Adaptive cruise control system and method incorporating regenerative braking and start-stop functions

Patent metadata

Field	Value
Publication number	US-9796385-B2
Application number	US-201313832902-A
Country	US
Kind code	B2
Filing date	Mar 15, 2013
Priority date	Mar 15, 2013
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A system according to the principles of the present disclosure includes a cruise control module, an engine control module, and a brake control module. The cruise control module determines a cruise torque request based on at least one of a following distance of a vehicle and a rate at which the vehicle is approaching an object. The engine control module determines a negative torque capacity of a powertrain. The powertrain includes an engine and an electric motor. The brake control module applies a friction brake when the cruise torque request is less than the negative torque capacity of the powertrain.

First claim

What is claimed is:

1. A system comprising:
a cruise control module that determines a cruise torque request based on at least one of a following distance of a vehicle to an object and a rate at which the vehicle is approaching the object;
an engine control module that determines a negative torque capacity of a powertrain in the vehicle, wherein the powertrain includes an engine and an electric motor;
a brake control module that:
applies a friction brake in the vehicle based on a determination that the cruise torque request is less than the negative torque capacity of the powertrain; and
refrains from applying the friction brake based on a determination that the cruise torque request is negative and greater than or equal to the negative torque capacity of the powertrain; and

a pedal position module that estimates a brake pedal position, wherein the engine control module:
receives a measured brake pedal position from a brake pedal position sensor;
determines a percentage of brake pedal depression based on at least one of the estimated brake pedal position and the measured brake pedal position;
stops the engine based on the measured brake pedal position when the friction brake is controlled based on the measured brake pedal position and the brake pedal depression percentage is greater than a first percentage; and
stops the engine based on the estimated brake pedal position when the friction brake is controlled based on the cruise torque request and the brake pedal depression percentage is greater than the first percentage.

2. The system of claim 1 wherein the cruise control module includes a desired deceleration module that determines a desired deceleration based on the at least one of the following distance and the approach rate.

3. The system of claim 2 wherein the brake control module controls a pressure of fluid supplied to the friction brake based on the desired deceleration.

4. The system of claim 1 wherein the cruise control module includes a powertrain torque request module that determines a powertrain torque request based on the cruise torque request and the negative torque capacity of the powertrain.

5. The system of claim 4 wherein the powertrain torque request module adjusts the powertrain torque request to the cruise torque request when the cruise torque request is greater than the negative torque capacity of the powertrain.

6. The system of claim 4 wherein the powertrain torque request module adjusts the powertrain torque request to the negative torque capacity of the powertrain when the cruise torque request is less than the negative torque capacity of the powertrain.

7. The system of claim 1 further comprising a motor torque capacity module that determines a negative torque capacity of the electric motor based on at least one of a power generation capacity of the electric motor, a power receiving capacity of a battery that supplies power to the electric motor, and a state-of-charge of the battery.

8. The system of claim 1 wherein the pedal position module estimates the brake pedal position based on a negative axle torque provided by the powertrain and a friction brake torque.

9. The system of claim 8 further comprising an axle torque estimation module that estimates the negative axle torque based on at least one of a motor torque request, a vehicle speed, and an amount of fuel provided to each cylinder of the engine.

10. The system of claim 1 wherein the brake control module controls the electric motor to apply a regenerative brake torque and refrains from applying the friction brake when the cruise torque request is negative and greater than or equal to the negative torque capacity of the powertrain.

11. The system of claim 1 wherein the pedal position module estimates the brake pedal position based on a brake pressure.

12. The system of claim 1 wherein the engine control module:
determines the brake pedal depression percentage based on the measured brake pedal position when the friction brake is controlled based on the measured brake pedal position; and
determines the brake pedal depression percentage based on the estimated brake pedal position when the friction brake is controlled based on the measured brake pedal position.

13. A method comprising:
determining a cruise torque request based on at least one of a following distance of a vehicle to an object and a rate at which the vehicle is approaching the object;
determining a negative torque capacity of a powertrain in the vehicle, wherein the powertrain includes an engine and an electric motor;
applying a friction brake in the vehicle based on a determination that the cruise torque request is less than the negative torque capacity of the powertrain;
refraining from applying the friction brake when based on a determination that the cruise torque request is negative and greater than or equal to the negative torque capacity of the powertrain;
estimating a brake pedal position;
receiving a measured brake pedal position from a brake pedal position sensor;
determining a percentage of brake pedal depression based on at least one of the estimated brake pedal position and the measured brake pedal position;
stopping the engine based on the measured brake pedal position when the friction brake is controlled based on the measured brake pedal position and the brake pedal depression percentage is greater than a first percentage; and
stopping the engine based on the estimated brake pedal position when the friction brake is controlled based on the cruise torque request and the brake pedal depression percentage is greater than the first percentage.

14. The method of claim 13 further comprising determining a desired deceleration based on the at least one of the following distance and the approach rate.

15. The method of claim 14 further comprising controlling a pressure of fluid supplied to the friction brake based on the desired deceleration.

16. The method of claim 13 further comprising determining a powertrain torque request based on the cruise torque request and the negative torque capacity of the powertrain.

17. The method of claim 16 further comprising adjusting the powertrain torque request to the cruise torque request when the cruise torque request is greater than the negative torque capacity of the powertrain.

18. The method of claim 16 further comprising adjusting the powertrain torque request to the negative torque capacity of the powertrain when the cruise torque request is less than the negative torque capacity of the powertrain.

19. The method of claim 13 further comprising determining a negative torque capacity of the electric motor based on at least one of a power generation capacity of the electric motor, a power receiving capacity of a battery that supplies power to the electric motor, and a state-of-charge of the battery.

20. The method of claim 13 further comprising estimating the brake pedal position based on a negative axle torque provided by the powertrain and a friction brake torque.

21. The method of claim 20 further comprising estimating the negative axle torque based on at least one of a motor torque request, a vehicle speed, and an amount of fuel provided to each cylinder of the engine.

22. The method of claim 13 further comprising controlling the electric motor to apply a regenerative brake torque and refraining from applying the friction brake when the cruise torque request is negative and greater than or equal to the negative torque capacity of the powertrai

Assignees

• Gm Global Tech Operations Llc

Inventors

• Krueger Eric E
• Klemmer Matthew J
• Bassey Kiana
• Whitney Christopher E
• O'Leary Patrick J

Classifications

• B60W2556/00

  Input parameters relating to data · CPC title

• B60W10/184

  with wheel brakes · CPC title

• Y10S903/947

  Characterized by control of braking, e.g. blending of regeneration, friction braking · CPC title

• B60W30/16 Primary

  Control of distance between vehicles, e.g. keeping a distance to preceding vehicle · CPC title

• Y10S903/93

  Conjoint control of different elements · CPC title