Abstract: A method for controlling a hybrid powertrain system includes employing a system constraints function to identify a feasible solution for an objective variable that satisfies a plurality of independent and dependent constraints for an objective function. The objective variable is associated with a parameter of the hybrid powertrain system. Upon determining that the system constraints function fails to provide a feasible solution for the objective variable that satisfies all of the independent and dependent constraints, a problem recomposition scheme is executed to remove all of the dependent constraints and then reapply and adjust selected ones of the dependent constraints to obtain a feasible solution for the system constraints function that achieves a preferred state for the objective variable.

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 hybrid powertrain system includes an internal combustion engine and a torque machine wherein electrical energy is controllably transferred between an electric energy storage device and the torque machine by a control system. A method for controlling the hybrid powertrain system includes monitoring a voltage, a current, and a power output of the electric energy storage device. A battery power control scheme is executed to control the output power of the electric energy storage device associated with the electrical energy transferred between the electric energy storage device and the torque machine. The battery power control scheme is disabled when the control system loses a power limit authority associated with the electrical energy transferred between the electric storage device and the torque machine during ongoing operation. The battery power control scheme is re-enabled when the control system regains the power limit authority.

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 hybrid controller for controlling a hybrid vehicle is set forth. The hybrid vehicle has an engine, an electric motor and an engine controller determining a crankshaft torque. The hybrid controller includes an optimization module determining an electric motor torque, determining an engine torque and communicating the engine torque from the hybrid controller to the engine controller. The hybrid controller also includes a motor control module controlling the electric motor based on the electric motor torque.

Abstract: A method to shift a powertrain system from a first operating mode to a second operating mode wherein a common clutch is activated to effect operation in both the first and second operating modes includes, in sequence, deactivating the common clutch, activating an oncoming clutch associated with the second operating mode and deactivating an off-going clutch associated with the first operating mode, and activating the common clutch.

Abstract: A method for adjusting hydraulic line pressure applied to one or more clutch devices in an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and at least one electric machine includes predicting a first plurality of powertrain parameters for an upcoming event. For each of a plurality of engine torques, a predicted output torque and a predicted clutch load are determined that minimize a total powertrain operating cost based on an operator torque request and the predicted first plurality of powertrain parameters. Hydraulic line pressure is adjusted based on the engine torque having a lowest powertrain operating cost among the plurality of available engine torques.

Abstract: A powertrain system includes a multi-mode transmission configured to transfer torque among an engine, torque machines, and an output member in one of a plurality of transmission ranges. A method for operating the powertrain system includes, in response to a command to disable one of the torque machines, converging minimum and maximum torque capacities of the one of the torque machines to zero and converging minimum and maximum engine torque system constraints to a single engine torque command in response to the minimum and maximum torque capacity limits of the one of the torque machines and an output torque request. Torque output from the engine is controlled including employing a fast engine actuator to control the engine in response to the output torque request, and maintaining torque output from the one of the torque machines at zero.

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 for controlling an electric power flow between a high-voltage battery and an electrically-powered torque machine of a powertrain system includes, upon violating a constraint associated with the electric power flow during operation of the powertrain system, executing a battery power control scheme for controlling the electric power flow including commanding an initial state for a parameter of the electric power flow, the initial state for the parameter of the electric power flow including a maximum estimated state for the parameter of the electric power flow occurring during one of a plurality of selected ones of previous timesteps.

Abstract: A method to control a hybrid powertrain including an engine, an electric machine, and a transmission through a transition from an initial operating point to a target operating point includes monitoring a break point in a non-convex data set defined by an engine torque below which a growl condition cannot occur and a threshold low motor torque required for the grown condition, comparing the target operating point to the break point, and controlling the powertrain based upon the target operating point and the comparing.

Abstract: A vehicle includes a torque generating device, a transmission, and a controller. The transmission has one or more clutches. The controller executes a method, which includes measuring an amount of slip across an identified offgoing clutches and determining whether the offgoing clutches have slipped prior to a modeled clutch torque capacity reaching zero. A status is assigned indicating that the offgoing clutches are released if the offgoing clutch has slipped prior to the modeled clutch capacity reaching zero. The controller induces slip across the identified offgoing clutches to a calibrated low, non-zero level after recording the value, including by enforcing the low, non-zero slip value using one or more acceleration profiles.

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 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 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 operating a powertrain system includes determining an objective function for an object component of interest of the powertrain system. Constraints are determined for a plurality of independent variables and dependent variables. Permutations of the objective function are evaluated with reference to the independent variables and the dependent variables. The objective function is evaluated to determine maximum and minimum values for the objective function for each of the permutations. Overall minimum and maximum values for the objective function are determined based upon the maximum and minimum values for the objective function for each of the permutations. Operation of the powertrain system associated with the object component of interest is controlled based upon the overall minimum and maximum values for the objective function.

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 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.