Abstract: A method of managing an operating state of an electrified powertrain includes a controller identifying a plurality of available operating regions defined by at least one available operating state of the powertrain, each operating region representing a distinct range of operating conditions. The available operating regions include an avoidance region defining a plurality of unwanted operating conditions and separating a first allowable operating region from a second allowable operating region such that the first and second allowable operating regions are noncontiguous. The method identifies at least one ideal operating condition in each of the available operating regions, determines a preferability factor and stabilization factor for each of a current and each of the ideal operating conditions, and arbitrates the factors to identify one of the current and ideal operating conditions as an optimized operating condition to produce a required parameter value.

Abstract: A multi-mode powertrain system is described, and includes an internal combustion engine and electric machines operative to transfer mechanical power through a gear train to an output member coupled to a driveline, wherein the electric machines electrically connect to a battery. The method includes determining an audible noise-based maximum engine speed, wherein the internal combustion engine generates an audible noise that is less than a threshold noise level when operating at a speed that is less than the audible noise-based maximum engine speed. The electric machines and the internal combustion engine are controlled responsive to an operator torque request including controlling the engine speed to be less than the audible noise-based maximum engine speed when battery power is greater than a minimum threshold.

Abstract: A method for controlling a powertrain includes, in response to an output torque request that includes deceleration, operating an internal combustion engine in a fuel cutoff state and in a cylinder deactivation state, controlling a clutch of a torque converter in an activated state, and operating an electric machine in a regenerative braking state. A state of the powertrain related to engine speed is monitored. The internal combustion engine is commanded to transition from the cylinder deactivation state to an all-cylinder state and the electric machine operates in the regenerative braking state including ramping down magnitude of regenerative braking torque when the engine speed is less than a first threshold speed. The torque converter clutch is commanded to a released state when the engine speed is less than a second threshold speed, with the first threshold speed being greater than the second threshold speed.

Abstract: An electric motor control system for a vehicle includes a vehicle speed module that determines a vehicle speed. A closed loop (CL) module determines a CL torque based on a difference between a target vehicle speed and the vehicle speed. A motor torque module determines a motor torque based on the CL torque and a motor torque request determined based on a position of an accelerator pedal. A switching control module controls switching of an inverter based on the motor torque to control application of power to an electric motor of the vehicle.

Abstract: A method for controlling a powertrain of a vehicle includes calculating, via a controller, an optimal torque target for the powertrain as a function of system limits of the vehicle. The method includes commanding, via transmission of an output torque signal, an actual output torque of the powertrain to pursue or follow the calculated optimal torque target during a steady-state torque request condition. Additionally, the method includes detecting a predetermined vehicle event during the steady-state torque request condition, and shaping the output torque signal via the controller. A variable gain factor may be used in response to detection of the predetermined vehicle event to allow the output torque signal to temporarily deviate from the calculated optimal torque target during the steady-state torque request condition. A powertrain has an engine, an electric machine, and a controller programmed to execute the method.

Abstract: A method for controlling a powertrain includes, in response to an output torque request that includes deceleration, operating an internal combustion engine in a fuel cutoff state and in a cylinder deactivation state, controlling a clutch of a torque converter in an activated state, and operating an electric machine in a regenerative braking state. A state of the powertrain related to engine speed is monitored. The internal combustion engine is commanded to transition from the cylinder deactivation state to an all-cylinder state and the electric machine operates in the regenerative braking state including ramping down magnitude of regenerative braking torque when the engine speed is less than a first threshold speed. The torque converter clutch is commanded to a released state when the engine speed is less than a second threshold speed, with the first threshold speed being greater than the second threshold speed.

Abstract: A method for controlling operation of a multi-mode powertrain system includes periodically determining a power cost difference between a first power cost and a second power cost. This includes determining the first power cost associated with operating the powertrain system with the engine operating in a presently commanded engine state in response to an operator torque request and determining the second power cost associated with an expected powertrain operation with the engine operating in a non-commanded engine state in response to the operator torque request. The first power cost is compared with the second power cost, and successive iterations of the periodically determined power cost difference between the first power cost and the second power cost are integrated to determine an integrated power cost difference. A transition to the non-commanded engine state is commanded when the integrated power cost difference is greater than a threshold.

Abstract: A vehicle system includes an electric motor, an internal combustion engine, and a heating system configured to transfer heat from the internal combustion engine to a passenger compartment of the vehicle. The system includes a controller configured to operate the electric motor and the internal combustion engine according to one of a plurality of drive cycle profiles. The controller selects the drive cycle profile based on an ambient temperature. The drive cycle profiles include a first drive cycle profile that commands power from the electric motor until the battery system reaches a predetermined state of charge and subsequently commands power from the internal combustion engine and a second drive cycle profile that commands power from the internal combustion engine and subsequently commands power from the electric motor.

Abstract: A method can be used to control a hybrid vehicle and includes the following steps: (a) receiving, via a control module, an input; (b) determining, via the control module, whether the hybrid vehicle is traveling on a highway based, at least in part, on a vehicle speed and an output torque request; (c) commanding, via the control module, the hybrid powertrain to switch from a charge-depletion mode to a blended mode if the hybrid vehicle is traveling on a highway; and (d) commanding, via the control module, the hybrid powertrain to use energy from the energy storage device via the electric motor-generator so as to maintain a substantially constant target state of charge (SOC) discharge rate.

Abstract: A powertrain system including an internal combustion engine, a transmission and an electric machine is described, and includes the electric machine rotatably coupled to a crankshaft of the internal combustion engine. The transmission is coupled to a driveline to transfer tractive torque and braking torque thereto. A method for controlling the electric machine includes determining a short-term axle torque capacity, a long-term axle torque capacity and a maximum regenerative braking stall torque capacity, and determining an operator request for braking. A preferred regenerative braking capacity is determined based upon the short-term axle torque capacity, the long-term regenerative braking capacity, the engine stall regenerative braking capacity and the operator request for braking. Torque output from the electric machine is controlled based upon the preferred regenerative braking capacity.

Abstract: A multi-mode powertrain system is described, and includes an internal combustion engine and electric machines operative to transfer mechanical power through a gear train to an output member coupled to a driveline, wherein the electric machines electrically connect to a battery. The method includes determining an audible noise-based maximum engine speed, wherein the internal combustion engine generates an audible noise that is less than a threshold noise level when operating at a speed that is less than the audible noise-based maximum engine speed. The electric machines and the internal combustion engine are controlled responsive to an operator torque request including controlling the engine speed to be less than the audible noise-based maximum engine speed when battery power is greater than a minimum threshold.

Abstract: A control-module implemented method for controlling a powertrain system comprising an internal combustion engine, at least one electric machine, a high-voltage battery and an electro-mechanical transmission operative to transmit torque to a driveline includes monitoring a state of charge (SOC) of a high-voltage battery configured to provide stored electrical power to a first electric machine, a second electric machine and at least one auxiliary load. A trickle-charging event is enabled only when the SOC of the high-voltage battery is less than a first SOC threshold. The trickle-charging event activates the first clutch coupled to a first planetary gear set. The trickle-charging event further coordinates a torque capacity of the activated first clutch and a charging set of torque commands between the engine, the first electric machine and the second electric machine to establish a net zero output torque condition.

Abstract: A powertrain system is described, including a method for controlling a control variable for an element thereof. The method includes determining an initial state transition threshold and an associated hysteresis band for an operating parameter related to the control variable. The hysteresis band is decayed based upon operation in a present state of the control variable for powertrain element, and a preferred control variable for the powertrain element is selected based upon a comparison of the operating parameter and the initial state transition threshold accounting for the decayed hysteresis band for the operating parameter. The element of the powertrain system is controlled to the preferred state for the control variable.

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 for a vehicle is described, and includes an internal combustion engine mechanically coupled to an electric machine to generate propulsion torque and electric power storable on an energy storage device. A method for controlling the powertrain system includes determining a first desired powertrain output power associated with a road load and determining a second desired powertrain output power associated with a feed-forward state-of-charge (SOC) for the energy storage device. The internal combustion engine and the electric machine are controlled responsive to the first and second desired powertrain output powers.

Abstract: A powertrain system employing multiple propulsion torque actuators is described. A method for controlling the powertrain system includes interpreting a driver request, including determining a driver torque request and a regenerative braking request based upon driver inputs to an accelerator pedal and a brake pedal. A desired request is determined based upon the driver torque request and the regenerative braking request. Torque limits for the powertrain system are coordinated based upon the desired request, the driver torque request, and a previous driver torque request to determine upper and lower output torque limits, and the upper and lower output torque limits are combined with system constraints to generate a final torque request. The final torque request is employed to determine torque commands for the propulsion torque actuators, and the propulsion torque actuators are controlled based upon the torque commands for the propulsion torque actuators.

Abstract: A method for controlling operation of a multi-mode powertrain system includes periodically determining a power cost difference between a first power cost and a second power cost. This includes determining the first power cost associated with operating the powertrain system with the engine operating in a presently commanded engine state in response to an operator torque request and determining the second power cost associated with an expected powertrain operation with the engine operating in a non-commanded engine state in response to the operator torque request. The first power cost is compared with the second power cost, and successive iterations of the periodically determined power cost difference between the first power cost and the second power cost are integrated to determine an integrated power cost difference. A transition to the non-commanded engine state is commanded when the integrated power cost difference is greater than a threshold.

Abstract: A multi-mode powertrain system includes a transmission configured to transfer torque among an internal combustion engine, torque machines and an output member. A method for controlling the powertrain system includes operating the multi-mode powertrain system to execute an engine intake manifold pump down mode, and aborting the engine intake manifold pump down mode and fueling the engine, wherein aborting is based upon intake manifold pressure and system constraints.

Abstract: A vehicle system includes an electric motor, an internal combustion engine, and a heating system configured to transfer heat from the internal combustion engine to a passenger compartment of the vehicle. The system includes a controller configured to operate the electric motor and the internal combustion engine according to one of a plurality of drive cycle profiles. The controller selects the drive cycle profile based on an ambient temperature. The drive cycle profiles include a first drive cycle profile that commands power from the electric motor until the battery system reaches a predetermined state of charge and subsequently commands power from the internal combustion engine and a second drive cycle profile that commands power from the internal combustion engine and subsequently commands power from the electric motor.

Abstract: A method for operating a multi-mode powertrain system includes monitoring an operator request for tractive power, and arbitrating the operator request for tractive power with axle torque constraints and crankshaft torque constraints. An immediate tractive torque request and a predicted tractive torque request are determined based upon the arbitrated operator request for tractive power. The predicted tractive torque request is shaped based upon driveability torque constraints. Operation of torque-generative devices of the multi-mode powertrain system are controlled based upon the predicted tractive torque request and the driveability-shaped predicted tractive torque request.