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 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 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.

Abstract: A vehicle includes an engine, a motor, and a gearbox. A clutch is configured to engage to transfer a reactive torque to at least one of the engine, the motor, and the gearbox. The clutch is configured to disengage during a transition from a present operating mode to a target operating mode. A controller is configured to determine an expected slip direction of the clutch, define a non-zero value based at least in part on the expected slip direction, and command the reactive torque to the non-zero value to control the clutch to induce slip during the transition from the present operating mode to the target operating mode.

Abstract: A powertrain system includes an internal combustion engine, a first electric machine and an electro-mechanical transmission operative to transmit torque to a driveline. A method for controlling the powertrain system in the presence of a controlled neutral operation of the electro-mechanical transmission being selected includes monitoring vehicle speed, and only when the monitored vehicle speed is indicative of a low-speed zone restricting a transition from a current engine operating state.

Abstract: A method to monitor a torque transfer device configured to transfer torque within an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and at least one electric machine includes executing a failure detection strategy in response to a detected slip condition of the torque transfer device. The failure detection strategy includes monitoring a magnitude of energy loss of the torque transfer device. A failure condition in the torque transfer device is detected when the magnitude of energy loss achieves a predetermined energy threshold.

Abstract: A powertrain system includes an internal combustion engine, at least one electric machine and an electro-mechanical transmission operative to transmit torque to a drive line. A method for controlling the powertrain system includes executing an engagement strategy of a one-way clutch device only having capacity in a first direction. The engagement strategy includes modeling a capacity of the one-way clutch device in accordance with a loading step change profile until a first capacity limit of the one-way clutch device is achieved. A continuous reactive load is applied to the one-way clutch device in the first direction to maintain engagement and inhibit lash of the one-way clutch device.

Abstract: A method to monitor a torque transfer device configured to transfer torque within an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and at least one electric machine includes executing a failure detection strategy in response to a detected slip condition of the torque transfer device. The failure detection strategy includes monitoring a magnitude of energy loss of the torque transfer device. A failure condition in the torque transfer device is detected when the magnitude of energy loss achieves a predetermined energy threshold.

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 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 system and method of controlling a clutch fill command based on the hydraulic state of an oncoming clutch is provided. A vehicle includes a hydraulically-actuated oncoming clutch that is configured to engage during a shift event from one operating mode of the vehicle to another. A controller is configured to generate a clutch fill command at an initial time such that completion of the clutch fill command is synchronized with an identified speed profile of the oncoming clutch. The oncoming clutch defines a real-time hydraulic state when the clutch fill command is generated. The controller is configured to generate a real-time acceptable speed margin for the oncoming clutch based at least partially on the real-time hydraulic state of the oncoming clutch. The controller is configured to cancel the clutch fill command if a real-time speed of the oncoming clutch is outside the generated real-time acceptable speed margin.

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 activating an oncoming clutch in a transmission includes monitoring rotational speeds of clutch elements of the oncoming clutch wherein the clutch elements are coupled to first and second rotationally independent torque actuators. A control speed profile for the first rotationally independent torque actuator is commanded. A speed profile of the oncoming clutch approaching zero speed is generated as is a control speed profile for the second rotationally independent torque actuator corresponding to a speed of the first rotationally independent torque actuator, the speed profile of the oncoming clutch, and an output speed of the transmission. A speed of the second rotationally independent torque actuator is controlled using the control speed profile for the second rotationally independent torque actuator. A speed of the oncoming clutch is monitored and the oncoming clutch is activated when the speed of the oncoming clutch is zero.

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 a transmission of a powertrain system includes executing a single source shortest path search to identify a preferred shift path originating with an initial powertrain state and terminating at a target powertrain state, wherein the single source shortest path search employs transition-specific costs and situational costs to identify the preferred shift path. The preferred shift path is executed to achieve the target powertrain state.

Abstract: A method for executing a transmission shift in a hybrid transmission including first and second electric machines includes executing a shift-through-neutral sequence from an initial transmission state to a target transmission state including executing an intermediate shift to neutral. Upon detecting a change in an output torque request while executing the shift-through-neutral sequence, possible recovery shift paths are identified. Available ones of the possible recovery shift paths are identified and a shift cost for each said available recovery shift path is evaluated. The available recovery shift path having a minimum shift cost is selected as a preferred recovery shift path and is executed to achieve a non-neutral transmission state.

Abstract: A method for executing a transmission shift in a hybrid transmission including first and second electric machines includes executing a shift-through-neutral sequence from an initial transmission state to a target transmission state including executing an intermediate shift to neutral. Upon detecting a change in an output torque request while executing the shift-through-neutral sequence, possible recovery shift paths are identified. Available ones of the possible recovery shift paths are identified and a shift cost for each said available recovery shift path is evaluated. The available recovery shift path having a minimum shift cost is selected as a preferred recovery shift path and is executed to achieve a non-neutral transmission state.

Abstract: A method for controlling a powertrain includes executing a shift, determining a plurality of input acceleration profiles for controlling an engine and an electric machine, determining an input speed profile, and controlling operation of the engine and the electric machine based upon the input speed profile.