A method for timing of a regeneration process of an exhaust gas system of a vehicle engine includes collecting, during operation of the vehicle, data on an exhaust gas regeneration capability as a function of time, establishing, from the collected data, a statistical probability function for the exhaust gas regeneration capability as a function of time, and identifying, from the probability function, one or several time periods that statistically are suitable and/or unsuitable for carrying out a regeneration process. A method for regeneration of an exhaust gas system of a vehicle engine is also provided.

A short cyclic thermal treatment process in an engine aftertreatment system of a diesel engine in a vehicle, which may be able to recover and/or retain NOx conversion performance of an engine aftertreatment system by keeping the system clean from unintended pollution like accumulated urea deposits. The thermal treatment process is controlled by a process controller, arranged to carry out a long cyclic cleaning process at a first time interval, at a first exhaust gas temperature higher than the operational temperature in regeneration mode; combined with a short cyclic thermal treatment process at a second time interval, at a second exhaust gas temperature higher than the operational temperature in non-regeneration mode; wherein the second elevated exhaust gas temperature is lower than the first temperature.

A method for desulphurising a nitrogen oxide accumulator catalytic converter of an exhaust gas system that includes the nitrogen oxide accumulator catalytic converter and at least one selective catalytic reduction catalytic converter disposed downstream of the nitrogen oxide accumulator catalytic converter, of an internal combustion engine, where a desulphurisation strategy, on the basis of which the nitrogen oxide accumulator catalytic converter is desulphurised, is adjusted to the ageing of the nitrogen oxide accumulator catalytic converter.

A method of controlling a heating element for providing heat to a catalyst of a catalytic converter, the method comprising: determining a catalyst performance characteristic as a function of time, and varying the amount of heating provided by the heating element in response to a change in the catalyst performance characteristic being greater than a predetermined amount.

A controller is configured to control an internal combustion engine. The controller is configured to execute a catalyst temperature-increasing control of increasing a temperature of the three-way catalyst device by introducing air-fuel mixture, which contains the fuel injected by a fuel injection valve, into an exhaust passage without burning the air-fuel mixture in a cylinder. The controller includes an air-fuel ratio control unit configured to control an air-fuel ratio of the air-fuel mixture during the execution of the catalyst temperature-increasing control such that the air-fuel ratio becomes a richer air-fuel ratio during a first period from a beginning of the catalyst temperature-increasing control to a specified air-fuel ratio switching timing than during a second period from the air-fuel ratio switching timing to a completion of the catalyst temperature-increasing control.

A control device comprising a first exhaust temperature calculation part calculating a temperature of exhaust flowing into a PM trapping device as a first exhaust temperature, a second exhaust temperature calculation part calculating a temperature of exhaust flowing out from the PM trapping device as a second exhaust temperature, a rate of change over time calculation part calculating a rate of change over time of the first exhaust temperature and a rate of change over time of the second exhaust temperature, and a judgment part judging if the PM trapping device is in a removed state removed from the exhaust passage based on a difference between the rate of change over time of the first exhaust temperature and the rate of change over time of the second exhaust temperature.

A method of adjusting the dosage of a reductant for an SCR catalyst, comprising: determining (110) an expected temperature profile in at least one axial section of the catalyst (70) for a defined period of time (t.sub.Sim); firstly simulating (120) the resulting amount of reductant beyond the at least one section of the catalyst with a first defined dosage of the reductant depending on the expected temperature profile determined; comparing the first simulated amount of reductant with a limit; depending on the result of the comparison, choosing a second defined dosage and secondly simulating (130, 160) a resulting amount of reductant beyond the at least one section of the catalyst (70) with the second dosage; comparing the second simulated amount of reductant with the limit; and adjusting (140, 150, 170, 180, 190, 195) the dosage for injection of the reductant into the catalyst based on the first and/or second comparison.

A measuring device for the determination of an ash loading of a particulate filter for an internal combustion engine of a motor vehicle, where a regeneration operation of the particulate filter is carried out such that, after termination of the regeneration operation, a predefined, minimum soot loading remains on the particulate filter. The measuring device is configured to determine an actual regeneration variable which is characteristic for a loading combustion operation during the regeneration operation of the particulate filter via a pressure sensor which is attached downstream in the exhaust gas flow of the particulate filter in the exhaust gas system of the internal combustion engine. The measuring device is further configured to determine the ash loading of the particulate filter dependent on the actual regeneration variable and a variable which is characteristic for the time duration of the regeneration operation.

An apparatus includes circuitry configured to calculate a temperature of exhaust flowing into an exhaust after-treatment system as a first exhaust temperature, calculate a temperature of exhaust flowing out from the exhaust after-treatment system as a second exhaust temperature, calculate a rate of change over time of the first exhaust temperature and a rate of change over time of the second exhaust temperature, and judge if the exhaust after-treatment system is in a removed state removed from the exhaust passage based on a difference between the rate of change over time of the first exhaust temperature and the rate of change over time of the second exhaust temperature.

An apparatus includes circuitry configured to calculate a temperature of exhaust flowing into an exhaust after-treatment system as a first exhaust temperature, calculate a temperature of exhaust flowing out from the exhaust after-treatment system as a second exhaust temperature, calculate a rate of change over time of the first exhaust temperature and a rate of change over time of the second exhaust temperature, and judge exhaust after-treatment system if the exhaust after-treatment system is in a removed state removed from the exhaust passage based on a difference between the rate of change over time of the first exhaust temperature and the rate of change over time of the second exhaust temperature.