Biased speed control for an electric machine in a hybrid vehicle
AssigneeFord Global Technologies, LLC
InventorBernard D. Nefcy
Life of this patent
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Abstract
A vehicle is provided with an engine, an electric machine connected to the engine by an upstream clutch, a transmission gearbox connected to the electric machine by a downstream clutch, and a controller. The controller is configured to: (i) slip a downstream clutch, (ii) limit a torque output of an electric machine to a threshold value, (iii) engage an upstream clutch while the downstream clutch is slipping, and (iii) engage the downstream clutch. A method for controlling an electric machine in a vehicle during an upstream torque disturbance is provided. The downstream clutch is slipped and the torque output of an electric machine is limited to a threshold value. The upstream clutch is engaged while the downstream clutch is slipping. The downstream clutch is engaged.
Claims19
A vehicle comprising:
- an engine;
- an electric machine connected to the engine by an upstream clutch;
- a transmission gearbox connected to the electric machine by a downstream clutch;
- and
- a controller configured to:
- (i) slip a downstream clutch, (ii) limit a torque output of an electric machine to a threshold value to isolate a driveline upstream of the downstream clutch and prevent locking the downstream clutch while the downstream clutch pressure is maintained, (iii) engage an upstream clutch while the downstream clutch is slipping, and (iii) engage the downstream clutch.
A method for controlling an electric machine in a vehicle during an upstream torque disturbance, the method comprising:
- slipping a downstream clutch;
- limiting a torque output of an electric machine to a threshold value to isolate a driveline upstream of the downstream clutch and prevent locking the downstream clutch while maintaining the downstream clutch pressure;
- engaging an upstream clutch while the downstream clutch is slipping;
- and
- engaging the downstream clutch.
A method for starting an engine in a hybrid vehicle using an electric machine, the method comprising:
- slipping a first clutch while starting the engine, the first clutch connecting the electric machine to the engine;
- operating the electric machine such that the torque output of the electric machine is biased to operate on one side of a predetermined torque value to maintain slip in a second clutch, the second clutch connecting the electric machine to a transmission;
- engaging the first clutch when the speed of the electric machine and the speed of the engine are synchronized;
- and
- engaging the second clutch after the first clutch is engaged.
Dependencies are inferred from the claim text.