Abstract: Methods and systems are provided for operating a hybrid vehicle during launch conditions from rest. In one example, a driver demand torque is held constant until a threshold vehicle speed is reached when a constant accelerator pedal position is present so that closing of a transmission input clutch may result in reduced driveline torque disturbances while a desired driver demand torque is delivered.

Abstract: Methods and systems are provided for operating a hybrid vehicle during launch conditions from rest. In one example, a threshold speed below which a clutch is closed during a vehicle launch is adjusted so that driver demand wheel torque is held constant for a constant accelerator pedal position until the clutch is closed.

Abstract: Methods and systems are provided for operating a hybrid vehicle during launch conditions from rest. In one example, a threshold speed below which a clutch is closed during a vehicle launch is adjusted so that driver demand wheel torque is held constant for a constant accelerator pedal position until the clutch is closed.

Abstract: Methods and systems are provided for operating a hybrid vehicle during launch conditions from rest. In one example, a driver demand torque is held constant until a threshold vehicle speed is reached when a constant accelerator pedal position is present so that closing of a transmission input clutch may result in reduced driveline torque disturbances while a desired driver demand torque is delivered.

Abstract: A system includes a computer including a processor and a memory, the memory storing instructions executable by the processor to plan a plurality of vehicle speeds for an upcoming road segment, adjust one or more of the planned speeds based on a predicted torque loss including a penalty based on a predicted torque impeller speed, and actuate a propulsion according to the planned speeds to lock a torque converter clutch.

Abstract: Systems and methods for operating a driveline of a hybrid vehicle are presented. In one example, the systems and methods determine a driveline disconnect boost time during vehicle operating conditions when it may be less noticeable. The driveline disconnect boost time may then be used to close a driveline disconnect clutch in a way that may reduce torque disturbances through the driveline.

Abstract: A vehicle includes a disconnect clutch selectively coupling an engine and an electric machine. The vehicle further includes a mechanical pump driven by the electric machine and operable to pressurize fluid for the clutch. The vehicle includes a controller programmed to, in response to the electric machine being inoperable, activate an auxiliary starter to start the engine, activate an electric pump operable to pressurize fluid to the clutch, and operate the engine to drive the mechanical pump.

Abstract: Powertrains may include a spring damper between the engine crankshaft and transmission input shaft. In some circumstances, an oscillation known as shuffle may occur in such powertrains. Active adjustment of engine torque is substantially more effective at mitigating shuffle oscillations if the engine torque includes a p-term proportional to displacement of the damper spring in addition to a d-term proportional to the speed difference across the damper. For various reasons, the spring displacement is difficult to measure directly. An observer algorithm is utilized to calculate a current estimated spring displacement based on a crankshaft speed sensor, a transmission input speed sensor, a wheel speed sensor, and past engine torques, using a dynamic model of the powertrain.

Abstract: Methods and systems are provided for operating a driveline of a hybrid vehicle that includes an internal combustion engine, an electric machine, and a transmission, where the transmission is downstream of the engine, and where the electric machine is downstream of the transmission. In one example, while the vehicle is being propelled solely via the electric machine, one or more gears of the transmission may be pre-engaged or selected, to prepare the driveline for an engine start event. In this way, driveline torque disturbance and delays in torque requests may be reduced or avoided upon a request for an engine start event.

Abstract: A vehicle includes a clutch to couple a motor and transmission, and a controller that, in response to a regenerative braking request and a temperature being within a first range, partially capacitizes the clutch for regenerative torque transfer therethrough with slip, and in response to another regenerative braking request and the temperature being within a second range less than the first, fully capacitizes the clutch prior to regenerative torque transfer therethough to preclude slip.

Abstract: A system includes a computer including a processor and a memory, the memory storing instructions executable by the processor to plan a plurality of vehicle speeds for an upcoming road segment, adjust one or more of the planned speeds based on a predicted torque loss including a penalty based on a predicted torque impeller speed, and actuate a propulsion according to the planned speeds to lock a torque converter clutch.

Abstract: Powertrains may include a spring damper between the engine crankshaft and transmission input shaft. In some circumstances, an oscillation known as shuffle may occur in such powertrains. Active adjustment of engine torque is substantially more effective at mitigating shuffle oscillations if the engine torque includes a p-term proportional to displacement of the damper spring in addition to a d-term proportional to the speed difference across the damper. For various reasons, the spring displacement is difficult to measure directly. An observer algorithm is utilized to calculate a current estimated spring displacement based on a crankshaft speed sensor, a transmission input speed sensor, a wheel speed sensor, and past engine torques, using a dynamic model of the powertrain.

Abstract: Systems and methods for operating a driveline of a hybrid vehicle are presented. In one example, the systems and methods determine a driveline disconnect boost time during vehicle operating conditions when it may be less noticeable. The driveline disconnect boost time may then be used to close a driveline disconnect clutch in a way that may reduce torque disturbances through the driveline.

Abstract: During a transmission upshift, a torque capacity of an off-going clutch is maintained at a non-zero state during the transition from the torque phase to the inertia phase and throughout a substantial portion of the inertia phase. This permits the inertia phase to be completed faster without an unacceptable increase in output torque during the torque phase. Monotonically reducing the off-going clutch torque and using feedback from an output torque sensor enable sufficiently precise control of the off-going clutch torque capacity during this interval.

Abstract: A vehicle is disclosed having a motor and engine selectively coupled to the motor via a clutch. The vehicle includes a controller configured to, in response to a vehicle wheel torque reversal, open the clutch to disconnect the engine from the motor, command the engine to enter a speed control mode, and control a motor output torque through a region surrounding the vehicle wheel torque reversal to reduce torque disturbances in a vehicle driveline.

Abstract: A vehicle includes a disconnect clutch selectively coupling an engine and an electric machine. The vehicle further includes a mechanical pump driven by the electric machine and operable to pressurize fluid for the clutch. The vehicle includes a controller programmed to, in response to the electric machine being inoperable, activate an auxiliary starter to start the engine, activate an electric pump operable to pressurize fluid to the clutch, and operate the engine to drive the mechanical pump.

Abstract: During a transmission upshift, a torque capacity of an off-going clutch is maintained at a non-zero state during the transition from the torque phase to the inertia phase and throughout a substantial portion of the inertia phase. This permits the inertia phase to be completed faster without an unacceptable increase in output torque during the torque phase. Monotonically reducing the off-going clutch torque and using feedback from an output torque sensor enable sufficiently precise control of the off-going clutch torque capacity during this interval.

Abstract: A hybrid vehicle includes an engine, an electric machine, a transmission, and a controller. The transmission is configured to alter clutch pressures in preparation for an upcoming shift between discrete gear ratios (e.g., input-to-output ratio). For example, the clutch pressures may spike to a heightened magnitude to prepare for the upcoming shift. The electric machine is configured to selectively propel the vehicle and perform regenerative braking. If regenerative braking demands occur during the clutch pressures being heightened during shift preparation, the controller is programmed to stop the preparing of the clutches. This can be done by reducing the clutch pressures back to their pre-preparation magnitude. The upcoming shift can be cancelled or delayed.

Abstract: Systems and methods for starting an engine of a hybrid powertrain or driveline that includes an engine and a driveline disconnect clutch are described. In one example, a motor/generator rotates one side of an open driveline disconnect clutch that is coupled to a transmission, and then closes the open driveline disconnect clutch in response to motor/generator acceleration being less than a threshold.

Abstract: A vehicle includes a powertrain and at least one controller programmed to, in response to a brake request and a shaft speed associated with a speed of the vehicle achieving a starting speed that is defined by a torque of the powertrain that changes with brake demand at a given shaft speed, reduce a regenerative torque limit that constrains regenerative braking torque over a blend-out duration based on the shaft speed.