Method and device for detecting absolute friction wear on at least one tire of a vehicle

Abstract

The invention relates to a method and an apparatus for determination of the wear on at least one tire of a vehicle, wherein the vehicle has a tire pressure monitoring system, consisting of a pressure sensor, a transmission unit and a reception unit, as well as a computer unit and a data memory having a database. Proceeding from a circumference of the tire (5) defined by the tire manufacturer and thereby a mantle surface having a length L=2πr, wherein r is the radius of the tire (5), the radius decreases during corresponding wear, and thereby the length of the mantle surface also decreases. The length of the flat pattern of a new tire is therefore greater, in terms of length, than the length of the flat pattern of a used tire. This is determined by a sensor (4), the value of which is transmitted by a first module (2) to a second module (3), which is fixed in place. There, the value L is calculated and compared with data in a database and evaluated.

Claims

1. A method for determination of the absolute friction wear on at least one tire of a vehicle, wherein the vehicle has a tire pressure monitoring system, comprising a pressure sensor, a transmission unit and a reception unit, as well as a computer unit and a data memory having a database, the method comprising the following method steps: a. determining by a sensor and providing as a data segment a complete revolution of the tire as well as a time required for the complete revolution of the tire; b. transmitting the data segment by way of the transmission unit and the reception unit to the computer unit; c. calculating a calculated value of an actual length L of a mantle surface of the tire with a radius r and storing in memory the calculated value as a stored length; d. comparing the actual length L with the stored length of the data segment in the data memory; e. comparing the calculated value of the actual length L stored in the data memory, as to whether the actual length L is shorter, the same, or longer; i. if the actual length L is longer, then repeating the determination according to step a; ii. if the actual length L is the same, then repeating the determination according to step a; iii. if the actual length L is shorter, then storing the calculated value of the actual length in the data memory and comparing the calculated value with a minimum value that is also stored in the data memory; I. if the actual length L is the same as or greater than the minimum value, then repeating the determination according to step a; II. if the actual length L is smaller than the minimum value, then issuing a warning message that a tire profile minimum dimension is no longer met.

2. The method according to claim 1, wherein the sensor for determination of the revolution is a gyroscope sensor.

3. The method according to claim 1, wherein the pressure sensor of the tire pressure monitoring system and the sensor for determination of the revolution of the tire are separate components.

4. The method according to claim 1, wherein the time required for the complete revolution of the tire is calculated based on a distance traveled and a related speed.

Description

DRAWINGS

(1) These show:

(2) FIG. 1 a fundamental diagram of the arrangement of the apparatus for determination of the tire wear;

(3) FIG. 2 a schematic for representation of the method for determination of the tire wear of a vehicle.

DESCRIPTION OF AN EXEMPLARY EMBODIMENT

(4) In FIGS. 1 and 2, the principle of the method for determination of tire wear of a vehicle F having at least one tire 5 is shown. The tire 5 rotates either in the direction of rotation 6 or counter to it. The apparatus 1 for carrying out the method comprises a first module 2 as well as a second module 3. The first module 2 is provided for recording the data, wherein the second module 3 is provided for evaluation and representation of the results of the data.

(5) The first module 2 comprises the sensor 4 for determination of the revolutions of a tire 5. This sensor 4 is either configured as a gyroscope sensor or it acts—as shown in FIG. 1—together with a further sensor, which is fixed in place on the body of the vehicle F. Furthermore, a tire pressure monitoring system 7 for determination of the pressure within the tire 5 is provided, consisting of a pressure sensor 8 and a transmission unit 9 for generation of a radio signal 10.

(6) The second module 3 is coupled with the first module 2 by way of the wireless segment or the radio signal 10 that proceeds from the transmission unit 9. This module 3 has a reception unit 11. A computer unit 12, which in turn interacts with a data memory 13, is coupled with the reception unit 11. The result of the computer unit 12 is shown on a display unit 14, preferably in the region of the vehicle driver.

(7) The sensor 4 for determination of the revolution of the tire 5 of the vehicle F transmits a data segment D, consisting of the number of revolutions and the time, after a revolution. The data segment D is transmitted to the reception unit 11, by way of the wireless segment 10, by the transmission unit 9, and is calculated there in the coupled computer unit 12. Proceeding from a tire circumference defined by the tire manufacturer, and thereby a mantle surface having a length L=2πr, wherein r is the radius of the tire 5, the radius r decreases during corresponding use. For this reason, first the length L of the mantle surface of the new tire 5 is stored in the data memory 13. Calculation of the data segment D, which is made available in measurement segments, now takes place in the computer unit 12, to obtain a new value L, which corresponds to the actual length of the mantle surface of the tire 5. This new value L is compared with the value L stored in the database.

(8) If the time for a revolution per tire is now shorter, and thereby the length of the mantle surface L is shorter than what was already stored in memory, then the new value is stored in memory, in such a manner that it is available for a new comparison.

(9) If the actual length L of the mantle surface of the tire 5 has dropped below a previously defined value, which is also stored in the data memory 13, then it is displayed in the region of the vehicle driver that the profile depth at least required for the defined tire 5 is no longer met. This has the consequence that this tire should be replaced.

(10) By means of the method, the profile depth can be measured as a function of the actual running output, by means of little technical effort, and a warning message can be issued if the value is no longer met.

REFERENCE SYMBOL LIST

(11) Method and apparatus for determination of the wear on at least one tire of a vehicle

(12) 1 apparatus

(13) 2 first module

(14) 3 second module

(15) 4 sensor

(16) 5 tire

(17) 6 direction of rotation

(18) 7 tire pressure monitoring system

(19) 8 pressure sensor

(20) 9 transmission unit

(21) 10 radio signal

(22) 11 reception unit

(23) 12 computer unit

(24) 13 data memory

(25) 14 display unit

(26) D data segment

(27) F vehicle

(28) L length