SELF-ADAPTIVE METHOD FOR ASSISTING TIRE INFLATION

• US 20160001614A1
• Filed: 02/25/2014
• Published: 01/07/2016
• Est. Priority Date: 02/28/2013
• Status: Active Grant

• Current Assignee: Continental Automotive France (Continental AG), Continental Automotive GmbH (Continental AG)
• Original Assignee: Continental Automotive France (Continental AG), Continental Automotive GmbH (Continental AG)
• Inventors: KESSLER, Sebastien, LEE, Jerome, DE VILLARDI, Sebastien
• Granted Patent: US 9,783,009 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: B60C 23/0437 Means for detecting electromagnetic field changes not being part of the signal transmission per se, e.g. strength, direction, propagation or masking
• CPC Class Codes: B60C 23/0455 Transmission control of wireless signals
• CPC Class Codes: B60C 23/0459 self triggered by motion sensor
• CPC Class Codes: B60C 23/0462 Structure of transmission protocol
• CPC Class Codes: B60C 23/0484 Detecting an ongoing tyre inflation

Abstract

A self-adaptive method for assisting tire inflation enables control of tire inflation. If the vehicle stops, the central unit of a TPMS (Tire Pressure Monitoring System) can change in a self-adaptive manner from the reception configuration of the “moving” mode at a high bit rate to a “stationary” mode at a low bit rate. At the same time, if there is a variation in the pressure of a tire, the corresponding wheel unit is set for transmission in “stationary” mode at a low bit rate. The power Pa received at the central unit varies according to a curve (20) which shows, in the illustrated example, two positions of poor reception. By replacing high bit rate transmission with low bit rate transmission, the signal/noise ratio is improved and there is a gain in reception sensitivity of about 5 dB, and the risks of disturbance of the received power are virtually eliminated.

Claims

1. A self-adaptive method for assisting the inflation of the tires of a vehicle, comprising continuously measuring at least the pressure of each tire (la to 1d) by means of a wheel unit (3a to 3d, transmitting messages, at a high bit rate, on the state of the tires (1a to 1d) via a wireless link (5a to 5d) between each wheel unit (3a to 3d) and a central unit (2), the central unit analyzing these messages continuously, and then transmitting information relating to the state of the tires (1a to 1d) to an information module (9), and continuously measuring (30, 44;

50) the moving/stationary state of the vehicle in order to inform the central unit (2) and the wheel unit (1a to 1d) of this state, wherein the messages are transmitted (38), when the vehicle is stationary, at a sufficiently low bit rate to enable the reception sensitivity of the central unit (2) to avoid virtually any disturbance in reception.

2. The self-adaptive method as claimed in claim 1, wherein, if a stationary state of the vehicle is detected by continuous measurement (30, 44;

50) for more than a specified duration, the central unit (2) is set to two possible configurations of the reception mode, namely a high bit rate “

moving”

mode (57) and a low bit rate “

stationary”

mode (53, 59), and if, additionally, a pressure variation (32, 46) of a tire (1a to 1d) is above a specified threshold, the corresponding wheel unit (3a to 3d) is set for transmission in “

stationary”

mode at a low bit rate (37), and, additionally, in “

moving”

mode at a high bit rate.

3. The self-adaptive method as claimed in claim 1, wherein the corresponding wheel unit (3a to 3d) is also set to “

moving”

mode at a high bit rate.

4. The self-adaptive method as claimed in claim 1, wherein the following steps are executed at each wheel unit (3a to 3d):

a moving or stationary state of the vehicle is detected by continuous measurement (30, 44), and if a moving state of the vehicle is detected, the wheel unit sets itself to “

moving”

mode (41) and the messages are transmitted (42) at a high bit rate;

if the continuous measurement (30) detects a stationary state of the vehicle, the wheel unit (1a to 1d) determines whether the pressure variation (test 32) of the tire (1a to 1d) is above a threshold value;

if the pressure variation (test 32) is below said threshold, the messages are transmitted at a high bit rate (42);

if the pressure variation (test 32) is above said threshold, the wheel unit (3a to 3d) sets itself to “

stationary”

mode (37), to transmit messages at a low bit rate in this mode (38) while the vehicle remains stationary for longer than a first specified duration (test 36).

if the stop is prolonged beyond said first specified duration (test 36), the method returns to an initial state (29) at the wheel unit.

5. The self-adaptive method as claimed in claim 4, wherein the following steps are executed for the wheel unit (1a to 1d), when it is in “

stationary”

mode (37);

the wheel unit continues to transmit at a low bit rate (38) while the vehicle remains stationary (test 44) and while the pressure variation, measured by a pressure test (46), is above a pressure threshold;

if the pressure variation measured by this pressure test (46) is below this threshold, the method remains in “

stationary”

mode (37) until the expiry of said first duration (test 36);

if a moving state of the vehicle is detected (test 44), the wheel unit sets itself to “

moving”

mode (41), and the messages are transmitted at a high bit rate.

6. The self-adaptive method as claimed in claim 4, wherein the wheel unit (1a to 1d), in “

stationary”

mode, also transmits messages at a high bit rate.

7. The self-adaptive method as claimed in claim 4, wherein the wheel unit (1a to 1d), in “

moving”

mode, does not transmit any message.

8. The self-adaptive method as claimed in claim 5, wherein the following steps are executed at the central unit (2):

a moving or stationary state of the vehicle is detected by continuous measurement (50), and if a moving state of the vehicle is detected, the messages are received at a high bit rate (57);

if the continuous measurement (50) detects a stationary state of the vehicle for longer than a second predetermined duration (51), the central unit (2) is set to “

stationary”

reception mode at a low bit rate;

if said second specified duration (51) has not expired, but a pressure variation of the tire (1a to 1d) is above a specified threshold (52), the central unit (2) is set to “

stationary”

reception mode at a low bit rate;

if the pressure variation remains below said predetermined value (52), the central unit (2) remains set to “

moving”

reception mode at a high bit rate.

9. The self-adaptive method as claimed in claim 8, wherein the central unit (2), in “

stationary”

mode (53, 59), also receives messages (54, 60) at a high bit rate.

10. The self-adaptive method as claimed in claim 8, wherein the central unit (2), in “

moving”

mode (57), also receives messages at a low bit rate.

11. The self-adaptive method as claimed in claim 8, wherein the first (36) and second (51) durations may be different for the central unit (2) and for each wheel unit (3a to 3d).

12. The self-adaptive method as claimed in claim 1, wherein the low bit rate is chosen according to a compromise between the desired sensitivity and the duration of the messages to be transmitted.

13. The self-adaptive method as claimed in claim 1, wherein the messages transmitted at a low bit rate (35, 38) are limited to information concerning the identification of a wheel unit (3a to 3d) and the measurement of the pressure of the corresponding tire (1a to 1d).

14. The self-adaptive method as claimed in claim 2, wherein the corresponding wheel unit (3a to 3d) is also set to “

moving”

mode at a high bit rate.

15. The self-adaptive method as claimed in claim 6, wherein the wheel unit (1a to 1d), in “

stationary”

mode, also transmits messages at a high bit rate.

16. The self-adaptive method as claimed in claim 5, wherein the wheel unit (1a to 1d), in “

moving”

mode, does not transmit any message.

17. The self-adaptive method as claimed in claim 1, wherein the following steps are executed at the central unit (2):

a moving or stationary state of the vehicle is detected by continuous measurement (50), and if a moving state of the vehicle is detected, the messages are received at a high bit rate (57);

if the continuous measurement (50) detects a stationary state of the vehicle for longer than a second predetermined duration (51), the central unit (2) is set to “

stationary”

reception mode at a low bit rate;

if said second specified duration (51) has not expired, but a pressure variation of the tire (1a to 1d) is above a specified threshold (52), the central unit (2) is set to “

stationary”

reception mode at a low bit rate;

if the pressure variation remains below said predetermined value (52), the central unit (2) remains set to “

moving”

reception mode at a high bit rate.

18. The self-adaptive method as claimed in claim 17, wherein the central unit (2), in “

stationary”

mode (53, 59), also receives messages (54, 60) at a high bit rate.

19. The self-adaptive method as claimed in claim 17, wherein the central unit (2), in “

moving”

mode (57), also receives messages at a low bit rate.

20. The self-adaptive method as claimed in claim 18, wherein the central unit (2), in “

moving”

mode (57), also receives messages at a low bit rate.