A technique is provided for compensating an untrimmed oxygen (O.sub.2) sensor utilized in operation of an exhaust gas recalculation (EGR) system associated with an engine. The technique includes, in one implementation, receiving a measurement from the O.sub.2 sensor at a known pressure, where the O.sub.2 sensor is positioned on an intake side of an engine system. Humidity compensation and pressure compensation are then determined for the O.sub.2 sensor measurement, where the pressure compensation is based in part on the humidity compensation. The EGR system is controlled using the untrimmed O.sub.2 sensor measurement that has been compensated for pressure and humidity.

A technique is provided for compensating an untrimmed oxygen (O.sub.2) sensor utilized in operation of an exhaust gas recalculation (EGR) system associated with an engine. The technique includes, in one implementation, receiving a measurement from the O.sub.2 sensor at a known pressure, where the O.sub.2 sensor is positioned on an intake side of an engine system. Humidity compensation and pressure compensation are then determined for the O.sub.2 sensor measurement, where the pressure compensation is based in part on the humidity compensation. The EGR system is controlled using the untrimmed O.sub.2 sensor measurement that has been compensated for pressure and humidity.

The invention has an object to control an EGR amount accurately in transient time. An ECU switches EGR control to the one-valve EGR control and the both-valve EGR control based on a request EGR amount. When the EGR control is switched to the one-valve EGR control from the both-valve EGR control, an EGR valve of one bank is closed first. Next, during a time period until an opening degree restriction time period elapses after the EGR valve is closed, an opening degree of an EGR valve of the other bank is restricted to be smaller than a one-valve target opening degree. Subsequently, when the opening degree restriction time period elapses, restriction of the opening degree of the EGR valve is cancelled, and the opening degree of the EGR valve is changes to the one-valve target opening degree.

The invention has an object to control an EGR amount accurately in transient time. An ECU switches EGR control to the one-valve EGR control and the both-valve EGR control based on a request EGR amount. When the EGR control is switched to the one-valve EGR control from the both-valve EGR control, an EGR valve of one bank is closed first. Next, during a time period until an opening degree restriction time period elapses after the EGR valve is closed, an opening degree of an EGR valve of the other bank is restricted to be smaller than a one-valve target opening degree. Subsequently, when the opening degree restriction time period elapses, restriction of the opening degree of the EGR valve is cancelled, and the opening degree of the EGR valve is changes to the one-valve target opening degree.

A control system and a control method for an internal combustion engine, which are capable of accurately calculating an in-cylinder gas amount and an EGR ratio by a relatively simple method even in a case where an in-cylinder gas temperature is changed by execution of internal EGR, and properly controlling the engine using the EGR ratio thus calculated. An in-cylinder gas amount Gact actually filled in the cylinder is calculated by correcting an ideal in-cylinder gas amount Gth, which is an amount of gases filled in a cylinder in an ideal state in which it is assumed that no exhaust gases of the engine are recirculated into the cylinder, using an ideal in-cylinder gas temperature Tcylth according to an in-cylinder gas temperature Tcyl, and an EGR ratio REGRT is calculated using the in-cylinder gas amount Gact and an intake air amount Gaircyl.

A method, a combustion engine controller, and a combustion engine incorporating the controller to implement the method are provided. The method includes determining a first dedicated exhaust gas recirculation (D-EGR) cylinder parameter value of a first D-EGR cylinder parameter associated with a first D-EGR cylinder of the combustion engine; and regenerating the first D-EGR cylinder responsive to the first D-EGR cylinder parameter value satisfying a threshold indicative of a carbon build-up level.

A system, method, and engine control module for energy ignition management of a combustion engine. The method may be performed by the system or the engine control module. The method includes determining operating conditions of the combustion engine, setting ignition energy characteristics for a dedicated EGR cylinder and a non-dedicated EGR cylinder based on the operating conditions. The ignition energy characteristics include at least one of magnitude of energy, current, voltage, and ignition energy duration. At least one characteristic of the ignition energy characteristics for the non-dedicated EGR cylinder is different than a corresponding characteristic for the dedicated EGR cylinder. The method also includes energizing ignition aid plugs based on the ignition energy characteristics.

An engine system may include: an engine including cylinders that generate a driving torque by combusting fuel; a first intake manifold connected to an intake line through which flows intake air into some of the plurality of cylinders; a second intake manifold supplying the intake air to the other cylinders of the plurality of cylinders through the first intake manifold; a first exhaust manifold connected to some cylinders that are connected to the first intake manifold; a second exhaust manifold connected to some other cylinders that are connected to the second intake manifold; a recirculation line branched from the second exhaust manifold to be coupled to the second intake manifold; a recirculation inlet valve disposed at a point at which the recirculation line and the second exhaust manifold are joined; and a manifold connection valve disposed on an intake line between the first intake manifold and the second intake manifold.

A method for estimating the ageing of an exhaust gas sensor (16) placed in an exhaust line (14) of a diesel internal combustion engine (10) of an industrial vehicle (1) includes: —acquiring (S100) an initial value of an estimated remaining lifetime (50) of the exhaust gas sensor; —measuring (S102) the time spent by the engine in each of several predefined engine operation modes during a predefined time period; —for each of the engine operation modes, calculating (S104) a lifetime loss value depending on the time spent by the engine in said engine operation mode during the predefined time period and on a predefined ageing rate associated to said engine operation mode; —updating (S106) the estimated remaining lifetime value by subtracting each calculated lifetime loss value from the initial value.

A method for estimating the ageing of an exhaust gas sensor (16) placed in an exhaust line (14) of a diesel internal combustion engine (10) of an industrial vehicle (1) includes: —acquiring (S100) an initial value of an estimated remaining lifetime (50) of the exhaust gas sensor; —measuring (S102) the time spent by the engine in each of several predefined engine operation modes during a predefined time period; —for each of the engine operation modes, calculating (S104) a lifetime loss value depending on the time spent by the engine in said engine operation mode during the predefined time period and on a predefined ageing rate associated to said engine operation mode; —updating (S106) the estimated remaining lifetime value by subtracting each calculated lifetime loss value from the initial value.