Regenerative braking method

Patent metadata

Field	Value
Publication number	US-10150371-B2
Application number	US-201615342395-A
Country	US
Kind code	B2
Filing date	Nov 3, 2016
Priority date	Nov 3, 2016
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

Abstract

A vehicle system includes a controller that is programmed to, in response to a speed differential between the vehicle and a forward detected object, decelerate the vehicle at a first rate during a first period via regenerative braking alone and decelerate the vehicle at a second rate during a second period, following the first period, to reduce a distance to the forward detected object from an initial distance to a minimum distance.

First claim

What is claimed is:

1. A vehicle system comprising:
a controller programmed to,
responsive to a speed differential between the vehicle and a forward detected object, decelerate the vehicle at a first rate during a first period via regenerative braking alone and decelerate the vehicle at a second rate during a second period, following the first period, to reduce a distance to the forward detected object from an initial distance to a minimum distance, and
responsive to a high energy condition where a ratio of the distance to the forward detected object and a vehicle speed is such that regenerative braking would exceed a regenerative braking limit by decelerating the vehicle according to a baseline rate, set the first rate to a value that is less than the second rate.

2. The vehicle system of claim 1 , wherein controller is programmed to set the first rate to a value that is greater than the second rate under a low energy condition where a ratio of the distance to the forward detected object and a vehicle speed is such that regenerative braking would not exceed a regenerative braking limit by decelerating the vehicle according to a baseline rate.

3. The vehicle system of claim 2 , wherein the first rate is greater than the baseline rate and the second rate is less than the baseline rate, the baseline rate being a constant deceleration rate that will reduce the speed differential from a current value to zero and reduce the distance to the forward detected object from the initial distance to the minimum distance.

4. The vehicle system of claim 2 , wherein the controller is programmed to decelerate the vehicle at the second rate during the second period via vehicle coasting.

5. The vehicle system of claim 1 , wherein the first rate is less than the baseline rate and the Currently Amended rate is greater than the baseline rate, the baseline rate being a constant deceleration rate that will reduce the speed differential from a current value to zero and reduce the distance to the forward detected object from the initial distance to the minimum distance.

6. The vehicle system of claim 1 , wherein the controller is programmed to decelerate the vehicle at the second rate during the second period via friction braking.

7. The vehicle system of claim 1 , wherein the controller is programmed to decelerate the vehicle at the second rate during the second period via a combination of regenerative braking and friction braking.

8. The vehicle system of claim 1 further comprising an electric machine configured to recharge a battery during regenerative braking, wherein decelerating the vehicle at the first rate maximizes regenerative braking power of the electric machine.

9. The vehicle system of claim 1 , wherein the controller is programmed to reduce the speed differential to zero upon obtaining the minimum distance.

10. A regenerative braking method comprising:
responsive to a speed differential between a vehicle and a forward detected object, decelerating the vehicle at a first rate during a first period via regenerative braking alone and decelerating the vehicle at a second rate during a second period, following the first period, to reduce a distance to the forward detected object from an initial distance to a minimum distance, and
responsive to a high energy condition where a ratio of the distance to the forward detected object and a vehicle speed is such that regenerative braking would exceed a regenerative braking limit by decelerating the vehicle according to a baseline rate, set the first rate to a value that is less than the second rate.

11. The method of claim 10 further comprising setting the first rate to a value that is greater than the second rate under a low energy condition where a ratio of the distance to the forward detected object and a vehicle speed is such that regenerative braking would not exceed a regenerative braking limit by decelerating the vehicle according to a baseline rate.

12. The method of claim 11 , wherein the first rate is greater than the baseline rate and the second rate is less than the baseline rate, the baseline rate being a constant deceleration rate that will reduce the speed differential from a current value to zero and reduce the distance to the forward detected object from the initial distance to the minimum distance.

13. The method of claim 11 , wherein the vehicle is decelerated at the second rate during the second period via vehicle coasting.

14. The method of claim 10 , wherein the first rate is less than the baseline rate and the second rate is greater than the baseline rate, the baseline rate being a constant deceleration rate that will reduce the speed differential from a current value to zero and reduce the distance to the forward detected object from the initial distance to the minimum distance.

15. The method of claim 10 , wherein the vehicle is decelerated at the second rate during the second period via friction braking.

16. The method of claim 10 , wherein the vehicle is decelerated at the second rate during the second period via a combination of regenerative braking and friction braking.

17. The method of claim 10 , wherein the speed differential is reduced to zero upon obtaining the minimum distance.

18. A vehicle comprising:
a generator; and
a controller programmed to, responsive to a distance to a forward object and a vehicle speed being such that regenerative braking at a linear baseline rate to maintain a minimum distance between the object and vehicle would exceed a regenerative braking limit, decelerate the vehicle at a first rate via the generator, and subsequently decelerate the vehicle at a second rate that is greater than the first rate.

19. The vehicle of claim 18 further comprising friction brakes, and wherein the vehicle is decelerated at the second rate via a combination of regenerative braking and friction braking.

20. The vehicle of claim 18 , wherein the first rate is less than the baseline linear rate and the second rate is greater than the baseline linear rate, the baseline linear rate being a constant deceleration rate that will reduce a speed differential between the vehicle and the forward object from a current value to zero and reduce the distance to the forward detected object from an initial distance to the minimum distance.

Assignees

• Ford Global Tech Llc
• Ford Global Tech Llc

Inventors

• Zenner Thomas
• Kok Daniel Benjamin
• Kapadia Jimmy

Classifications

• B60L7/18 Primary

  Controlling the braking effect (B60L7/12, B60L7/14, B60L7/16 take precedence) · CPC title

• B60L2240/12

  Speed · CPC title

• B60T2201/02

  Active or adaptive cruise control system; Distance control · CPC title

• B60T8/17

  Using electrical or electronic regulation means to control braking {(detecting or indicating faulty operation B60T8/885)} · CPC title

• B60L7/26 Primary

  Controlling the braking effect · CPC title