Abstract: A hybrid powertrain includes an engine, an electric machine, and a transmission. A method to control the powertrain includes monitoring operation of the powertrain, determining whether conditions necessary for growl to occur excluding motor torque and engine torque are present, and if the conditions are present controlling the powertrain based upon avoiding a powertrain operating region wherein the growl is enabled.

Abstract: A method is provided for optimizing the cycling frequency between engine on/off states in a vehicle having a controller and auto start/auto stop functionality. The method includes detecting an engine state cycling event, measuring a plurality of vehicle operating values, and using the controller to optimize the cycling frequency via at least one of: automatically adjusting an interval between an auto start event and an auto stop event when each of a first set of the vehicle operating values exceeds a corresponding threshold, and temporarily inhibiting the auto start/auto stop functionality when any value in a second set of the vehicle operating values falls outside of a hysteresis band created around the second set. A vehicle includes an engine and a controller having an algorithm for optimizing the cycling frequency between engine on/off states as set forth above.

Abstract: A hybrid control system comprises a power loss (PL) determination module, a hysteresis estimation module, and a mode determination module. The PL determination module determines a power loss of a hybrid drivetrain based on an engine speed, a motor speed, and a vehicle speed. The hysteresis estimation module determines an average power loss of the hybrid drivetrain based on the power loss and determines a hysteresis power loss of the hybrid drivetrain based on the average power loss. The mode determination module selects an operation mode of the hybrid drivetrain based on the hysteresis power loss. The hybrid control system controls the hybrid drivetrain based on the operation mode.

Abstract: A method is provided for optimizing the cycling frequency between engine on/off states in a vehicle having a controller and auto start/auto stop functionality. The method includes detecting an engine state cycling event, measuring a plurality of vehicle operating values, and using the controller to optimize the cycling frequency via at least one of: automatically adjusting an interval between an auto start event and an auto stop event when each of a first set of the vehicle operating values exceeds a corresponding threshold, and temporarily inhibiting the auto start/auto stop functionality when any value in a second set of the vehicle operating values falls outside of a hysteresis band created around the second set. A vehicle includes an engine and a controller having an algorithm for optimizing the cycling frequency between engine on/off states as set forth above.

Abstract: A hybrid control system comprises a power loss (PL) determination module, a hysteresis estimation module, and a mode determination module. The PL determination module determines a power loss of a hybrid drivetrain based on an engine speed, a motor speed, and a vehicle speed. The hysteresis estimation module determines an average power loss of the hybrid drivetrain based on the power loss and determines a hysteresis power loss of the hybrid drivetrain based on the average power loss. The mode determination module selects an operation mode of the hybrid drivetrain based on the hysteresis power loss. The hybrid control system controls the hybrid drivetrain based on the operation mode.