A device for predicting an exhaust gas recirculation rate of an internal combustion engine, which comprises an inlet system and at least one exhaust gas recirculation valve, is described. The device comprises a sensor arranged in the inlet system for determining the composition of the gas, a sensor for determining the position of the exhaust gas recirculation valve, and an evaluation apparatus. The evaluation apparatus is configured to determine and output a prediction of the exhaust gas recirculation rate based on a corrected estimate of the exhaust gas recirculation rate, wherein the estimate is based on the position of the exhaust gas recirculation valve and is corrected based on the composition of the gas as determined using the sensor.

A cylinder-inflow EGR gas amount is estimated, a misfire limit EGR gas amount is calculated on the basis of an engine operation state, and the misfire limit EGR gas amount is compared with the cylinder-inflow EGR gas amount to predict whether a misfire occurs. When the misfire is predicted, a misfire avoidance control is executed. Further, an actual misfire countermeasure effect amount in a case of the execution of the misfire avoidance control is calculated, and the actual misfire countermeasure effect amount is compared with a required misfire countermeasure effect amount to determine whether the misfire is avoidable when the misfire avoidance control is executed. If the misfire is unavoidable even if the misfire avoidance control is executed, a delay restriction value of an ignition timing to avoid the misfire is calculated, and the amount of a delay in the ignition timing is restricted using the delay restriction value.

Methods and systems are provided for determining degradation of an EGR cooler based on differential pressure across the EGR cooler during EGR flow. In one example, the differential pressure across the EGR cooler may be based on differential pressure across an EGR valve and a pressure downstream from the EGR valve with and without EGR flow. The pressure downstream from the EGR valve may be a compressor inlet pressure or an intake manifold pressure in a low pressure EGR system or high pressure EGR system, respectively.

A sensor for detecting the oxygen content in the intake tract of an internal combustion engine includes: a sensor element having a measurement electrode; a metal cap that surrounds the sensor element; a heat dissipation element that connects the sensor element and the metal cap; and a bracket for the sensor element. The bracket is in the form of a plastic housing configured to accommodate evaluation electronics for the sensor element.

A method of controlling exhaust gas recirculation (EGR) for controlling recirculation of exhaust gas discharged from a combustion chamber of an engine includes: a data obtaining operation of obtaining data about an engine state and a gas supply state; a current EGR rate calculating operation of calculating a current EGR rate of supply gas based on the data; a demand EGR rate setting operation of setting a demand EGR rate matched with the data in a pre-made target EGR rate map; an error calculating operation of calculating a difference between the demand EGR rate and the current EGR rate; and a control operation of making the current EGR rate follow the demand EGR rate by changing a recirculation rate of the exhaust gas by adjusting an inhalation side pressure of the supply gas according to the difference.

There is provided an internal combustion engine control apparatus having an exhaust gas recirculation amount estimation unit that learns the relationship between an exhaust gas recirculation valve opening area calculated by an exhaust gas recirculation valve opening area calculation unit and an opening degree of the exhaust gas recirculation valve and estimates an recirculation amount of exhaust gas utilized in controlling an internal combustion engine, based on the relationship between the exhaust gas recirculation valve opening area and the opening degree of the exhaust gas recirculation valve.

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.

A control device of an internal combustion engine calculates on the basis of the air-fuel ratio difference a correction for the estimated fuel supply amount correction for correcting the estimated fuel supply amount to make the estimated and detected air-fuel ratios correspond to each other and calculates correction values for the fuel supply difference compensation and the air amount detection difference compensation by dividing the correction value for the estimated fuel supply amount correction, using the fuel supply and air amount detection difference proportions, and performing the air-fuel ratio control, using the corrected estimated fuel supply and detected air amounts. The correction value for the estimated fuel supply amount correction is divided to the correction values for the fuel supply difference compensation and the air amount detection difference compensation such that a value equivalent to the air-fuel ratio difference becomes equal to the air-fuel ratio difference, using these correction values.

A system and method are provided for estimating an operating parameter of an exhaust manifold of an engine. In the system, a flow value is determined that corresponds to a flow rate of exhaust gas through an EGR conduit fluidly coupled between the exhaust manifold and the intake manifold. The EGR conduit includes an exhaust gas cooler disposed in-line with the EGR conduit and a property of the exhaust gas exiting an exhaust gas outlet of the cooler is measured. The operating parameter of the exhaust manifold is estimated as a function of at least the flow value and the property of the exhaust gas exiting the exhaust gas outlet of the cooler. Illustratively, the operating parameter of the exhaust manifold may be exhaust manifold pressure and/or temperature.

An anomaly determination unit includes an EGR amount acquisition section configured to acquire an actual amount of an EGR amount, which is a flow rate of EGR gas; an estimation amount computation section configured to compute an estimated amount of the EGR amount based on a working gas pressure, which is a pressure of working gas in which the EGR gas and intake air are mixed, an EGR temperature, which is a temperature of the EGR gas immediately upstream of an EGR valve, an EGR pressure, which is a pressure of the EGR gas immediately upstream of the EGR valve, and an opening degree instruction value for the EGR valve; and a determination section configured to determine the presence or absence of an anomaly in the EGR valve based on the divergence between the actual amount of the EGR amount and the estimated amount.