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.

Selective catalytic reduction systems are known and are generally included in exhaust systems of diesel engines in order to treat the exhaust gases of such engines. Such systems involve the introduction of diesel exhaust fluid (DEF) into exhaust gas flowing in an exhaust passage of an engine. When dosing DEF onto a hydrolysis catalyst in a SCR system, the DEF will under certain conditions cool the hydrolysis catalyst sufficiently to either slow down or effectively prevent ammonia release, which creates a lag or delay in the function of the hydrolysis catalyst. This limits the amount of control which can be exerted over ammonia storage in the SCR catalyst, and NOx conversion. In a first step, a set of measurement data is received from one or more sensors provided in the system. Subsequently, a first set of characteristics associated with a state of a component of the catalytic system, a second set of characteristics associated with an output of the catalytic system and a third set of characteristics associated with a bias and a scaling factor in the system are derived. In a third step, the derived sets of characteristics are used to control the catalytic system.

A method for detecting an opening time of a valve, includes receiving a valve current profile of the valve and processing the valve current profile using at least a slope reflection detector to determine a status of the valve based on an output of the slope reflection detector.

A device for diagnosing a particulate filter suitable for: determining a measured pressure time profile, and a theoretical pressure time profile upstream of the filter, implementing, on each profile: low-pass filtering to obtain a first filtered time profile, second low-pass filtering of the first filtered time profile to obtain a second filtered time profile, calculating a difference between the second filtered time profile and the first filtered time profile, obtaining an absolute value of the calculated difference, and calculating an integral of the absolute value, and, from a comparison between the two integrals, a diagnosis of the particulate filter.

Embodiments described herein methods can be used in particulate filter regeneration, such as particulate filters used for filtering the exhaust of an engine, e.g., a diesel engine. Systems herein can be configured to dispense combustion gas(es) into housing were a particulate filter is contained and to ignite the combustion gases. Methods for conducting a safety verification process of such systems are disclosed, as well as methods for regenerating the filters. Still other embodiments are described.

The disclosure relates to a method and a device for diagnosing coking of a secondary air system of an internal combustion engine. The secondary air system has an intake air line for providing secondary air, a secondary air pump for compressing the secondary air, a secondary air valve for controlling the secondary air injection, a pressure sensor that is arranged in the secondary air system downstream of the secondary air pump and upstream of the secondary air valve, and an injection line for injecting the secondary air into an exhaust tract of the internal combustion engine.

A method determines a sensor error of a sensor in an exhaust gas system of a motor vehicle. One step of the method involves determining at least one actual sensor signal of the sensor. Another step of the method involves determining at least one target sensor signal of the sensor by means of a model. A further step of the method involves determining the sensor error of the sensor according to a deviation between the actual sensor signal of the sensor and the target sensor signal of the sensor.

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 method of estimating the oxygen storage capacity of a catalyst includes providing an engine system having an internal combustion engine and an exhaust system having a catalyst and an oxygen sensor, providing a three-way catalyst observer model having a Kalman filter and a three-way catalyst kinetic model, estimating a three-way catalyst next time step state and a modeling error, linearizing the three-way catalyst observer model, filtering the estimated three-way catalyst next time step state, and calculating a covariance.

Embodiments described herein methods can be used in particulate filter regeneration, such as particulate filters used for filtering the exhaust of an engine, e.g., a diesel engine. Systems herein can be configured to dispense combustion gas(es) into housing were a particulate filter is contained and to ignite the combustion gases. Methods for conducting a safety verification process of such systems are disclosed, as well as methods for regenerating the filters. Still other embodiments are described.