Method of estimating the temperature of the air in the internal cavity of a tire and application to the detection of abnormal operating of a running-flat system

• US 7,338,201 B2
• Filed: 12/22/2005
• Issued: 03/04/2008
• Est. Priority Date: 10/18/2001
• Status: Expired due to Fees

• Current Assignee: Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Original Assignee: Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Inventors: Shepherd, Russell, Abinal, Richard, Berger, Eric
• Primary Examiner(s): Verbitsky; Gail
• Assistant Examiner(s): Jagan; Mirellys
• Application Number:
  US11/316,571
• Publication Number:
  US 20060193368A1
• Time in Patent Office: 803 Days
• Field of Search: 374/1, 374/142, 374/153
• US Class Current: 374/1
• CPC Class Codes: B60C 23/20 Devices for measuring or signalling tyre temperature only

Abstract

A method of estimating the temperature of the air in the internal cavity of a tire in which:

• • prior to normal operation, a series of running tests are carried out on the tire provided with a means of measuring the internal air temperature at given speeds V and external temperatures T_amb, the tire supporting a given load and the cavity being at a given internal relative pressure, and an adjustment is made to a function giving the temperature of the internal air T_ai according to the parameters of speed and external temperature; and
  • in normal operation, the tire equipping a vehicle under the above conditions of load and relative pressure, the internal air temperature is estimated according to the speed of the vehicle and the temperature external to the vehicle.

The method ia applied to the detection of abnormal operating in particular of a running-flat system.

Claims

1. A method of estimating a temperature of air in an internal cavity of a tire, comprising:

prior to normal operation of the tire, carrying out a series of running tests on the tire with the tire being provided with a means of measuring the temperature of the air in the cavity at given speeds V and external temperatures T_amb, the tire supporting a given load and the cavity being at a given internal relative pressure; and

an adjustment is made to a function

T_ai=F(V,T_amb),

which gives the temperature of the internal air T_ai according to the parameters of speed and external temperature

wherein during normal operation of the tire, the tire equips a vehicle under conditions of load and relative pressure in the cavity in accordance with the function as adjusted prior to normal operation of the tire, and the temperature of the internal air in the cavity is estimated according to the speed of the vehicle and the temperature external to the vehicle.

2. A method according to claim 1, in which the internal temperature T_ai is given by:

$T_{\mathrm{ai},n}=T_{\mathrm{SS}}-\left(T_{\mathrm{SS}}-T_{\mathrm{ai},n-1}\right)<br><br>\exp <br><br><br><br>\left(\frac{4}{\mathrm{\tau <br><br>}}<br><br>\left(t_n-t_{n-1}\right)\right)$

where T_ai,n is an internal temperature estimated at time t_n, T_ai,n-1 is an internal temperature estimated at time t_n-1, Tss is an internal temperature at thermal equilibrium under the given test conditions, and τ

is an adjustment coefficient; and

$T_{\mathrm{SS}}=\left(a+{\mathrm{bT}}_{\mathrm{amb}}\right)<br><br>V^{\left(c=T_{\mathrm{amb}}<br><br>d\right)}+T_{\mathrm{amb}}$

where a,b,c and d are adjustment coefficients.

3. A method according to claim 1, in which, during tests carried out prior to normal operation, the relative pressure in the cavity corresponds to the normal relative pressure of the tire when the tire is cold.

4. A method according to claim 1, wherein the tire forms part of a running-flat system, and during tests carried out prior to normal operation the relative pressure in the cavity is substantially zero.