Abstract: A powertrain includes a propulsion system having first and second torque sources, and first and second drive axles respectively connected to and independently driven by the first and second torque sources. A permissible range of torque contribution from the torque sources to the respective first and second drive axles is defined by a component torque window. The powertrain includes sensors for detecting a dynamic driving maneuver of a vehicle having the powertrain. A controller executes a method to adjust a size and/or orientation of a chassis torque window during the detected dynamic driving maneuver, determine an optimally efficient axle torque operating point that falls on a torque line within the component torque window in proximity to the chassis torque window, and command the torque contribution via transmission of torque control signals to the first and second torque sources to achieve the optimally efficient axle torque operating point.

Abstract: A powertrain includes a propulsion system having first and second torque sources, and first and second drive axles respectively connected to and independently driven by the first and second torque sources. A permissible range of torque contribution from the torque sources to the respective first and second drive axles is defined by a component torque window. The powertrain includes sensors for detecting a dynamic driving maneuver of a vehicle having the powertrain. A controller executes a method to adjust a size and/or orientation of a chassis torque window during the detected dynamic driving maneuver, determine an optimally efficient axle torque operating point that falls on a torque line within the component torque window in proximity to the chassis torque window, and command the torque contribution via transmission of torque control signals to the first and second torque sources to achieve the optimally efficient axle torque operating point.

Abstract: A method for controlling a powertrain system includes deactivating a motor disconnect clutch during vehicle operation. Motor speed is decreased to a first inactive speed threshold and an inverter circuit is controlled to an inactive state while monitoring the motor speed. The inverter circuit is deactivated, and when the motor speed decreases to a second inactive speed threshold, the inverter circuit is pulse-activated to operate the electric machine to increase motor speed to the first inactive speed threshold, and then deactivated. The inverter circuit is activated to increase the motor speed to synchronize with speed of the driveline prior to activating the motor disconnect clutch.

Abstract: A method for controlling a powertrain system includes deactivating a motor disconnect clutch during vehicle operation. Motor speed is decreased to a first inactive speed threshold and an inverter circuit is controlled to an inactive state while monitoring the motor speed. The inverter circuit is deactivated, and when the motor speed decreases to a second inactive speed threshold, the inverter circuit is pulse-activated to operate the electric machine to increase motor speed to the first inactive speed threshold, and then deactivated. The inverter circuit is activated to increase the motor speed to synchronize with speed of the driveline prior to activating the motor disconnect clutch.

Abstract: A method to start operation of an internal combustion engine of a hybrid powertrain includes initiating rotation of a crankshaft of the engine with at least one electric machine in accordance with a first ramping profile until a first predetermined speed is achieved in response to an engine start event during a cold start condition. Engine speed is monitored and the engine is fired while controlling the engine speed to maintain the first predetermined speed with the at least one electric machine. The first ramping profile is adjusted at a rate corresponding to an estimated rate at which the engine speed is increasing during the engine firing. When at least one predetermined combustion quality parameter is achieved, the engine speed is controlled in accordance with a second ramping profile until a second predetermined speed is achieved based on controlling combustion parameters of the engine.

Abstract: A hybrid transmission includes a transmission having a selectable clutch device effective when engaged to mechanically couple an internal combustion engine to a first axle at a fixed engine speed to axle speed ratio. A method for starting the engine includes executing an engine start event including spinning and fueling the engine such that an engine speed to axle speed ratio exceeds the fixed engine speed to axle speed ratio, and engaging said selectable clutch device after the engine speed to axle speed ratio exceeds the fixed engine speed to axle speed ratio.

Abstract: Methods and apparatus are provided for torque control in an electric all wheel drive (e AWD) vehicle. The apparatus is a system having at least one propulsion system capable of determining a desired torque command and torque capability data for a primary and secondary axle. Also included are one or more active chassis systems capable of providing chassis system data and a processor coupled for processing the desired torque command, the torque capability data and the chassis system data to provide a maximum torque limit and a minimum torque limit for the secondary axle. In this way, at least one propulsion system processes the desired torque signal and the maximum torque limit and the minimum torque limit to provide an electric motor torque command and an engine torque command for the eAWD vehicle. A method for torque control in an eAWD vehicle is also provided.

Abstract: A method for starting an internal combustion engine in a hybrid powertrain having an electric torque machine mechanically coupled to the internal combustion engine includes monitoring a temperature state of the hybrid powertrain, determining a maximum discharging power limit of the high-voltage battery corresponding to the temperature state of the hybrid powertrain, estimating an engine drag torque associated with the temperature state of the hybrid powertrain, selecting a preferred engine cranking speed associated with the estimated engine drag torque and achievable at less than the maximum discharging power limit of the high-voltage battery, and controlling the electric torque machine to generate a magnitude of motor torque output sufficient to crank the internal combustion engine at the preferred engine cranking speed.

Abstract: A hybrid transmission includes a transmission having a selectable clutch device effective when engaged to mechanically couple an internal combustion engine to a first axle at a fixed engine speed to axle speed ratio. A method for starting the engine includes executing an engine start event including spinning and fueling the engine such that an engine speed to axle speed ratio exceeds the fixed engine speed to axle speed ratio, and engaging said selectable clutch device after the engine speed to axle speed ratio exceeds the fixed engine speed to axle speed ratio.

Abstract: A method to start operation of an internal combustion engine of a hybrid powertrain includes initiating rotation of a crankshaft of the engine with at least one electric machine in accordance with a first ramping profile until a first predetermined speed is achieved in response to an engine start event during a cold start condition. Engine speed is monitored and the engine is fired while controlling the engine speed to maintain the first predetermined speed with the at least one electric machine. The first ramping profile is adjusted at a rate corresponding to an estimated rate at which the engine speed is increasing during the engine firing. When at least one predetermined combustion quality parameter is achieved, the engine speed is controlled in accordance with a second ramping profile until a second predetermined speed is achieved based on controlling combustion parameters of the engine.

Abstract: Methods and apparatus are provided for torque control in an electric all wheel drive (e AWD) vehicle. The apparatus is a system having at least one propulsion system capable of determining a desired torque command and torque capability data for a primary and secondary axle. Also included are one or more active chassis systems capable of providing chassis system data and a processor coupled for processing the desired torque command, the torque capability data and the chassis system data to provide a maximum torque limit and a minimum torque limit for the secondary axle. In this way, at least one propulsion system processes the desired torque signal and the maximum torque limit and the minimum torque limit to provide an electric motor torque command and an engine torque command for the eAWD vehicle. A method for torque control in an eAWD vehicle is also provided.

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 of externally charging a powertrain includes monitoring a voltage level of a first battery, determining when the monitored voltage level is below a first voltage threshold, and when the monitored voltage level is below the first voltage threshold, charging the first battery by supplying power from an external power source and increasing voltage of the power supplied by the external power source within the powertrain.

Abstract: A method for starting an internal combustion engine in a hybrid powertrain having an electric torque machine mechanically coupled to the internal combustion engine includes monitoring a temperature state of the hybrid powertrain, determining a maximum discharging power limit of the high-voltage battery corresponding to the temperature state of the hybrid powertrain, estimating an engine drag torque associated with the temperature state of the hybrid powertrain, selecting a preferred engine cranking speed associated with the estimated engine drag torque and achievable at less than the maximum discharging power limit of the high-voltage battery, and controlling the electric torque machine to generate a magnitude of motor torque output sufficient to crank the internal combustion engine at the preferred engine cranking speed.

Abstract: A hybrid powertrain system includes an internal combustion engine operatively connected to a second torque machine to transmit torque to an output member. A method for operating the hybrid powertrain system includes monitoring an operator torque request, determining an output torque command based upon the operator torque request, commanding a transition between an engine-off state and an engine-on state, monitoring an engine crank angle, spinning the engine unfueled, estimating cylinder pressure based upon the engine crank angle during the spinning of the engine, predicting a cylinder pulse torque based upon the cylinder pressure, determining a cancellation torque for the second torque machine based upon the predicted cylinder pulse torque, and controlling motor torque output from the second torque machine based upon the cancellation torque and the output torque command.

Abstract: A method of operating an engine control system includes reducing pressures within cylinders of an engine based on an auto start command signal including: receiving a torque request signal; calculating a powertrain output torque; and controlling air flow to the engine based on the powertrain output torque. During a startup of the engine: electric motor torque is increased to a predetermined level and reduced to increase a current speed of the engine; combustion torque of the engine is activated and increased after the current speed is within a predetermined range and a manifold absolute pressure is less than a predetermined level; and the electric motor torque is increased based on a crankshaft output torque signal to increase a crankshaft output torque subsequent to the reducing of the electric motor torque and while performing the activating of the combustion torque.

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 control system for an engine includes an engine control module (ECM) that operates in a first mode and a second mode. The ECM generates an idle speed signal and a transmission load signal that is based on an idle speed of the engine. The hybrid control module (HCM) increases electric motor torque to increase a current speed of the engine based on the idle speed signal and the transmission load signal. The HCM controls the current speed when in the first mode. The ECM controls the current speed when in the second mode. The HCM transfers control of the current speed to the ECM when at least one of the current speed matches the idle speed and a combustion torque output of the engine is equal to a requested crankshaft output torque.

Abstract: A hybrid powertrain system includes an internal combustion engine operatively connected to a second torque machine to transmit torque to an output member. A method for operating the hybrid powertrain system includes monitoring an operator torque request, determining an output torque command based upon the operator torque request, commanding a transition between an engine-off state and an engine-on state, monitoring an engine crank angle, spinning the engine unfueled, estimating cylinder pressure based upon the engine crank angle during the spinning of the engine, predicting a cylinder pulse torque based upon the cylinder pressure, determining a cancellation torque for the second torque machine based upon the predicted cylinder pulse torque, and controlling motor torque output from the second torque machine based upon the cancellation torque and the output torque command.

Abstract: A method of externally charging a powertrain includes monitoring a voltage level of a first battery, determining when the monitored voltage level is below a first voltage threshold, and when the monitored voltage level is below the first voltage threshold, charging the first battery by supplying power from an external power source and increasing voltage of the power supplied by the external power source within the powertrain.