A control device for an internal combustion engine is provided with a target air-fuel ratio setting part including a first setting control part performing normal control alternately switching a target air-fuel ratio between a predetermined first lean air-fuel ratio and a predetermined first rich air-fuel ratio and a second setting control part performing control for restoration of the storage amount stopping normal control and increasing the oxygen storage amount of a second catalyst when an output air-fuel ratio of a third air-fuel ratio sensor becomes a predetermined rich judgment air-fuel ratio or less. Further, the second setting control part is configured to set the target air-fuel ratio to a predetermined second lean air-fuel ratio larger than the first lean air-fuel ratio at the time of start of the control for restoration of the storage amount and set the target air-fuel ratio to a predetermined third lean air-fuel ratio smaller than the second lean air-fuel ratio after an exhaust with a larger air-fuel ratio than the stoichiometric air-fuel ratio flows out from the first catalyst in the time period of setting the target air-fuel ratio to the second lean air-fuel ratio.

The invention relates to a method (200) for operating an internal combustion engine (110) having at least one catalytic converter (122), wherein control interventions of a lambda control for controlling an exhaust gas composition of the internal combustion engine are deactivated, comprising ascertaining a current exhaust gas composition upstream of the at least one catalytic converter (122), determining a current oxygen fill level of the at least one catalytic converter (122) on the basis of the ascertained current exhaust gas composition, ascertaining (210) a planned control intervention on a composition of an air-fuel mixture supplied to the internal combustion engine (110) on the basis of the determined current oxygen fill level of the at least one catalytic converter, ascertaining a current exhaust gas composition (123) downstream of the at least one catalytic converter (122), ascertaining a future exhaust gas composition (123) downstream of the at least one catalytic converter (122) resulting on the basis of an air-fuel mixture already supplied to the internal combustion engine (110), and reactivating the lambda control and specifying (260) a control intervention to be carried out as a function of the planned control intervention and the current exhaust gas composition (123) downstream of the at least one catalytic converter (122), and/or as a function of the planned control intervention and the future exhaust gas composition. Furthermore, a processing unit (130) and a computer program for carrying out such a method (200) are proposed.

The invention relates to controlling engine braking of an internal combustion engine wherein the method includes setting the engine in an engine braking mode comprising i) interrupting fuel supply to a first cylinder, ii) restricting the flow of gas through an exhaust duct using an adjustable flow restricting member, and iii) controlling inlet and exhaust valves of the first cylinder in a compression-release mode comprising controlling the valves to compress gas in a combustion chamber when the piston moves towards the top dead center position (TDC) and release compressed gas into the exhaust duct when the piston is near the TDC. The method includes, prior to ii and iii: reducing a total gas mass flow rate through the engine by controlling, for at least one of valve, reducing a valve lift and/or adjusting a timing of a valve opening or closing so as to reduce the gas mass flow rate through the cylinder.

Provided is a control device configured to be able to execute, in an engine which includes a DOC, a DPF, and a temperature increase unit including an exhaust throttle valve, for increasing a temperature of each of the DOC and the DPF, a forced regeneration process of removing PM deposited on the DPF by increasing the temperature of the DPF. The control device includes a flow rate estimation part configured to estimate an intake flow rate of a combustion gas sent into a cylinder of the engine. The flow rate estimation part is configured to estimate a first intake flow rate, which is the intake flow rate in the forced regeneration process, from an opening degree of the exhaust throttle valve and a first state amount which indicates an operation state of the engine including a rotation speed of the engine, based on a first relationship representing a relationship between the first intake flow rate, and the opening degree of the exhaust throttle valve and the first state amount, in the forced regeneration process.

A monitoring system and method for detecting clogging through fouling of an air filter (3) of an internal combustion engine (5) comprising a differential pressure sensor means (7) for determining a differential pressure between an ambient environment and a position directly downstream of the air inlet filter. The system further comprising at least one exhaust flow sensor means (9) for determining the exhaust flow, and a controller (13) which is communicatively connected to each of the sensor means for processing information therefrom. The controller is arranged for determining a first filter resistance coefficient based on, at least, a measurement of the differential pressure, and the exhaust flow. The system is arranged for, using the controller, to calculate a second filter coefficient based on the historic evolution of the first filter coefficient, the controller further arranged for comparing the second filter coefficient to a boundary value, and generating a clogging alarm signal when the second filter coefficient exceeds said boundary value.

Systems, methods, and computer-readable storage media for emulating a turbocharger speed sensor of a turbocharger in an engine. A processor executing the method can receive data from a plurality of sensors in the engine, wherein the data includes: an exhaust manifold pressure of the engine; an exhaust mass flow of the engine; and an injection angle of fuel in the engine. The processor enters the data as inputs into an artificial neural network, where the artificial neural network is trained to receive the inputs and output a speed of the turbocharger of the engine, then receives an output from the artificial neural network which is the speed of the turbocharger.

Methods and systems for improving fuel economy and reducing emissions of a vehicle with an electric motor, an engine, an energy storage device, and a controller are disclosed. The method includes obtaining current state information including a current hybrid control surface, and determining a target hybrid control surface for the vehicle based on the current state information.

Various embodiments of the teachings herein include a method for determining the nitrogen oxide content and/or ammonia content in the exhaust gas of an internal combustion engine with a catalytic converter arranged in an exhaust tract and an exhaust gas sensor downstream of the catalytic converter. In some embodiments, the method comprises: determining an operating state of the internal combustion engine, the operating state indicating either lean operation or rich operation of the internal combustion engine; generating a signal using the exhaust gas sensor; and determining the nitrogen oxide content and/or ammonia content in the exhaust gas at least partially based on the determined operating state of the internal combustion engine and the signal.

An exhaust gas system includes an exhaust gas pipe through which exhaust gas flows in a flow direction and which has a pipe wall. A flange is arranged in the pipe wall and has a passage opening provided with an internal thread. A gas sensor, in particular a particle sensor, is provided for sensing the concentration of soot particles contained in the exhaust gas and has a threaded housing portion that is provided with an external thread and is screwed into the passage opening. An annular gap is produced between a radial outer face of the threaded housing portion and a passage-opening inner circumferential portion which protrudes into the interior of the exhaust gas pipe. The flange has a flow guiding element which extends over a downstream part of the circumference of the threaded housing portion and which is provided for limiting or largely preventing a flow around the gas sensor in the annular gap.

A system and approach for catalyst model parameter identification with modeling accomplished by an identification procedure that may incorporate a catalyst parameter identification procedure which may include determination of parameters for a catalyst device, specification of values for parameters and component level identification. Component level identification may be of a thermal model, adsorption and desorption, and chemistry. There may then be system level identification to get a final estimate of catalyst parameters.