An EGR control device includes: a drive unit, a basic opening degree deriving unit, a measurement unit, a memory unit, a correction opening degree deriving unit and a control unit. The drive unit varies an opening degree of an EGR valve. The basic opening degree deriving unit derives a basic EGR valve opening degree based on an operating condition of an engine. The measurement unit measures a temperature in the downstream side of a position of where EGR gas is recirculated in an intake passage. In the memory unit, information acquired in advance is stored. The information indicates a relationship between the opening degree and a temperature difference. The correction opening degree deriving unit derives a correction opening degree with reference to the information. The control unit controls the drive unit such that the opening degree of the EGR valve becomes a target EGR valve opening degree by correcting the basic EGR valve opening degree with the correction opening degree.

To provide a controller and a control method for an internal combustion engine capable of estimating exhaust gas temperature at any estimation positions of the exhaust pipe with good accuracy by taking into consideration a temperature drop of exhaust gas by heat radiation of the exhaust pipe. A controller for an internal combustion engine is provided with an outlet gas temperature calculator that calculates an outlet gas temperature which is a temperature of exhaust gas at an outlet of a combustion chamber, based on the driving condition; a heat radiation amount calculator that calculates a temperature decrease amount of the exhaust gas by heat radiation of an exhaust pipe from the outlet of the combustion chamber to an estimation position; and an exhaust gas temperature estimation calculator that estimate an exhaust gas temperature at the estimation position by subtracting the temperature decrease amount from the outlet gas temperature.

Methods and systems are provided for cleaning an exhaust particulate filter by routing air via the exhaust particulate filter during a vehicle-off condition. In one example, during vehicle-off conditions, a turbocharger may be reverse rotated via an electric motor or an engine may be reverse rotated via an electric machine to route air via the exhaust particulate filter and the soot collected from the particulate filter may then be deposited on an air filter coupled to the intake manifold. During a subsequent engine start, the soot from the intake air filter may be routed to the engine cylinders for combustion.

A method and apparatus are disclosed for operating an internal combustion engine equipped with a turbocharger and an exhaust gas recirculation pipe fluidly connecting an exhaust gas line to an air intake duct upstream of a compressor of the turbocharger. A value of a parameter indicative of a temperature of a portion of the exhaust gas recirculation pipe is determined. Exhaust gas recirculation via the exhaust gas recirculation pipe is prevented when the determined value is lower than a predetermined threshold value thereof. The air intake duct portion of compressed air exiting from the compressor is recirculated via the portion of the exhaust gas recirculation pipe.

A method and apparatus are disclosed for operating an internal combustion engine equipped with a turbocharger and an exhaust gas recirculation pipe fluidly connecting an exhaust gas line to an air intake duct upstream of a compressor of the turbocharger. A value of a parameter indicative of a temperature of a portion of the exhaust gas recirculation pipe is determined. Exhaust gas recirculation via the exhaust gas recirculation pipe is prevented when the determined value is lower than a predetermined threshold value thereof. The air intake duct portion of compressed air exiting from the compressor is recirculated via the portion of the exhaust gas recirculation pipe.

Provided is a control device for an internal combustion engine, which is capable of suppressing occurrence of knocking due to pre-ignition and occurrence of misfire even when an operating state in a previous cycle changes in a subsequent cycle. When a ratio of change in heat of air-fuel mixture, which is an index indicating how a heat of air-fuel mixture in the previous cycle changes in the subsequent cycle, does not fall within an allowable range, a variable valve control mechanism capable of changing a valve-closing timing of an exhaust valve for adjusting an internal EGR gas amount is controlled by using an optimum value of exhaust valve close (EVC) timing derived by correcting a set valve-closing timing of the exhaust valve so that the ratio of change in heat of air-fuel mixture falls within the allowable range.

The influenced of condensed water on an EGR device is alleviated. A device (100) that controls a cooling system including adjusting means for being able to adjust a circulation amount of coolant in a first flow passage, including an engine cooling flow passage, an EGR cooling flow passage and a radiator flow passage, and a second flow passage, including the engine cooling flow passage, the EGR cooling flow passage and a bypass flow passage and not including the radiator flow passage, includes: measuring means for measuring a temperature of the coolant; limiting means for limiting circulation of the coolant at starting an internal combustion engine; and control means for circulating the coolant preferentially through the second flow passage via control over the adjusting means based on the measured temperature in a period in which circulation of the coolant is limited.