Granted Patent B2

US 12,447,970 · App. 18/160,035 · Granted Oct 21, 2025

Inventor: Thomas S. Hawley (Ann Arbor, MI)

Assignees: TOYOTA MOTOR ENGINEERING & MANUFACTURING NORTH AMERICA, INC.; TOYOTA JIDOSHA KABUSHIKI KAISHA

B60W30/188B60W10/04B60W30/143B60W40/12B60W50/14B60T2201/04B60W2510/18B60W2520/00

Abstract

Claims (56)

1. A method comprising:

detecting a braking behavior to set a target speed of a vehicle to descend downgrade; and

activating a downhill speed control of the vehicle based on the detected braking behavior,

wherein the downhill speed control comprises applying a powertrain torque feedback to limit an acceleration of the vehicle to hold the target speed of the vehicle while descending downgrade; and

wherein detecting the braking behavior comprises:

determining a vehicle speed change between a first vehicle speed at a start of a brake application, and a second vehicle speed at an end of the brake application, and

comparing the vehicle speed change to a speed change threshold, the speed change threshold being a non-zero value; and

activating the downhill speed control is based on the vehicle speed change exceeding the speed change threshold.

2. The method of claim 1 , further comprising canceling the downhill speed control based on at least one of:

a depressing of an accelerator pedal of the vehicle for longer than a timer; or

an acceleration of the vehicle to a speed greater than a target speed threshold.

3. The method of claim 2 , wherein the canceling the downhill speed control is based on the depressing of the accelerator pedal, the method further comprising:

detecting a downhill grade; and

setting the timer based on the detected downhill grade.

4. The method of claim 1 , further comprising activating the downhill speed control based on the target speed being within a predetermined range from a posted speed limit.

5. The method of claim 1 , wherein the applying the powertrain torque feedback comprises adjusting a powertrain torque to achieve a vehicle acceleration at or near 0 m/s 2 while descending downgrade.

6. The method of claim 1 , wherein the speed change threshold is preset by a user of the vehicle.

7. A powertrain torque control system comprising:

a logic device configured to:

detect a braking behavior to set a target speed of a vehicle to descend downgrade; and

activate a downhill speed control of the vehicle based on the detected braking behavior,

wherein the downhill speed control comprises applying a powertrain torque feedback to limit an acceleration of the vehicle to hold the target speed of the vehicle while descending downgrade; and

wherein the logic device is configured to:

determine a vehicle speed change between a first vehicle speed at a start of brake application and a second vehicle speed at an end of the brake application;

compare the vehicle speed change to a speed change threshold, the speed change threshold being a non-zero value; and

activate the downhill speed control based on the vehicle speed change exceeding the speed change threshold.

8. The powertrain torque control system of claim 7 , wherein the logic device is configured to cancel the downhill speed control based on at least one of:

a depressing of an accelerator pedal of the vehicle for longer than a timer; or

an acceleration of the vehicle to a speed greater than a target speed threshold.

9. The powertrain torque control system of claim 8 , wherein the logic device is configured to:

cancel the downhill speed control based on the depressing of the accelerator pedal;

detect a downhill grade; and

set the timer based on the detected downhill grade.

10. The powertrain torque control system of claim 7 , wherein the logic device is configured to set the speed change threshold to a value preset by a user of the vehicle.

11. The powertrain torque control system of claim 7 , wherein the logic device is configured to activate the downhill speed control based on the target speed being within a predetermined range from a posted speed limit.

12. The powertrain torque control system of claim 7 , wherein the logic device is configured to adjust a powertrain torque to achieve a vehicle acceleration at or near 0 m/s 2 while descending downgrade.

13. A vehicle comprising the powertrain torque control system of claim 7 .

14. A vehicle comprising:

a powertrain; and

a powertrain torque control system configured to:

detect a braking behavior to set a target speed of the vehicle to descend downgrade, and

activate a downhill speed control of the vehicle based on the detected braking behavior,

wherein the downhill speed control comprises applying a powertrain torque feedback to limit an acceleration of the vehicle to hold the target speed of the vehicle while descending downgrade; and

wherein the powertrain torque control system is configured to:

determine a vehicle speed change between a first vehicle speed at a start of a brake application and a second vehicle speed at an end of the brake application;

compare the vehicle speed change to a speed change threshold, the speed change threshold being a non-zero value;

activate the downhill speed control based on the vehicle speed change exceeding the speed change threshold; and

set the target speed to the second vehicle speed.

15. The vehicle of claim 14 , wherein the powertrain torque control system is configured to adjust a negative torque applied by the powertrain to achieve a vehicle acceleration at or near 0 m/s 2 while descending downgrade.

16. The vehicle of claim 14 , wherein the powertrain torque control system is configured to:

detect a downhill grade;

set a pedal timer based on the detected downhill grade; and

cancel the downhill speed control based on a depressing of an accelerator pedal of the vehicle for longer than the pedal timer.

17. The vehicle of claim 14 , wherein the

speed change threshold is preset by a user of the vehicle.

18. The vehicle of claim 14 , wherein the powertrain torque control system is configured to activate the downhill speed control based on the target speed being within a predetermined range from a posted speed limit.

Assignments (2)

Continuity (1)

References Cited (21)