Abstract: A powertrain system includes an internal combustion engine, a multi-mode transmission having a plurality of torque machines, and a driveline. A method to determine extrema for an objective function employed to control operation of the powertrain system includes establishing an objective component equation related to an objective function and corresponding to an object component of interest. A plurality of linear constraints and a non-linear constraint are imposed on the objective component equation. The objective component equation is solved in relation to the plurality of linear constraints and the non-linear constraint to determine the extrema for the objective function. The extrema for the objective function are employed to control operation of the powertrain system.

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 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 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 microprocessor driven two dimensional search engine examines transmission operating points within a plurality of search range spaces and assists in determining properties associated with the driveline at various operating points within the space. The size of the space is reduced by rearrangement of data.

Abstract: A method for operating a powertrain system to transfer torque among an engine, torque machines, and a driveline in response to an output torque request includes executing a selection scheme to evaluate operating in a plurality of candidate powertrain states including a pseudo-electric vehicle (EV) range responsive to the output torque request. A respective minimum cost for operating the powertrain system in each of the candidate powertrain states including the pseudo-EV range is determined. A preferred powertrain state is selected, and is one of the candidate powertrain states including the pseudo-EV range associated with a minimum of the respective minimum costs. The powertrain system is controlled in the preferred powertrain state responsive to the output torque request.

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 the powertrain includes executing a dual closed-loop control scheme that includes determining an engine-based output torque range employed in a first feedback loop and simultaneously determining a control acceleration-based output torque range employed in a second feedback loop. Engine commands are controlled responsive to the engine-based output torque range and simultaneously a control acceleration is controlled responsive to the control acceleration-based output torque range to achieve an output torque of the powertrain system responsive to an output torque request.

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 transmission operative to transfer power between a plurality of power actuators and an output member, and an energy storage device. A method for controlling the powertrain system includes establishing a first set of electric power limits and a second set of electric power limits for the energy storage device, determining a preferred input power from a first power actuator based upon the first set of electric power limits, determining a first set of power constraints for constraining input power from the first power actuator and a second set of power constraints for constraining output power from the output member based upon a second set of electric power limits, and controlling operation of the powertrain system based upon the preferred input power, the first set of power constraints, and the second set of power constraints.

Abstract: A method for controlling a powertrain includes monitoring a desired synchronous transmission shift during deceleration of an output member including a desired operating range state, monitoring an output speed, predicting output deceleration through the desired synchronous transmission shift, determining a penalty cost associated with the desired synchronous transmission shift based upon an input speed profile resulting from the predicted output deceleration and from the desired synchronous transmission shift, and executing the synchronous transmission shift based upon the penalty cost.

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 determining a desired acceleration profile for the internal combustion engine, determining a constrained acceleration profile by imposing prioritized constraints on the desired acceleration profile, integrating the constrained acceleration profile to determine a preferred speed profile, determining a preferred acceleration profile including a derivative of the preferred speed profile constrained by minimum and maximum hard acceleration constraints, and controlling operation of the internal combustion engine in response to the preferred acceleration profile and the preferred speed profile.

Abstract: A method for operating a powertrain system to transfer torque among an engine, torque machines, and a driveline includes identifying a speed/torque search window responsive to a parameter affecting engine power output and the output torque request. A search is executed to determine a preferred engine operating point for operating the powertrain system in response to an output torque request. The search includes determining a candidate power cost associated with operating the powertrain system at the candidate engine torque and candidate engine speed for each of a plurality of candidate engine speeds and candidate engine torques within the speed/torque search window. A preferred engine operating point is determined as the candidate engine speed and the candidate engine torque 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.

Abstract: A hybrid powertrain system includes a transmission device operative to transfer power between an input member, a torque machine and an output member, the output member coupled to a driveline coupled to a wheel to transfer tractive torque therebetween. A method for controlling the hybrid powertrain system includes monitoring an operator torque request, determining an operating range state of the transmission device, determining a net output torque to the output member based upon the operator torque request, determining a lash state of the driveline, and determining a command for transferring output torque to the output member based upon the operating range state of the transmission device, the net output torque, and the lash state of the driveline.

Abstract: A powertrain system includes an engine and a multi-mode transmission configured to transfer torque among the engine, first and second torque machines, and an output member. The input member includes a clutch element configured to prevent rotation of the engine in a first direction. In response to an output torque request when the engine is in an OFF state, the motor torques from the first and second torque machines are controlled in response to the output torque request including controlling the motor torque from the first torque machine at a positive torque greater than a minimum positive torque and controlling the motor torque from the second torque machine responsive to the output torque request and responsive to the motor torque from the first torque machine.

Abstract: A hybrid transmission includes first and second electric machines. A method for operating the hybrid transmission in response to a command to execute a shift from an initial continuously variable mode to a target continuously variable mode includes increasing torque of an oncoming clutch associated with operating in the target continuously variable mode and correspondingly decreasing a torque of an off-going clutch associated with operating in the initial continuously variable mode. Upon deactivation of the off-going clutch, torque outputs of the first and second electric machines and the torque of the oncoming clutch are controlled to synchronize the oncoming clutch. Upon synchronization of the oncoming clutch, the torque for the oncoming clutch is increased and the transmission is operated in the target continuously variable mode.

Abstract: A powertrain system includes an internal combustion engine, a multi-mode transmission having a plurality of torque machines, and a driveline. A method for deactivating a torque transfer clutch of the multi-mode transmission includes imposing prioritized clutch torque constraints to an off-going clutch. The constraints include minimum and maximum long-term desired clutch torque constraints that are superseded by minimum and maximum soft clutch torque constraints that are superseded by minimum and maximum short-term desired clutch torque constraints that are superseded by minimum and maximum hard clutch torque constraints. The off-going clutch is controlled in response to the prioritized clutch torque constraints.

Abstract: A hybrid diesel-electric powertrain includes a diesel engine in power flow communication with an electric motor and a controller. The diesel engine and electric motor are each configured to generate a respective torque in response to a provided torque command. The controller is in communication with the electric motor, the diesel engine, and an accelerator pedal, and configured to receive a driver torque request from the accelerator pedal. In response to the driver torque request, the controller is further configured to command the diesel engine to generate an output torque that is less than a smoke limit torque, and command the electric motor to generate an output torque equal to the difference between the driver torque request and the output torque of the diesel engine.

Abstract: A powertrain system includes an internal combustion engine, a multi-mode transmission, torque machines, and a driveline. A method for operating the powertrain system to transfer torque among the engine, torque machine, and driveline includes controlling operation of the powertrain system in a pseudo-gear range in response to an output torque request including operating the transmission in a variable mode transmission range and controlling a magnitude of torque output to the driveline in response to an output torque request and in proportion to a magnitude of input torque from the engine.

Abstract: A system for a vehicle includes a constraint module that generates a plurality of constraints. An output torque module generates a commanded output torque based on a torque request and the plurality of constraints. A split torque module determines a first torque and a second torque to be applied to a transmission of the vehicle based on the plurality of constraints and the commanded output torque. A first one of the plurality of constraints corresponding to a first clutch is adjusted from a first range of values to a second range of values that is different from the first range of values in response to a command to offload the first clutch.