Tire pressure monitoring systems and methods

• US 8,612,088 B2
• Filed: 04/14/2011
• Issued: 12/17/2013
• Est. Priority Date: 04/14/2011
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH, Robert Bosch LLC (Robert Bosch GmbH)
• Original Assignee: Robert Bosch GmbH
• Inventors: Milburn, Kenneth
• Primary Examiner(s): Trammell, James
• Assistant Examiner(s): ALSOMIRI, MAJDI A
• Application Number:
  US13/086,714
• Publication Number:
  US 20120265395A1
• Time in Patent Office: 978 Days
• Field of Search: 701/29.2, 701/34.4, 701/70, 701/74, 701/93, 701/96, 303/113.1, 303/121, 303/159, 303/168, 303/169, 303/177, 303/179, 303/182, 303/186, 188/180, 188/181.A, 188/181.C, 188/181.R, 188/197, 180/170, 180/178, 180/179, 180/197, 340/425.5, 340438-444, 123350-352, 324/161, 361/242
• US Class Current: 701/29.2
• CPC Class Codes: B60C 23/061 by monitoring wheel speed measuring distance traversed on the ground by vehicles G01C22/00

Abstract

A system for determining if a tire of a vehicle is improperly inflated. The system includes a radar, a wheel speed sensor, and a controller. The radar is configured to emit a signal to detect a reflection of the signal off of an object positioned perpendicular to the vehicle, and to output an indication of a speed of the vehicle. The wheel speed sensor is configured to sense a speed of a wheel of the vehicle. The controller is configured to receive the indication of the speed of the vehicle from the radar, to calculate a speed of the vehicle based on the sensed speed of the wheel, and to determine a tire of the wheel is improperly inflated when the speed of the vehicle calculated using the wheel speed sensor varies by more than a predetermined amount from the speed of the vehicle determined using the radar signal.

Claims

1. A system for determining if a tire of a vehicle is improperly inflated, the system comprising:

a radar configured to emit a signal generally parallel to a surface the vehicle is traveling on, to detect a reflection of the signal off of an object positioned perpendicular to the vehicle, and to output an indication of a speed of the vehicle;

a wheel speed sensor configured to sense a speed of a wheel of the vehicle; and

a controller coupled to the radar and the wheel speed sensor, the controller configured to receive the indication of the speed of the vehicle from the radar, to calculate a speed of the vehicle based on the sensed speed of the wheel, and to determine that a tire of the wheel is improperly inflated when the speed of the vehicle calculated using the wheel speed sensor varies by more than a predetermined amount from the speed of the vehicle determined by the radar, the controller slowing the vehicle when the tire of the wheel is determined to be improperly inflated.

2. The system of claim 1, further comprising a second wheel speed sensor configured to sense a speed of a second wheel of the vehicle, the controller configured to calculate a speed of the vehicle based on the sensed speed of the second wheel, and to determine a tire of the second wheel is improperly inflated when the speed of the vehicle calculated using the second wheel speed sensor varies by more than a predetermined amount from the speed of the vehicle determined by the radar.

3. The system of claim 1, wherein the controller executes an error routine when the tire is improperly inflated.

4. The system of claim 3, wherein the error routine includes providing an indication to a user that the tire is improperly inflated.

5. The system of claim 3, wherein the error routine causes the vehicle to perform a safety function.

6. The system of claim 1, wherein the controller is configured to perform a calibration function.

7. The system of claim 6, wherein the calibration function includes operating the vehicle and calibrating the speed of the vehicle calculated using the wheel speed sensor to the speed of the vehicle determined by the radar.

8. The system of claim 6, wherein the calibration function is performed by receiving an indication of size of the wheel and tire.

9. The system of claim 1, further comprising a second wheel speed sensor configured to sense a speed of a second wheel of the vehicle, a third wheel speed sensor configured to sense a speed of a third wheel of the vehicle, a fourth wheel speed sensor configured to sense a speed of a fourth wheel of the vehicle, the controller able to determine that the tire, a second tire on the second wheel, a third tire on the third wheel, and a fourth tire on the fourth wheel have all become under-inflated at about the same time.

10. The system of claim 1, wherein the radar emits the signal in a direction forward of the vehicle.

11. The system of claim 1, wherein the radar emits the signal in a direction rearward of the vehicle.

12. A method of detecting an improperly inflated tire on a vehicle, the method comprising:

a controller entering a tire calibration mode based on an input from a driver;

a radar emitting a signal in a forward direction generally parallel to a surface the vehicle is traveling on;

the radar detecting a reflection of the signal off of an object positioned perpendicular to the vehicle;

determining a speed of the vehicle based on the signal;

detecting a speed of a wheel of the vehicle;

the controller determining a circumference of the tire based on the determined speed of the vehicle and the detected speed of the wheel;

the controller determining a calculated speed of the vehicle based on the detected speed of the wheel after exiting the calibration mode; and

the controller determining a tire of the wheel is improperly inflated when the calculated speed of the vehicle varies by more than a predetermined amount from the speed of the vehicle determined based on the signal.

13. The method of claim 12, further comprising detecting a speed of a second wheel of the vehicle, determining a second calculated speed of the vehicle based on the detected speed of the second wheel, and determining a tire of the second wheel is improperly inflated when the second calculated speed of the vehicle varies by more than a predetermined amount from the speed of the vehicle determined based on the signal.

14. The method of claim 12, further comprising executing an error routine when the tire is improperly inflated.

15. The method of claim 12, further comprising providing an indication to a user that the tire is improperly inflated.

16. The method of claim 12, further comprising performing a safety function when the tire is improperly inflated.

17. The method of claim 12, further comprising calibrating the calculated speed to the wheel and tire.

18. The method of claim 17, further operating the vehicle to calibrate the calculated speed of the vehicle to the speed of the vehicle determined by the emitted signal.

19. The method of claim 12, further comprising receiving an indication of size of the wheel and tire to calibrate the calculated speed.