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.
Claims20
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, (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;
- 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.