A system and method for providing torque-assist to a rotary shaft of an internal combustion engine control an electric machine in response to operation of an exhaust gas recirculation (EGR) valve to assist the rotation of the rotary shaft. The system and method facilitate periodic operation of the EGR valve to purge condensation without objectionable torque reduction when the engine is operating near full load.

An upper-limit threshold value and a lower-limit threshold value of a fore-and-aft differential pressure of an EGR control valve is calculated based on an intake-air quantity detected by an airflow meter. An actual fore-and-aft differential pressure of the EGR control valve is calculated from detected values of an upstream-side pressure sensor and a downstream-side pressure sensor. Then, these threshold values are compared with the actual fore-and-aft differential pressure, and when the actual fore-and-aft differential pressure exceeds the upper-limit threshold value or when the actual fore-and-aft differential pressure is less than the lower-limit threshold value, it is determined that the pressure loss of an intake and exhaust system has changed. If it is determined that the pressure loss of an intake and exhaust system has changed, EGR is inhibited, and if not so, EGR is permitted to be performed. These threshold values are varied depending on a target EGR rate.

A first recirculation system includes a first adjuster to adjust the exhaust-gas flow rate in a first path connecting an upstream position of a turbine of a VG turbocharger to a downstream position of a compressor. A second recirculation system includes a second adjuster to adjust the exhaust-gas flow rate in a second path connecting a downstream position of the turbine to an upstream position of the compressor. A recirculation controller switches between a single use activating the first or second recirculation system and a combination use activating both systems by controlling the adjusters. A pressure controller executes feedback control of an intake-system pressure through adjusting the opening of vanes, and executes feedforward control without the feedback control during a predetermined period from the switching from the single use to the combination use.

A first recirculation system includes a first adjuster to adjust the exhaust-gas flow rate in a first path connecting an upstream position of a turbine of a VG turbocharger to a downstream position of a compressor. A second recirculation system includes a second adjuster to adjust the exhaust-gas flow rate in a second path connecting a downstream position of the turbine to an upstream position of the compressor. A recirculation controller switches between a single use activating the first or second recirculation system and a combination use activating both systems by controlling the adjusters. A pressure controller executes feedback control of an intake-system pressure through adjusting the opening of vanes, and executes feedforward control without the feedback control during a predetermined period from the switching from the single use to the combination use.

Provided is an internal combustion engine control device capable of appropriately correcting a flow rate of EGR gas. Therefore, an internal combustion engine control device 20 includes moisture amount calculation units 301 and 302, a dew condensation calculation unit 303, and an EGR correction unit 304. The moisture amount calculation unit 301 calculates a total moisture amount contained in the mixed gas. The dew condensation calculation unit 303 calculates a dew condensation generation amount WQcon in an intercooler based on the total moisture amount. The EGR correction unit 304 corrects a flow rate of the EGR gas based on the dew condensation generation amount WQcon.

Methods and systems are provided for maintaining combustion stability in a multi-fuel engine. In one example, a system may include first and second fuel systems to deliver liquid and gaseous fuels, respectively, to at least one cylinder of the engine, and a controller. The controller may be configured to supply the gaseous fuel to the at least one cylinder, inject the liquid fuel to the at least one cylinder to compression ignite the liquid fuel and combust the gaseous fuel in the at least one cylinder, and retard an injection timing of the injection of the liquid fuel based on a measured parameter associated with auto-ignition of end gases subsequent to the compression-ignition of the liquid fuel. In some examples, the controller may further be configured to adjust an amount of the gaseous fuel relative to an amount of the liquid fuel based on the measured parameter.

Methods and systems are provided for a condensation mitigation device. In one example, a system may include a vortex generator arranged in a flow channel of a compressor along with a condensate collection device configured to direct condensate away from compressor blades of the compressor.

Intake noise suppression techniques for a forced-induction engine having a low pressure exhaust gas recirculation (LPEGR) system configured to recirculate exhaust gas produced by the engine to an intake system of the engine via an EGR port comprise receiving, from a mass air flow (MAF) sensor of the engine, a MAF signal indicative of measured airflow through the intake system, detecting, based on the MAF signal, intake system conditions that are indicative of audible noise, and in response to detecting the detected intake system conditions that are indicative of audible noise, at least partially closing a differential pressure (dP) valve to mitigate or eliminate the intake system conditions and the corresponding audible noise, wherein the MAF sensor is disposed in the intake system upstream from the dP valve.

Intake noise suppression techniques for a forced-induction engine having a low pressure exhaust gas recirculation (LPEGR) system configured to recirculate exhaust gas produced by the engine to an intake system of the engine via an EGR port comprise receiving, from a mass air flow (MAF) sensor of the engine, a MAF signal indicative of measured airflow through the intake system, detecting, based on the MAF signal, intake system conditions that are indicative of audible noise, and in response to detecting the detected intake system conditions that are indicative of audible noise, at least partially closing a differential pressure (dP) valve to mitigate or eliminate the intake system conditions and the corresponding audible noise, wherein the MAF sensor is disposed in the intake system upstream from the dP valve.

An apparatus for controlling a low-pressure exhaust gas recirculation (LP-EGR) system for freezing prevention includes an intake air temperature sensor configured to measure a temperature of intake air introduced from outside, at least one engine driving sensor used to diagnose and learn a driving state of an engine, the LP-EGR system configured such that at least a portion of exhaust gas flows into the LP-EGR system as intake air, and a controller configured to perform diagnosis and learning of the driving state of the engine using the at least one engine driving sensor or to operate the LP-EGR system depending on the temperature of the intake air measured by the intake air temperature sensor when coasting conditions of a vehicle are satisfied.