Vehicle speed estimation for 4WD vehicles under wheel-spinning situations

• US 8,423,258 B2
• Filed: 03/29/2012
• Issued: 04/16/2013
• Est. Priority Date: 03/29/2011
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH, Robert Bosch LLC (Robert Bosch GmbH)
• Original Assignee: Robert Bosch GmbH
• Inventors: Robinson, Rick, Li, Qingyuan, Wu, Hsien-cheng
• Primary Examiner(s): MARC-COLEMAN, MARTHE Y
• Application Number:
  US13/433,539
• Publication Number:
  US 20120253627A1
• Time in Patent Office: 383 Days
• Field of Search: 701/88, 701/82, 701/80, 701/84, 701/89, 701/90, 701/70, 701/71, 701/74, 702/142, 702/141, 702/145, 702/146, 702/148, 180/197, 180/248, 180/233, 303/150, 303/151, 303/153, 303/138, 303/139
• US Class Current: 701/88
• CPC Class Codes: B60T 2250/042 Reference speed calculation in ASR or under wheel spinning condition
• CPC Class Codes: B60T 2270/202 for all-wheel drive vehicles
• CPC Class Codes: B60T 8/175 Brake regulation specially adapted to prevent excessive wheel spin during vehicle acceleration, e.g. for traction control safety devices for propulsion unit control responsive to, or preventing, skidding of wheels B60K28/16
• CPC Class Codes: B60T 8/1769 specially adapted for vehicles having more than one driven axle, e.g. four-wheel drive vehicles

Abstract

Systems and methods for detecting wheel-spinning situations of a vehicle. One system includes a controller. The controller is configured to determine a speed of each wheel of the vehicle based on information received from a plurality of wheel speed sensors, to identify a second slowest wheel of the vehicle based on the speed of each wheel, to calculate a vehicle acceleration torque based on an acceleration of the second slowest wheel of the vehicle and a mass of the vehicle, to calculate a torque ratio based on the vehicle acceleration torque and a wheel drive torque, and to activate a traction control system when the torque ratio is greater than a predetermined threshold.

Claims

1. A system for detecting wheel-spinning situations of a vehicle, the system comprising:

a controller configured to determine a speed of each wheel of the vehicle based on information received from a plurality of wheel speed sensors, to identify a second slowest wheel of the vehicle based on the speed of each wheel, to calculate a vehicle acceleration torque based on an acceleration of the second slowest wheel of the vehicle and a mass of the vehicle, to calculate a torque ratio based on the vehicle acceleration torque and a wheel drive torque, and to activate a traction control system when the torque ratio is greater than a predetermined threshold.

2. The system of claim 1, wherein the predetermined threshold is approximately 1.0.

3. The system of claim 1, wherein the predetermined threshold is approximately 3.0.

4. The system of claim 1, further comprising the plurality of wheel speed sensors, wherein each of the plurality of wheel speed sensors is associated with a wheel of the vehicle.

5. The system of claim 1, wherein the controller is further configured to calculate the acceleration of the second slowest wheel.

6. The system of claim 1, wherein the controller is further configured to calculate a differential of the torque ratio, to calculate a vehicle acceleration, to calculate a vehicle speed, and to determine if the vehicle is traveling on a gravel road.

7. The system of claim 6, wherein the controller is configured to activate the traction control system when the differential of the torque ratio is greater than approximately zero, the vehicle acceleration is greater than a second predetermined threshold, the vehicle speed is less than a third predetermined threshold, the wheel drive torque is greater than a fourth predetermined threshold, and the vehicle is not traveling on a gravel road.

8. The system of claim 1, wherein the controller is further configured to determine an adjustment factor for a reference speed associated with the traction control system.

9. The system of claim 8, wherein the controller is configured to activate the traction control system when a vehicle speed is greater than a sum of the adjustment factor and the reference speed.

10. The system of claim 9, wherein the controller is configured to set the reference speed based on a vehicle model reference speed.

11. A computer-implemented method for detecting wheel-spinning situations of a vehicle, the method comprising:

receiving, at a processor, information from a plurality of wheel speed sensors;

determining, at the processor, a speed of each wheel of the vehicle based on the information from the plurality of wheel speed sensors;

identifying, at the processor, a second slowest wheel of the vehicle based on the speed of each wheel,

calculating, at the processor, a vehicle acceleration torque based on an acceleration of the second slowest wheel of the vehicle and a mass of the vehicle,

calculating, at the processor, a torque ratio based on the vehicle acceleration torque and a wheel drive torque, and

activating a traction control system when the torque ratio is greater than a predetermined threshold.

12. The method of claim 11, wherein activating a traction control system includes activating the traction control system when the torque ratio is greater than approximately 3.0.

13. The method of claim 11, further comprising calculating an acceleration of the second acceleration of the second slowest wheel.

14. The method of claim 11, further comprising calculating a differential of the torque ratio, calculating a vehicle acceleration, calculating a vehicle speed, and determining if the vehicle is traveling on a gravel road.

15. The method of claim 14, wherein activating the traction control system includes activating the traction control system when the differential of the torque ratio is greater than approximately zero, the vehicle acceleration is greater than a second predetermined threshold, the vehicle speed is less than a third predetermined threshold, the wheel drive torque is greater than a fourth predetermined threshold, and the vehicle is not traveling on a gravel road.