Abstract: A method for controlling a powertrain system in response to a command to execute a multi-state shift event for the transmission includes determining an initial output torque limit and determining an initial commanded output torque based upon the initial output torque limit. The powertrain system is controlled to generate torque in response to the initial commanded output torque prior to completion of a first state transition of the multi-state shift event that includes a commanded torque reduction. After completion of the first state transition of the multi-state shift event that includes the commanded torque reduction, a torque ramp rate is determined, and the initial commanded output torque is adjusted based upon the torque ramp rate. The powertrain system is controlled to generate torque in response to the initial commanded output torque and the adjusted initial commanded output torque during a remainder of the multi-state shift event.

Abstract: A system according to the principles of the present disclosure includes a power determination module and a powertrain control module that includes a state selection module. The power determination module can estimate power required to travel at a desired speed on a roadway segment located in an anticipated path of a vehicle based upon an estimated slope of the roadway segment. The powertrain control module can control operational states of a hybrid powertrain. The powertrain control module includes a state selection module that can determine whether a current operational state is capable of producing the estimated power based upon a state of charge of a vehicle battery. The state selection module can also switch to another operational state that is capable of producing the estimated power if the current operational state is incapable of producing the estimated power.

Abstract: A system according to the principles of the present disclosure includes a power determination module and a powertrain control module that includes a state selection module. The power determination module can estimate power required to travel at a desired speed on a roadway segment located in an anticipated path of a vehicle based upon an estimated slope of the roadway segment. The powertrain control module can control operational states of a hybrid powertrain. The powertrain control module includes a state selection module that can determine whether a current operational state is capable of producing the estimated power based upon a state of charge of a vehicle battery. The state selection module can also switch to another operational state that is capable of producing the estimated power if the current operational state is incapable of producing the estimated power.

Abstract: A method for controlling a powertrain system in response to a command to execute a multi-state shift event for the transmission includes determining an initial output torque limit and determining an initial commanded output torque based upon the initial output torque limit. The powertrain system is controlled to generate torque in response to the initial commanded output torque prior to completion of a first state transition of the multi-state shift event that includes a commanded torque reduction. After completion of the first state transition of the multi-state shift event that includes the commanded torque reduction, a torque ramp rate is determined, and the initial commanded output torque is adjusted based upon the torque ramp rate. The powertrain system is controlled to generate torque in response to the initial commanded output torque and the adjusted initial commanded output torque during a remainder of the multi-state shift event.

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 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 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 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 method of controlling a transmission includes detecting an occurrence of a downshift in the transmission from a first gear ratio to a second gear ratio. A determination is made whether the vehicle is operating within a freeway speed range, and whether an accelerator pedal is depressed at least a minimum percentage of a fully depressed position. When the downshift from the high gear ratio to the low gear ratio is detected, the vehicle is operating within the freeway speed range, and the accelerator pedal is depressed at least the minimum percentage of the fully depressed position, a countdown timer is started to count down from a pre-defined time to zero. An upshift of the transmission from the second gear ratio to the first gear ratio is restricted while the countdown timer defines a time that is greater than zero.

Abstract: A method of managing available operating states in an electrified powertrain includes: identifying a plurality of operating states; determining an allowable hardware operating speed range for each of the plurality of operating states; determining a real operating speed range for each of the plurality of operating states; determining an ideal operating speed range for each of the plurality of operating states, the ideal operating speed range being a subset of the allowable real operating speed range; indicating an operating state of the plurality of operating states as ideal-allowed if an actual output speed of the electrified powertrain is within the ideal operating speed range for that operating state; and commanding the electrified powertrain to operate within one of the operating states that is indicated as ideal-allowed.

Abstract: A method of controlling a transmission includes detecting an occurrence of a downshift in the transmission from a first gear ratio to a second gear ratio. A determination is made whether the vehicle is operating within a freeway speed range, and whether an accelerator pedal is depressed at least a minimum percentage of a fully depressed position. When the downshift from the high gear ratio to the low gear ratio is detected, the vehicle is operating within the freeway speed range, and the accelerator pedal is depressed at least the minimum percentage of the fully depressed position, a countdown timer is started to count down from a pre-defined time to zero. An upshift of the transmission from the second gear ratio to the first gear ratio is restricted while the countdown timer defines a time that is greater than zero.

Abstract: A method for stabilizing selection between a plurality of operating range states of an electro-mechanical transmission configured to transfer torque among an engine, at least one electric machine, and a driveline includes requesting execution of a shift from a first operating range state to a second operating range state. Costs associated with operating the transmission in each of the plurality of operating range states including the first and second operating range states are monitored and an energy differential between the first and second operating range states is determined based on the monitored costs. The shift from the first operating range state to the second operating range state is executed only if the energy differential achieves an integration threshold.

Abstract: A method for stabilizing selection between a plurality of operating range states of an electro-mechanical multi-mode transmission configured to transfer torque among an engine, at least one electric machine, and a driveline includes requesting operation of the transmission in a preferred operating range state while a shift from a first operating range state to a second operating range state is in progress prior to achieving the second operating range state. Powertrain information is monitored and compared to a driver perception threshold only if a change of mind condition is detected. The shift to the second operating range state is avoided and a shift to the preferred operating range state is commanded if the powertrain information does not violate the driver perception threshold.

Abstract: A method of managing available operating states in an electrified powertrain includes: identifying a plurality of operating states; determining an allowable hardware operating speed range for each of the plurality of operating states; determining a real operating speed range for each of the plurality of operating states; determining an ideal operating speed range for each of the plurality of operating states, the ideal operating speed range being a subset of the allowable real operating speed range; indicating an operating state of the plurality of operating states as ideal-allowed if an actual output speed of the electrified powertrain is within the ideal operating speed range for that operating state; and commanding the electrified powertrain to operate within one of the operating states that is indicated as ideal-allowed.

Abstract: A method for determining a preferred engine speed and a preferred engine torque of a selected operating range state of an electro-mechanical multi-mode transmission configured to transfer torque among an engine, at least one electric machine and a drive includes selecting between of a first search window and a second search window. Each of the first and second search windows includes a two-dimensional search window definable by a first axis having minimum and maximum engine speed values and a second axis having minimum and maximum engine torque values. A plurality of candidate operating points within the selected one of the first and second search windows is iteratively generated. One of the plurality of candidate operating points within the selected one of the first and second search windows is iteratively determined as an optimum operating point.

Abstract: A powertrain system includes a multi-mode transmission configured to transfer torque among an engine, torque machines, and a driveline. A method for controlling operation of the powertrain system includes determining a bias engine speed based upon an engine speed. A search is executed including determining a respective candidate power cost for operating the powertrain system in response to an output torque request, and determining a respective candidate driveability cost for the candidate engine speed based upon the bias engine speed. The search also selects one of the candidate engine speeds and candidate engine torques that achieves a minimum of a combination of the respective candidate driveability cost and the respective candidate power cost as a preferred engine speed and preferred engine torque. Operation of the powertrain system is controlled based upon the preferred engine speed and preferred engine torque.

Abstract: A method for operating a powertrain system includes selecting a plurality of candidate transmission ranges associated with a present powertrain operating point and deselecting candidate transmission ranges not associated with the present powertrain operating point. A high resolution engine speed/torque search is executed for each of the selected candidate transmission ranges. A low resolution engine speed/torque search is executed for each of the deselected candidate transmission ranges. Each search is executed to determine a respective minimum power cost for operating the powertrain system in one of the candidate transmission ranges in response to an output torque request and output speed. A preferred transmission range is determined from the candidate transmission ranges. A preferred engine operating point is determined corresponding to the minimum power cost for the preferred transmission range.

Abstract: A method for operating a powertrain system including a multi-mode transmission configured to transfer torque among an engine, torque machines, and a driveline, includes executing a first search to determine a first engine operating point within an all-cylinder state and a corresponding operating cost for operating the powertrain system in response to an output torque request. A second search is executed to determine a second engine operating point within a cylinder deactivation state and a corresponding operating cost for operating the powertrain system in response to the output torque request. One of the first and second engine operating points is selected as a preferred engine operating point based upon the operating costs and the engine is controlled at the preferred engine operating point in the corresponding one of the all-cylinder state and the cylinder deactivation state.

Abstract: A method for operating a powertrain system to transfer torque among an engine, torque machines, and a driveline includes executing a search to determine a preferred engine operating point for operating the powertrain system in a transmission range in response to an output torque request. The search includes employing a candidate torque normalization ratio to determine a candidate engine torque from a normalized torque search space, and determining a candidate power cost associated with operating the powertrain system at the candidate engine torque for each of a plurality of candidate engine speeds within an input speed range and a plurality of candidate torque normalization ratios. A preferred engine speed is determined, and includes the candidate engine speed corresponding to the one of the candidate engine torques associated with a minimum of the candidate power costs. Engine operation is controlled responsive to the preferred engine speed.

Abstract: A powertrain system includes a multi-mode transmission configured to transfer torque among an engine, torque machines, and a driveline. A method for controlling operation of the powertrain system includes determining a bias engine speed based upon an engine speed. A search is executed including determining a respective candidate power cost for operating the powertrain system in response to an output torque request, and determining a respective candidate driveability cost for the candidate engine speed based upon the bias engine speed. The search also selects one of the candidate engine speeds and candidate engine torques that achieves a minimum of a combination of the respective candidate driveability cost and the respective candidate power cost as a preferred engine speed and preferred engine torque. Operation of the powertrain system is controlled based upon the preferred engine speed and preferred engine torque.