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 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 are provided for identifying degradation in components of a compressor recirculation valve (CRV). One method includes differentiating between degradation of a throttle of the CRV and a position sensor of the CRV based on each of a throttle inlet pressure and commanded position of the throttle of the CRV. The method also includes utilizing output from the position sensor of the CRV in response to the commanded position of the throttle of the CRV.

Abstract: Methods and systems for operating an engine that includes an electrically operated throttle are disclosed. In one example, mitigating actions are taken in response to degradation of the electrically operated throttle so that the engine may be operated in a way that allows a driver to reach a service area.

Abstract: Methods and systems are provided for operating an electric supercharger as an on-board air pump and/or vacuum pump. During conditions when a vehicle is not being propelled and the vehicle engine is idling, a portion of an air intake passage is sealed and the supercharger is operated to deliver compressed air into the sealed portion. Compressed air can then be picked up directly from the sealed portion for use in tire inflation, or picked up via an ejector to provide vacuum for vacuum actuators.

Abstract: Methods and systems are provided for determining a cylinder air charge based on a boost manifold volume of an engine. In one example, a method may include inducing a compressor surge event, and updating the boost manifold volume in response to a difference between an actual surge pressure and an expected surge pressure. The method further includes determining the cylinder air charge based on the updated boost manifold volume.

Abstract: Methods and systems are provided for diagnosing compressor bypass valve degradation. In one example, a method may include indicating degradation of a compressor bypass valve coupled in a compressor bypass based on intake aircharge temperature measured upstream of a compressor inlet via an air charge temperature sensor.

Abstract: Systems and methods for generating auxiliary torque are provided. In one example, a method for controlling a supercharger comprises, responsive to requested torque exceeding spark authority of an engine, varying a current applied to a motor of the supercharger to provide an amount of torque to a crankshaft of the engine. In this way, a supercharger can be controlled to compensate for an engine torque shortfall.

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.

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 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 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.

Abstract: Methods and systems are provided for diagnosing an air filter for a vehicle. In one example, a method may include actuating a motor to flow air through the air filter during engine off, and indicating air filter replacement based on an air pressure measurement while actuating the motor.

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 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 turbine temperature control in an engine system having multiple staged charge boosting devices. In one example, compressed air is provided by a turbocharger compressor until an outlet temperature of the compressor reaches a limit.

Abstract: Methods and systems are provided for operating an electric supercharger as an on-board air pump and/or vacuum pump. During conditions when a vehicle is not being propelled and the vehicle engine is idling, a portion of an air intake passage is sealed and the supercharger is operated to deliver compressed air into the sealed portion. Compressed air can then be picked up directly from the sealed portion for use in tire inflation, or picked up via an ejector to provide vacuum for vacuum actuators.

Abstract: Methods and systems are provided for controlling boost pressure in a staged engine system comprising a turbocharger and an upstream electric supercharger based on altitude. During vehicle operation at higher altitudes, where vacuum availability for wastegate actuation is limited, boost pressure may be provided by operating the electric supercharger more aggressively. The wastegate may be used for boost control once the vacuum reserve is replenished.

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 are provided for identifying degradation in components of a compressor recirculation valve (CRV). One method includes differentiating between degradation of a throttle of the CRV and a position sensor of the CRV based on each of a throttle inlet pressure and commanded position of the throttle of the CRV. The method also includes utilizing output from the position sensor of the CRV in response to the commanded position of the throttle of the CRV.