When a temperature increasing process is performed, a CPU sets a target temperature of a catalyst to be lower when a coolant temperature is low than when the coolant temperature is high. The CPU decreases an increase coefficient of fuel in the temperature increasing process when a value obtained by subtracting an estimated value of a temperature of the catalyst from the target temperature is equal to or less than a first prescribed value.

A variety of methods and arrangements for controlling the exhaust gas temperature of a lean burn, skip fire controlled internal combustion engine are described. In one aspect, an engine controller includes an aftertreatment system monitor and a firing timing determination unit. The aftertreatment monitor obtains data relating to a temperature of one or more aftertreatment elements, such as a catalytic converter. Based at least partly on this data, the firing timing determination unit generates a firing sequence for operating the engine in a skip fire manner such that the temperature of the aftertreatment element is controlled within its effective operating range.

In an opposed-piston engine which includes a catalytic aftertreatment device in its exhaust system an exhaust gas condition indicating a catalyst temperature of the aftertreatment device is monitored. When the catalyst temperature is near or below a light-off temperature, a catalyst light-off procedure is executed to elevate the temperature of the catalyst.

A method of two-step variable valve lift (VVL) operation learning control for a vehicle may include: applying, by a lift controller, a VVL control to an electric two-step VVL system; determining, by the lift controller, whether the vehicle is running in an electric vehicle (EV) mode; and when the vehicle is running in the EV mode, performing, by the lift controller, a learning time securing control of allowing a VVL operation learning to be performed by engine operating for an operation avoidance area and an operation avoidance time which are applied to a secondary lift of an exhaust valve.

Methods and systems for operating an engine that includes an after treatment system are described. In one example, traffic data and navigation system data are a basis for deciding whether or not to increase heat output of an engine to ensure operation of the after treatment system. In particular, one or more actuators may be adjusted to minimize fuel consumption and/or reduce feedgas emissions while generating sufficient heat to maintain after treatment system operation.

Provided is an internal combustion engine control device capable of maintaining an activation temperature of a catalyst while suppressing deterioration of an exhaust gas in a hybrid engine. To this end, the internal combustion engine control device of the present invention controls an internal combustion engine in an engine for a hybrid vehicle. The internal combustion engine has a catalyst that purifies the harmful substances in the exhaust gas and a catalyst temperature detection unit that detects the temperature of the catalyst. Then, when the temperature of the catalyst detected by the catalyst temperature detection unit does not reach a predetermined temperature, the internal combustion engine control device performs a catalyst temperature rise control for increasing the temperature of the catalyst and performs motoring.

In an engine device, when executing normal control that performs fuel injection and ignition as control of an engine, a controller estimates, in the case of a stoichiometric air-fuel ratio, an exhaust gas temperature based on first thermal energy that is based on a combustion gas temperature, a combustion gas quantity, and specific heat of combustion gas, estimates, in the case of a lean air-fuel ratio, the exhaust gas temperature based on the first thermal energy and second thermal energy that is based on an air temperature, a surplus air quantity, and specific heat of air, and estimates, in the case of a rich air-fuel ratio, the exhaust gas temperature based on the first thermal energy and third thermal energy that is based on a fuel temperature, a surplus fuel quantity, specific heat of fuel, and evaporation latent heat of fuel.

To keep medium purification efficiency at a high level and prevent deterioration of emission performance. An aspect of the present invention includes: a downstream equivalence ratio calculation unit that calculates a catalyst downstream exhaust gas equivalence ratio by using a catalyst statistical model that receives at least a detection value of an air-fuel ratio sensor on an upstream side of a catalyst and outputs a catalyst downstream exhaust gas equivalence ratio; an oxygen output calculation unit that calculates an output value of an oxygen sensor by using an oxygen sensor statistical model that receives the catalyst downstream exhaust gas equivalence ratio and outputs an output value of the oxygen sensor on the downstream side of the catalyst; a downstream equivalence ratio correction unit that corrects the catalyst downstream exhaust gas equivalence ratio calculated by the downstream equivalence ratio calculation unit based on a calculation result of the oxygen output calculation unit and the detection value of the oxygen sensor; and an air-fuel ratio control unit that controls an air-fuel ratio of an air-fuel mixture of an internal combustion engine based on the corrected catalyst downstream exhaust gas equivalence ratio and air-fuel ratio target value.

The present disclosure generally relates to a computer implemented method for controlling an exhaust gas aftertreatment system (EATS), specifically applying a scheme for preventing heat reduction at the EATS based on the estimated heat reduction. The present disclosure also relates to a corresponding exhaust gas aftertreatment system (EATS) and a computer program product.

In an opposed-piston engine which includes a catalytic aftertreatment device in its exhaust system an exhaust gas condition indicating a catalyst temperature of the aftertreatment device is monitored. When the catalyst temperature is near or below a light-off temperature, a catalyst light-off procedure is executed to elevate the temperature of the catalyst.