A method for controlling an exhaust aftertreatment system for vehicles includes: determining, by a controller, whether or not a designated regeneration operation is finished; accumulating, by the controller, a first amount of NO.sub.x emission measured by a rear end NO.sub.x sensor of an selective catalytic reduction (SCR) apparatus and a second amount of NO.sub.x emission calculated by an NO.sub.x emission amount model respectively for a first reference period of time immediately after the regeneration operation is finished; determining, by the controller, whether or not a difference between an accumulated value of the first amount of NO.sub.x emission and an accumulated value of the second amount of NO.sub.x emission exceeds a reference value when the first reference period of time has elapsed; and correcting, by the controller, a model purification efficiency using a sensor purification efficiency when the difference between the accumulated values exceeds the reference value.

A method for controlling an exhaust aftertreatment system for vehicles includes: determining, by a controller, whether or not a designated regeneration operation is finished; accumulating, by the controller, a first amount of NO.sub.x emission measured by a rear end NO.sub.x sensor of an selective catalytic reduction (SCR) apparatus and a second amount of NO.sub.x emission calculated by an NO.sub.x emission amount model respectively for a first reference period of time immediately after the regeneration operation is finished; determining, by the controller, whether or not a difference between an accumulated value of the first amount of NO.sub.x emission and an accumulated value of the second amount of NO.sub.x emission exceeds a reference value when the first reference period of time has elapsed; and correcting, by the controller, a model purification efficiency using a sensor purification efficiency when the difference between the accumulated values exceeds the reference value.

A catalyst deterioration detection device is provided to detect deterioration of a catalyst provided in an exhaust passage of an internal combustion engine. The catalyst deterioration detection device includes a storage device and processing circuitry. The storage device stores map data specifying a mapping that uses time series data of an excess amount variable in a first predetermined period and time series data of a downstream detection variable in a second predetermined period as inputs to output a deterioration level variable. The processing circuitry executes an acquisition process that acquires data, a deterioration level variable calculation process that calculates a deterioration level variable of the catalyst based on an output of the mapping using the data acquired by the acquisition process as an input. The map data includes data that is learned through machine learning.

Determining the presence of a particle filter in the exhaust gas tract of an engine, with the steps of determining a first exhaust gas temperature curve which occurs in the exhaust gas tract upstream of the particle filter; measuring a second exhaust gas temperature curve by a first temperature sensor arranged downstream of the particle filter; determining a first heat quantity by integration over a specific time of a first heat flow curve determined by a first exhaust gas mass flow, a first specific heat capacity and the first exhaust gas temperature curve; determining a second heat quantity by integration over the specific time of a second heat flow curve determined by a second exhaust gas mass flow, a second specific heat capacity and the second exhaust gas temperature curve, evaluating the first heat quantity and the second heat quantity to determine the presence of the correct particle filter.

A method of manufacturing an on-board diagnostic (OBD) limit part and a method of testing to evaluate an OBD system. The method of manufacturing the OBD limit part includes introducing a contaminant to an selective catalytic reduction (SCR) catalyst and contacting the contaminant with the SCR catalyst for a selected period of time. The method of manufacturing utilizes a vessel, the contaminant, and the SCR catalyst. The OBD limit part is a combination of the contaminant and the SCR catalyst within the vessel. The method of testing to evaluate the OBD system includes collecting data related to an exhaust gas before and after the exhaust gas is exposed to the OBD limit part, collecting an indication provided by the OBD system, and comparing the data related to the exhaust gas and the indication provided by the OBD system. The method of testing to evaluate the OBD system utilizes a system that includes an exhaust gas source, a first and a second fluid path, the OBD limit part, and the OBD system.

The present invention relates to a method for diagnosing aftertreatment of exhaust gases resulting from combustion, wherein at least a first substance resulting from said combustion is reduced by supplying additive to an exhaust gas stream resulting from said combustion and use of a first reduction catalytic converter. The method includes: estimating an accumulated expected reduction of said first substance during a first period of time, determining an accumulated actual reduction of said first substance during a period of time at least substantially overlapping said first period of time, and generating a signal indicating a fault in said reduction of said first substance when said accumulated actual reduction differs from said accumulated expected reduction by a predetermined difference in occurrence of said first substance. The invention also relates to a corresponding system.

A method for monitoring a concentration of a corrosive gas including at least observing at least one gas fuse, the gas fuse having at least one metal wire, which is configured for breaking due to corrosion if exposed to the corrosive gas in a way that a time-integrated concentration of the corrosive gas exceeds a critical value.

A method for determining a reference value of a presence of at least one substance (NO.sub.x) occurring in an exhaust gas stream of an internal combustion engine (101), wherein the at least one substance is subjected to exhaust treatment, the exhaust treatment being carried out in dependence on the reference value (Em.sub.ref; E.sub.mref,1; Em.sub.ref,2) When the internal combustion engine (101) is started: accumulating the occurrence (Em.sub.ACC,1; Em.sub.ACC,2) of the at least one substance (NO.sub.x) downstream from the exhaust treatment during a first period, and determining whether to redetermine the reference value (Em.sub.ref; Em.sub.ref,1; Em.sub.ref,2) based on the accumulated occurrence (Em.sub.ACC,1; Em.sub.ACC2) of the at least one substance (NO.sub.x).

A method for determining a presence of a particle filter in the exhaust gas tract of a petrol-operated internal combustion engine comprises: determining a measured differential pressure curve from a first pressure curve measured in the exhaust gas tract using a first pressure sensor arranged upstream of an installation position of the particle filter, and a second pressure curve measured using a second pressure sensor arranged downstream of an installation position determining a first result curve with a first low-pass filtration of the measured differential pressure curve; determining a second result curve by means of a second low-pass filtration of the first result curve; determining a first differential result curve by forming the difference between the first result curve and the second result curve; determining a first amount result curve by forming the amount of the first differential result curve; determining an expected differential pressure curve.

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.