Method and device for filtering information emitted by a pressure sensor mounted on a wheel of a vehicle
First Claim
1. A method for filtering information emitted, on the basis of pressure measurements taken by a pressure sensor arranged in a wheel unit mounted on a wheel of a vehicle equipped with a tire, to a central unit mounted on said vehicle, wherein the wheel unit:
- measures periodically, with a period θ
, a value representative of the pressure of the air in the tire, and from this deduces any variations Δ
P in pressure between the values of the pressures successively measured, in parallel, with the same period θ
, measures a value representative of the temperature of the air in the tire, and, when a variation Δ
P in pressure between two successively measured pressure values is greater, in terms of absolute value, than a predetermined threshold Sp, the wheel unit;
calculates the variation Δ
T between the two temperature values measured at the same instants as said measured pressures, from this deduces a compensation coefficient Cp such that Cp=Δ
P/Δ
T, and commands the wheel unit to emit a signal representative of a pressure variation to the central unit if;
a) Δ
T=0, or if b) the compensation coefficient Cp is positive and higher than a determined threshold coefficient Cp1, or if c) the compensation coefficient Cp is negative and does not lie between a minimum threshold and a maximum threshold.
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Accused Products
Abstract
The invention relates to a method for filtering information emitted, on the basis of pressure measurements taken by a pressure sensor mounted on a wheel of a vehicle equipped with a tire, to a central unit mounted on said vehicle. According to this method, a value representative of the pressure of the air in the tire is measured periodically, with a period θ, and from this any possible variations ΔP in pressure between the values of the pressures successively measured are deduced; in parallel, with the same period θ, a value representative of the temperature of the air in the tire is measured. In addition, when there is a variation ΔP in pressure between two measured pressure values, that is greater in terms of absolute value than a predetermined threshold Sp, the variation ΔT between the two temperature values measured at the same instants as said measured pressures is calculated. The emission of a signal representative of a variation in pressure to the central unit is commanded only if the comparative change in the pressure and in the measured temperature might be representative of a variation of the amount of air in the tire.
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Citations
5 Claims
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1. A method for filtering information emitted, on the basis of pressure measurements taken by a pressure sensor arranged in a wheel unit mounted on a wheel of a vehicle equipped with a tire, to a central unit mounted on said vehicle, wherein the wheel unit:
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measures periodically, with a period θ
, a value representative of the pressure of the air in the tire, and from this deduces any variations Δ
P in pressure between the values of the pressures successively measured,in parallel, with the same period θ
, measures a value representative of the temperature of the air in the tire,and, when a variation Δ
P in pressure between two successively measured pressure values is greater, in terms of absolute value, than a predetermined threshold Sp, the wheel unit;
calculates the variation Δ
T between the two temperature values measured at the same instants as said measured pressures,from this deduces a compensation coefficient Cp such that Cp=Δ
P/Δ
T, andcommands the wheel unit to emit a signal representative of a pressure variation to the central unit if;
a) Δ
T=0, or ifb) the compensation coefficient Cp is positive and higher than a determined threshold coefficient Cp1, or if c) the compensation coefficient Cp is negative and does not lie between a minimum threshold and a maximum threshold. - View Dependent Claims (2, 3, 5)
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4. A device for filtering information emitted, on the basis of pressure measurements taken by a pressure sensor arranged in a wheel unit mounted on a wheel of a vehicle equipped with a tire, to a central unit mounted on said vehicle, said device being characterized in that it comprises, mounted on said wheel:
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means of measuring a value representative of the pressure of the air in the tire, means of measuring a value representative of the temperature in the tire, a calculation unit connected to the measurement means and programmed to;
periodically, with a period θ
, acquire the measured values representative of the pressure of the air in the tire and calculate any possible variations Δ
p in pressure between the values of the pressures successively measured,in parallel, with the same period θ
, acquire the measured values representative of the temperature of the air in the tire,and, when a variation Δ
P in pressure between two successively measured pressure values is greater in terms of absolute value, than a predetermined threshold Sp;
calculate the variation Δ
T between the two temperature values measured at the same instants as said measured pressures,from this deduce a compensation coefficient Cp such that Cp=Δ
P/Δ
T, andcommand the wheel unit to emit a signal representative of a pressure variation to the central unit if;
a) Δ
T=0, or ifb) the compensation coefficient Cp is positive and higher than a determined threshold coefficient Cp1, or if c) the compensation coefficient Cp is negative and does not lie between a minimum threshold and a maximum threshold.
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Specification