US 12,552,206 B2Granted

Slow leak detection system for vehicle tires

AssigneeCompagnie Generale Des Etablissements Michelin

InventorsChase Siuta, Antoine Godmond

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Abstract

A system for detecting leaks of tires of a vehicle is provided that includes sensors that measure pressure and temperature of the tires. The system has a processor that obtains the data from the sensors and detects a leak of one of the tires by using a natural leak model and/or a damage comparison model. The natural leak model uses temperature measurements of the tires to detect leakage of the tire which can be a slow leak of the tire. The damage comparison model detects leakage of the tire by comparing it to other tires on the vehicle.

Claims16

Dependent claims

A system for detecting a leak, comprising:

a first sensor that obtains pressure and temperature data from a first tire of a vehicle;
a second sensor that obtains pressure and temperature data from a second tire of the vehicle;
a third sensor that obtains pressure and temperature data from a third tire of the vehicle;
a fourth sensor that obtains pressure and temperature data from a fourth tire of the vehicle;
a processor that obtains data from the first, second, third and fourth sensors and uses a natural leak model and/or a damage comparison model to determine if the first tire is leaking, wherein:
the natural leak model comprising:
wherein the processor resamples the pressure measurements of the first sensor to a fixed sample rate if the pressure measurements are not all ready in a fixed sample rate, and wherein the processor calculates a set of normalized pressure readings at different times;
wherein the processor calculates a pressure predicted for the first tire at a particular time by using the normalized pressure at a previous time, the time difference between the particular time and the previous time, and the temperature measurement of the first sensor at the particular time;
wherein the processor calculates a prediction interval using the pressure predicted, and if the normalized pressure at the particular time falls below the prediction interval at the particular time the processor detects a leak under the natural leak model of the first tire if this remains the case for a sufficient number of future measured normalized pressures beyond the normalized pressure at the particular time;
and
wherein the damage comparison model comprising:
wherein the processor calculates a pressure daily ratio (r(t)) for the first tire at different times, for the second tire at the different times, for the third tire at the different times, and for the fourth tire at the different times;
wherein the processor calculates the rate(t) for the first tire by the equation rate(t)=P(t)*(1−r(t)) in which P(t) is the pressure of the first tire at time t and r(t) is the pressure daily ratio r for the first tire at the time t;
wherein the processor calculates the rate(t) for the second tire by the equation rate(t)=P(t)*(1−r(t)) in which P(t) is the pressure of the second tire at time t and r(t) is the pressure daily ratio r for the second tire at the time t;
wherein the processor calculates the rate(t) for the third tire by the equation rate(t)=P(t)*(1−r(t)) in which P(t) is the pressure of the third tire at time t and r(t) is the pressure daily ratio r for the third tire at the time t;
wherein the processor calculates the rate(t) for the fourth tire by the equation rate(t)=P(t)*(1−r(t)) in which P(t) is the pressure of the fourth tire at time t and r(t) is the pressure daily ratio r for the fourth tire at the time t;
wherein the processor calculates for the first tire an estimated number of days (Ndays(t)) at different times before the first tire reaches a pressure threshold by the equation Ndays(t)=(P(t)−Pthresh)/rate(t) in which Pthresh is a constant, P(t) is the pressure of the first tire at time t, and rate(t) is the previously calculated rate(t) for the first tire;
wherein the processor calculates rate differences at the different times between the first tire and the second tire by the equation diffi(t)=rateest(t)−ratei(t) in which diffi(t) is the rate difference between the first and second tire at time t, rateest(t) is the previously calculated rate(t) for the first tire at time t, and ratei(t) is the previously calculated rate(t) of the second tire;
wherein the processor calculates rate differences at the different times between the first tire and the third tire by the equation diffi(t)=rateest(t)−ratei(t) in which diffi(t) is the rate difference between the first and third tire at time t, rateest(t) is the previously calculated rate(t) for the first tire at time t, and ratei(t) is the previously calculated rate(t) of the third tire;
wherein the processor calculates rate differences at the different times between the first tire and the fourth tire by the equation diffi(t)=rateest(t)−ratei(t) in which diffi(t) is the rate difference between the first and fourth tire at time t, rateest(t) is the previously calculated rate(t) for the first tire at time t, and ratei(t) is the previously calculated rate(t) of the fourth tire;
wherein the processor calculates cumulative damage of the first tire in view of the second tire by the following equation:
D
=
∑
t
c
*
(
diff
i
(
t
)
N
days
(
t
)
)
a
wherein diffi(t) is the previously calculated diffi(t) rate difference between the first and second tire at time t, Ndays(t) is the previously calculated first tire estimated number of days (Ndays(t)) at time t, wherein c and a are constants, and wherein the summation is performed over at least the last 1 day of time;
wherein the processor calculates cumulative damage of the first tire in view of the third tire by the following equation:
D
=
∑
t
c
*
(
diff
i
(
t
)
N
days
(
t
)
)
a
wherein diffi(t) is the previously calculated diffi(t) rate difference between the first and third tire at time t, Ndays(t) is the previously calculated first tire estimated number of days (Ndays(t)) at time t, wherein c and a are constants, and wherein the summation is performed over at least the last 1 day of time;
wherein the processor calculates cumulative damage of the first tire in view of the fourth tire by the following equation:
D
=
∑
t
c
*
(
diff
i
(
t
)
N
days
(
t
)
)
a
wherein diffi(t) is the previously calculated diffi(t) rate difference between the first and fourth tire at time t, Ndays(t) is the previously calculated first tire estimated number of days (Ndays(t)) at time t, wherein c and a are constants, and
wherein the summation is performed over at least the last 1 day of time;
wherein the processor compares the cumulative damage D of the first tire in view of the second tire, the first tire in view of the third tire, and the first tire in view of the fourth tire to an accumulated rate limit to detect a leak of the first tire under the damage comparison model;
and
a display that outputs the detected leak of the first tire by the processor.

84 more elements

Dependencies are inferred from the claim text.

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Abstract

A system for detecting a leak, comprising:

a first sensor that obtains pressure and temperature data from a first tire of a vehicle;
a second sensor that obtains pressure and temperature data from a second tire of the vehicle;
a third sensor that obtains pressure and temperature data from a third tire of the vehicle;
a fourth sensor that obtains pressure and temperature data from a fourth tire of the vehicle;
a processor that obtains data from the first, second, third and fourth sensors and uses a natural leak model and/or a damage comparison model to determine if the first tire is leaking, wherein:
the natural leak model comprising:
wherein the processor resamples the pressure measurements of the first sensor to a fixed sample rate if the pressure measurements are not all ready in a fixed sample rate, and wherein the processor calculates a set of normalized pressure readings at different times;
wherein the processor calculates a pressure predicted for the first tire at a particular time by using the normalized pressure at a previous time, the time difference between the particular time and the previous time, and the temperature measurement of the first sensor at the particular time;
wherein the processor calculates a prediction interval using the pressure predicted, and if the normalized pressure at the particular time falls below the prediction interval at the particular time the processor detects a leak under the natural leak model of the first tire if this remains the case for a sufficient number of future measured normalized pressures beyond the normalized pressure at the particular time;
and
wherein the damage comparison model comprising:
wherein the processor calculates a pressure daily ratio (r(t)) for the first tire at different times, for the second tire at the different times, for the third tire at the different times, and for the fourth tire at the different times;
wherein the processor calculates the rate(t) for the first tire by the equation rate(t)=P(t)*(1−r(t)) in which P(t) is the pressure of the first tire at time t and r(t) is the pressure daily ratio r for the first tire at the time t;
wherein the processor calculates the rate(t) for the second tire by the equation rate(t)=P(t)*(1−r(t)) in which P(t) is the pressure of the second tire at time t and r(t) is the pressure daily ratio r for the second tire at the time t;
wherein the processor calculates the rate(t) for the third tire by the equation rate(t)=P(t)*(1−r(t)) in which P(t) is the pressure of the third tire at time t and r(t) is the pressure daily ratio r for the third tire at the time t;
wherein the processor calculates the rate(t) for the fourth tire by the equation rate(t)=P(t)*(1−r(t)) in which P(t) is the pressure of the fourth tire at time t and r(t) is the pressure daily ratio r for the fourth tire at the time t;
wherein the processor calculates for the first tire an estimated number of days (Ndays(t)) at different times before the first tire reaches a pressure threshold by the equation Ndays(t)=(P(t)−Pthresh)/rate(t) in which Pthresh is a constant, P(t) is the pressure of the first tire at time t, and rate(t) is the previously calculated rate(t) for the first tire;
wherein the processor calculates rate differences at the different times between the first tire and the second tire by the equation diffi(t)=rateest(t)−ratei(t) in which diffi(t) is the rate difference between the first and second tire at time t, rateest(t) is the previously calculated rate(t) for the first tire at time t, and ratei(t) is the previously calculated rate(t) of the second tire;
wherein the processor calculates rate differences at the different times between the first tire and the third tire by the equation diffi(t)=rateest(t)−ratei(t) in which diffi(t) is the rate difference between the first and third tire at time t, rateest(t) is the previously calculated rate(t) for the first tire at time t, and ratei(t) is the previously calculated rate(t) of the third tire;
wherein the processor calculates rate differences at the different times between the first tire and the fourth tire by the equation diffi(t)=rateest(t)−ratei(t) in which diffi(t) is the rate difference between the first and fourth tire at time t, rateest(t) is the previously calculated rate(t) for the first tire at time t, and ratei(t) is the previously calculated rate(t) of the fourth tire;
wherein the processor calculates cumulative damage of the first tire in view of the second tire by the following equation:
D
=
∑
t
c
*
(
diff
i
(
t
)
N
days
(
t
)
)
a
wherein diffi(t) is the previously calculated diffi(t) rate difference between the first and second tire at time t, Ndays(t) is the previously calculated first tire estimated number of days (Ndays(t)) at time t, wherein c and a are constants, and wherein the summation is performed over at least the last 1 day of time;
wherein the processor calculates cumulative damage of the first tire in view of the third tire by the following equation:
D
=
∑
t
c
*
(
diff
i
(
t
)
N
days
(
t
)
)
a
wherein diffi(t) is the previously calculated diffi(t) rate difference between the first and third tire at time t, Ndays(t) is the previously calculated first tire estimated number of days (Ndays(t)) at time t, wherein c and a are constants, and wherein the summation is performed over at least the last 1 day of time;
wherein the processor calculates cumulative damage of the first tire in view of the fourth tire by the following equation:
D
=
∑
t
c
*
(
diff
i
(
t
)
N
days
(
t
)
)
a
wherein diffi(t) is the previously calculated diffi(t) rate difference between the first and fourth tire at time t, Ndays(t) is the previously calculated first tire estimated number of days (Ndays(t)) at time t, wherein c and a are constants, and
wherein the summation is performed over at least the last 1 day of time;
wherein the processor compares the cumulative damage D of the first tire in view of the second tire, the first tire in view of the third tire, and the first tire in view of the fourth tire to an accumulated rate limit to detect a leak of the first tire under the damage comparison model;
and
a display that outputs the detected leak of the first tire by the processor.

84 more elements