Temperature compensated lift-throttle regenerative braking

• US 6,588,860 B2
• Filed: 05/09/2001
• Issued: 07/08/2003
• Est. Priority Date: 05/09/2001
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Kosik, Richard C., Sanderson, William F. Jr., Pate, Steven Otis
• Primary Examiner(s): Butler, Douglas C.
• Assistant Examiner(s): SICONOLFI, ROBERT
• Application Number:
  US09/851,676
• Publication Number:
  US 20020167221A1
• Time in Patent Office: 790 Days
• Field of Search: 701/70, 701/71, 701/73, 701/80, 180/165, 318/362, 318/326, 303/151, 303/152, 303/191
• US Class Current: 303/152
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 2240/662 Temperature
• CPC Class Codes: B60L 2260/24 Coasting mode
• CPC Class Codes: B60L 7/18 Controlling the braking effect B60L7/12, B60L7/14, B60L7/16 take precedence
• CPC Class Codes: B60T 2270/602 ABS features related thereto
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2555/20 Ambient conditions, e.g. wind or rain
• CPC Class Codes: B60W 30/18127 Regenerative braking
• CPC Class Codes: B60W 30/194 related to low temperature conditions, e.g. high viscosity of hydraulic fluid
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y10S 903/947 Characterized by control of braking, e.g. blending of regeneration, friction braking

Abstract

The amount of regenerative braking that is applied to the wheels (105) of a vehicle (100) is based on ambient temperature and a lift-throttle event. An ambient temperature sensor (108) monitors the temperature around the vehicle. Based on the temperature, a map is selected (204, 212, 214). If a lift-throttle event occurs, then the map is applied (206, 208). Compression regenerative braking is reduced to zero if an anti-lock braking system event occurs or if the throttle is re-applied, or both (216, 218, 220, 222).

Claims

1. A method for controlling the amount of regenerative braking force applied to wheels of a vehicle, the method comprising the steps of:

determining an ambient temperature around a vehicle;

selecting a first compression regenerative braking function as a selected compression regenerative braking function based on the ambient temperature;

detecting a lift-throttle event; and

in response to the lift-throttle event, applying the selected compression regenerative braking function to determine a regenerative braking force to a wheel of the vehicle.

2. The method of claim 1 wherein the step of selecting the first compression regenerative braking function includes the step of selecting the first compression regenerative braking function as the selected compression regenerative braking function if the ambient temperature is equal to or greater than a first threshold.

3. The method of claim 2 further comprising the steps of:

prior to applying the selected compression regenerative braking function;

determining whether the ambient temperature is less than a second threshold;

if the ambient temperature is less than the second threshold, then selecting a second compression regenerative braking function as the selected compression regenerative braking function.

4. The method of claim 3 further comprising the step of:

prior to applying the selected compression regenerative braking function;

determining whether the ambient temperature is between the first threshold and the second threshold; and

if the ambient temperature is between the first threshold and the second threshold, then selecting a third compression regenerative braking function as the selected compression regenerative braking function.

5. The method of claim 1 wherein the selected compression regenerative braking function determines, as a function of a vehicle speed, a current to be supplied by an electric motor that controls wheels of the vehicle.

6. The method of claim 4 wherein the third compression regenerative braking function is a function of the first compression regenerative braking function and the second compression regenerative braking function.

7. The method of claim 6 wherein the third compression regenerative braking function is a linear interpolation between the first compression regenerative braking function and the second compression regenerative braking function.

8. The method of claim 3 wherein the first threshold is about 15 degrees Celsius and the second threshold is about 4 degrees Celsius.

9. The method of claim 4 further comprising the steps of:

after applying the selected compression regenerative braking function;

detecting an anti-lock brake event; and

in response to the anti-lock brake event, rapidly reducing an amount of compression regenerative braking being applied to zero.

10. A vehicle comprising:

a sensor that monitors an ambient temperature around the vehicle;

a processor coupled to the sensor to receive the ambient temperature;

wherein the processor;

selects a first compression regenerative braking function as a selected compression regenerative braking function based on the ambient temperature; and

in response to a lift-throttle event, applies the selected compression regenerative braking function to determine a regenerative braking force to a wheel of the vehicle.

11. The vehicle of claim 10 wherein the lift-throttle event is detected by an accelerator position sensor.

12. The vehicle of claim 11 wherein the processor selects the first compression regenerative braking function as the selected compression regenerative braking function if the ambient temperature is equal to or greater than a first threshold.

13. The vehicle of claim 12 wherein the processor, prior to applying the selected compression regenerative braking function:

determines whether the ambient temperature is less than a second threshold; and

if the ambient temperature is less than the second threshold, then selects a second compression regenerative braking function as the selected compression regenerative braking function.

14. The vehicle of claim 13 wherein the processor, prior to applying the selected compression regenerative braking function:

determines whether the ambient temperature is between the first threshold and the second threshold; and

if the ambient temperature is between the first threshold and the second threshold, then selects a third compression regenerative braking function as the selected compression regenerative braking function.

15. The vehicle of claim 14 wherein the third compression regenerative braking function is a function of the first compression regenerative braking function and the second compression regenerative braking function.

16. The method of claim 15 wherein the third compression regenerative braking function is a linear interpolation between the first compression regenerative braking function and the second compression regenerative braking function.

17. The method of claim 13 wherein the first threshold is about 15 degrees Celsius and the second threshold is about 4 degrees Celsius.

18. The method of claim 10 wherein the selected compression regenerative braking function determines a current to be supplied by an electric motor that controls wheels of the vehicle as a function of a vehicle speed.

19. An apparatus for controlling compression regenerative braking to a wheel of a vehicle, the apparatus comprising:

a processor that;

receives an indication of an ambient temperature about the vehicle;

selects a first compression regenerative braking function as a selected compression regenerative braking function based on the ambient temperature; and

in response to a lift-throttle event, applies the selected compression regenerative braking function to determine a regenerative braking force to the wheel of the vehicle.

20. The apparatus of claim 19 wherein the selected compression regenerative braking function determines a current to be supplied by an electric motor that controls the wheel of the vehicle as a function of a speed of the vehicle.