GOOD CHECKING FOR VEHICLE WHEEL SPEED SENSORS

• US 20110066319A1
• Filed: 08/20/2010
• Published: 03/17/2011
• Est. Priority Date: 08/24/2009
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH, Robert Bosch LLC (Robert Bosch GmbH)
• Original Assignee: Robert Bosch GmbH
• Inventors: Bechtler, Henrik, Bhadange, Ravi, Patil, Nachiket, Stapel, Dietmar, Schwab, Michael, Mallmann, Stefan, Klier, Willy, Tokonaga, Takeshi, Eesmann, Joerg
• Granted Patent: US 8,467,929 B2
• Time in Patent Office: Days
• US Class Current: 701/34
• CPC Class Codes: B60T 2270/413 Plausibility monitoring, cross check, redundancy
• CPC Class Codes: B60T 2270/416 Wheel speed sensor failure
• CPC Class Codes: B60T 8/885 using electrical circuitry

Abstract

A controller for determining whether a previously-detected vehicle wheel speed sensor malfunction still exists. The controller includes an electronic, non-volatile memory, and an electronic processing unit connected to the electronic, non-volatile memory. The electronic processing module includes a malfunction monitoring module, a failure handling module, and a signal checking module. The malfunction monitoring module monitors the operation of at least one wheel speed sensor and generates a fault signal when the at least one sensor malfunctions. The failure handling module causes drive cycle information and the fault information to be stored in the electronic, non-volatile memory. The signal checking module performs a signal check on information from the at least one wheel speed sensor. A tell-tale indicator is deactivated and/or a vehicle control system resumes normal operation if the wheel speed sensor passes the signal check.

Claims

1. A controller for determining whether a previously-detected vehicle wheel speed sensor malfunction still exists, the controller comprising:

an electronic, non-volatile memory; and

an electronic processing unit connected to the electronic, non-volatile memory, the electronic processing module including,

a malfunction monitoring module that monitors the operation of at least one vehicle sensor and generates a fault signal when the at least one vehicle sensor malfunctions, the fault signal containing fault information and causing at least one of a tell-tale indicator to be activated and a vehicle control system to modify its operation from a first operating state to a second operating state,

a failure handling module that causes drive cycle information and the fault information to be stored in the electronic, non-volatile memory, and

a signal checking module that performs a signal check on information from the at least one vehicle sensor, the signal check including

retrieving drive cycle information for a wheel speed sensor from the electronic, non-volatile memory,

comparing an output of the wheel speed sensor to a pre-determined range, the wheel speed sensor passing the signal check if the output of the wheel speed sensor is within the pre-determined range for a pre-determined amount of time,

generating a reset signal, if the wheel speed sensor passes the signal check, the reset signal causing at least one of the tell-tale indicator to be deactivated and the vehicle control system to resume operation in the first operating state.

2. The controller of claim 1, wherein the controller is mounted in a vehicle.

3. The controller of claim 2, wherein the previously-detected vehicle wheel speed sensor malfunction is one of an implausible sensitivity of the wheel speed sensor, an interference of the wheel speed sensor, and a stuck signal received from the wheel speed sensor.

4. The controller of claim 3, wherein the wheel speed sensor is one of a plurality of wheel speed sensors and the controller compares a speed detected by each of the plurality of wheel speed sensors, the controller determining that a wheel speed sensor fault still exists if the difference between the fastest speed detected by one of the plurality of wheel speed sensors and the slowest speed detected by one of the plurality of wheel speed sensors exceeds a threshold.

5. The controller of claim 4, wherein the controller checks if the difference between the fastest speed detected by one of the plurality of wheel speed sensors and the slowest speed detected by one of the plurality of wheel speed sensors is less than the threshold for a pre-determined period of time.

6. The controller of claim 5, wherein the controller checks if the speed detected by each of the plurality of wheel speed sensors exceeds a second threshold.

7. The controller of claim 6, wherein the plurality of wheel speed sensors pass the signal check if the controller has not detected interference at the plurality of wheel speed sensors, the speed detected by each of the plurality of wheel speed sensors exceeds the second threshold, and the difference between the fastest speed detected by one of the plurality of wheel speed sensors and the slowest speed detected by one of the plurality of wheel speed sensors is less than the threshold for the pre-determined period of time.

8. The controller of claim 2, wherein the previously-detected vehicle wheel speed sensor malfunction is a wheel speed sensor swapped sensor fault.

9. The controller of claim 8, wherein the signal check is executed only when the vehicle is turning.

10. The controller of claim 9, wherein the controller determines that the vehicle is turning if an absolute value of a yaw rate of the vehicle is greater than a threshold.

11. The controller of claim 9, wherein the controller calculates a wheel speed sensor yaw rate and a lateral acceleration yaw rate.

12. The controller of claim 11, wherein the wheel speed sensor passes the signal check if the difference between the wheel speed sensor yaw rate and the lateral acceleration yaw rate is less than a second threshold for a pre-determined period of time.

13. The controller of claim 2, wherein the previously-detected vehicle wheel speed sensor malfunction is a wheel speed sensor missing teeth fault.

14. The controller of claim 13, wherein the controller monitors a signal from the wheel speed sensor and is configured to detect one or more missing teeth in the wheel speed sensor.

15. The controller of claim 14, wheel speed sensor passes the signal check if the controller does not detect the one or more missing teeth for a pre-determined period of time.