exhaust gas with an increased amount of nitrogen oxide into the particulate filter.

Abstract: A method of establishing a mass flow rate of air entering an engine includes establishing an input voltage by an energy supply device to energize a mass-air-flow sensor. The method also includes generating an output frequency via the mass-air-flow sensor in response to the mass flow rate of air entering the engine and determining the flow rate using the generated output frequency. The method additionally includes comparing the generated output frequency with a predetermined threshold output frequency that corresponds to the established input voltage. Additionally, the method includes selecting the determined flow rate as the established flow rate if the generated output frequency is at or below the predetermined threshold output frequency. Furthermore, the method includes selecting a predetermined alternative algorithm to generate the established flow rate if the generated output frequency is above the predetermined threshold output frequency. A system for establishing the mass flow rate is also provided.

Abstract: A method of establishing a mass flow rate of air entering an engine includes establishing an input voltage by an energy supply device to energize a mass-air-flow sensor. The method also includes generating an output frequency via the mass-air-flow sensor in response to the mass flow rate of air entering the engine and determining the flow rate using the generated output frequency. The method additionally includes comparing the generated output frequency with a predetermined threshold output frequency that corresponds to the established input voltage. Additionally, the method includes selecting the determined flow rate as the established flow rate if the generated output frequency is at or below the predetermined threshold output frequency. Furthermore, the method includes selecting a predetermined alternative algorithm to generate the established flow rate if the generated output frequency is above the predetermined threshold output frequency. A system for establishing the mass flow rate is also provided.

Abstract: An amount of particulate matter accumulated in a particulate filter of an exhaust system is estimated by preloading a memory location with a plurality of hybrid models. Each hybrid model estimates an amount of particulate matter accumulated in the particulate filter between a pair of operating points. An estimated amount of particulate matter accumulated in the particulate filter is stored in the memory location for each hybrid model. Each hybrid model is ranked based on estimation accuracy during operating conditions and the highest ranked hybrid model is selected. The estimated amount of particulate matter accumulated in the particulate filter corresponding to the highest ranked hybrid model is added to the soot estimation value stored in the memory location that corresponds to a ranked hybrid model to provide a soot estimation value of a cumulative estimated amount of particulate matter contained in the particulate filter for the ranked hybrid model.

Abstract: A particulate estimation system is configured for estimating a mass of particulate matter accumulated in a particulate filter of an exhaust system. The system includes a memory device, an interface, and a controller. The memory device stores a plurality of modules. Each of the plurality of modules is configured to uniquely estimate an amount of the particulate matter accumulated within the particulate filter over a period of time. The interface receives a plurality of input signals. The plurality of input signals correspond to a plurality of modules that are stored in the memory device. The controller derives a hybrid model based on the input signals. The hybrid model is configured to provide an output that is an estimation of the amount of particulate matter accumulated within the particulate filter over the period of time as a function of the plurality of input signals.

Abstract: A method unloads hydrocarbon emissions deposited by an exhaust gas on an after-treatment device that is employed in an exhaust system for an internal combustion engine. The method includes determining whether the engine has been operating at a preset idle speed for a predetermined amount of time. The method also includes increasing the preset idle speed by a predetermined value if the engine has been operating at a preset idle speed for a predetermined amount of time. The increasing of the engine idle speed increases a flow rate of the exhaust gas to the after-treatment device and unloads the deposited hydrocarbon emissions. A system for unloading hydrocarbon emissions deposited on an after-treatment device and a vehicle employing such a system are also disclosed.

Abstract: A method for controlling regeneration of an exhaust after-treatment device for an internal combustion engine in a vehicle includes establishing a baseline value for a mass of soot collected in the exhaust after-treatment device. The baseline value is a threshold mass of soot to be reached for regenerating the filter, and is determined as a function of a speed of the engine and a quantity of fuel entering the engine. The method also includes modifying the baseline value in response to an engine operating parameter that alters a fuel-air ratio of a combustible mixture entering the engine to generate a modified baseline value. The method additionally includes regenerating the exhaust after-treatment device using the modified baseline value. A system for controlling regeneration of an exhaust after-treatment device for an internal combustion engine is also provided.

Abstract: A method of controlling the regeneration of a particulate filter includes defining a regeneration trigger limit for at least one operating parameter of the vehicle, modifying the regeneration trigger limit based upon a sensed ambient operating condition and a sensed vehicle operating condition to define a modified regeneration trigger limit, and regenerating the particulate filter when the modified regeneration trigger limit for the operating parameter is reached.