Abstract: A method and apparatus is provided for regenerating an after-treatment device associated with an exhaust system of an internal combustion engine. A lambda error control provides a lambda error signal based upon a measured lambda value and a predetermined lambda value indicative of rich operation. An after-injection map provides an after-injection preset based upon a speed and a torque of the internal combustion engine. A main injection map provides a torque-making main injection preset based upon the speed of the internal combustion engine and the torque of the internal combustion engine. A controller is configured to provide an after-injection quantity signal based upon the after-injection preset, the lambda error signal and a main injection quantity signal based upon the main injection preset and the lambda error signal such that the measured lambda value is maintained within a regeneration range.

Abstract: A method and apparatus is provided for regenerating an after-treatment device associated with an exhaust system of an internal combustion engine. A lambda error control provides a lambda error signal based upon a measured lambda value and a predetermined lambda value indicative of rich operation. An after-injection map provides an after-injection preset based upon a speed and a torque of the internal combustion engine. A main injection map provides a torque-making main injection preset based upon the speed of the internal combustion engine and the torque of the internal combustion engine. A controller is configured to provide an after-injection quantity signal based upon the after-injection preset, the lambda error signal and a main injection quantity signal based upon the main injection preset and the lambda error signal such that the measured lambda value is maintained within a regeneration range.

Abstract: An aftertreatment system for an internal combustion system includes an exhaust duct, an oxidation catalyst disposed in the exhaust duct and a particulate filter disposed in the exhaust duct downstream of the oxidation catalyst. The internal combustion engine is operated to perform a regeneration process of the particulate filter. A first value of exhaust gas temperature in the exhaust duct between the oxidation catalyst and the particulate filter is determined. A second value of exhaust gas temperature in the exhaust duct downstream of the particulate filter is determined. A malfunctioning of the oxidation catalyst is determined when the first value of exhaust gas temperature is below a first predetermined threshold value thereof and contemporaneously the second value of exhaust gas temperature is above a second predetermined threshold value thereof during the regeneration process.

Abstract: An aftertreatment system for an internal combustion system includes an exhaust duct, an oxidation catalyst disposed in the exhaust duct and a particulate filter disposed in the exhaust duct downstream of the oxidation catalyst. The internal combustion engine is operated to perform a regeneration process of the particulate filter. A first value of exhaust gas temperature in the exhaust duct between the oxidation catalyst and the particulate filter is determined. A second value of exhaust gas temperature in the exhaust duct downstream of the particulate filter is determined. A malfunctioning of the oxidation catalyst is determined when the first value of exhaust gas temperature is below a first predetermined threshold value thereof and contemporaneously the second value of exhaust gas temperature is above a second predetermined threshold value thereof during the regeneration process.

Abstract: A method is disclosed for managing the transition between a lean combustion mode and a rich combustion mode, or vice versa. After a regeneration demand, or at the end of the regeneration phase, the air mass flow is modified from a first set point to a new set point within a predetermined time depending on the engine conditions. An air mass percentage value is cyclically calculated and compared with a target value. When the target value is reached, the fuel path is then suddenly switched to compensate the torque change due to different combustion modes and to achieve the desired rich or lean condition.

Abstract: A method is provided for controlling the regeneration process of a LNT device for the treatment of exhaust produced by an internal combustion engine. The method includes, but is not limited to storing a plurality of parameters in the form of preset values which relate to admissible regenerating conditions, receiving a regeneration request, measuring the current values of the parameters to define the current operating conditions of the engine and the LNT device, comparing the current values with the preset values of a corresponding parameter to evaluate if the current operating conditions of the engine and of the LNT device satisfy the admissible regenerating conditions for carrying out the regeneration process, and inhibiting the regeneration process if at least one current value of a corresponding parameter does not satisfy the admissible regenerating conditions for carrying out the regeneration process.