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.

A method to control an internal combustion engine provided with an exhaust system for the exhaust gases of a vehicle having an exhaust duct and an exhaust gas after-treatment system comprising at least one catalytic converter arranged along the exhaust duct; a burner suited to introduce the exhaust gases into the exhaust duct to speed up the heating of said at least one catalytic converter, wherein a combustion chamber is defined inside the burner which receives fuel from an injector, designed to inject the fuel inside the combustion chamber and the fresh air by means of an air feeding circuit provided with a pumping device that feeds the air, a shut-off valve arranged upstream of the burner and a mass air flow sensor interposed between the pumping device and the shut-off valve; the method provides the following steps: calculating the thermal power required to reach the nominal operating temperature of said at least one catalytic converter; determining the objective air flow rate to be fed to the burner to obtain said thermal power required to reach the nominal operating temperature of said at least one catalytic converter; determining the nominal number of revolutions with which to operate the pumping device by means of a map depending on the objective air flow rate, on the ambient pressure, on the ambient temperature and on the pressure of the air entering the burner; determining a closed-loop contribution of the number of revolutions with which to operate the pumping device by means of a PID controller which tries to zero a difference between the objective air flow rate and the air flow rate detected by the mass air flow sensor; determining a further contribution of the number of revolutions with which to operate the pumping device depending on the integral action of the PID controller under stationary conditions; and determining the actual number of revolutions with which to operate the pumping device by the sum of the nominal number of revolutions, the closed-loop contribution of the number of revolutions with which to operate the pumping device and the further contribution of the number of revolutions with which to operate the pumping device.

A method for diagnosing a NOx sensor is provided. The method includes receiving data indicative of operating conditions of an engine or an aftertreatment system; determining, during a first period of time, that an amount of NOx output from the aftertreatment system satisfies a low NOx operating mode condition; determining, during a second period of time, that operating conditions for ammonia slip are present based on data regarding operation of the aftertreatment system; responsive to the determination that operating conditions for ammonia slip are present, determining that the amount of NOx output from the aftertreatment system satisfies a high NOx operating mode condition; comparing a difference between a minimum value from the first period of time and a maximum value from a second period of time to a diagnostic threshold; and responsive to the difference being less than the diagnostic threshold, setting an alert.

A heating system includes a plurality of heater elements, a plurality of switches connected to the plurality of heater elements, a set of predetermined performance information including heater information specific for each heater element, at least one temperature sensor measuring temperature of at least one heater element from among the plurality of heater elements, and a heater control unit in communication with the temperature sensor(s). The heater control unit controls the heater elements differently, via the switches, based on the heater information and the measured temperature from the temperature sensor(s).

Systems and methods for controlling a regeneration process of catalyst(s) are disclosed. The method includes receiving, via Kalman filter, initial estimation from a previous instance of time. The initial estimation includes one or more first estimated inside temperature(s) and/or first estimated outlet temperature of A/T catalyst. An output from a simulation model may be generated to calculate a mean and covariance. Sensor measurement covariance may be compared against the mean and covariance of the output to update Kalman filter gain and process covariance. A weighted average may be calculated between sensor measurements and mean of the output to generate a second estimation for the next instance of time, wherein weight is based on Kalman filter gain. The second estimation includes one or more second estimated inside temperature(s) and/or second estimated outlet temperature of A/T catalyst to control the mass flow rate in diesel engine via a closed loop control system.

A method (200) for ascertaining a catalytic converter state is proposed, wherein an exhaust-gas catalytic converter (130) is monitored on the basis of a catalytic converter model. Here, the catalytic converter model is adapted (250) in a manner dependent on measured values detected by means of one or more sensors (145, 147), wherein a frequency and/or a degree of the adaptation of the catalytic converter model is detected (260). The catalytic converter state is ascertained (270) as non-critical if the frequency and/or the degree of the adaptation do not exceed a predeterminable threshold value or is ascertained (270) as critical if the frequency and/or the degree of the adaptation exceed the predeterminable threshold value.

Methods and systems are provided for a turbocharger. In one example, a method may include flowing bleed air to control a catalyst temperature. The bleed air is directed from a bleed port of a compressor of an engine system.

The disclosure relates to a self-adaptive oil spraying control system and method for a biodiesel engine. The control system includes an exhaust pipe, a gas sensor, a control module and an oil sprayer, wherein the exhaust pipe is connected to the oil sprayer, the gas sensor is mounted in the exhaust pipe, and the gas sensor and the oil sprayer are connected to the control module respectively. According to the control method, a main spray advance angle of the engine is subjected to closed-loop control directly through comparison between an idling steady state NO.sub.x emission signal and an idling steady state NO.sub.x emission value of pure diesel when the engine uses the biodiesel, so that emission of NO.sub.x in the exhaust is reduced. Compared with the prior art, the disclosure has the advantages of no need of detecting a biodiesel ratio, high efficiency, good effect and the like.

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).

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.