Abstract:
Methods and systems are provided for adjusting a reference voltage for an intake manifold oxygen sensor based on ingestion of hydrocarbons from a fuel system canister and/or an engine crankcase. During conditions when purge or crankcase ventilation hydrocarbons are ingested in the intake aircharge, the intake oxygen sensor is transitioned from operating at a lower reference voltage to a higher reference voltage where the effects of the ingested hydrocarbons on the sensor output are nullified. An EGR dilution of the intake aircharge is estimated based on the output of the sensor at the higher reference voltage while an amount of hydrocarbons ingested is estimated based on a difference between sensor outputs at the higher and lower reference voltages.
Abstract:
Methods and systems are provided for using compressor recirculation flow via a venturi to enhance low pressure EGR flow. The opening of a compressor recirculation valve can be adjusted based on EGR flow demand to recirculate cooled compressed air through a venturi while generating vacuum for drawing EGR. The approach allows for concurrent EGR control and surge control.
Abstract:
Methods and systems are provided for varying a proportion of compressed air recirculated to a compressor inlet from a location downstream of the compressor and upstream of a charge air cooler and a location downstream of the charge air cooler. A temperature-controlled compressor recirculation flow is used to reduce condensation from EGR being ingested into the compressor. The temperature-controlled compressor recirculation flow is also used to address compressor surge.
Abstract:
Methods and systems are provided for providing auxiliary heat to a pre-compressor duct wall to reduce condensate formation. A coolant valve may control the delivery of heated engine coolant to the pre-compressor duct wall. The coolant valve may be adjusted based on condensate formation at the pre-compressor duct wall.
Abstract:
Methods and systems are provided for re-combustion of exhaust in a cylinder of a multi-cylinder engine in order to increase the temperature of the exhaust for enhancing catalytic conversion within the multi-cylinder engine. In one example, a method may include expelling combusted gases from the cylinder into an intake manifold via an intake valve during an exhaust stroke, in order to rebreathe in the combusted gases from the intake manifold via the intake valve in a subsequent intake stroke.
Abstract:
An exhaust gas recirculation system for an engine includes a conduit, and a mixer. The conduit is configured to direct to direct exhaust gas away from an exhaust manifold. The mixer is configured to direct exhaust gas from the conduit, into an engine air intake system. The mixer is arranged with an exhaust gas mixing volute chamber having a plurality of mixing vanes configured to direct the exhaust gas into a central intake airflow upstream of an intake manifold.
Abstract:
Methods and systems are provided for expediting heating of an engine and an emissions device upon cold startup of the engine. In one example, a method may include prior to cold startup of an engine, operating an e-compressor and opening a recirculation valve of a recirculation passage coupled across the e-compressor to flow compressed intake air from an outlet of the e-compressor through the recirculation passage to an inlet of the e-compressor and starting the engine upon a temperature at the outlet of the e-compressor reaching a threshold and continuing to operate the e-compressor while the engine is on. The heated intake air resulting from the flow of compressed intake air through the recirculation passage raises a temperature of combustion and a temperature of exhaust gas, which may decrease catalyst light-off time of the emissions device.
Abstract:
Methods and systems are provided for an engine system configured with a wide range active compressor and high pressure EGR. In one example, a compressor may include an active casing treatment with a slideable sleeve may be adjusted to direct air flow through either a choke slot and surge slot to control compressor efficiency, thereby maintaining EGR flow. In another example, the compressor may comprise a variable inlet device to regulate air flow through the compressor, thereby adjusting compressor efficiency and also maintaining EGR flow.
Abstract:
Methods and systems are provided for adjusting engine operation based on wirelessly received weather data in conjunction with engine sensor outputs. In one example, a method may comprise receiving a first measurement of a weather parameter from one or more engine sensors and a second measurement of the weather parameter from weather data, the weather data provided by a wireless weather service. The method may further comprise determining accuracies for the first and second measurements, generating an estimate of the weather parameter based on the accuracies of the first and second measurements, and adjusting at least one engine operating parameter based on the generated estimate.
Abstract:
Methods and systems are provided for a vehicle wirelessly communicating with a central server. In one example, a method may include monitoring faults and sending engine conditions along with driver inputs to the central server for processing.