An engine system includes an internal combustion engine, an energy storage device configured to provide electrical power, and an electrified air-boost system powered by the electrical power from the energy storage device to boost intake air to the engine, with the electrified air-boost system further including an electrical machine and a pressure device driven by the electrical machine to output boosted intake air to the engine. The engine system also includes a controller operably connected with the electrified air-boost system, with the controller configured to monitor engine speed and engine load during operation of the engine, identify an impending engine stall condition based on the monitored engine speed and engine load, and when the impending engine stall condition is identified, temporarily operate the electrified air-boost system to boost the intake air to the engine, thereby boosting a torque output of the engine.

Methods and systems of controlling operation of a dual fuel engine are provided, comprising determining a target exhaust temperature, sensing an actual exhaust temperature, determining an exhaust temperature deviation by comparing the actual exhaust temperature to the target exhaust temperature, comparing the exhaust temperature deviation to a threshold, adjusting at least one of an intake throttle, a wastegate, a compressor bypass valve, an exhaust throttle, a VGT and engine valve timing when the exhaust temperature deviation exceeds the threshold to control charge-flow to the engine, and continuing the adjusting until the exhaust temperature deviation is less than the threshold.

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.

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.

A control device of a vehicle capable of improving acceleration responsiveness and suppressing increase in the NOx emission amount when a required torque is increased during a steady lean operation. A target air-fuel ratio (AFCMD) is set according to an accelerator pedal operation of a driver. When the driver depresses an accelerator pedal to make an acceleration request during the lean operation, in which the AFCMD is set to a predetermined lean air-fuel ratio (AFLN), air-fuel ratio reduction control is executed to reduce the AFCMD according to the acceleration request. In the air-fuel ratio reduction control, when the AFCMD calculated according to a required torque (TRQCMD) is smaller than a limit air-fuel ratio (AFLMT), the AFCMD is set to the AFLMT, and the AFLMT is set to a value smaller than the AFLN set in a steady state of the lean operation and larger than a theoretical air-fuel ratio (AFST).

A control device of a vehicle capable of improving acceleration responsiveness and suppressing increase in the NOx emission amount when a required torque is increased during a steady lean operation. A target air-fuel ratio (AFCMD) is set according to an accelerator pedal operation of a driver. When the driver depresses an accelerator pedal to make an acceleration request during the lean operation, in which the AFCMD is set to a predetermined lean air-fuel ratio (AFLN), air-fuel ratio reduction control is executed to reduce the AFCMD according to the acceleration request. In the air-fuel ratio reduction control, when the AFCMD calculated according to a required torque (TRQCMD) is smaller than a limit air-fuel ratio (AFLMT), the AFCMD is set to the AFLMT, and the AFLMT is set to a value smaller than the AFLN set in a steady state of the lean operation and larger than a theoretical air-fuel ratio (AFST).

Methods and systems are provided for engine braking in a vehicle. In one example, a method may include deactivating fueling to at least one cylinder of an engine, increasing an air mass provided to the engine via an electric boosting device, and adjusting an exhaust valve opening timing of the at least one cylinder in response to a request for engine braking. In this way, an amount of engine braking torque may be increased with reduced wear to engine system components.

Methods and systems are provided for engine braking in a vehicle. In one example, a method may include deactivating fueling to at least one cylinder of an engine, increasing an air mass provided to the engine via an electric boosting device, and adjusting an exhaust valve opening timing of the at least one cylinder in response to a request for engine braking. In this way, an amount of engine braking torque may be increased with reduced wear to engine system components.

Systems, methods and apparatus are disclosed for providing or maintaining a target surge margin at the compressor during steady state engine operating conditions and to avoid compressor surge during transients by controlling a compressor recirculation valve position to a commanded position. The estimated surge margin can be determined in response to the measured pressure ratio across the compressor, an estimated compressor flow, and a compressor map for the compressor.

A system and method of controlling a turbocharged engine system includes receiving a boost mode selection signal and controlling the turbocharged engine system in response to the boost mode selection signal.