Method and equipment for monitoring tyre wear, and vehicle on-board wear-monitoring system

Patent metadata

Field	Value
Publication number	US-10286735-B2
Application number	US-201515127178-A
Country	US
Kind code	B2
Filing date	Apr 15, 2015
Priority date	Apr 18, 2014
Publication date	May 14, 2019
Grant date	May 14, 2019

Abstract

A reliable and precise measurement of tire tread wear, by using wide-band (UWB) pulses and analyzing the signature obtained by reflection of these pulses from the tread, in order to deduce its state of wear therefrom. The tire wear monitoring device ( 100 ) includes a control unit ( 110 ) for signal control and data processing, this control unit ( 110 ) being coupled to a generator of ultra wide band or UWB signals ( 120 ), which is itself coupled to an antenna for incident UWB pulse transmission ( 140 ), and an antenna for receiving the UWB pulses ( 150 ) reflected from at least one interface of the tire tread, the reception antenna ( 150 ) being coupled to a pulse signal receiver ( 180 ) which is itself coupled to the control unit ( 110 ).

First claim

The invention claimed is:

1. A method for monitoring the wear of a tread ( 10 ) of a vehicle tire ( 1 ), where the tread ( 10 ) has an inner layer ( 11 ) with an inner interface ( 11 a ), an intermediate layer incorporating at least one metal reinforcement interface ( 12 , 13 ), and an outer layer ( 14 ) with an inner interface, which includes a groove bottom ( 14 a ), and a grooved outer interface ( 14 b ), the vehicle tire being capable of traveling while forming a contact patch ( 1 E) of the grooved outer face ( 14 b ) on a road ( 2 ), the method comprising:
transmitting, from a source arranged near the vehicle tire ( 1 ), at least one wide band (UWB) incident pulse signal (i 1 ) toward the outer layer ( 14 ) containing the contact patch ( 1 E) of the vehicle tire ( 1 ) on the road ( 2 );
receiving ( 31 , 150 , 310 ) pulses (iR 1 to iR 6 ) reflected by the interfaces ( 11 a , 12 , 13 , 14 a , 14 b ) of the tread ( 10 ) and by the road ( 2 );
determining a wear signature of said tread by measuring relative delays exhibited by reflected pulses relative to an instant of transmission (t 0 ) of the incident pulse (i 1 ), said determined wear signature being defined based on the relative delays exhibited by at least one of the pulses (iR 5 , iR 6 ) reflected by the road ( 2 ) and the grooved outer interface ( 14 b ), and the relative delays of the pulses (iR 4 ; iR 2 , iR 3 ) reflected by at least one of the inner groove bottom interface ( 14 a ) and said at least one metal reinforcement interface ( 12 , 13 ); and
triggering an alarm upon detection that the wear signature corresponds to a critical state of the tread ( 10 ) defined with respect to the predetermined risk of losses of adhesion of the contact patch ( 1 E) of the vehicle tire ( 1 ) on the road ( 2 ).

2. The wear monitoring method as claimed in claim 1 ,
wherein the wear signature is regularly sampled from a plurality of successive incident pulses to produce a plurality of successively sampled wear signatures, and
wherein the successively sampled wear signatures are compared in order to determine a periodicity of transmission of the incident pulse signals based on a corresponding mileage.

3. The wear monitoring method as claimed in claim 2 , further comprising at least one of:
comparing a relative delay exhibited by a pulse reflected by the grooved outer interface ( 14 b ) in an area outside the contact patch ( 1 E) with the relative delays of the wear signature; and
analyzing tire load and pressure data supplied by a dedicated detection system, deducing corrections of the relative delays of the reflected pulses, and modifying the wear signature accordingly.

4. The wear monitoring method as claimed in claim 1 , further comprising at least one of:
comparing a relative delay exhibited by a pulse reflected by the grooved outer interface ( 14 b ) in an area outside the contact patch ( 1 E) with the relative delays of the wear signature; and
analyzing tire load and pressure data supplied by a dedicated detection system, deducing corrections of the relative delays of the reflected pulses, and modifying the wear signature accordingly.

5. A tire wear monitoring device ( 100 , 100 ′) for monitoring the wear of a tread ( 10 ) of a vehicle tire ( 1 ), where the tread has an inner layer ( 11 ) with an inner interface ( 11 a ), an intermediate layer incorporating at least one metal reinforcement interface ( 12 , 13 ), and an outer layer ( 14 ) with an inner interface, which includes a groove bottom ( 14 a ), and a grooved outer interface ( 14 b ), the vehicle tire being capable of traveling while forming a contact patch ( 1 E) of the grooved outer face ( 14 b ) on a road ( 2 ), comprising:
a control unit ( 110 ) for signal control and data processing;
a generator ( 120 ) of ultra wide band (UWB) signals (Se), said generator ( 120 ) coupled to said control unit ( 110 );
one or more antennas configured to transmit incident UWB pulses and receive reflected UWB pulses ( 150 ) reflected from at least one interface of the tire tread; and
a pulse signal receiver ( 180 ), said pulse signal receiver ( 180 ) coupled to said control unit ( 110 ),
wherein said control unit is configured to
transmit, from the one or more antennas arranged near the vehicle tire ( 1 ), at least one wide band (UWB) incident pulse signal (i 1 ) toward the outer layer ( 14 ) containing the contact patch ( 1 E) of the vehicle tire ( 1 ) on the road ( 2 ),
receive, via the one or more antennas, pulses (iR 1 to iR 6 ) reflected by the interfaces ( 11 a , 12 , 13 , 14 a , 14 b ) of the tread ( 10 ) and by the road ( 2 ),
determine a wear signature of said tread by measuring relative delays exhibited by reflected pulses relative to an instant of transmission (t 0 ) of the incident pulse (i 1 ), said determined wear signature being defined based on the relative delays exhibited by at least one of the pulses (iR 5 , iR 6 ) reflected by the road ( 2 ) and the grooved outer interface ( 14 b ), and the relative delays of the pulses (iR 4 ; iR 2 , iR 3 ) reflected by at least one of the inner groove bottom interface ( 14 a ) and said at least one metal reinforcement interface ( 12 , 13 ), and
trigger an alarm upon detection that the wear signature corresponds to a critical state of the tread ( 10 ) defined with respect to the predetermined risk of losses of adhesion of the contact patch ( 1 E) of the vehicle tire ( 1 ) on the road ( 2 ).

6. The wear monitoring device as claimed in claim 5 , wherein the one or more antennas comprise two separate antennas, a first of said two antennas configured for transmission ( 140 ) and a second of said two antennas configured for reception ( 150 ).

7. The wear monitoring device as claimed in claim 6 , wherein the one or more antennas have unidirectional transmission means and directional reception means.

8. The wear monitoring device as claimed in claim 6 ,
wherein a pulse amplifier ( 130 ) is arranged between an output of the pulse signal generator ( 120 ) and the one or more antennas, and
wherein a filter assembly ( 160 ), coupled to a low-noise amplifier ( 170 ), is fitted between the one or more antennas and an input of the pulse signal receiver ( 180 ).

9. The wear monitoring device as claimed in claim 6 , wherein:
the UWB pulse signal generator ( 120 ) comprises a digital-analog converter (DAC) ( 121 ) that converts an initial signal (s 1 ) launched by the control unit ( 110 ) and modulated via a baseband transmission clock ( 122 ), said converter ( 121 ) being coupled to a mixer ( 124 ) via a filter ( 123 ) so that a modulated and filtered signal (Sa) carries a brief pulse of a radio frequency (RF) signal supplied by an RF oscillator ( 125 ), also under control of the control unit ( 110 ), a duration of the initial signal being adjusted so that a carried signal corresponds to a frequency spectrum with a width of at least 25% of the central frequency value of said frequency spectrum, before being amplified ( 130 ) and then transmitted by the transmission antenna ( 140 ) in the form of a UWB pulse signal; and
the UWB pulse signal receiver ( 180 ) comprises a mixer ( 181 ) coupled to an analog-digital converter/sampler (ADCS) ( 182 ), said ADCS being coupled to the control unit ( 110 ) and configured to perform sampling upon a reflected UWB pulse signal received from the one or more antennas and mixed, after filtering ( 160 ) and amplification ( 170 ), with an RF signal supplied by a local radio frequency oscillator ( 184 ) which is also under control of the control unit ( 110 ), the sampling being timed by a baseband clock ( 183 ) under control of the control unit ( 110 ), to supply a digital UWB pulse signal (Sn) to the c

Assignees

• Continental Automotive France
• Continental Automotive Gmbh

Inventors

• Guinart Nicolas
• Benbouhout Rachid
• Huard Jean-Charles

Classifications

• B60C23/0408

  transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver · CPC title

• B60C11/246 Primary

  Tread wear monitoring systems · CPC title

• G01S13/0209

  Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband · CPC title

• G01M17/02

  Tyres · CPC title

• B60C11/243

  Tread wear sensors, e.g. electronic sensors · CPC title