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 method for managing a threshold increase in output torque capability in a vehicle includes detecting the threshold increase in output torque capability using a controller, and automatically limiting, via the controller, a rate of change of an actual output torque from a transmission of the vehicle in response to the threshold increase. The actual output torque is provided via a traction motor solely using battery power from an energy storage system. The method may include calculating a difference between the threshold increase and the actual output torque, and limiting the rate of change using a rate that is proportional to the difference. A vehicle includes the ESS, a transmission, and a controller. An output member of the transmission is powered using electrical energy from the ESS. The controller manages an increase in output torque capability as noted above.

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 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 method for controlling a powertrain system including an internal combustion engine coupled to a multi-mode transmission in response to a command to execute a shift from a first EVT Mode range to a second EVT Mode range includes executing a first shift from the first EVT Mode range to an intermediate transmission range. The multi-mode transmission operates in the intermediate transmission range and the engine is controlled at an engine torque command that corresponds to an output torque request. A second shift is executed from the intermediate transmission range to the second transmission range. The powertrain system operates in the second transmission range to transfer torque to an output member of the transmission.

Abstract: A method for controlling a powertrain system includes determining minimum and maximum states for an object component of interest based upon a plurality of linear constraints that are associated with operating parameters for the torque machines and the multi-mode transmission. Minimum and maximum objective battery powers are determined based upon the minimum and maximum states for the object component of interest. When the minimum and maximum objective battery powers are outside the minimum and maximum battery power limits, a problem recomposition process is executed to recompose the minimum and maximum battery power limits and the linear constraints. Recomposed minimum and maximum states for the object component of interest are determined based upon the recomposed minimum and maximum battery power limits and the recomposed linear constraints. The recomposed minimum and maximum states for the object component of interest are employed to control the powertrain system.

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 of controlling a fluid pump to supply lubricating fluid to a plurality of fluid requiring components in a hybrid vehicle powertrain includes selecting a component-required flow rate for each respective component using a determined operating speed and torque for that respective component. Once the each component-required flow rate is selected, the system flow rate is set to the maximum component-required flow rate of the plurality of component-required flow rates. The fluid pump is then commanded to supply fluid to each of the plurality of fluid requiring components at the system flow rate.

Abstract: A method of operating a hybrid powertrain including an engine, an electric motor and a high voltage battery includes preventing fuel flow to the engine when the high voltage battery includes a state of charge at or above a pre-defined upper limit, and when the hybrid powertrain is operating in a second fueling condition in which fuel flow to the engine is preferably maintained. The engine is rotated with torque supplied by the electric motor to maintain rotation of the engine without producing any engine torque.

Abstract: A powertrain including an engine and torque machines is configured to transfer torque through a multi-mode transmission to an output member. A method for controlling the powertrain includes employing a closed-loop speed control system to control torque commands for the torque machines in response to a desired input speed. Upon approaching a power limit of a power storage device transferring power to the torque machines, power limited torque commands are determined for the torque machines in response to the power limit and the closed-loop speed control system is employed to determine an engine torque command in response to the desired input speed and the power limited torque commands for the torque machines.

Abstract: A multi-mode transmission for a powertrain system includes a high-voltage electrical system with a high-voltage battery and high-voltage electrical bus coupled to a power inverter electrically coupled to torque machines configured to transform electric power to torque. A method for controlling the multi-mode transmission includes monitoring voltage and current on the high-voltage electrical bus, and estimating electric power limits for the high-voltage electric bus including a constrained battery power command based upon a total motor torque electrical power for the torque machines. Torque commands for the torque machines are constrained in response to the estimated electric power limits for the high-voltage electric bus. Operation of the torque machines of the multi-mode transmission is controlled in response to the torque commands for the torque machines.

Abstract: A controller architecture for a vehicle including a multi-mode powertrain system includes an engine controller having a control routine for determining and executing engine torque commands responsive to a hybrid engine torque command, and a control routine for determining a propulsion axle torque command responsive to an output torque request. The controller architecture further includes transmission controller having a control routine for selecting and effecting operation of the passive transmission in a preferred gear responsive to the output torque request. The controller architecture further includes a hybrid controller having control routines for determining and executing torque commands for each of the non-combustion torque machines and for determining the hybrid engine torque command to achieve a desired axle torque in response to the propulsion axle torque command with the passive transmission operating in the preferred gear.

Abstract: A method to execute a shift in a powertrain including a plurality of torque generative devices rotatably connected through a first clutch includes operating the powertrain in a continuously variable operating range state, and monitoring a command to execute the shift including monitoring a target speed for a first torque generative device, and monitoring a command to disengage the first clutch. The first clutch is shifted from an engaged state to a disengaged state, including operating a torque phase of the first clutch wherein the first clutch is transitioned from the engaged state to the disengaged state, and simultaneous with the torque phase, operating an inertia speed phase of the first clutch wherein a speed of the first torque generative device is transitioned from an initial speed to the target speed.

Abstract: A method for controlling output torque of a hybrid powertrain system includes determining a constrained output torque in response to an operator torque request, and determining maximum and minimum output torque limits. A time-rate change in the constrained output torque at each of a plurality of torque breakpoints is determined. A desired output torque is determined. A preferred output torque is determined as the desired output torque adjusted using the time-rate changes in the constrained output torque at the plurality of torque breakpoints and limited within the maximum and minimum output torque limits. Torque outputs of torque generators of the hybrid powertrain system are controlled in response to the preferred output torque.

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 controlling torque in a vehicle including monitoring a plurality of factors associated with an output torque request in response to an output torque request rate of change exceeding a predetermined threshold, and controlling rate limiting of a delivered output torque to achieve the output torque request rate of change based on the plurality of factors associated with the output torque request.

Abstract: A powertrain system includes an electric machine mechanically coupled to an internal combustion engine mechanically coupled to a transmission. A method for operating the powertrain system includes determining an engine stall threshold rate during engine operation in a low load condition. A time-rate change in an accessory load is controlled by the electric machine operating in an electric power generating mode in response to the engine stall threshold rate during the engine operation in the low load condition.

Abstract: A powertrain system includes an internal combustion engine and an electric machine coupled via a torque transfer device to a transmission. A method for operating the powertrain system to transfer torque to a driveline includes establishing an operating torque security limit that is a default torque security limit. The operating torque security limit is set to an override limit when engine speed is less than a threshold speed. A torque security fault is detected only when a combined torque output from the internal combustion engine and the electric machine to the torque transfer device deviates from an operator torque request by an amount greater than the operating torque security limit.