Abstract: Methods are provided for identifying degradation in components of a compressor recirculation valve (CRV). One method may include inferring degradation of the CRV based on adaptation of a compressor surge line outside an expected range.

Abstract: Methods and systems are provided for improving surge control in a boosted engine system configured with an electric motor to provide electrical boost assistance. Tip-in and tip-out surge are addressed by increasing the opening of a compressor recirculation valve and coordinating the recirculation valve opening with adjustments to an exhaust waste-gate position and a power output by the electric motor. The adjustments enable an intake airflow to be provided that operates the compressor outside a surge region while providing a target boost pressure as operator torque demand increases or decreases.

Abstract: Methods and systems are provided for controlling a boosted engine system, having a turbocharger and a charge air cooler, to limit overheating of a compressor outlet. In one example, a method includes predicting an engine torque profile based on current and future engine operating conditions. The method then models a compressor outlet temperature profile and reduces engine torque output to limit overheating of the compressor outlet.

Abstract: Methods and systems are provided for diagnosing an exhaust waste-gate valve via an electric boost assist motor of an electric turbocharger. Degradation of the waste-gate valve is inferred based on the motor torque profile of the motor after commanding the waste-gate valve to an open or closed position on a torque transient. Deviation of the motor torque profile from the expected profile is used to infer if the valve is stuck open or closed, and actions are taken accordingly.

Abstract: Methods and systems are provided for increasing vehicle maneuverability when operating on sand, snow, or rocky terrain, as well as while performing cornering and sliding maneuvers. Boost path actuators are held in positions that enable manifold pressure to be held above barometric pressure as torque demand changes, including when torque demand drops. Engine torque is reduced or raised via adjustments to one or more of fuel delivery, spark timing, and intake throttle opening.

Abstract: Methods and systems are provided for expediting charging of a battery before entry into a zero emissions zone. In one example, the battery is charged with a ratio of motor torque drawn from a first electric motor of an electric turbocharger and a second electric motor of an HEV driveline. The ratio is coordinated with adjustments to an exhaust waste-gate and an intake throttle so as to maintain operator torque demand and propel the vehicle while charging the battery.

Abstract: Methods and systems are provided for increasing vehicle maneuverability when operating on sand, snow, or rocky terrain, as well as while performing cornering and sliding maneuvers. Boost path actuators are held in positions that enable manifold pressure to be held above barometric pressure as torque demand changes, including when torque demand drops. Engine torque is reduced or raised via adjustments to one or more of fuel delivery, spark timing, and intake throttle opening.

Abstract: Methods and systems are provided for diagnosing an exhaust waste-gate valve via an electric boost assist motor of an electric turbocharger. Degradation of the waste-gate valve is inferred based on the motor torque profile of the motor after commanding the waste-gate valve to an open or closed position on a torque transient. Deviation of the motor torque profile from the expected profile is used to infer if the valve is stuck open or closed, and actions are taken accordingly.

Abstract: Methods and systems are provided for controlling boost pressure in a staged engine system comprising a turbocharger and an upstream electric supercharger. In one example, a method may include coordinating the operation of the electric supercharger and an electric supercharger bypass valve and to open the electric supercharger bypass valve to reduce the extent and duration of electric supercharger overboost.

Abstract: Methods and systems are provided for coordinated control of a compound boosting system, including a first compressor staged upstream of a second compressor in an engine intake. In one example, a method may include operating the second, downstream compressor in steady-state to achieve an overall pressure ratio across the compound boosting system while operating the first, upstream compressor transiently, based on an airflow shortfall at the downstream compressor. A timing and amount of electric assistance provided to transiently operate the first, upstream compressor may be adjusted dynamically as the pressure ratio across the second compressor changes.

Abstract: Methods and systems are provided for diagnosing the electrical efficiency of an electric supercharger staged upstream of a turbocharger. During idling conditions, a step-wise incremented signal may be commanded to an electric motor driving the supercharger compressor and changes in compressor speed and total vehicle current may be measured at each step. Degradation of electrical efficiency of the supercharger may be inferred based on deviations between the actual change in compressor speed and total vehicle current relative to the change expected for the given step, and mitigating actions may be accordingly performed.

Abstract: Methods and systems are provided for controlling boost pressure in a staged engine system comprising a turbocharger and an upstream electric supercharger. In one example, a method may include accelerating an electric supercharger to choke the flow of air to the engine in the event of turbocharger overboost.

Abstract: Methods and systems are provided for warming an engine and/or engine fluids. In one example, a method may comprise powering on an electric motor of an intake boost device to generate heat, circulating coolant and/or engine oil through the boost device to absorb the heat produced by the boost device, and then flowing the coolant and/or engine oil to the engine to transfer the heat absorbed from the boost device to the engine. In this way, an engine may be warmed without running the engine rich by using the heat generated by the electric motor of the boost device to warm the engine.

Abstract: Methods and systems are provided for coordinated control of a compound boosting system, including a first compressor staged upstream of a second compressor in an engine intake. In one example, a method may include operating the second, downstream compressor in steady-state to achieve an overall pressure ratio across the compound boosting system while operating the first, upstream compressor transiently, based on an airflow shortfall at the downstream compressor. A timing and amount of electric assistance provided to transiently operate the first, upstream compressor may be adjusted dynamically as the pressure ratio across the second compressor changes.

Abstract: Methods and systems are provided for improving surge control in a boosted engine system configured with an electric motor to provide electrical boost assistance. Tip-in and tip-out surge are addressed by increasing the opening of a compressor recirculation valve and coordinating the recirculation valve opening with adjustments to an exhaust waste-gate position and a power output by the electric motor. The adjustments enable an intake airflow to be provided that operates the compressor outside a surge region while providing a target boost pressure as operator torque demand increases or decreases.

Abstract: Methods and systems are provided for controlling a boosted engine system, having a turbocharger and a charge air cooler, to limit overheating of a compressor outlet. In one example, a method includes predicting an engine torque profile based on current and future engine operating conditions. The method then models a compressor outlet temperature profile and reduces engine torque output to limit overheating of the compressor outlet.

Abstract: Methods and systems are provided for warming an engine and/or engine fluids. In one example, a method may comprise powering on an electric motor of an intake boost device to generate heat, circulating coolant and/or engine oil through the boost device to absorb the heat produced by the boost device, and then flowing the coolant and/or engine oil to the engine to transfer the heat absorbed from the boost device to the engine. In this way, an engine may be warmed without running the engine rich by using the heat generated by the electric motor of the boost device to warm the engine.

Abstract: Methods and systems are provided for expediting charging of a battery before entry into a zero emissions zone. In one example, the battery is charged with a ratio of motor torque drawn from a first electric motor of an electric turbocharger and a second electric motor of an HEV driveline. The ratio is coordinated with adjustments to an exhaust waste-gate and an intake throttle so as to maintain operator torque demand and propel the vehicle while charging the battery.

Abstract: Methods and systems are provided for controlling a boosted engine system, having a turbocharger and a charge air cooler, to limit overheating of a compressor outlet. In one example, a method includes predicting an engine torque profile based on current and future engine operating conditions. The method then models a compressor outlet temperature profile and reduces engine torque output to limit overheating of the compressor outlet.

Abstract: Methods and systems are provided for controlling a wastegate coupled to a turbine. In one example, a method may include during steady engine operation, actuating a wastegate to introduce an oscillation in boost pressure, and updating gain of a wastegate feedback controller responsive to the oscillation in boost pressure.