Abstract: A powertrain system is described, and includes an internal combustion engine and an electric machine configured to generate propulsion torque responsive to a driver torque request. A method for operating the powertrain system includes determining, in response to a request to execute an engine autostart operation, whether a driveline torque sag may occur. The method further includes forgoing executing the engine autostart operation when it is determined that a driveline torque sag will occur during the execution of the engine autostart operation.

Abstract: A powertrain system is described, and includes an internal combustion engine and an electric machine configured to generate propulsion torque responsive to a driver torque request. A method for operating the powertrain system includes determining, in response to a request to execute an engine autostart operation, whether a driveline torque sag may occur. The method further includes forgoing executing the engine autostart operation when it is determined that a driveline torque sag will occur during the execution of the engine autostart operation.

Abstract: A vehicle includes an engine, a transmission, and an electrical system. The electrical system has an auxiliary starter motor connected to a crankshaft of the engine, a high-voltage motor generator unit (MGU) connected to the crankshaft, and a controller. Execution of instructions by a processor causes the controller to determine a set of powertrain conditions in response to a requested autostart of the engine, e.g., state of charge and/or power limits of a high-voltage energy storage system (HV-ESS), torque limits of the MGU, and/or a crank angle of the engine. The controller determines whether the requested autostart may not succeed relative to a time or noise standard using the set of powertrain conditions, and transmits an autostart command to the MGU when the requested autostart may succeed. The controller transmits the autostart command to the auxiliary starter motor when the requested autostart will not succeed.

Abstract: A vehicle includes an engine, a transmission, and an electrical system. The electrical system has an auxiliary starter motor connected to a crankshaft of the engine, a high-voltage motor generator unit (MGU) connected to the crankshaft, and a controller. Execution of instructions by a processor causes the controller to determine a set of powertrain conditions in response to a requested autostart of the engine, e.g., state of charge and/or power limits of a high-voltage energy storage system (HV-ESS), torque limits of the MGU, and/or a crank angle of the engine. The controller determines whether the requested autostart may not succeed relative to a time or noise standard using the set of powertrain conditions, and transmits an autostart command to the MGU when the requested autostart may succeed. The controller transmits the autostart command to the auxiliary starter motor when the requested autostart will not succeed.

Abstract: A method includes determining an amount of power currently available from a battery for tractive torque as an amount of power stored in the battery less an amount of power required to power other vehicle components, and less an amount of power required to start the engine. An output torque limit when torque is provided only by the motor and power required to provide the output torque limit are determined based on test data. A maximum output torque is calculated by multiplying the amount of power determined to be currently available for tractive torque by a ratio of the output torque limit to the amount of power required to provide the output torque limit. The current output torque may be reduced at a predetermined rate until within a predetermined range of the lesser of the maximum output torque and the output torque limit if an engine start is requested.

Abstract: A method controls an amount of time required to commence transmitting torque of an internal combustion engine equipped with a stop/start feature to a transmission configured to transmit the torque of the engine to drive-wheels in a vehicle. The method includes determining whether a start of the engine is likely. The method also includes pre-filling with fluid a hydraulically-actuated clutch that is configured to connect the engine to the transmission when the start of the engine is likely. Accordingly, the amount of time required to commence transmitting torque of the engine to the transmission is reduced. A system employs the method for controlling an amount of time required to commence transmitting torque of the engine.

Abstract: An example hybrid vehicle includes a control unit that generates a control signal representing an expected torque, a first actuator that generates a first torque, a second actuator that generates a second torque associated with operating characteristics of the second actuator, and a gearbox that can receive the torque generated by the first and second actuators. A controller can determine whether the first torque produced by the first actuator is substantially the same as the expected torque based on one or more operating characteristics of the second actuator. An example method includes deriving an actual torque of the first actuator based on the operating characteristics of the second actuator, defining a torque deviation from the actuator torque and the expected torque, comparing the torque deviation to a calibration threshold, and diagnosing that the first actuator has failed if the torque deviation exceeds the calibration threshold.

Abstract: A method controls an amount of time required to commence transmitting torque of an internal combustion engine equipped with a stop/start feature to a transmission configured to transmit the torque of the engine to drive-wheels in a vehicle. The method includes determining whether a start of the engine is likely. The method also includes pre-filling with fluid a hydraulically-actuated clutch that is configured to connect the engine to the transmission when the start of the engine is likely. Accordingly, the amount of time required to commence transmitting torque of the engine to the transmission is reduced. A system employs the method for controlling an amount of time required to commence transmitting torque of the engine.

Abstract: A method includes determining an amount of power currently available from a battery for tractive torque as an amount of power stored in the battery less an amount of power required to power other vehicle components, and less an amount of power required to start the engine. An output torque limit when torque is provided only by the motor and power required to provide the output torque limit are determined based on test data. A maximum output torque is calculated by multiplying the amount of power determined to be currently available for tractive torque by a ratio of the output torque limit to the amount of power required to provide the output torque limit. The current output torque may be reduced at a predetermined rate until within a predetermined range of the lesser of the maximum output torque and the output torque limit if an engine start is requested.

Abstract: A method for controlling spark timing in an internal combustion engine. The method includes determining, in response to a knock sensor mounted to the engine, a spark offset to the scheduled spark timing for the engine at relatively low engine speed which is applied to the scheduled spark timing at relatively high engine speeds. This offset is applied in conjunction with a time-varying spark retardation bias. The offset is removed at a rate proportional to the time varying spark retard bias. The bias increases if either a relatively large torque is demanded from the engine or the engine is at the relatively high speed and relatively high air charge condition; otherwise, the bias is decreased with time.

Abstract: A method for controlling spark timing in an internal combustion engine. The method includes determining, in response to a knock sensor mounted to the engine, a spark offset to the scheduled spark timing for the engine at relatively low engine speed which is applied to the scheduled spark timing at relatively high engine speeds. This offset is applied in conjunction with a time-varying spark retardation bias. The offset is removed at a rate proportional to the time varying spark retard bias. The bias increases if either a relatively large torque is demanded from the engine or the engine is at the relatively high speed and relatively high air charge condition; otherwise, the bias is decreased with time.