An internal combustion engine is equipped with a downstream temperature sensor arranged in an intake passage, an upstream temperature sensor arranged in the intake passage upstream of the downstream temperature sensor, an EGR temperature sensor arranged in an EGR passage, and an airflow meter arranged in the intake passage. A control device corrects a temperature detected by each of the temperature sensors based on an amount of deviation of the temperature detected by that one of the temperature sensors upon activation of the control device after the lapse of a prescribed time or more since stoppage of the internal combustion engine from a reference temperature. Then, the control device calculates a flow rate of EGR gas based on the corrected temperature of that one of the temperature sensors and a flow rate of intake air, and detects the clogging of the EGR passage based on the flow rate.

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.

Methods and systems are provided for calibrating an effective area associated with an exhaust gas recirculation valve and/or a variable orifice associated with the exhaust gas recirculation valve. In one example, a method may include attaining a first steady-state intake pressure with the exhaust gas recirculation valve closed, determining a second steady-state intake pressure and a differential pressure across the variable orifice with the exhaust gas recirculation valve open, and estimating the variable orifice effective area based on the second steady-state intake pressure and the differential pressure. In this way, a calibration table may be updated for an exhaust gas recirculation control apparatus that includes an exhaust gas recirculation valve and a variable orifice, such that an actual amount of recirculated exhaust gas reflects a commanded amount.

A storage device stores mapping data and association data. The mapping data defines a mapping that outputs an estimated value of the temperature of a catalyst using a warm-up operation amount variable and the previous value of the estimated value as an input. The association data associates the integrated value of an intake air amount of an internal combustion engine from the startup of the engine and the temperature of the catalyst. The execution device repeatedly calculates the estimated value based on the output of the mapping. When the correspondence relationship between the integrated value and the estimated value is different from the correspondence relationship between the integrated value and the temperature of the catalyst in the association data, the warm-up process is determined to have an anomaly.

An internal combustion engine is equipped with a water injector for cooling the internal combustion engine by a spray of atomized water into the intake track or combustion chamber prior to ignition. The atomized water spray may be in the intake manifold or directly in the cylinder. The water is injected at a volume of between a ratio of about 95% fuel to about 5% water and about 50% fuel and about 50% water. The temperature of the internal combustion engine is maintained at between about 95° C. and about 200° C. during operation.

Systems, apparatus, and methods are disclosed that include a divided exhaust engine with at least one primary EGR cylinder and a plurality of non-primary EGR cylinders. The systems, apparatus and methods control the amount of recirculated exhaust gas in a charge flow in response to EGR fraction deviation conditions.

A method of controlling exhaust gas recirculation in the internal combustion engine includes: sensing one or more sensing signals indicative of operating conditions of an internal combustion engine, producing, as a function of the sensing signal or signals sensed, an exhaust gas recirculation control signal for controlling exhaust gas recirculation in the internal combustion engine, producing, e.g., via a “virtual” sensor including a neural network, a particulate size distribution signal indicative of the particulate size distribution in the exhaust of the internal combustion engine, correcting the exhaust gas recirculation control signal as a function of the particulate size distribution control signal, thereby producing a corrected exhaust gas recirculation control signal, and controlling exhaust gas recirculation in the internal combustion engine as a function of the corrected exhaust gas recirculation control signal.

An internal combustion engine is equipped with a water injector for cooling the internal combustion engine by a spray of atomized water into the intake track or combustion chamber prior to ignition. The atomized water spray may be in the intake manifold or directly in the cylinder. The water is injected at a volume of between a ratio of about 95% fuel to about 5% water and about 50% fuel and about 50% water. The temperature of the internal combustion engine is maintained at between about 95° C. and about 200° C. during operation.

A novel control device for an internal combustion engine capable of highly accurately estimating an EGR amount (rate) during the transient state is provided. A first EGR rate is determined using, as an input, a detection signal of an EGR sensor provided on the downstream side of a throttle valve which adjusts the flow rate of a mixed gas of air and EGR gas flowing through an intake pipe, a second EGR rate is estimated by calculating a predetermined equation using, as an input, at least a detection signal of an air flow sensor and an EGR valve opening degree sensor, a third EGR rate is determined by carrying out delay processing on the second EGR rate corresponding to a response delay of the EGR sensor, and the second EGR rate is subjected to learning correction by reflecting a difference between the third EGR rate and the first EGR rate.

Calibration techniques for forced-induction engines having low pressure cooled exhaust gas recirculation (LPCEGR) systems include commanding an EGR to a fully-closed position, after the EGR valve has reached the fully-closed position, commanding the engine to operate at fixed steady-state conditions for a calibration period, wherein the fixed steady-state conditions comprise at least a fixed throttle valve angle, a fixed injected fuel mass, and a fixed cylinder air/fuel ratio (AFR), during the calibration period, increasingly opening the EGR valve and monitoring a AFR of exhaust gas produced by the engine, calibrating an EGR fraction estimation and EGR transport delay model based on previously measured and/or modeled total engine flow and the monitored exhaust gas AFR during the calibration period, and storing the calibrated model at a memory of a controller of the engine for future usage to improve engine operation.