Provided is an engine control device capable of, when performing control of an in-cylinder oxygen concentration according to engine operation state, controlling an engine to accurately realize vehicle behavior intended by a driver, while suppressing generation of knock noises due to abnormal combustion. The engine control device comprises: a basic target torque-determining part (61) configured to determine a basic target torque based on a driving state of a vehicle including manipulation of an accelerator pedal; a torque reduction amount-determining part (63) configured to determine a torque reduction amount based on a driving state of the vehicle other than the manipulation of the accelerator pedal; a final target torque-determining part (65) configured to determine a final target torque based on the basic target torque and the torque reduction amount; and an engine control part (69) configured, based on a fuel injection parameter preliminarily set correspondingly to an operation state of an engine, to control a fuel injector to enable the engine to output the final target torque, and, when the final target torque changes correspondingly to a change in the torque reduction amount, to correct the fuel injection parameter.

An object is to provide a control device for an internal combustion engine, at an inexpensive price, whereby it is possible to suppress a decrease in the exhaust gas performance of the internal combustion engine due to an environmental change or damage from aging. The present invention relates to a control device for an internal combustion engine which controls an EGR amount by adjusting an opening degree of an EGR valve (20) disposed in an EGR channel (16), the control device comprising temperature detection units (24, 26, 30), a pressure detection unit (28), a unit (48) to calculate a basic opening degree of the EGR valve, a unit (44, 56) to calculate an estimate value of at least one of an air-excess ratio or an intake oxygen concentration on the basis of detection values obtained by the temperature detection units and the pressure detection unit, a unit (46, 48) to calculate a target value of the estimate value, a unit (50) to calculate a correction factor K on the basis of the estimate air-excess ratio s and the target air-excess ratio t, a unit (52) to calculate the opening-degree command value D for the EGR valve on the basis of the basic opening degree Db and the correction coefficient K, and a unit (54) to control the EGR valve on the basis of the opening-degree command value D.

Methods and systems are provided for a single heat exchanger coupled to a main exhaust passage upstream of one or more exhaust catalysts or in between two exhaust catalysts for exhaust heat recovery and exhaust gas recirculation (EGR) cooling. In one example, in the pre-catalyst configuration of the heat exchanger, during exhaust heat recovery, a portion of exhaust may be routed via the heat exchanger while the remaining portion of exhaust may be routed directly to the exhaust catalysts, and fueling may be adjusted on a per-cylinder basis to maintain a target exhaust air-fuel-ratio at the exhaust catalysts.

A friction loss management system for an engine, comprises a combustion engine comprising a crankshaft and a plurality of cylinders, a reciprocating piston assembly connected to the crankshaft, a fuel injector connected to an injection controller, an intake valve connected to an intake valve controller, and an exhaust valve connected to an exhaust valve controller. A control unit comprises at least one set of control algorithms configured to receive engine power demand data, and determine a number of cylinders of the plurality of cylinders for deactivation based on the received engine power demand data and further based on sensed or stored friction values for the plurality of cylinders. Determining the number of cylinders of for deactivation minimizes friction between the plurality of cylinders and their respective reciprocating piston assembly by selecting a cylinder combination of active cylinders and deactivated cylinders with the lowest total friction while meeting engine power demand.

The present invention provides a catalyst diagnosis device that enables precisely grasping a variation of AFR and diagnosing a deteriorated condition of the catalyst based on the variation. A timer counts elapsed time Tosc until downstream AFU (AFRd) meets a predetermined threshold condition when the fuel injection quantity is corrected by increasing or decreasing it so that as to the AFRu, the transition from either of leanness or richness to the other is repeated with the stoichiometric area between the leanness and the richness. An OSA calculating section calculates an Oxygen Storage Amount (OSA) as a function of the AFR, Mfuel, Ne and Tosa. An OPA calculating section calculates an Oxygen Purge Amount (OPA) as a function of the AFR, Mfuel, Ne and Topa. A deterioration diagnosing section diagnoses a deteriorated condition of the catalyst C on the basis of at least one of the OSA and OPA.

A friction loss management system for an engine, comprises a combustion engine comprising a crankshaft and a plurality of cylinders, a reciprocating piston assembly connected to the crankshaft, a fuel injector connected to an injection controller, an intake valve connected to an intake valve controller, and an exhaust valve connected to an exhaust valve controller. A control unit comprises at least one set of control algorithms configured to receive engine power demand data, and determine a number of cylinders of the plurality of cylinders for deactivation based on the received engine power demand data and further based on sensed or stored friction values for the plurality of cylinders. Determining the number of cylinders of for deactivation minimizes friction between the plurality of cylinders and their respective reciprocating piston assembly by selecting a cylinder combination of active cylinders and deactivated cylinders with the lowest total friction while meeting engine power demand.

An exhaust gas control apparatus for an internal combustion engine includes: a catalyst which is capable of storing oxygen; a downstream air-fuel ratio sensor that detects the air-fuel ratio of outgoing exhaust gas flowing out of the catalyst; an air-fuel ratio control unit that controls the air-fuel ratio of incoming exhaust gas flowing into the catalyst; and a catalyst state estimation unit that estimates the activity of the catalyst. The air-fuel ratio control unit controls the air-fuel ratio of the incoming exhaust gas so that the air-fuel ratio of the outgoing exhaust gas detected by the downstream air-fuel ratio sensor is maintained at a target air-fuel ratio. The air-fuel ratio control unit sets the target air-fuel ratio to a richer value when the activity of the catalyst is equal to or higher than a predetermined value than when the activity of the catalyst is lower than the predetermined value.

A method for operating an engine system including an internal combustion engine and an exhaust gas aftertreatment device, including: carrying out a fill level control to control a fill level of the exhaust gas aftertreatment device as a function of a predefined fill level setpoint value; operating a pilot control for the fill level control; and adapting the pilot control as a function of a deviation between a measured lambda value and a modeled lambda value.

A method of operating a dedicated-EGR engine includes providing a rich air-fuel mixture to a dedicated cylinder; combusting the rich air-fuel mixture in the dedicated cylinder; modeling the combustion of the rich air-fuel mixture in the dedicated cylinder; estimating the composition of the combustion products in the dedicated cylinder based on interpolation of chemical reaction models of stoichiometric and rich combustion. The method further includes mixing the combustion products from the dedicated cylinder with air to produce an intake mixture; estimating a mass fraction of reformate and a mass fraction of burned gas in the intake mixture; providing the intake mixture to the intake ports of all of the cylinders of the dedicated-EGR engine; combusting an air-fuel mixture in a non-dedicated cylinder of the engine; and controlling an engine control parameter based on the estimated mass fractions of reformate and burned gas in the intake mixture.

An air-fuel ratio detection device 1, 1 comprises: a sensor element 2, 2 including a sensor cell 10; a voltage application circuit 40, 40 applying voltage to the sensor cell; a current detector 42, 42 detecting an output current of the sensor cell; an air-fuel ratio calculating part 61 configured to calculate an air-fuel ratio of an exhaust gas; and a parameter detecting part 62 configured to detect or calculate a temperature correlation parameter correlated with a temperature of the sensor element. The air-fuel ratio calculating part is configured to calculate the air-fuel ratio of the exhaust gas based on the temperature correlation parameter and the output current detected when a predetermined voltage is applied to the sensor cell.