Torque converter clutch capacity based on regenerative braking request
A vehicle includes an engine, a transmission, and an electric machine configured to provide drive torque and regenerative braking torque. The electric machine is selectively coupled to the engine via a clutch. The vehicle additionally includes a torque converter with an associated bypass clutch coupling the electric machine and transmission. The bypass clutch has an associated torque capacity. The vehicle further includes a controller. The controller is configured to, in response to a braking request indicative of an anticipated regenerative braking request, increase the torque capacity prior to the regenerative braking event by a quantity corresponding to an anticipated regenerative braking torque associated with the anticipated regenerative braking event.
1. A vehicle comprising:
an engine;
a transmission;
an electric machine configured to provide drive torque and regenerative braking torque, the electric machine being selectively coupled to the engine via a clutch;
a torque converter and associated bypass clutch coupling the electric machine and transmission, the bypass clutch having an associated torque capacity; and
a controller configured to, in response to a braking request indicative of an anticipated regenerative braking event, increase the torque capacity prior to the regenerative braking event by a quantity corresponding to an anticipated regenerative braking torque associated with the anticipated regenerative braking event.
2. The vehicle of claim 1 , wherein the braking request is initiated by a driver actuation of a brake pedal.
3. The vehicle of claim 1 , wherein the braking request is initiated by a driver release of an accelerator pedal.
4. The vehicle of claim 1 , wherein the controller is configured to increase the torque capacity at a rate based on a capacitization response rate of the bypass clutch.
5. The vehicle of claim 1 , wherein the controller is further programmed to increase hydraulic pressure in the bypass clutch to increase the torque capacity of the bypass clutch.
6. A method of controlling a vehicle having an engine, a traction motor, a clutch configured to selectively couple the engine and traction motor, and a torque converter with associated bypass clutch coupling the motor to a gearbox, the method comprising:
in response to an anticipated application of regenerative braking torque associated with a braking request, increasing a torque capacity of the bypass clutch by a quantity corresponding to the anticipated regenerative braking torque; and
in response to the braking request, controlling the traction motor to provide regenerative braking torque after the torque capacity is increased.
7. The method of claim 6 , wherein the braking request is initiated by a driver actuation of a brake pedal.
8. The method of claim 6 , wherein the braking request is initiated by a driver release of an accelerator pedal.
9. The method of claim 6 , wherein the torque capacity is increased at a rate based on a capacitization response rate of the bypass clutch.
10. The method of claim 6 , wherein the increasing of torque capacity of the bypass clutch includes increasing hydraulic pressure in the torque converter bypass clutch.
11. A vehicle comprising:
traction wheels;
an electric machine configured to provide regenerative braking torque to the traction wheels;
a clutch configured to selectively operatively couple the electric machine and traction wheels; and
at least one controller configured to, in response to an anticipated increase in magnitude of an input torque to the clutch based on a braking request, increase a torque capacity associated with the clutch prior to the increase in magnitude.
12. The vehicle of claim 11 , wherein the braking request is initiated by a driver actuation of a brake pedal.
13. The vehicle of claim 11 , wherein the braking request is initiated by a lift pedal braking request.
14. The vehicle of claim 11 , wherein the controller is configured to increase the torque capacity at a rate based on a capacitization response rate of the clutch.
15. The vehicle of claim 11 , wherein the at least one controller is further programmed to increase hydraulic pressure in the clutch to increase the torque capacity of the clutch.