NEGATIVE DRIVELINE TORQUE CONTROL INCORPORATING TRANSMISSION STATE SELECTION FOR A HYBRID VEHICLE

• US 20080314661A1
• 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: Soliman, Ihab, Aswani, Deepak
• Granted Patent: US 7,841,433 B2
• Time in Patent Office: Days
• US Class Current: 180/65.4
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/442 Series-parallel switching type
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 10/24 including control of energy storage means
• 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 2510/18 Braking system
• CPC Class Codes: B60W 2540/16 Ratio selector 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: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

In one embodiment, a hybrid propulsion system for a passenger vehicle is provided. The system comprises at least one drive wheel; a first motor coupled to the drive wheel; a second motor; a transmission including a first end coupled to the drive wheel and a second end coupled to the second motor; and a control system configured to control operation of the first and second motor to each provide vehicle braking torque, wherein transmission state is adjusted in response to an amount of braking torque provided by the first motor and an amount of braking torque provided by the second motor.

Claims

1. A hybrid propulsion system for a vehicle, comprising:

at least one drive wheel;

a first motor coupled to the drive wheel;

a second motor;

a transmission including a first end coupled to the drive wheel and a second end coupled to the second motor; and

a control system configured to control operation of the first and second motor to each provide vehicle braking torque, wherein transmission state is adjusted in response to an amount of braking torque provided by the first motor and an amount of braking torque provided by the second motor.

2. The system of claim 1, wherein the transmission state is an engaged state of the transmission.

3. The system of claim 1, wherein the transmission state is a gear of the transmission.

4. The system of claim 1, wherein the transmission state is a torque ratio of the transmission and wherein the torque ratio is increased responsive to an increase in the amount of braking torque provided by the second motor.

5. The system of claim 1, wherein the control system is further configured to perform a first mode, wherein braking torque is provided by the first motor, the second motor does not provide braking torque, and wherein the transmission is disengaged.

6. The system of claim 5, further comprising an internal combustion engine coupled to the second motor, wherein the control system is further configured to perform a second mode wherein the first motor provides vehicle braking torque, the second motor provides torque to rotate an internal combustion engine of the vehicle, and wherein the transmission is disengaged.

7. The system of claim 6, wherein the control system is further configured to perform a third mode, wherein at least the engine and the first motor provide braking torque and the transmission is engaged.

8. The system of claim 7, wherein the control system is further configured to perform a fourth mode, wherein at least the engine provides braking torque and the first motor does not provide braking torque.

9. A hybrid propulsion system for a vehicle, comprising:

at least one drive wheel;

a first motor coupled to the drive wheel, said first motor configured to generate electrical energy from kinetic energy received at the drive wheel;

a second motor configured to generate electrical energy from kinetic energy received at the drive wheel;

a transmission including a first end coupled to the first motor and a second end coupled to the second motor;

a control system configured to vary a relative level of electrical energy generated by the first motor and the second motor in response to an operating condition to provide vehicle braking.

10. The system of claim 9, wherein the operating condition includes a torque ratio of the transmission.

11. The system of claim 9, wherein the control system is configured to vary a selected gear of the transmission responsive to a relative level of electrical energy generated by the first motor and the second motor.

12. The system of claim 9, wherein the operating condition includes a rate of deceleration of the drive wheel.

13. The system of claim 12, wherein the level of electrical energy generated by the second motor is increased relative to the level of electrical energy generated by the first motor with an increasing rate of deceleration of the drive wheel.

14. The system of claim 9, further comprising an internal combustion engine coupled to the second motor, and wherein the control system is further configured to adjust a speed ratio between the first end and the second end of the transmission in response to a rotational speed of the engine.

15. The system of claim 9, wherein the operating condition includes an efficient operating range of at least one of the first motor and the second motor.

16. A method of controlling a hybrid propulsion system for a vehicle including at least an internal combustion engine and an electric motor, wherein said engine is coupled to at least one drive wheel of the vehicle via a transmission, the method comprising:

receiving a vehicle braking request;

adjusting a state of the transmission to increase a level of braking force provided to the drive wheel of the vehicle by the engine in response to the vehicle braking request; and

varying a level of torque exchanged between the electric motor and the drive wheel responsive to the level of braking force provided by the engine.

17. The method of claim 16, wherein the electric motor is coupled to an opposite side of the transmission from the engine.

18. The method of claim 16, wherein the electric motor is coupled directly to a crankshaft of the engine.

19. The method of claim 16, wherein said varying the level of torque exchanged between the electric motor and the drive wheel includes absorbing torque from the drive wheel at the motor to further increase the level of braking force.

20. The method of claim 16, wherein said motor converts torque absorbed from the drive wheel to electrical energy, and wherein the method further comprises storing at least a first portion of said electrical energy at an energy storage device of the vehicle;

and supplying a second portion of said electrical energy to a second motor of the vehicle and operating said second motor to supply torque to said engine.