An internal combustion engine comprises an exhaust purification catalyst arranged in an exhaust passage of the internal combustion engine and being able to store oxygen in inflowing exhaust gas and an air-fuel ratio sensor arranged at a downstream side of the exhaust purification catalyst in a direction of exhaust flow and detecting an air-fuel ratio of exhaust gas flowing out from the exhaust purification catalyst and stops or decreases a feed of fuel to a combustion chamber as fuel cut control. The abnormality diagnosis system calculates a characteristic of change of an air-fuel ratio based on an output air-fuel ratio output from the air-fuel ratio sensor at the time when the output air-fuel ratio first passes a part of an air-fuel ratio region of a stoichiometric air-fuel ratio or more after an end of the fuel cut control, and diagnoses abnormality of the air-fuel ratio sensor based on the characteristic of change of the air-fuel ratio. As a result, the diagnosis system can diagnose the abnormality of deterioration of response of the downstream side air-fuel ratio sensor when necessary without fail when performing fuel cut control.

In a control apparatus for an internal combustion engine in which processing of regenerating the NOx storage capacity of an NSR catalyst is carried out in accompany with processing of diagnosing an abnormality in an exhaust gas purification device including the NSR catalyst, the present invention is intended to suppress the fluctuation of torque at the time of regenerating the NOx storage capacity of the NSR catalyst, and to terminate abnormality diagnostic processing quickly. According to the invention, by setting an engine air fuel ratio, which has been set to a lean air fuel ratio before the processing of regenerating the NOx storage capacity of the NSR catalyst is started, to a weak lean air fuel ratio which is lower than a basic lean air fuel ratio and higher than a stoichiometric air fuel ratio, it becomes possible to suppress the fluctuation of torque at the time of regeneration processing being started, and to terminate abnormality diagnostic processing at an early period of time.

A method of regenerating a lean NOx trap (LNT) of an exhaust purification system provided with the LNT and a selective catalytic reduction (SCR) catalyst may include: determining whether a regeneration release condition of the LNT is satisfied; determining whether a regeneration demand condition of the LNT is satisfied; and performing regeneration of the LNT if the regeneration release condition of the LNT and the regeneration demand condition of the LNT are satisfied. In particular, the regeneration release condition of the LNT is satisfied if all of an engine operating condition, an LNT state condition, and a lambda sensor synchronization condition are satisfied.

A method for controlling regeneration a catalyst by an exhaust gas purification device includes: measuring a temperature of exhaust gas flowing into a first catalyst unit; estimating a NO.sub.x amount loaded into the first catalyst unit and a slip amount of NO.sub.x of the first catalyst unit by using the temperature and an amount of the exhaust gas of the first catalyst unit; calculating a temperature of a second catalyst unit by using the temperature of the first catalyst unit; and estimating a NO.sub.x amount flowing into the second catalyst unit by using at least one of the slip amount of NO.sub.x of the first catalyst unit and the temperature of the second catalyst unit.

A method for cleaning an SCR system, wherein reducing agent is supplied to an exhaust flow upstream of an SCR catalyst (260), NO.sub.X contents of the exhaust flow are determined upstream and downstream of the SCR catalyst (260) and reducing agent crystals are removed by a high-temperature procedure. The steps are determining (s430) a ratio (K1) between NO.sub.X contents downstream and upstream of the SCR catalyst (260), raising the temperature (s440) of the exhaust flow to vaporize reducing agent crystals with a view to cleaning, determining (s450) a ratio (Kn) between respective NO.sub.X contents determined downstream and upstream of the SCR catalyst (260) at a temperature (T2) of the SCR catalyst (260) at which reducing agent crystals vaporize, comparing (s460) the ratios (K1, Kn) and using this comparison as a basis for deciding whether reducing agent crystals have been removed to an intended extent. Also a computer program product containing program code (P) for a computer (200; 210) for implementing the method according to the invention. The invention relates also to a device and a motor vehicle equipped with the device.

A computer-implemented method for detecting a manipulation of a technical device. The method includes: providing time characteristics of operating variables having system variable(s) and/or a correction variable for an intervention in the technical device which correspond to time series of values of the operating variables for each of consecutive time steps; using a data-based manipulation detection model in each current time step to ascertain one or more output variable(s) that correspond at least to a portion of the operating variables as a function of input variables which include at least a portion of the operating variables. The manipulation detection model includes an autoencoder having a first recurrent neural network, a prediction model having a second recurrent neural network, and an evaluation model, the outputs of the autoencoder and the prediction model being combined with one another and then conveyed to an evaluation model for an ascertainment of the output variables.

Systems, apparatuses, and methods include an upstream exhaust analysis circuit structured to determine a characteristic of an exhaust gas stream entering a nitrous oxide (NOx) storage catalyst; a prediction circuit structured to predict a downstream NOx concentration of an exhaust gas stream exiting the NOx storage catalyst based on a model of a NOx storage capacity or a dynamic response of the NOx storage catalyst; a downstream exhaust analysis circuit structured to determine a downstream NOx concentration of the exhaust gas stream exiting the NOx storage catalyst; and a comparison circuit structured to compare the predicted downstream NOx concentration to the determined downstream NOx concentration, and determine a health of the NOx storage catalyst based on the comparison.

A method for warming an aftertreatment system of an engine system while an engine of the engine system is not running comprising starting at least one of an electric compressor and an electric heater using stored electrical energy and passing air through the engine system to at least a portion of the aftertreatment system when the engine of the engine system is not running.

A method for diagnosing a diesel oxidation catalyst fault includes: obtaining an standard molar enthalpy of formation-revolution speed-load table; obtaining a revolution speed, a load, a temperature difference of front and rear exhaust pipes, and a casing temperature, obtaining an standard molar enthalpy of formation corresponding to the revolution speed and the load from the standard molar enthalpy of formation-revolution speed-load table, and calculating an actual formation enthalpy corresponding to the temperature difference of front and rear exhaust pipes and the casing temperature from the temperature difference of front and rear exhaust pipes and the casing temperature; calculating a standard reaction enthalpy from the standard molar enthalpy of formation and standard conversion efficiency; and diagnosing a diesel oxidation catalyst fault by comparing the actual formation enthalpy with the standard reaction enthalpy. The method is capable of realizing online fault diagnosis on a diesel oxidation catalyst without the disassembly of the diesel oxidation catalyst.

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.