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 controller calculates a specific humidity of an intake air based on a relative humidity of the intake air, an intake air temperature, and an intake air pressure. Then the controller calculates a water vapor amount in the intake air based on the specific humidity and a mass flow rate of the intake air obtained from an air intake rate. By calculating the water vapor amount in the intake air based on information that directly represents the status of the intake air, this water vapor amount may be calculated more accurately. As a result, a generation amount of condensed water may be estimated more accurately. Therefore, accumulation of condensed water may be suppressed while recirculating as much of a low pressure exhaust gas as possible, and thus fuel economy may be sufficiently improved.

To provide a controller and a control method for an internal combustion engine capable of reducing the calculation error of recirculation exhaust gas amount due to changes with time of the internal combustion engines, and humidity change of intake air, and also capable of reducing the calculation error of recirculation exhaust gas amount at transient operation. The controller and the control method for the internal combustion engine calculates humidity detecting EGR rate based on intake-air humidity and manifold humidity, calculates humidity detecting opening area which realizes humidity detecting recirculation flow rate calculated based on humidity detecting EGR rate, calculates learned opening area corresponding to present opening degree of EGR valve using learning value of opening area calculated based on humidity detecting opening area, and calculates flow rate of recirculation exhaust gas for control based on learned opening area.

The invention relates to a method for operating an internal combustion engine comprising: determining a first set point value of a volume of air to be taken into the combustion chamber of the internal combustion engine within one working cycle thereof by retrieving the first set point value from a first characteristic map stored in a memory device of an electronic computing device as a function of a current engine speed of the internal combustion engine and as a function of a torque to be provided by the internal combustion engine; and determining a second set point value by retrieving the second set point value from a second characteristic map stored in the memory device of the electronic computing device as a function of a current engine speed of the internal combustion engine and as a function of a current volume of air supplied to the combustion chamber.

A system for controlling condensation of water within an intake manifold of an engine is disclosed. The system may have a humidity sensor. The humidity sensor may be configured to generate a signal indicative of a humidity of intake air. The system may also have a controller communicably coupled to the humidity sensor. The controller may be configured to receive the signal indicative of the humidity of the intake air. The controller may be also configured to control an operational parameter of at least one of the engine and an engine component to maintain the humidity of the intake air within the intake manifold below a predetermined threshold.

A control apparatus for an internal combustion engine that includes an EGR channel and an EGR valve is configured, when the internal combustion engine is in a warm-up process and when an intake air flow rate that is a flow rate of air supplied to the internal combustion engine main body is less than or equal to a predetermined value, to open the EGR valve with a minute opening degree that is an opening degree smaller than a minimum opening degree of the EGR valve with which a condensed water in an exhaust-channel-side portion that is a portion of the EGR channel on a side closer to the exhaust channel relative to the EGR valve flows into an intake-channel-side portion that is a portion of the EGR channel on a side closer to the intake channel relative to the EGR valve.

A controller is configured to control an internal combustion engine that includes an exhaust gas temperature sensor. The exhaust gas temperature sensor detects, as an exhaust gas temperature, a temperature of exhaust gas flowing through an exhaust passage. The controller is configured to execute an estimation process that estimates a generation amount per unit time of condensed water generated in the exhaust passage. In the estimation process, the controller estimates a lower value of the generation amount for a higher value of the exhaust gas temperature that is detected by the exhaust gas temperature sensor.

A method of controlling a split inflow of condensate water in a hybrid engine includes: determining whether condensate water is generated from an exhaust gas recirculation (EGR) device of a hybrid electric vehicle (HEV); determining an amount of the condensate water introduced into an hybrid engine; determining whether a vehicle speed of the HEV is within a predetermined speed range; determining whether a request torque of the HEV is within a predetermined torque range; determining whether a duration time of the vehicle speed within the predetermined speed range, and a duration time of the request torque within the predetermined torque range are greater than or equal to a predetermined duration time, respectively; and when the determined duration times are greater than or equal to the predetermined duration time, increasing an engine torque of the HEV.

Provided is a control device for an internal combustion engine. The internal combustion engine includes, in an exhaust passage, an electrically heated catalyst device in which a catalyst is supported on a conductive base material) that generates heat when energized. The control device includes an electronic control unit configured to control the internal combustion engine such that, in a case where condensate is generated in the exhaust passage on the upstream side of the catalyst device in an exhaust flow direction, an engine output in a region where an engine load is equal to or greater than a predetermined load becomes smaller than in a case where condensate is not generated.

In a method for estimating water content of exhaust gas, a first gas concentration at a first position in an exhaust passage, a second gas concentration at a second position downstream of the first position, and a gas temperature at the second position are obtained. A saturated water vapor at the gas temperature is calculated as a water content at the second position. By using the water content at the second position and the second gas concentration, an excess air amount of a fuel-air mixture supplied to a combustion apparatus is calculated based on a chemical reaction formula of combustion of the mixture. By using the excess air amount and the first gas concentration, a water content at the first position is estimated.