The present invention relates to a method for correcting a supply of additive to an exhaust gas stream resulting from combustion in an internal combustion engine. A first aftertreatment component being arranged for oxidation of nitric oxide into nitrogen dioxide, and a reduction catalytic converter being arranged downstream said first aftertreatment component. Additive is supplied to said exhaust gas stream for reduction of nitrogen oxides in said reduction catalytic converter, the additive being supplied in proportion to an occurrence of nitrogen oxides in said exhaust gas stream, said proportion being subject to correction. The method includes: supplying unburned fuel to said exhaust gas stream upstream said first aftertreatment component to reduce oxidation of nitric oxide into nitrogen dioxide in said first aftertreatment component, and correcting said supply of additive to said exhaust gas stream when supplying unburned fuel to said exhaust gas stream.

A hybrid electric vehicle and a catalyst heating control method are configured to select a point in time at which catalyst heating control is performed and to perform a follow-up measure based on the selected point in time. The catalyst heating control method includes performing mode switching from a first mode in which only a drive motor is used as a driving source to a second mode in which an engine is driven in a state in which a drive shaft and the engine are disconnected from each other to start heating of a catalyst of the engine. When demand torque higher than a maximum output of the drive motor occurs before the catalyst heating is completed, the second mode is maintained until the demand torque is greater than the sum of the maximum output and a predetermined margin.

The present invention relates to a method for correcting a supply of additive to an exhaust gas stream resulting from combustion in an internal combustion engine. A first aftertreatment component being arranged for oxidation of nitric oxide into nitrogen dioxide, and a reduction catalytic converter being arranged downstream said first aftertreatment component. Additive is supplied to said exhaust gas stream for reduction of nitrogen oxides in said reduction catalytic converter, the additive being supplied in proportion to an occurrence of nitrogen oxides in said exhaust gas stream, said proportion being subject to correction. The method includes: supplying unburned fuel to said exhaust gas stream upstream said first aftertreatment component to reduce oxidation of nitric oxide into nitrogen dioxide in said first aftertreatment component, and correcting said supply of additive to said exhaust gas stream when supplying unburned fuel to said exhaust gas stream.

The subject matter of the present invention relates to trained machine-learning models (300), methods (200, 400) and apparatuses (500) allowing a future resonant frequency of a catalyst for selective reduction of nitrogen oxides (SCR) to be predicted, the resonant frequency being representative of a concentration of a reducing agent within the SCR. The SCR forms part of a system for after-treatment of a flow of exhaust gases of an internal combustion engine with which a motor vehicle is provided. The general principle of the invention is based on the observation of correlations between the resonant frequency of an SCR and the concentration of ammonia present within the SCR. This observation led the inventor to envision using machine learning to create a trained machine-learning model in order to predict the resonant frequency of an SCR. In the invention, the trained machine-learning model is a so-called predictive model in which significant correlations are discovered in a set of past observations and in which it is sought to generalize these correlations to cases that have not yet been observed.

When an internal combustion engine is driven at a low rate below a certain threshold value, exemplary embodiments as disclosed herein allow and restrict a reductant flow to an injector in repeating allowing cycles and restricting cycles. During the allowing cycles the controller is set to keep the reductant flow as close as possible a determined low point setpoint value. During the restricted cycles the reductant flow is prevented.

The present disclosure relates to an exhaust gas aftertreatment system and method for controlling same. The exhaust gas aftertreatment system comprises: a reductant dosing device; a selective catalytic reduction device arranged downstream of the reductant dosing device; an ammonia slip catalyst arranged downstream of the SCR device; a feedback NOx sensor arranged downstream of the SCR device and upstream of the ammonia slip catalyst; a tailpipe NOx sensor arranged downstream of the ammonia slip catalyst; and a control device configured for: providing an initial dosing of reductant from the reductant dosing device; obtaining a feedback signal from the feedback NOx sensor and a tailpipe NOx signal from the tailpipe NOx sensor; and adjusting the dosing of reductant until the feedback signal exceeds the tailpipe NOx signal by a value within a predetermined positive interval.

A reductant delivery system for an internal combustion engine is arranged to inject a reductant into the exhaust aftertreatment system upstream of a catalytic device. A method for controlling the reductant delivery system includes operating the fluidic pump at a preset state, operating the injector at a zero-flow state, and monitoring, via a pressure sensor, a pressure in the reductant delivery system upstream of the injector to determine a zero-flow pressure. The injector is activated under a preset condition and an actual pressure drop upstream of the injector is monitored. A pressure drop deviation is determined based upon the actual pressure drop upstream of the injector and an expected pressure drop upstream of the injector. An adjustment to the activation of the injector is determined based upon the pressure drop deviation, and the injector is controlled based upon the adjustment.

Method for operating an internal combustion engine which has a gas combustion system and an exhaust gas post-treatment system. Exhaust gas that leaves the gas combustion system is directed to at least one CH4 oxidation catalytic converter of the exhaust gas post-treatment system. The CH4/NO2 mole ratio in the exhaust gas is set in a defined fashion by at least one gas-combustion-system-side and/or exhaust-gas-post-treatment-system-side measure upstream of at least one CH4 oxidation catalytic converter.

System and methods for detecting NH.sub.3 slip using cross-sensitivity of an NO.sub.x sensor may include accessing a temperature value for a catalyst and determining the temperature value for the catalyst exceeds a predetermined value. If the temperature exceeds the predetermined value, a system-out NO.sub.x measurement signal from the system-out NO.sub.x sensor and an estimated system-out NO.sub.x value are used to calculate a delta value. A flag is set indicative of NH.sub.3 slip for an exhaust system responsive to an average of delta values for a predetermined period of time exceeding a predetermined value. If the temperature does not exceed the predetermined value, then an average of a plurality of system-out NO.sub.x measurement signals can be calculated and a flag is set indicative of NH.sub.3 slip responsive to the calculated average for a predetermined period of time exceeding a predetermined value.

Disclosed is an exhaust gas aftertreatment system (1) for a diesel engine, the exhaust gas aftertreatment system comprising: a treatment agent tank (2) for storing an exhaust gas treatment agent; a metering injection module (4), with the injection of the metering injection module (4) being controlled with a determined duty ratio signal according to a desired injection amount; a supply module (3) connected between the treatment agent tank (2) and the metering injection module (4) for supplying the exhaust gas treatment agent to the metering injection module (4); an exhaust gas treatment agent pipe (6) connected between the metering injection module (4) and the supply module (3); a pressure sensor for measuring the system pressure in the exhaust gas treatment agent pipe (6); and a controller (7); wherein the controller (7) is configured to receive a system pressure signal from the pressure sensor during injection of the metering injection module (4), and detect an injection abnormality of the metering injection module (4) based on at least a first amount, which represents an actual injection amount and is determined by the system pressure signal, and a second amount, which represents a theoretical injection amount and is determined by a corresponding duty ratio signal. A corresponding injection abnormality detection method is further disclosed. The injection abnormality detection method is simple and reliable.