Systems and methods for controlling a dosing of reductant for an internal combustion engine system including a catalyst are disclosed. The method includes measuring a value indicative of inlet temperature of the catalyst. When the inlet temperature is less than or equal to a first threshold, the method includes adjusting the dosing of reductant according to a first process. When the inlet temperature is greater than the first threshold, the method includes adjusting the dosing of reductant according to a second process, the second process being different than the first process.

The present disclosure relates to a control unit (8) for controlling reactivation of a lean NOx trap (LNT) disposed in an exhaust system (3) connected to an internal combustion engine (2), the control unit (8). The control unit (8) has at least one processor (11) configured to generate a reactivate flag (RF) for the LNT (6). A memory device (12) having instructions stored therein is coupled to the at least one processor (11). The at least one processor (11) is configured to generate the reactivate flag (RF) when the exhaust gas supplied to the LNT (6) is lean and an LNT temperature (T.sub.LNT) is greater than or equal to a predefined LNT temperature threshold (T1). The present disclosure also relates to a method of controlling reactivation of the LNT (6). The present disclosure also relates to a vehicle comprising reactivation control apparatus.

A method is provided for managing the light-off of a 3-way catalytic converter that is located in an exhaust line of a petrol engine having a plurality of cylinders with each cylinder having at least one exhaust valve. The method includes calculating a value of enthalpy of exhaust gases to make it possible to determine a quantity of heat supplied to the three-way catalyst, determining a threshold enthalpy value signaling the light-off of the catalyst, and stopping of activation of the three-way catalyst upon determining the value of the enthalpy that was calculated has reached the threshold enthalpy value.

In a process for adapting an amount of reducing agent for a removal of nitrogen oxides from the gases in an exhaust line, a first alignment of the amounts of nitrogen oxides measured by upstream and downstream sensors is performed without injection of agent and with a catalyst of the system emptied of ammonia. A second alignment of the estimated reduction of nitrogen oxides with the measured reduction is performed by a difference between amounts of nitrogen oxides upstream and downstream during a substoichiometric injection of reducing agent without creating a store of ammonia in a catalyst of the system with a first correction of the amount of agent. A third alignment of an estimated efficiency of retaining nitrogen oxides with a efficiency measured by the sensors is performed, this third alignment taking place via a second correction of the amount of reducing agent injected as an adaptive correction.

An exhaust aftertreatment system includes a catalyst, an exhaust conduit system, a first sensor, a second sensor, a reductant pump, a dosing module, and a reductant delivery system controller. The exhaust conduit system is coupled to the catalyst. The first sensor is coupled to the exhaust conduit system upstream of the catalyst and configured to obtain a current first measurement upstream of the catalyst. The second sensor is coupled to the exhaust conduit system downstream of the catalyst and configured to obtain a current second measurement downstream of the catalyst. The reductant pump is configured to draw reductant from a reductant source. The dosing module is fluidly coupled to the reductant pump and configured to selectively provide the reductant from the reductant pump into the exhaust conduit system upstream of the catalyst. The reductant delivery system controller is communicable with the first sensor, the second sensor, the reductant pump, and the dosing module.

An urea injection control system for an internal combustion engine, specifically adapted to apply a scheme for decreasing a NOx level downstream of a selective catalytic reduction catalyst of an ICE related exhaust gas aftertreatment system. The present disclosure also relates to a corresponding computer implemented method and a computer program product.

A system comprising an aftertreatment system comprising: a catalyst member, and a first exhaust conduit upstream of the catalyst member; a first temperature sensor operatively coupled to the catalyst member; a flow sensor coupled to the first exhaust conduit; and a controller. The controller determines a temperature of the catalyst member, a flow rate of exhaust within the first exhaust conduit, and a space velocity of the exhaust within the catalyst member. The controller determines a first degradation value indicative of a degradation of the catalyst member. The controller determines a first difference between the first degradation value and a first degradation reference value and a second difference between the first degradation value and a second degradation reference value. After determining that the first difference is less than the second difference, the controller selects a first calibration metric. The controller determines a first efficiency value associated with the catalyst member.

The invention concerns a method for controlling regeneration of an exhaust gas aftertreatment system (7, 8) of an internal combustion engine (4) arranged on a vehicle (1), wherein the vehicle (1) is provided with a control system configured to control the regeneration in at least a first regeneration strategy mode comprising a first set of predetermined actions to be taken for controlling initialization and performance of regeneration processes. The method comprises the steps of: (100)—adapting the control system so as to be configured to alternatively control the regeneration in a second regeneration strategy mode, wherein the second regeneration strategy mode comprises a second set of predetermined actions to be taken for controlling initialization and performance of regeneration processes, and wherein the first and second regeneration strategy modes differ from each other in that the first and second set of predetermined regeneration control actions differ from each other; (200)—collecting, during operation of said vehicle (1) or of another vehicle, data on an exhaust gas regeneration capability of said vehicle (1) or the other vehicle as a function of time; and (300)—evaluating, based on the collected data and the difference between the first and second regeneration strategy modes, whether the first or the second regeneration strategy mode is the most suitable for said vehicle (1) if operating under conditions corresponding to the operational conditions for the vehicle for which data were collected. The invention also concerns a vehicle arranged to be the subject of such a method and to a computer program product, a computer readable medium and a control system related to performance of the steps of the above method.

A method includes acquiring nitrogen oxide (NOx) data indicative of a first amount of NOx in an exhaust flow exiting an engine and a second amount of NOx in the exhaust flow exiting an exhaust aftertreatment system coupled to the engine where the exhaust aftertreatment system including a selective catalytic reduction (SCR) system including a SCR catalyst; determining a NOx conversion efficiency fault is present within the exhaust aftertreatment system based on the first amount of NOx and the second amount of NOx; monitoring an actual amount of NOx in the exhaust flow downstream of the SCR catalyst; determining an expected amount of NOx downstream of the SCR catalyst; and determining the SCR catalyst is responsible for the NOx conversion efficiency fault in response to the actual amount of NOx differing from the expected amount of NOx by more than a threshold amount.

The present invention relates to a method for diagnosing aftertreatment of exhaust gases resulting from combustion, wherein at least a first substance resulting from said combustion is reduced by supplying additive to an exhaust gas stream resulting from said combustion and use of a first reduction catalytic converter. The method includes: estimating an accumulated expected reduction of said first substance during a first period of time, determining an accumulated actual reduction of said first substance during a period of time at least substantially overlapping said first period of time, and generating a signal indicating a fault in said reduction of said first substance when said accumulated actual reduction differs from said accumulated expected reduction by a predetermined difference in occurrence of said first substance. The invention also relates to a corresponding system.