Abstract: A method for operating a powertrain system including a torque machine coupled to a drive wheel of a vehicle includes determining a regenerative braking capacity of the powertrain system. In response to a net operator torque request including a braking torque request, a friction braking torque command to operate a friction brake system and a regenerative braking torque request for the torque machine are coincidentally generated, a torque command is generated for controlling operation of the torque machine in response to the regenerative braking torque request, and the friction braking torque command is adjusted by an amount corresponding to a difference between the braking torque request and the regenerative braking torque request.

Abstract: A method for determining output torque capabilities in a transmission having a first, second, and third node, each of which has a speed and acceleration. The method includes controlling the speed of the first node, calculating a real maximum long-term output torque capability (raw max LT) as a function of at least the acceleration and the speed of the first and second nodes, and calculating an inertialess maximum long-term output torque capability (inertialess max LT), which is identical to the raw max LT except that the inertialess max LT ignores torque capability due to acceleration of the first node. The raw max LT and the inertialess max LT are compared to determine an operating capability for the transmission. The first node may be an input node for the transmission. The method may include determining a new effective minimum long-term output torque capability (new effective min LT) by similar considerations.

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 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 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 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 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 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.

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 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 operating a hybrid powertrain system includes monitoring operation of the torque machine, and limiting the motor torque output from the torque machine to a maximum allowable motor torque that is associated with an acceptable audible noise level when the motor speed of the torque machine is within a motor speed range associated with objectionable audible noise.

Abstract: A method of controlling output torque in a hybrid or electric vehicle transmissions includes calculating a first long-term output torque constraint and a first short-term output torque constraint. A first effective output torque constraint is determined from at least one of the first long-term and short-term output torque constraints. The first effective output torque constraint is bounded by both of the first long-term and short-term output torque constraints. The method may further include calculating a rate limit, such that determining the first effective output torque constraint includes restricting the magnitude of changes in the first long-term output torque constraint to the calculated rate limit. A spread between the first short-term output torque constraint and the first effective output torque constraint may be measured, and the rate limit calculated as a function of that spread. The rate limit may also be calculated with an inversely-proportional relationship to the spread.

Abstract: A method for operating a powertrain system including a torque machine coupled to a drive wheel of a vehicle includes determining a regenerative braking capacity of the powertrain system. In response to a net operator torque request including a braking torque request, a friction braking torque command to operate a friction brake system and a regenerative braking torque request for the torque machine are coincidentally generated, a torque command is generated for controlling operation of the torque machine in response to the regenerative braking torque request, and the friction braking torque command is adjusted by an amount corresponding to a difference between the braking torque request and the regenerative braking torque request.

Abstract: A method for determining output torque capabilities in a transmission having a first, second, and third node, each of which has a speed and acceleration. The method includes controlling the speed of the first node, calculating a real maximum long-term output torque capability (raw max LT) as a function of at least the acceleration and the speed of the first and second nodes, and calculating an inertialess maximum long-term output torque capability (inertialess max LT), which is identical to the raw max LT except that the inertialess max LT ignores torque capability due to acceleration of the first node. The raw max LT and the inertialess max LT are compared to determine an operating capability for the transmission. The first node may be an input node for the transmission. The method may include determining a new effective minimum long-term output torque capability (new effective min LT) by similar considerations.

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 method of determining output torque constraints for a powertrain having a plurality of components includes monitoring individual component limits, including a first motor limit, a first torque transmitting mechanism limit, and a battery power limit. Each of the individual component limits includes a minimum and a maximum individual limit due to each respective component. The method also determines whether each of the individual component limits can be satisfied by selecting a first torque value. The method sets an output torque constraint by selecting the first torque value, if the first torque value satisfies each of the individual component limits. The method selects a second torque value if the first torque value does not satisfy each of the individual component limits, and prioritizes the first motor limit, then the first torque transmitting mechanism limit, and then the battery power limit.

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

Abstract: A method controls a motor generator unit (MGU) aboard a vehicle. An event signal is generated using a transmission controller, with the event signal predicting a transient vehicle event, e.g., auto start, transmission shift, fuel cycling, etc. The event signal is received by a motor controller, which determines a predicted level of motor output torque required from the MGU during the transient vehicle. Electromagnetic flux of the MGU is increased to a calibrated threshold level prior to commencement of the transient vehicle event. The MGU may be used for regenerating energy during the transient vehicle event. The MGU is then used to facilitate execution of the transient vehicle event. A vehicle having the MGU uses a controller(s) to automatically increase electromagnetic flux of the MGU prior to the transient vehicle event using the method as noted above.

Abstract: A method of determining output torque constraints for a powertrain having a plurality of components includes monitoring individual component limits, including a first motor limit, a first torque transmitting mechanism limit, and a battery power limit. Each of the individual component limits includes a minimum and a maximum individual limit due to each respective component. The method also determines whether each of the individual component limits can be satisfied by selecting a first torque value. The method sets an output torque constraint by selecting the first torque value, if the first torque value satisfies each of the individual component limits. The method selects a second torque value if the first torque value does not satisfy each of the individual component limits, and prioritizes the first motor limit, then the first torque transmitting mechanism limit, and then the battery power limit.

Abstract: A method of controlling output torque in a hybrid or electric vehicle transmissions includes calculating a first long-term output torque constraint and a first short-term output torque constraint. A first effective output torque constraint is determined from at least one of the first long-term and short-term output torque constraints. The first effective output torque constraint is bounded by both of the first long-term and short-term output torque constraints. The method may further include calculating a rate limit, such that determining the first effective output torque constraint includes restricting the magnitude of changes in the first long-term output torque constraint to the calculated rate limit. A spread between the first short-term output torque constraint and the first effective output torque constraint may be measured, and the rate limit calculated as a function of that spread. The rate limit may also be calculated with an inversely-proportional relationship to the spread.