METHOD FOR OPERATING AN ELECTRIC DRIVE MODULE

• US 20160272067A1
• Filed: 03/18/2015
• Published: 09/22/2016
• Est. Priority Date: 03/18/2015
• Status: Active Grant

• Current Assignee: E-aam Driveline Systems Ab (American AXLE & Manufacturing Holdings Incorporated)
• Original Assignee: E-aam Driveline Systems Ab (American AXLE & Manufacturing Holdings Incorporated)
• Inventors: Gavling, Emil K., Trnnberg, Gabriel
• Granted Patent: US 9,783,061 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 15/2036 Electric differentials, e.g. for supporting steering vehicles
• CPC Class Codes: B60L 2240/22 Yaw angle
• CPC Class Codes: B60L 3/104 by indirect measurement of vehicle speed
• CPC Class Codes: B60L 3/106 for maintaining or recovering the adhesion of the drive wheels
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

The present teachings provide a method for controlling transmission of power to a set of wheels of a vehicle. The method can include providing a drive module configured to provide an amount of drive torque for powering the set of vehicle wheels. The method can include determining a yaw rate of the vehicle and a first set of vehicle parameters. The method can include determining a reference yaw rate of the vehicle based on the first set of vehicle parameters. The method can include calculating a yaw rate error based on the yaw rate and the reference yaw rate. The method can include reducing the amount of drive torque provided by the drive module to the vehicle wheels based on the yaw rate error.

Claims

1. A method for controlling transmission of power to a set of wheels of a vehicle, the method comprising:

providing a drive module configured to provide an amount of drive torque for powering the set of vehicle wheels;

determining a yaw rate of the vehicle and a first set of vehicle parameters;

determining a reference yaw rate of the vehicle based on the first set of vehicle parameters;

calculating a yaw rate error based on the yaw rate and the reference yaw rate; and

reducing the amount of drive torque provided by the drive module to the vehicle wheels based on the yaw rate error.

2. The method of claim 1, further comprising reducing the amount of drive torque provided by the drive module to the vehicle wheels when the yaw rate error is greater than a first predetermined error value, wherein the yaw rate error is equal to the difference between the yaw rate and the reference yaw rate.

3. The method of claim 1, wherein the first set of vehicle parameters includes a requested steering angle, a vehicle velocity, an estimated surface friction, and a set of predetermined vehicle characteristics.

4. The method of claim 1, wherein the drive module includes an electric motor configured to provide the amount of drive torque for powering the set of vehicle wheels, and wherein the step of reducing the amount of drive torque provided by the drive module to the vehicle wheels based on the yaw rate error further includes:

limiting an amount of electrical power to the electrical motor.

5. The method of claim 1, further comprising:

determining a yaw acceleration of the vehicle;

determining a reference yaw acceleration based on a second set of vehicle parameters;

calculating a yaw acceleration error based on the yaw acceleration and the reference yaw acceleration; and

reducing the amount of drive torque provided by the drive module to the vehicle wheels based on the yaw acceleration error.

6. The method of claim 5, further comprising reducing the amount of drive torque provided by the drive module to the vehicle wheels when the yaw acceleration error is greater than a second predetermined error value, wherein the yaw acceleration error is equal to the difference between the yaw acceleration and the reference yaw acceleration.

7. The method of claim 5, wherein the second set of vehicle parameters includes a requested steering angle, a vehicle velocity, an estimated surface friction, and a set of predetermined vehicle characteristics.

8. The method of claim 5, wherein the drive module includes an electric motor configured to provide the amount of drive torque for powering the set of vehicle wheels, and the method further comprises:

limiting an amount of electrical power to the electrical motor when either the yaw rate error is greater than a first predetermined value, or the yaw acceleration error is greater than a second predetermined value.

9. A method for controlling transmission of power to a set of wheels of a vehicle, the method comprising:

providing a drive module configured to provide an amount of drive torque for powering the set of vehicle wheels;

determining a yaw acceleration of the vehicle;

determining a reference yaw acceleration based on a first set of vehicle parameters;

calculating a yaw acceleration error based on the yaw acceleration and the reference yaw acceleration; and

reducing the amount of drive torque provided by the drive module to the vehicle wheels based on the yaw acceleration error.

10. The method of claim 9, further comprising reducing the amount of drive torque provided by the drive module to the vehicle wheels when the yaw acceleration error is greater than a first predetermined error value, wherein the yaw acceleration error is equal to the difference between the yaw acceleration and the reference yaw acceleration.

11. The method of claim 9, wherein the first set of vehicle parameters includes a requested steering angle, a vehicle velocity, an estimated surface friction, and a set of predetermined vehicle characteristics.

12. The method of claim 9, wherein the drive module includes an electric motor configured to provide the amount of drive torque for powering the set of vehicle wheels, and wherein the step of reducing the amount of drive torque provided by the drive module to the vehicle wheels based on the yaw acceleration error further includes:

limiting an amount of electrical power to the electrical motor.

13. A method for controlling transmission of power to a set of wheels of a vehicle, the method comprising:

providing a drive module configured to provide an amount of drive torque for powering the set of vehicle wheels;

determining a first coefficient of friction between the set of vehicle wheels and an operating surface during an acceleration event;

setting a minimum coefficient of friction to equal the first coefficient of friction;

determining a maximum torque amount based on the minimum coefficient of friction; and

limiting the drive torque that is provided by the drive module to the maximum torque amount during the acceleration event.

14. The method of claim 13, further comprising:

determining an amount of torque requested by an operator of the vehicle;

wherein the acceleration event begins when the amount of torque requested is greater than or equal to a first predetermined amount of torque, and the acceleration event ends when the amount of torque requested is less than a second predetermined amount of torque.

15. The method of claim 14, wherein the first predetermined amount of torque is equal to the second predetermined amount of torque.

16. The method of claim 14, further comprising:

calculating a second coefficient of friction between the set of vehicle wheels and the operating surface during the acceleration event; and

setting the minimum coefficient of friction to the second coefficient of friction if the second coefficient of friction is less than the first coefficient of friction.

17. The method of claim 14, further comprising:

limiting the drive torque that is provided by the drive module to the maximum torque amount until an end of the acceleration event.

18. The method of claim 13, further comprising:

determining a lateral acceleration and a longitudinal acceleration of the vehicle;

wherein the first coefficient of friction is estimated based on the lateral and longitudinal accelerations of the vehicle.

19. The method of claim 13, further comprising:

determining an amount of slippage of the set of vehicle wheels; and

limiting the drive torque that is provided by the drive module only when the amount of slippage is greater than a predetermined slippage value.

20. The method of claim 13, further comprising:

calculating one of a yaw rate error and a yaw acceleration error; and

reducing the drive torque that is provided by the drive module based on the one of the yaw rate error and the yaw acceleration error;

wherein the yaw rate error is calculated based on a yaw rate of the vehicle and a reference yaw rate, and the yaw acceleration error is based on a yaw acceleration of the vehicle and a reference yaw acceleration.