The disclosure concerns an internal combustion engine comprising an exhaust camshaft, an intake camshaft, a turbocharger, and a control system. The turbocharger comprises a compressor. A timing of the exhaust camshaft and a timing of the intake camshaft are controllable by the control system, which is configured to: store a compressor map related to the compressor, store a reference area within the compressor map, and determine at least two parameters. In response to the at least two parameters indicating that a current operational point of the compressor is outside the reference area, the control system changes the timing of the exhaust camshaft to advance closing of the exhaust valve, and the timing of the intake camshaft to delay opening of the intake valve.

A method for operating an internal combustion engine. The method includes: operating the internal combustion engine including a lambda regulation, which sets a fuel quantity to be supplied in accordance with a predefined setpoint lambda value, at preset times, carrying out a filter cleaning operation for a fuel tank ventilation, as a function of the presence of a release condition of the internal combustion engine, carrying out an adaptation of the lambda regulation by adapting at least one adaptation parameter as a function of operating variables of the internal combustion engine, at active filter cleaning operation and upon the presence of the release condition, operating variables which are required to carry out the adaptation of the lambda regulation being recorded, at deactivated filter cleaning operation and presence of the release condition, the adaptation of the lambda regulation being carried out as a function of the recorded operating variables.

A controller for a hybrid vehicle controls an electric motor such that a motor torque is input to a crankshaft in order to compensate for a decrease in an engine torque when a cylinder deactivation control is executed, the decrease resulting from suspension of combustion in one or some of cylinders. The controller calculates an engine torque calculated value using an engine rotation speed, a motor rotation speed, and the motor torque. The controller diagnoses that the cylinder deactivation control is functioning normally when the engine torque calculated value is less than a torque determination value and diagnose that the cylinder deactivation control is not functioning normally when the engine torque calculated value is not less than the torque determination value during the execution of the cylinder deactivation control.

A variety of methods and arrangements for reducing noise, vibration and harshness (NVH) in a skip fire engine control system are described. In one aspect, a firing sequence is used to operate the engine in a skip fire manner. A smoothing torque is determined that is applied to a powertrain by an energy storage/release device. The smoothing torque is arranged to at least partially cancel out variation in torque generated by the skip fire firing sequence. Various methods, powertrain controllers, arrangements and computer software related to the above operations are also described.

A method for diagnosing a part of a powertrain system is provided. The powertrain system comprising an internal combustion engine system having an internal combustion engine provided with a plurality of cylinders, each cylinder being provided with an air inlet valve and an exhaust gas valve, the method comprising the steps of operating any one of the inlet valve and the exhaust valve for any one of the cylinders to adjust the frequency and/or duration of air pulses during different load conditions of the internal combustion engine; determining an operational behaviour of the part of the powertrain system in response to the adjusted frequency and/or duration of the air pulses; and comparing the determined operational behaviour of the part of the powertrain system with an expected behaviour of the part of the powertrain system.

A control apparatus of an internal combustion engine having an injector which directly injects fuel into a combustion chamber of a cylinder and a spark plug which ignites an air-fuel mixture containing the fuel injected by the injector includes an air-fuel ratio acquisition unit acquiring an air-fuel ratio of the air-fuel mixture in the combustion chamber, a nitrogen oxide concentration acquisition unit acquiring a concentration of nitrogen oxide in a combustion gas exhausted from the internal combustion engine, and a stratification level estimation unit estimating a level of stratification as a measure of level of distribution of the air-fuel mixture at a predetermined air-fuel ratio or below in a vicinity of the spark plug. The stratification level estimation unit estimates the level of stratification according to the air-fuel ratio acquired by the air-fuel ratio acquisition unit and the concentration of nitrogen oxide acquired by the nitrogen oxide concentration acquisition unit.

A method for starting an internal combustion engine comprises the steps of: providing an internal combustion engine having at least one cylinder and a piston supported at a crankshaft for repeated reciprocal movement in the cylinder so as to define a main combustion chamber, the internal combustion engine further having an ignition device arranged in said cylinder with an igniter portion and a fuel injector which are both arranged at a pre-chamber, wherein the pre-chamber has a plurality of orifices for providing fluid communication between said pre-chamber and the main combustion chamber, injecting fuel in the pre-chamber, and igniting the injected fuel in the pre-chamber for pre-heating of the pre-chamber prior to injecting fuel in the main combustion chamber for combusting the injected fuel in the main combustion chamber.

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.

In a method for operating an internal combustion engine of a motor vehicle having an automatic transmission, a torque generated by the internal combustion engine is reduced as a function of an operating state of a drive train of the motor vehicle. As a function of an excess of combustion air occurring when the torque is reduced and supplied to the internal combustion engine by an exhaust gas turbocharger, fuel combustion efficiency in at least one combustion chamber of the internal combustion engine, which is related to the torque generated by the combustion chamber, is reduced. The combustion efficiency is reduced by at least one late post-injection of fuel into the at least one combustion chamber of the internal combustion engine.

A control apparatus for an engine includes a crank angle sensor and a processor. The processor acquires a first crank angular velocity difference which is a change in a crank angular velocity in a first region. The first region includes a rotational change correlated with an engine torque output. The processor acquires a second crank angular velocity difference which is a change in the crank angular velocity in a second region. The second region includes a rotational change correlated with a combustion rate attributable to an air-fuel ratio. In a case where the first crank angular velocity difference is less than or equal to a first threshold and the second crank angular velocity difference is less than or equal to a second threshold, the processor performs an increase correction on a fuel amount to be supplied to the engine.