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 method for maximizing regenerative energy captured by an electric machine in a powertrain including an engine, the electric machine and a transmission device configured to transfer torque through a driveline includes detecting an operator brake request and monitoring a time between the detected operator brake request and a preceding operator brake request that was last detected. A maximized regenerative deceleration event is initiated if the time exceeds a predetermined threshold time that includes monitoring a current fixed gear ratio that is selected from among a plurality of fixed gear ratios of the transmission device when the operator brake request is detected and applying a magnitude of torque at the axle that is sufficient for achieving a maximum capability of the electric machine to capture regenerative energy in the current fixed gear ratio.

Abstract: A powertrain system includes an engine coupled to a multi-mode transmission configured to transfer tractive torque to an output member coupled to a ground wheel. A method for operating the powertrain system includes identifying an undesirable operating region for the multi-mode transmission associated with driveline growl including an input torque range and an output torque range. In response to a command to traverse the undesirable operating region from a first operating region to a second operating region, a fast engine torque transition is executed including controlling the engine as a fast-adjusting torque actuator to control input torque from the engine to the multi-mode transmission and correspondingly controlling motor torque from a torque machine to the multi-mode transmission to maintain output torque from the multi-mode transmission responsive to an output torque request while traversing the undesirable operating region from the first operating region to the second operating region.

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 to control an output torque of a powertrain in response to an incipient transient speed event within the powertrain includes determining an incipient transient speed event, determining a maximum output torque capability profile based upon the incipient transient speed event, determining a minimum value of the maximum output torque capability profile, and limiting the output torque to not greater than the minimum value of the maximum output torque capability profile until the incipient transient speed event is concluded.

Abstract: A vehicle includes torque sources, a transmission, and a controller programmed to execute a method. In executing the associated method, the controller determines whether continuous output torque is required through a torque exchange. When continuous output torque is required, the controller synchronizes and fills the oncoming clutch, estimates capacity of the oncoming clutch, and expands a short-term torque capacity of the oncoming clutch during the torque exchange, doing so in response to a control objective having a threshold priority. Onset of the torque exchange delays until the short-term torque capacity is sufficient for receiving all torque load from the offgoing clutch without affecting output torque.

Abstract: A vehicle includes torque sources, a transmission, and a controller programmed to execute a method. In executing the associated method, the controller determines whether continuous output torque is required through a torque exchange. When continuous output torque is required, the controller synchronizes and fills the oncoming clutch, estimates capacity of the oncoming clutch, and expands a short-term torque capacity of the oncoming clutch during the torque exchange, doing so in response to a control objective having a threshold priority. Onset of the torque exchange delays until the short-term torque capacity is sufficient for receiving all torque load from the offgoing clutch without affecting output torque.

Abstract: A multi-mode transmission is configured to transfer torque among an internal combustion engine, torque machines and an output member. A method for controlling shifting in the transmission includes, in response to a command to execute a range shift in the transmission to a target transmission range: applying mechanical braking torque to reduce output torque from the transmission to off-load torque from an off-going clutch, operating in a pseudo-gear range to synchronize an oncoming clutch, and applying the oncoming clutch to establish the transmission in the target range.

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 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 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 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 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 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 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 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 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 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.