A method for reducing sensor noise in an automobile vehicle NOx sensor offset diagnostic includes: connecting an exhaust system to an engine of an automobile vehicle; sensing a condition of the exhaust system using at least one NOx sensor; identifying when the at least one NOx sensor is at a low noise condition; and running a diagnostic to identify conditions of the at least one NOx sensor. The method further includes selecting one of the low noise condition as the engine in an after-run condition or as the engine in an engine idle condition.

The present disclosure relates to a method for determining urea feeding in an exhaust gas aftertreatment system (100,200), the exhaust gas aftertreatment system (100,200) being connectable to an internal combustion engine (101,201) operating under an engine operating condition, the system (100,200) comprising a first Selective Catalytic Reduction (SCR1) system comprising a first selective reduction catalyst (SCR1c) and a first doser (103,203) configured for feeding urea upstream the SCR1 system, at least one Particulate Filter (PF) downstream the SCR1 system or as a substrate for the SCR1c and a second Selective Catalytic Reduction (SCR2) system downstream the PF, the SCR2 system comprising a second selective reduction catalyst (SCR2c) and a second doser (104,204) configured for feeding urea upstream the SCR2c, the method comprising the steps of estimating the amount of particles in the PF; and determining the amount of urea to be fed by the respective first and second doser (4,5) based on the engine operating condition and such that: a) the amount of particles in the PF is within a predefined particle amount range, and, b) the NOx level of the exhaust gas exiting the SCR2 system is within a predetermined NOx level range. The present disclosure also relates to an exhaust gas aftertreatment system (100,200) and a vehicle comprising the exhaust gas aftertreatment system (100,200), a computer program comprising program code means for performing the steps of the method, a computer readable medium carrying a computer program comprising program code means for performing the steps of the method and a control unit for controlling urea feeding in the exhaust gas aftertreatment system (100,200).

A system for controlling emissions of a motor-vehicle spark-ignition internal combustion engine includes first and second exhaust gas treatment devices and a secondary air feeding system for feeding secondary air into an exhaust gas conduit, between the first and second exhaust gas treatment devices. The secondary air feeding system is activated only when engine load is greater than a predetermined load value and/or when engine rotational speed is greater than a predetermined speed value. In this condition, an air/fuel ratio of the engine is kept at a value lower than the stoichiometric value, so as to feed the engine with a rich mixture. In one example, an electronic controller is configured for controlling activation of the secondary air feeding system on the basis of a map, as a function of values of the engine load and rotational speed. The map is predetermined depending upon specific characteristics of the engine.

To keep catalyst purification efficiency high and prevent deterioration of emission performance. Therefore, an internal combustion engine control device according to an aspect of the present invention includes: an oxygen storage ratio calculation unit that calculates an oxygen storage ratio of a catalyst based on a catalytic reaction model having at least a detection value of a first exhaust gas sensor disposed on an upstream side of the catalyst as an input; a statistical model calculation unit that predicts a catalyst downstream exhaust gas concentration using a statistical model having an oxygen storage ratio as an input and a catalyst downstream exhaust gas concentration as an output; and an air-fuel ratio correction amount calculation unit that calculates an air-fuel ratio correction amount of an air-fuel mixture of an internal combustion engine based on a future catalyst downstream exhaust gas concentration calculated by the statistical model calculation unit.

An aftertreatment system comprises a SCR system, a reductant injector operatively coupled to the SCR system, and a reductant insertion assembly operatively coupled to the reductant injector. The reductant insertion assembly comprises a pump configured to pump the reductant through the reductant injector. A controller is operatively coupled to the reductant insertion assembly and configured to receive predetermined calibration values of the pump corresponding to delivery of a reductant by the pump through a calibration injector. The controller determines a desired flow rate value of the reductant into the SCR system. The controller determines an insertion time of the reductant injector for delivering the reductant through the reductant injector based on the desired flow rate value, a pump operating parameter value of the pump and the predetermined calibration values, and activates the reductant injector for the insertion time.

A method for reducing sensor noise in an automobile vehicle NOx sensor offset diagnostic includes: connecting an exhaust system to an engine of an automobile vehicle; sensing a condition of the exhaust system using at least one NOx sensor; identifying when the at least one NOx sensor is at a low noise condition; and running a diagnostic to identify conditions of the at least one NOx sensor. The method further includes selecting one of the low noise condition as the engine in an after-run condition or as the engine in an engine idle condition.

An assembly for treating gaseous emissions has a ceramic substrate body through which extend passages. The assembly has metal wires in selected ones of the passages, a first section of each wire electrically connected at one end thereof to an end of a second wire section and a distal end of the second section electrically connected to one end of a third wire section. The first and third wire sections are composed of a material having a lower electrical resistance than that of the second wire section. Part of each second wire section is located in a respective one of the selected passages.

Disclosed is a device for injecting ammonia in gaseous form into an exhaust line of a combustion engine, the device including a supervisor, an evaporation chamber incorporating a heater for heating a quantity of reducing agent thus releasing ammonia in gaseous form that exits the evaporation chamber via a pipe opening into the exhaust line. The control supervisor is associated with an internal first pressure sensor housed in the evaporation chamber and with a second pressure sensor intended to be housed in the exhaust line, including a calculator calculating a quantity of ammonia to be injected into the exhaust line at a given instant as a function of the pressure values from the first and second pressure sensors.

Controlling exhaust after-treatment in a heavy-duty motor vehicle includes operating a diesel engine of a heavy-duty truck such that the diesel engine generates an exhaust gas flow that enters an exhaust after-treatment system of the heavy-duty truck, the exhaust after-treatment system including a selective catalytic reduction system, measuring a level of NO.sub.x gases in the exhaust gas flow downstream of the selective catalytic reduction system, and controlling a diesel exhaust fluid injector upstream of the selective catalytic reduction system to inject diesel exhaust fluid into the exhaust gas flow upstream of the selective catalytic reduction system at an injection rate that is based on the measured level of NO.sub.x gases.

A method for controlling a filtering efficiency of a filter including a filtering area between an inflow area and an outflow area. Determining a present exhaust mass flow into the filter. Determining a pressure drop across the filter from the inflow area and the outflow area of the filter. Normalizing the measured pressure drop to provide a normalized pressure drop according to a predetermined normalization pressure level at a predetermined temperature for a model filter. Comparing the normalized pressure drop to a pressure drop model including a relation between the pressure drop across a filter and exhaust mass flow to the filter. Determining a pressure deviation between the normalized pressure drop and a pressure drop value calculated based on the pressure drop model and the present exhaust gas flow. Controlling the pressure drop across the filter for reducing the pressure deviation.