To keep catalyst purification efficiency high and prevent deterioration of emission performance. Therefore, an internal combustion engine control device according to an aspect of the present invention includes: an oxygen storage ratio calculation unit that calculates an oxygen storage ratio of a catalyst based on a catalytic reaction model having at least a detection value of a first exhaust gas sensor disposed on an upstream side of the catalyst as an input; a statistical model calculation unit that predicts a catalyst downstream exhaust gas concentration using a statistical model having an oxygen storage ratio as an input and a catalyst downstream exhaust gas concentration as an output; and an air-fuel ratio correction amount calculation unit that calculates an air-fuel ratio correction amount of an air-fuel mixture of an internal combustion engine based on a future catalyst downstream exhaust gas concentration calculated by the statistical model calculation unit.

A method for adaptation of a detected camshaft position of a camshaft in an internal combustion engine with: Detection of an ACTUAL gas signal in a gas space that is associated with the camshaft and is associated with a detected camshaft position; Processing of the gas signal to produce an ACTUAL gas criterion; Modeling of multiple simulated gas criteria, each of which is associated with a target camshaft position; Determination of a simulated gas criterion with the least deviation from the ACTUAL gas criterion; Determination of an ACTUAL camshaft position that corresponds to the simulated gas criterion with the least deviation from the ACTUAL gas criterion; Determination of a camshaft position correction value from the difference between the ACTUAL camshaft position determined and the detected camshaft position; Determination of corrected camshaft positions by correcting the detected camshaft positions with the camshaft position correction value.

An engine system includes: an engine main body; an intake pipe; a mass flow sensor that is provided in the intake pipe and outputs a measurement value of an amount of air passing through the intake pipe; an exhaust pipe; a removal device that is provided in the exhaust pipe and removes an air pollutant included in an exhaust gas passing through the exhaust pipe; a recirculation pipe; a recirculation valve that controls a flow rate of the exhaust gas flowing from the recirculation pipe to the intake pipe; a regeneration control unit that closes the recirculation valve; an air amount calculation unit that calculates a theoretical value of an amount of air flowing to the intake side of the engine main body on the basis of a quantity of state of the engine main body during the regeneration process; and a correction unit.

An injector failure cylinder diagnosis method based on signal deviation of an injector failure diagnosis system measures, by a controller, noise/vibration signals due to the combustion of an engine, separates an injector abnormal frequency band signal as an injector signal from the noise/vibration signals, divides cylinder number time series data, which use a signal maximum value of the noise/vibration signals as a cylinder #1, into segments, extracts a feature vector after confirming a segment number of the cylinder #1 with a vibration reduction signal of the noise/vibration signals re-measured using one of the cylinders as an idle cylinder and sorting it by injector causing vibration time series data, and confirms a failure injector with the feature vector, thereby independently diagnosing whether the injector for each cylinder is normal or abnormal considering the deviation of the noise/vibration signals between the injectors for each cylinder from the measured noise and vibration signals.

An ECU includes a cooling water temperature sensor, an intake air temperature sensor, a storage unit, a determination unit, and a calibration unit. In an after-run control performed after the internal combustion engine stops, the determination unit compares a cooling water temperature Tw detected by the cooling water temperature sensor with a first threshold value T1 and determines that the environment is not the cold environment in which an EGR differential pressure sensor is likely to be frozen, if the cooling water temperature Tw is equal to or higher than the first threshold value T1, or if the cooling water temperature Tw is less than the first threshold value T1 but is equal to or higher than a second threshold value T2 which is lower than the first threshold value T1 and an intake air temperature Ta from the intake air temperature sensor is equal to or higher than a third threshold value T3, and determines that the environment is the cold environment otherwise. When the environment is determined as not to be the cold environment, the calibration unit obtains a calibration reference value based on the detection value from the EGR differential pressure sensor. The storage unit stores the calibration reference value obtained by the calibration unit.

Various embodiments include a method for operating an internal combustion engine with a three-way catalytic converter with lambda control, comprising: monitoring a NO.sub.x sensor for a lambda value downstream of the converter; setting a threshold value determining a lambda setpoint value upstream of the converter using the difference between the setpoint value of the electrical signal and the measured electrical signal if the signal is below the threshold; if above the threshold value, determining the lambda setpoint value upstream of the converter using the difference between a NH.sub.3 setpoint value of the NO.sub.x sensor and the measured NH.sub.3 signal of the NO.sub.x sensor; and if the measured NH.sub.3 concentration is higher than the NH.sub.3 setpoint value, increasing the lambda setpoint value upstream of the converter and, if the measured NH.sub.3 concentration is lower than the NH.sub.3 setpoint value, reducing the lambda setpoint value upstream of the converter.

Methods and systems are provided for reducing errors in estimated fuel rail pressure incurred at the time of a scheduled injection event due to engine-driven cyclic fuel rail pressure changes. In one example, a pulse-width commanded during a scheduled injection event is determined as a function fuel rail pressure samples collected over a moving window that is customized for the corresponding fuel injector. In another example, the commanded pulse-width is determined as a function of an average fuel rail pressure sampled during a quiet zone of injector operation and predicted fuel rail pressure altering events occurring between the quiet zone and the scheduled injection event.

A method of adaptively predicting, during operation of a pump, a mass of fuel pumped by the pump during a pumping event to a fuel accumulator (“Q.sub.pump”) to control operation of the pump is provided, comprising: generating an adaptive model of operation of the pump, including estimating a start of pumping (“SOP”) position of a plunger of the pump, estimating Q.sub.pump, determining a converged value of the estimated SOP position, and determining a converged value of the estimated Q.sub.pump; using the adaptive model to predict Q.sub.pump by inputting to the model the converged value of the estimated SOP position, a measured pressure of fuel in the fuel accumulator and a measured temperature of fuel in the fuel accumulator; and controlling operation of the pump in response to the predicted Q.sub.pump.

A control apparatus for an internal combustion engine includes an exhaust gas sensor that has a sensor element and a heater for electrically heating the sensor element, a sensor circuit that detects the electric current generated by the exhaust gas sensor, a controller configured to: carry out starting processing to start the internal combustion engine, learn a value of the output of the sensor circuit when the starting processing is carried out by the controller, and control a temperature of the sensor element by using the heater, and controls the temperature of the sensor element to less than the predetermined temperature until the learning of the output value of the sensor circuit by the controller is completed after the starting processing is carried out by the controller.

A control system of an internal combustion engine comprises an air-fuel ratio sensor 40, 41 detecting an air-fuel ratio of exhaust gas, a current detecting device 61 detecting an output current of the air-fuel ratio sensor, a voltage applying device 60 applying voltage to the air-fuel ratio sensor, and a voltage control part 81 configured to control voltage applied to the air-fuel ratio sensor through the voltage applying device. The voltage control part is configured to set the applied voltage to a reference voltage determined so that the output current becomes zero when an air-fuel ratio of inflowing exhaust gas flowing into the air-fuel ratio sensor is a stoichiometric air-fuel ratio, and correct the reference voltage so that the output current detected by the current detecting device becomes zero when it is judged that the air-fuel ratio of the inflowing exhaust gas is the stoichiometric air-fuel ratio.