Torque control for vehicles with independent front and rear propulsion systems

Patent metadata

Field	Value
Publication number	US-9662974-B2
Application number	US-201514620018-A
Country	US
Kind code	B2
Filing date	Feb 11, 2015
Priority date	Feb 11, 2015
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

Methods and systems for controlling torque for a front axle and a rear axle of a vehicle with independent front and rear propulsion systems are provided. A data unit is configured to obtain data for one or more parameters of a vehicle while the vehicle is being driven. A processor is coupled to the data unit, and is configured to provide torque to at least facilitate providing torque the front axle and the rear axle independently based on the one or more parameters.

First claim

What is claimed is:

1. A method comprising:
obtaining data for one or more parameters of a vehicle while the vehicle is being driven, the one or more parameters comprising an actual slip angle and a desired slip angle for the vehicle, the vehicle having a front axle and a rear axle; and
providing torque to the front axle and the rear axle independently based on the actual slip angle and the desired slip angle, wherein the step of providing torque comprises reducing torque to both the front axle and the rear axle if a rate of change of the actual slip angle is greater than a predetermined threshold and the actual slip angle is greater than the desired slip angle.

2. The method of claim 1 , wherein the step of providing torque further comprises increasing the torque to one of the front axle or the rear axle and decreasing torque to the other of the front axle or the rear axle, based on the one or more parameters, while maintaining a level of overall torque for the vehicle.

3. The method of claim 1 , wherein:
the step of obtaining data further comprises obtaining data for an actual yaw rate and a desired yaw rate for the vehicle; and
the step of providing torque further comprises providing torque to the front axle and the rear axle independently based on the actual yaw rate and the desired yaw rate.

4. The method of claim 1 , wherein:
the step of obtaining data further comprises obtaining data for an actual yaw rate and a desired yaw rate for the vehicle; and
the step of providing torque comprises:
reducing torque to the front axle by a first amount and reducing torque to the rear axle by a second amount that is less than the first amount if an absolute value of the desired yaw rate is greater than an absolute value of the actual yaw rate; and
reducing torque to the front axle by a third amount and reducing torque to the rear axle by a fourth amount that is greater than the third amount if the absolute value of the actual yaw rate is greater than the absolute value of the actual yaw rate.

5. The method of claim 3 , wherein:
the step of obtaining data comprises obtaining data for an actual slip angle and a desired slip angle for the vehicle; and
the step of providing torque comprises reducing torque to the front axle and increasing torque to the rear axle if a rate of change of the actual slip angle is less than a first predetermined threshold, a product of the desired yaw rate and the actual yaw rate is greater than or equal to zero, and a difference between an absolute value of the desired yaw rate and an absolute value of the actual yaw rate is greater than a second predetermined threshold.

6. The method of claim 3 , wherein:
the step of obtaining data comprises obtaining data for an actual slip angle and a desired slip angle for the vehicle; and
the step of providing torque comprises increasing torque to the front axle and decreasing torque to the rear axle if a rate of change of the actual slip angle is less than a first predetermined threshold, a product of the desired yaw rate and the actual yaw rate is greater than or equal to zero, and a difference between an absolute value of the actual yaw rate and an absolute value of the actual yaw rate is greater than a second predetermined threshold.

7. The method of claim 3 , wherein:
the step of obtaining data comprises obtaining data for an actual slip angle and a desired slip angle for the vehicle; and
the step of providing torque comprises decreasing torque to the front axle and decreasing torque to the rear axle if a rate of change of the actual slip angle is less than a first predetermined threshold and a product of the desired yaw rate and the actual yaw rate is less than zero.

8. A system comprising:
a data unit configured to obtain data for one or more parameters of a vehicle while the vehicle is being driven, the one or more parameters comprising an actual slip angle and a desired slip angle for the vehicle, the vehicle having a front axle and a rear axle; and
a processor coupled to the data unit and configured to at least facilitate reducing torque to both the front axle and the rear axle if a rate of change of the actual slip angle is greater than a predetermined threshold and the actual slip angle is greater than the desired slip angle.

9. The system of claim 8 , wherein the processor is configured to at least facilitate:
increasing the torque to one of the front axle or the rear axle and decreasing torque to the other of the front axle or the rear axle, based on the one or more parameters, while maintaining a consistency between overall torque and a driver requested torque for the vehicle.

10. The system of claim 8 , wherein:
the data unit is configured to obtain a velocity of the vehicle; and
the processor is configured to at least facilitate providing torque to the front axle and the rear axle independently based on the one or more parameters, provided that the velocity is less than a predetermined threshold.

11. The system of claim 8 , wherein:
the data unit is configured to obtain data for an actual yaw rate and a desired yaw rate for the vehicle; and
the processor is configured to at least facilitate providing torque to the front axle and the rear axle independently based on the actual yaw rate and the desired yaw rate.

12. The system of claim 8 , wherein:
the data unit is configured to obtain data for an actual yaw rate and a desired yaw rate for the vehicle; and
the processor is configured to at least facilitate:
reducing torque to the front axle by a first amount and reducing torque to the rear axle by a second amount that is less than the first amount if an absolute value of the desired yaw rate is greater than an absolute value of the actual yaw rate; and
reducing torque to the front axle by a third amount and reducing torque to the rear axle by a fourth amount that is greater than the third amount if the absolute value of the actual yaw rate is greater than the absolute value of the actual yaw rate.

13. The system of claim 11 , wherein:
the data unit is configured to obtain data for an actual slip angle and a desired slip angle for the vehicle; and
the processor is configured to at least facilitate reducing torque to the front axle and increasing torque to the rear axle if a rate of change of the actual slip angle is less than a first predetermined threshold, a product of the desired yaw rate and the actual yaw rate is greater than or equal to zero, and a difference between an absolute value of the desired yaw rate and an absolute value of the actual yaw rate is greater than a second predetermined threshold.

14. The system of claim 11 , wherein:
the data unit is configured to obtain data for an actual slip angle and a desired slip angle for the vehicle; and
the processor is configured to at least facilitate increasing torque to the front axle and decreasing torque to the rear axle if a rate of change of the actual slip angle is less than a first predetermined threshold, a product of the desired yaw rate and the actual yaw rate is greater than or equal to zero, and a difference between an absolute value of the actual yaw rate and an absolute value of the actual yaw rate is greater than a second predetermined threshold.

15. The system of claim 11 , wherein:
the data unit is configured to obtain data for an actual slip angle and a desired slip angle for the vehicle; and
the processor is configured to at least facilitate decreasing torque to the front axle and decreasing torque to the rear axle if a rate of change of the actual slip angle is less than a predetermined threshold and a product of the desired y

Assignees

• Gm Global Tech Operations Llc

Inventors

• Mao Xiaofeng
• Klingler Thomas A
• Krueger Eric E

Classifications

• B60K2023/0833

  for adding torque to the rear wheels · CPC title

• B60K2001/001

  one motor mounted on a propulsion axle for rotating right and left wheels of this axle · CPC title

• B60K2023/0825

  for adding torque to the front wheels · CPC title

• B60W2720/30

  Wheel torque · CPC title

• B60K1/00

  Arrangement or mounting of electrical propulsion units (B60K7/00 takes precedence; arrangement or mounting of plural diverse prime-movers for mutual or common propulsion B60K6/00) · CPC title