Abstract: An ignition control system and method for an engine having a two-step variable valve lift (VVL) system utilizes an ignition control system comprising a plurality of spark plugs each configured to generate one or more ignition strikes during a combustion event in a respective cylinder of the engine and a controller configured to detect a low-to-high or high-to-low lift mode transition of the VVL system and, in response to detecting the low-to-high or high-to-low lift mode transition of the VVL system, command the ignition control system to perform multi-strike ignition for at least one combustion event, wherein commanding the multi-strike ignition mitigates or eliminates at least one of engine torque variations and increased engine emissions resulting from poor combustion quality caused by residual exhaust components within the cylinder from a previous combustion event prior to the low-to-high or high-to-low lift mode transition of the VVL system.

Abstract: 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.

Abstract: A low speed pre-ignition detection, mitigation, and driver notification system and method utilize a controller to analyze a knock signal from a knock sensor to detect LSPI knock of the engine and in response to detecting the LSPI knock, enrich a fuel/air ratio of the engine and limit a torque output of the engine to a level that is less than a maximum torque output of the engine, and when enriching the fuel/air ratio of the engine and limiting the torque output of the engine does not mitigate the LSPI knock, output at least one message for a driver of the vehicle instructing the driver to take remedial action to mitigate the LSPI knock.

Abstract: Techniques for controlling a forced-induction engine having a low pressure exhaust gas recirculation (LPEGR) system comprise determining a desired differential pressure (dP) at an inlet of a boost device based on an engine mass air flow (MAF) and a speed of the engine, wherein the engine further comprises a dP valve disposed upstream from an EGR port and a throttle valve disposed downstream from the boost device, determining a desired EGR mass fraction based on at least the engine MAF and the engine speed, determining a maximum throttle inlet pressure (TIP) based on the engine speed, the desired EGR mass fraction, and a barometric pressure, and performing coordinated control of the dP valve and the throttle valve based on the desired dP and the maximum TIP, respectively, thereby extending EGR operability to additional engine speed/load regions and increasing engine efficiency.

Abstract: A low speed pre-ignition detection, mitigation, and driver notification system and method utilize a controller to analyze a knock signal from a knock sensor to detect LSPI knock of the engine and in response to detecting the LSPI knock, enrich a fuel/air ratio of the engine and limit a torque output of the engine to a level that is less than a maximum torque output of the engine, and when enriching the fuel/air ratio of the engine and limiting the torque output of the engine does not mitigate the LSPI knock, output at least one message for a driver of the vehicle instructing the driver to take remedial action to mitigate the LSPI knock.

Abstract: A calibration system and method for a spark ignition engine of a vehicle involve artificially weighting engine dynamometer data in high engine load regions and using it to generate training data for an artificial neutral network (ANN). A plurality of ANNs are trained using the training data and the plurality of ANNs are then filtered based on their maximum error to obtain a filtered set of trained ANNs. A statistical analysis is performed on each of the filtered set of trained ANNs including determining a set of statistical metrics for each of the filtered set of trained ANNs and then one of the filtered set of trained ANNs having a best combination of error at high engine loads and the set of statistical error metrics is then selected. Finally, an ANN calibration is generated using the selected one of the filtered set of trained ANNs.

Abstract: A calibration system and method for a spark ignition engine of a vehicle involve artificially weighting engine dynamometer data in high engine load regions and using it to generate training data for an artificial neutral network (ANN). A plurality of ANNs are trained using the training data and the plurality of ANNs are then filtered based on their maximum error to obtain a filtered set of trained ANNs. A statistical analysis is performed on each of the filtered set of trained ANNs including determining a set of statistical metrics for each of the filtered set of trained ANNs and then one of the filtered set of trained ANNs having a best combination of error at high engine loads and the set of statistical error metrics is then selected. Finally, an ANN calibration is generated using the selected one of the filtered set of trained ANNs.

Abstract: Techniques for controlling a forced-induction engine having a low pressure exhaust gas recirculation (LPEGR) system comprise determining a desired differential pressure (dP) at an inlet of a boost device based on an engine mass air flow (MAF) and a speed of the engine, wherein the engine further comprises a dP valve disposed upstream from an EGR port and a throttle valve disposed downstream from the boost device, determining a desired EGR mass fraction based on at least the engine MAF and the engine speed, determining a maximum throttle inlet pressure (TIP) based on the engine speed, the desired EGR mass fraction, and a barometric pressure, and performing coordinated control of the dP valve and the throttle valve based on the desired dP and the maximum TIP, respectively, thereby extending EGR operability to additional engine speed/load regions and increasing engine efficiency.

Abstract: 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.

Abstract: Systems and methods for a turbocharged gasoline engine utilize a controller configured to receive a set of parameters including a measured pressure delta across an exhaust gas recirculation (EGR) valve disposed in a low pressure EGR (LPEGR) system of the engine and a measured pressure at an outlet of a differential pressure (dP) valve disposed in and distinct from a throttle valve of an induction system of the engine. The controller is further configured to determine a set of modeled pressures based on the set of parameters, a target EGR valve mass flow, a target EGR valve delta pressure, a current dP valve mass flow, and a pressure at an outlet of the air filter, determine target positions for the EGR valve and the dP valve based on the set of modeled pressures, and control the EGR valve and the dP valve based on their respective target positions.

Abstract: Systems and methods for a turbocharged gasoline engine utilize a controller configured to receive a set of parameters including a measured pressure delta across an exhaust gas recirculation (EGR) valve disposed in a low pressure EGR (LPEGR) system of the engine and a measured pressure at an outlet of a differential pressure (dP) valve disposed in and distinct from a throttle valve of an induction system of the engine. The controller is further configured to determine a set of modeled pressures based on the set of parameters, a target EGR valve mass flow, a target EGR valve delta pressure, a current dP valve mass flow, and a pressure at an outlet of the air filter, determine target positions for the EGR valve and the dP valve based on the set of modeled pressures, and control the EGR valve and the dP valve based on their respective target positions.

Abstract: Systems and methods for a turbocharged gasoline engine utilize an exhaust gas concentration sensor disposed upstream from an exhaust gas recirculation pickup point of a low pressure EGR (LPEGR) system of the engine and a controller configured to receive a measured air/fuel ratio of the exhaust gas from the sensor, determine an air/fuel ratio of the exhaust gas at the EGR pickup point, determine an air/fuel ratio of the exhaust gas at an inlet and outlet of an EGR cooler, determine first/second sets of exhaust gas fractions and fuel fractions upstream/downstream from an EGR port that is upstream from a compressor in an induction system of the engine, and control at least one of a wastegate valve, a throttle valve, a fuel injector, and a spark plug based on the sets of second exhaust gas fractions and fuel fractions to prevent misfires of the engine.

Abstract: A control system and method utilize an exhaust oxygen (O2) sensor and a controller configured to operate a turbocharged engine in a scavenging mode, and while the operating the engine in the scavenging mode: command a target in-cylinder air/fuel ratio (FA) for achieving a target exhaust gas FA, adjust the measurement of the exhaust O2 sensor based on a scavenging ratio and the target in-cylinder FA to obtain a modified O2 concentration, adjust an exhaust system temperature modeled by a thermal model to obtain a modified exhaust system temperature, and adjust the target in-cylinder FA based on the modified O2 concentration and the modified exhaust system temperature.

Abstract: A control system and method utilize an intake manifold absolute pressure (MAP) and an engine speed (RPM) sensor and a controller configured to obtain a model surface relating various measurements of the RPM sensor and valve overlap durations to modeled scavenging ratios of an engine, obtain a calibrated multiplier surface relating various measurements of the MAP and RPM sensors to measured scavenging ratios of the engine, determine a modeled scavenging ratio of the engine based on the measured engine speed and a known overlap duration using the model surface, determine a scavenging ratio multiplier based on the measured MAP and measured engine speed using the calibrated multiplier surface, determine the scavenging ratio of the engine by multiplying the modeled scavenging ratio by the scavenging ratio multiplier, and control the engine based on the scavenging ratio.