Powertrain torque control during shift to four-wheel drive in automated-driving mode
AssigneeFord Global Technologies, LLC
InventorsMichael Frey, Filip Tomik, Richard David Bruns
Life of this patent
Estimating the term…
Abstract
A vehicle includes a primary axle, a secondary axle, and a powertrain. The powertrain has an engine coupled to the primary axle and selectively coupled to the secondary axle. The vehicle also includes a clutch associated with the secondary axle. A controller is programmed to, responsive to (i) a request to shift from two-wheel drive to four-wheel drive and (ii) a current engine-torque command exceeding a torque limit associated with the clutch, override the current engine-torque command to reduce a torque of the engine below the torque limit, and, responsive to the torque of the engine being less the torque limit, command engagement of the clutch.
Claims20
A vehicle comprising:
- a primary axle;
- a secondary axle;
- a powertrain including an engine coupled to the primary axle and selectively coupled to the secondary axle;
- a clutch associated with the secondary axle;
- and
- a controller programmed to, responsive to (i) a request to shift from two-wheel drive to four-wheel drive and (ii) a current engine-torque command exceeding a torque limit associated with the clutch:
- override the current engine-torque command to reduce a torque of the engine below the torque limit, and
- responsive to the torque of the engine being less the torque limit, command engagement of the clutch.
A vehicle comprising:
- a primary axle;
- a secondary axle;
- a prime mover coupled to the primary axle;
- a clutch associated with the secondary axle and configured to selectively couple to the secondary axle to the prime mover;
- and
- a controller programmed to, when the vehicle is in an automated-driving mode:
- command a first torque to the prime mover based on a user-specified vehicle-speed set point that is set independent of an accelerator pedal position, and
- in response to (i) the first torque exceeding a threshold and (ii) a request to engage the clutch, command a second torque to the prime mover that is less the first torque to facilitate engagement of the clutch.
A method of shifting a vehicle from two-wheel drive to four-wheel drive when cruise control is activated, the method comprising:
- overriding a current engine-torque command to reduce a torque of the engine below a torque limit in response to a request to shift from two-wheel drive to four-wheel drive;
- commanding engagement of a clutch to shift from two-wheel drive to four-wheel drive in response to the torque of the engine being less the torque limit;
- and
- discontinuing the override in responsive to the clutch engaging.
Dependencies are inferred from the claim text.