System for determining a change in vehicle tire pressure

• US 20050030170A1
• Filed: 05/07/2004
• Published: 02/10/2005
• Est. Priority Date: 05/09/2003
• Status: Active Grant

• Current Assignee: Harman Becker Automotive Systems GmbH (Samsung Electronics Co. Ltd.)
• Original Assignee: Harman Becker Automotive Systems GmbH (Samsung Electronics Co. Ltd.)
• Inventors: Rieck, Michael, Wietzke, Joachim
• Granted Patent: US 7,187,273 B2
• Time in Patent Office: Days
• US Class Current: 340/443
• CPC Class Codes: B60C 23/061 by monitoring wheel speed measuring distance traversed on the ground by vehicles G01C22/00

Abstract

A tire pressure diagnostic system for vehicles is provided for diagnosing tire pressure for at least one of the tires based on the traveled distance of the vehicle and input indicative of the tire movement. The diagnosis of the tire pressure may be based on comparing the traveled distance of the vehicle with a distance determined based on the output from a tire sensor and a predetermined tire radius of the tire under proper inflation. The diagnosis of the tire pressure may also be based on comparing an actual radius of the vehicle, determined by the traveled distance of the vehicle, with a predetermined radius of the vehicle under proper inflation. The diagnosis of the tire pressure may further be based on comparing the number of wheel rotations, determined from the tire movement input, with a number of rotations determined based on the traveled distance and the predetermined radius under proper inflation.

Claims

1. A tire pressure diagnostic method for at least one tire in a moving vehicle, comprising:

determining a first traveled distance d1 based on output from at least one tire movement sensor and a predetermined value of a radius of the tire;

receiving a plurality of navigational inputs;

determining a second traveled distance d2 from the plurality of navigational inputs; and

comparing d1 and d2 to diagnose the tire'"'"'s inflation.

2. The tire pressure diagnostic method of claim 1 where the output from the tire movement sensor comprises data indicative of the number N of tire rotations.

3. The tire pressure diagnostic method of claim 1 where the output from the tire movement sensor comprises data indicative of wheel pulses sensed from the tire.

4. The tire pressure diagnostic method of claim 1 where comparing d1 and d1 comprises;

calculating a difference between d1 and d2; and

determining whether the difference between d1 and d2 exceeds a predetermined value.

5. The tire pressure diagnostic method of claim 1 where determining the first distance traveled d1 is according to the following equation:

d1=2π

rN,

where r is the predetermined value of the radius of the tire and N a number of rotations of the tire.

6. The method of claim 1 where determining the second distance traveled d2 comprises:

detecting a GPS signal of the vehicle;

receiving additional input relating to the position or movement of the vehicle;

integrating the GPS signal with the additional input; and

obtaining an absolute position of the vehicle.

7. The method according to claim 1, comprising calculating the radius r_act of the tire from the second traveled distance d2 and the number of tire rotations N.

8. The method of claim 7 where the actual radius r_act is determined according to the following equation:

d2=2π

r_actN,

9. The method of claim 8 where r_act is determined at regular intervals from between about 1 to about 10 seconds.

10. The method of claim 7 where r_act is the predetermined value for the radius of the tire for the calculation of d1.

11. The method of claim 6 where the additional input is provided by a motion detector.

12. The method of claim 11 where the motion detector includes a compass, a gyroscopic device, a steering wheel limit switch, a right-left acceleration sensors, map matching or any combination thereof.

13. The method of claim 1 comprising obtaining output from tire movement sensors for each tire of the vehicle.

14. A tire pressure diagnostic method for at least one tire in a moving vehicle, comprising:

detecting a value indicative of a number of rotations N of the tire;

receiving a plurality of inputs relative to the position or movement of the vehicle;

integrating the plurality of inputs;

determining an actual traveled distance d2 from the plurality of inputs;

determining an actual radius r_act of the tire from the actual traveled distance d2 and the number of tire rotations N; and

comparing the actual radius r_act to a predetermined radius.

15. The method of claim 14 where the actual radius is determined from the following equation:

d2=2π

r_actN.

16. The method of claim 14 where receiving the plurality of inputs comprises detecting a GPS signal of a moving vehicle, and receiving additional input relating to the position or movement of the vehicle.

17. The method according to claim 14, where r_act is determined at regular intervals from between about 1 to about 10 seconds.

18. The method according to claim 15 where the additional input is provided by a motion detector.

19. The method according to claim 18 where the motion detector is a compass, a gyroscopic device, a steering wheel limit switch, right-left acceleration sensors, map matching or any combination thereof.

20. A tire pressure diagnostic method for at least one tire in a moving vehicle, comprising:

detecting a value indicative of a number N1 of rotations of the tire;

receiving a plurality of inputs relating to the position or movement of the vehicle;

integrating the plurality of inputs;

determining an actual traveled distance d2 from the plurality of inputs;

calculating a number of rotations N2 of the tire from the actual traveled distance d2; and

comparing the actual number of rotations N1 with the calculated number of rotations N2 to diagnose tire pressure.

21. The method of claim 20 where comparing N1 and N2 comprises determining whether the difference between N1 and N2 exceeds a predetermined value.

22. The method of claim 20 where calculating the number of rotations N2 is according to the equation:

d2=2π

rN2,

where r is a predetermined value of the radius of the tire and N2 is the number of rotations of the tire.

23. The method of claim 22 where receiving the plurality of inputs comprises detecting a GPS signal of a moving vehicle, and receiving additional input relating to the position or movement of the vehicle.

24. The method of claim 23 where the additional information is provided by a motion detector.

25. The method according to claim 24 where the motion detector is a compass, a gyroscopic device, a steering wheel limit switch, right-left acceleration sensors, map matching or any combination thereof.

26. A tire diagnostic system for determining a change of inflation pressure in a tire in a moving vehicle having at least one tire, comprising:

a sensor cooperating with each tire for sensing a value indicative of the number N of rotations of the tire;

a calculating unit for determining a first traveled distance d1 of the vehicle;

a global positioning receiver for receiving a global positioning signal;

at least one motion detector for receiving additional navigational input;

an integrating unit for integrating input received from the global positioning receiver and the at least one motion detector;

a calculating unit for determining an actual distance traveled; and

a warning device.

27. The system of claim 26 where the integrating unit comprises a Kalman filter.

28. The system of claim 26 where the motion detector comprises a compass, gyroscopic device, steering wheel limit switch, right-left acceleration sensors, map matching or any combination thereof.

29. The system of claim 26 where the additional input comprises vehicle position or movement.

30. The system of claim 26 where the additional information comprises tire position or movement.

31. A tire pressure diagnostic system for a vehicle comprising:

logic for receiving a plurality of navigational inputs;

logic for determining a traveled distance of the vehicle based on the plurality of navigational inputs;

logic for receiving input indicative of tire movement; and

logic for diagnosing tire pressure for at least one of the tires based on the traveled distance of the vehicle and the input indicative of the tire movement.

32. The tire pressure diagnostic system of claim 31, where the plurality of navigational inputs comprises a GPS input and a motion detector input.

33. The tire pressure diagnostic system of claim 31, where the traveled distance of the vehicle is a second traveled distance d2;

and

where the logic for diagnosing tire pressure for at least one of the tires comprises;

logic for determining a first traveled distance d1 based on output from at least one tire movement sensor and a predetermined value of a radius of the tire; and

logic for comparing d1 and d2 to diagnose the tire'"'"'s inflation.

34. The tire pressure diagnostic system of claim 31, where the traveled distance of the vehicle is an actual traveled distance d2;

where the input indicative of tire movement comprises a value indicative of a number of rotations N of the tire; and

where the logic for diagnosing tire pressure for at least one of the tires comprises;

determining an actual radius r_act of the tire from the actual traveled distance d2 and the number of tire rotations N; and

comparing the actual radius r_act to a predetermined radius.

35. The tire pressure diagnostic system of claim 31, where the traveled distance of the vehicle is an actual traveled distance d2;

where the input indicative of tire movement comprises a value indicative of a number of rotations N1 of the tire; and

where the logic for diagnosing tire pressure for at least one of the tires comprises;

calculating a number of rotations N2 of the tire from the actual traveled distance d2; and

comparing the actual number of rotations N1 with the calculated number of rotations N2 to diagnose tire pressure.

36. A tire pressure diagnostic system for a vehicle comprising:

logic for receiving input from a motion detector for positions along a traveled distance;

logic for matching the positions of the vehicle to segments in a map database based on the input from the motion detector;

logic for determining a value corresponding to the traveled distance of the vehicle based on the segments matched to the positions of the vehicle;

logic for receiving input indicative of tire movement of at least one tire; and

logic for diagnosing tire pressure for the at least one tire based on the traveled distance value and the input indicative of the tire movement.