EP0751018A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A method and equipment for detecting the presence of a deflated tyre in a motor vehicle
Assignee: Fiat Auto SpA
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Filing: 1996-06-24
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Granted: —
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Expires: 2016-06-24
Abstract
Abstract The angular velocity (ω i ) of each wheel is detected and corresponding velocity signals or data are generated and are processed in a processing unit (EPU) which is arranged to calculate the difference between the sum of the signals relating to two diagonally-opposed wheels (1, 4) and the sum of the signals relating to the other two wheels (2, 3). The unit (EPU) generates an alarm signal when the difference exceeds a reference value. Before the difference is calculated, the velocity signals (ω I ) are modified according to predetermined calibration factors (K i ) which are specific to each wheel (1-4) and are updated and stored periodically.
Inventors
- 👤 Maurizio Cisternino
- 👤 Fulvio Cascio
- 👤 Francesco De Cristofaro
- 👤 Erica Bargis
- 👤 Cesare Ponti
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 01:16
CPC Classifications
B; B60; B60C; B60C23/00; B60C23/06; B60C23/061
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
267 words
A method of detecting the presence of an at least partially deflated tyre in a motor vehicle with four wheels (1-4) having respective tyres, comprising the steps of: detecting the angular velocity (ω i ) of each wheel and generating corresponding velocity signals or data, processing these velocity signals or data in a processing unit (EPU) arranged to calculate the difference between the sum of the signals or data relating to one pair of diagonally-opposed wheels (1, 4) and the sum of the velocity signals or data relating to the other pair of wheels (2, 3), and to generate an alarm signal indicative of the fact that a tyre is at least partially deflated when the difference exceeds a predetermined reference value, the method being characterized in that, before the difference is calculated, the velocity signals or data (ω i ) are modified according to predetermined calibration factors (K i ) which are specific to each wheel (1-4) and are updated and stored periodically, the calibration factors (K i ) being determined each time in predetermined running conditions, by the detection of the angular velocity (ω i ) of each wheel (1-4), the calculation in the unit (EPU) of the value of the average velocity (ω ave ) of the four wheels (1-4), and the adoption, as the calibration factor (K i ) for each wheel (1-4), of the ratio between the average velocity (ω ave ) and the detected velocity (ω i ) of the wheel (1-4), the difference then being calculated with the use of the velocity signals or data (Ω i ) thus modified.
Claim 2
Dependent Claim
60 words
A method according to Claim 1, characterized in that the said calibration fators (K i ) are determined whilst the vehicle (V) is moving along an essentially straight path at a speed of advance within a predetermined range of values and whilst the absolute value of the average angular acceleration of the wheels (1-4) is less than a predetermined value.
Claim 3
Dependent Claim
29 words
A method according to Claim 2, characterized in that the calibration factors (K i ) are determined whilst the braking system of the motor vehicle (V) is not activated.
Claim 4
Dependent Claim
294 words
Equipment for detecting the presence of an at least partially deflated tyre in a motor vehicle (V) with four wheels (1-4) having respective tyres, comprising velocity sensor means (S1-S4) for providing signals or data indicative of the angular velocity of each wheel (1-4), and an electronic processing unit (EPU) connected to the sensor means (S1-S4) and arranged to calculate the difference between the sum of the velocity signals or data relating to one pair of diagonally-opposed wheels (1, 4) and the sum of the velocity signals or data relating to the other pair of wheels (2, 3), and to generate an alarm signal indicative of the fact that a tyre is at least partially deflated when the difference exceeds a predetermined reference value, the equipment being characterized in that the electronic processing unit (EPU) is arranged to modify the velocity signals or data (ω i ) before the calculation of the difference, the modification being effected by means of predetermined calibration factors (K i ) which are specific to each wheel (1-4) and are updated and stored periodically, the unit (EPU) being arranged to determine the calibration factors (K i ) each time in predetermined running conditions of the motor vehicle ( V ) by the detection of the angular velocity (ω i ) of each wheel (1-4), the calculation of the value of the average velocity (ω ave ) of the four wheels (1-4) and the adoption, as the calibration factor (K i ) for each wheel (1-4), of the ratio between the average velocity (ω ave ) and the detected velocity (ω i ) of the wheel (1-4), the unit (EPU) then being arranged to calculate the difference with the use of the velocity signals or data (Ω i ) thus modified.
Claim 5
Dependent Claim
64 words
Equipment according to Claim 4, characterized in that the electronic processing unit (EPU) is arranged to determine the calibration factors (K i ) whilst the vehicle (V) is moving along an essentially straight path at a speed of advance within a predetermined range of values and whilst the absolute value of the average acceleration of the wheels (1-4) is less than a predetermined value.
Claim 6
Dependent Claim
36 words
Equipment according to Claim 5, also characterized in that the electronic processing unit (EPU) is arranged to determine the calibration factors (K i ) whilst the braking system of the motor vehicle (V) is not activated.
References Cited (Backward Citations)
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