A CPU performs a regeneration process of stopping combustion control in one or some of cylinders and making the air-fuel ratio of an air-fuel mixture in the other cylinders or cylinder richer than a theoretical air-fuel ratio, when the amount of PM collected by a GPF increases. In performing the regeneration process, the CPU itself compensates for a fall in the output of an internal combustion engine by gradually increasing the filling efficiency of the other cylinders or cylinder. It should be noted, however, that since the output of the internal combustion engine temporarily fluctuates, the CPU compensates for the fluctuations through the use of a second motor-generator. The CPU varies the retardation amount of a timing of starting the regeneration process with respect to a timing of gradually increasing the filling efficiency, in accordance with the state of a battery.

Methods and systems for operating an engine that includes adjustable poppet valve timing and an exhaust gas recirculation valve are described. In one example, the exhaust gas recirculation valve is opened and the timing of the poppet valves is retarded so that an amount of fresh air that is pumped by the engine to an after treatment device may be reduced.

A skip fire control system for an engine of a vehicle includes a set of sensors configured to measure a set of operating parameters of the engine corresponding to a volumetric efficiency of the engine, a set of sub-systems having a set of operational states that affect transitions between different firing patterns/fractions of the engine, and a controller configured to, based on the set of operating parameters and the set of operational states of the set of sub-systems, determine a best firing pattern/fraction by taking into account losses or penalties to transition at least some of the set of operational states of the set of sub-systems to obtain a target firing pattern/fraction, and control the engine based on the target firing pattern/fraction to maximize an efficiency of the engine.

A control apparatus for an internal combustion engine performs a first acquisition process for acquiring a first index value corresponding to an integrated amount of intake air during a performance of the fuel cutoff process, and a cancellation process for cancelling the fuel cutoff process when the first index value becomes equal to or larger than a first predetermined value during the performance of the fuel cutoff process. Besides, the control apparatus performs a second acquisition process for acquiring a second index value corresponding to an elapsed time from the end of the fuel cutoff process to the subsequent start of the fuel cutoff process, and a change process for making the first predetermined value smaller when the second index value is small in starting the fuel cutoff process than when the second index value is large in starting the fuel cutoff process.

A vehicle control apparatus includes a detector that detects an external temperature of a vehicle, a vehicle speed, and a coolant temperature of an engine, an input device that receives a signal for ON or OFF operations of a heating control, and a controller configured for determining a heating load depending on the heating control when the external temperature is less than a predetermined temperature and the signal for the ON operation of the heating control is input, and controls an operation of an integrated thermal management valve, a deactivation operation of cylinders included in the engine, and an operation of an active air flap, according to at least one of the heating load and the coolant temperature.

A classifier capable of predicting if cylinder valves of an engine commanded to activate or deactivate failed to activate or deactivate respectively. In various embodiments, the classifier can be binary or multi-class Logistic Regression, or a Multi-Layer Perceptron (MLP) classifier. The variable displacement engine can operate in cooperation with a variable displacement engine using cylinder deactivation (CDA) or skip fire, including dynamic skip fire and/or multi-level skip fire.

A system includes an exhaust aftertreatment system in exhaust gas receiving communication with an engine including a plurality of cylinders where the engine is structured to operate according to low load conditions and where a controller is structured to determine that at least one diesel emissions fluid (DEF) doser is frozen based on at least one of an ambient air temperature and a DEF source temperature. The controller is structured to operate the engine according to a skip-fire mode in response to a DEF flag indicating that the at least one DEF doser is frozen. The skip-fire mode comprises firing a portion of the plurality of cylinders that is less than a total amount of cylinders of the plurality of cylinders. The controller is structured to discontinue the skip-fire mode in response to determining that the at least one DEF doser is likely thawed.

An internal combustion engine may include a first piston reciprocatingly disposed in a first cylinder, a combustion chamber fluidly coupled with the first cylinder, and an ignition source at least partially disposed within the combustion chamber. An intake valve may provide selective fluid communication between an intake system and the combustion chamber, and an exhaust valve may provide selective fluid communication between an exhaust system and the combustion chamber. A second piston may be reciprocatingly disposed within a second cylinder. An inlet associated with the second cylinder may be fluidly coupled with the intake system, and an outlet may be fluidly coupled with one or more of the first cylinder and the combustion chamber. A crankshaft may be coupled with the first piston and the second piston for rotational motion associated with reciprocating movement of the first piston and the second piston.

Methods and systems are provided for providing secondary air to an exhaust system during catalyst warm-up. In one example, a method may include, during a cold start condition, operating an engine with a first number of cylinders unfired and a remaining number of cylinders fired during an engine cycle, opening an intake valve of an unfired cylinder of the first number of cylinders during an expansion stroke of the unfired cylinder, and opening an exhaust valve of the unfired cylinder during a compression stroke of the unfired cylinder. In this way, the unfired cylinders may provide the secondary air to the exhaust system during a stroke that increases mixing of the secondary air with burned exhaust gas from fired cylinders, thus increasing exotherm production in the exhaust system to increase a temperature of the catalyst.

A hybrid vehicle includes a multi-cylinder engine, an exhaust gas control apparatus including a catalyst for removing exhaust gas from the multi-cylinder engine, an electric motor, and a control device configured to execute catalyst temperature increase control for stopping fuel supply to at least one cylinder and making an air-fuel ratio in each of remaining cylinders rich in a case where a temperature increase of a catalyst is requested during a load operation of the multi-cylinder engine, execute control such that an electric motor supplements insufficient drive power due to the execution of the catalyst temperature increase control, and change the air-fuel ratio in at least one of the remaining cylinders to a lean side after a temperature of the exhaust gas control apparatus becomes equal to or higher than a determination threshold value during the execution of the catalyst temperature increase control.