System and Method of Extending Regenerative Braking in a Hybrid Electric Vehicle

• US 20080314663A1
• Filed: 06/20/2007
• Published: 12/25/2008
• Est. Priority Date: 06/20/2007
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Ramaswamy, Deepa, Yamazaki, Mark Steven
• Granted Patent: US 7,971,666 B2
• Time in Patent Office: Days
• US Class Current: 180/165
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/20 the prime-movers consisting of electric motors and internal combustion engines, e.g. HEVs
• CPC Class Codes: B60K 6/448 Electrical distribution type
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60L 1/02 to electric heating circuits
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 2270/12 of exhaust
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/24 including control of energy storage means
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• 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 2510/083 : Torque
• CPC Class Codes: B60W 2710/0616 : Position of fuel or air injector
• CPC Class Codes: B60W 30/18127 : Regenerative braking
• CPC Class Codes: B60W 30/18136 : Engine braking
• CPC Class Codes: F02D 13/04 : using engine as brake
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

A method of generating brake force to decelerate a vehicle is provided. The vehicle includes an internal combustion engine coupled to an input of a first electric energy device, the first electric energy device having an output coupled to a transmission device, and a second electric energy conversion device coupled downstream of the transmission device, the first and second electric energy conversion devices being powered at least by a battery. The method includes during a deceleration condition, generating brake torque via the second electric energy conversion device to generate electric energy storable in the battery; and rotating the internal combustion engine via torque output from the first electric energy device to deplete electric energy from the battery.

Claims

1. A method of generating brake force to decelerate a vehicle comprising an internal combustion engine coupled to an input of a first electric energy device, the first electric energy device having an output coupled to a transmission device, and a second electric energy conversion device coupled downstream of the transmission device, the first and second electric energy conversion devices being powered at least by a battery, the method comprising:

during a deceleration condition, generating brake torque via the second electric energy conversion device to generate electric energy storable in the battery;

while

rotating the internal combustion engine via torque output from the first electric energy device to deplete electric energy from the battery.

2. The method of claim 1 further comprising:

decoupling the output of the first electric energy conversion device from the transmission device.

3. The method of claim 1 further comprising:

adjusting the internal combustion engine to operate at a rich fuel-air ratio for a predetermined period upon detection of the deceleration condition.

4. The method of claim 1 further comprising:

deactivating injection of fuel into at least one cylinder of the internal combustion engine during the deceleration condition.

5. The method of claim 4 further comprising:

adjusting a valve timing of at least one of an intake valve and an exhaust valve of the at least one cylinder to adjust the amount of electric energy being depleted from the battery.

6. The method of claim 1 wherein the deceleration condition is based on a position of at least one of an accelerator pedal and a brake pedal of the vehicle.

7. The method of claim 1 wherein the first electric energy conversion device rotates the internal combustion engine when a state of charge of the battery is above a threshold level.

8. A vehicle comprising:

an internal combustion engine coupled to a first electric energy conversion device;

a transmission device having an input and an output, the input coupled to the first electric energy conversion device;

a second electric energy conversion device coupled downstream of the output of the transmission device, the second electric energy device providing torque output to at least one wheel;

a battery for powering at least the first electric energy conversion device and the second electric energy conversion device; and

a control system, the control system adjusting at least one of the first electric energy device and the second electric energy control device to produce brake torque to the at least one wheel and storing electric energy produced from the brake torque in the battery during a first mode of operation, and adjusting the second electric energy conversion device to produce brake torque to the at least one wheel and storing electric energy produced by the second electric energy conversion device in the battery and adjusting the first electric energy conversion device to produce torque to rotate the internal combustion engine to deplete electric energy from the battery during a second mode of operation.

9. The vehicle of claim 8 wherein the control system decouples the input of the transmission device from the first electric energy conversion device during the second mode of operation.

10. The vehicle of claim 8 wherein the control system adjusts the torque output of the first electric energy conversion device and the torque output of the second electric energy conversion device to produce brake torque to the at least one wheel during a third mode of operation.

11. The vehicle of claim 8 wherein the control system switches from the third mode of operation to the second mode of operation based on a state of charge of the battery being above a threshold level.

12. The vehicle of claim 8 wherein the control system deactivates fuel injection into at least one cylinder of the internal combustion engine during the second mode of operation.

13. The vehicle of claim 12 wherein the control system adjusts valve timing of at least one of an intake valve and an exhaust valve of the at least one cylinder to adjust an amount of electric energy being depleted from the battery.

14. The vehicle of claim 12 wherein the control system adjusts the air-fuel ratio of the internal combustion engine to operating rich for a predetermined period prior to deactivating fuel injection.

15. A vehicle comprising:

an internal combustion engine coupled to a first electric energy conversion device;

a transmission device having an input and an output, the input coupled to the first electric energy conversion device;

a second electric energy conversion device coupled downstream of the transmission;

a battery for powering at least the first electric energy conversion device and the second electric energy conversion device; and

a control system, the control system adjusting a torque output of the second electric energy conversion device to meet a desired deceleration condition and thereby generate electric energy, decoupling the first electric energy conversion device from the transmission input, and adjusting an operating efficiency of the first electric energy conversion device to draw an amount of electric energy from the battery that is based on the amount of electric energy generated by the second electric energy conversion device when the battery state of charge is beyond a threshold level.

16. The vehicle of claim 15 wherein the control system is configured to adjust at least one of the torque output of first electric energy conversion device and the torque output of the second electric energy conversion device to meet the desired deceleration condition when the battery state of charge is below the threshold level.

17. The vehicle of claim 15 wherein adjusting the operating efficiency of the first electric energy conversion device includes adjusting a rotor speed of the first electric energy conversion device.

18. The vehicle of claim 15 wherein the desired deceleration condition is based on a position of at least one of an accelerator pedal and a brake pedal of the vehicle.

19. The vehicle of claim 15 wherein the threshold level is a substantially high battery state of charge.

20. The vehicle of claim 15 wherein the deceleration condition does not include rapid deceleration of the vehicle.