Patent ID: 8032272

Claim:
A method of determining the rotary, rotationally immobile or mobile, state of a vehicle wheel, according to which the wheel is fitted with an active motion sensor (Cp) suitable for delivering an oscillatory output signal during a rotation of said wheel, and said output signal is analyzed instantly so as to deduce from its form the rotary state of the wheel, said determining method being characterized in that each instant analysis of the output signal delivered by the motion sensor (Cp) consists: A) firstly, at an instant t 1 , in connecting the motion sensor (Cp) to an analog circuit (I 1 , 3 ), termed the storage circuit, comprising at least one capacitor ( 3 ), and interposed between said motion sensor and a first input of electronic comparison means ( 4 ), and in electrically energizing the motion sensor (Cp) in such a way as to store in the capacitor ( 3 ) a value V 1 , termed the reference value, representative of the value of the output signal delivered by the motion sensor (Cp) at the instant t 1 , then B), at at least one instant t 2 =t 1 +Δt, with Δt predetermined time span, in connecting the motion sensor (Cp) to a second input of the comparison means ( 4 ), and in electrically energizing said motion sensor and said comparison means, in such a way as to compare the reference value V 1 with a value V 2 representative of the value of the output signal delivered by the motion sensor (Cp) at the instant t 2 , and to deliver a diagnostic signal representative: of a rotationally immobile state of the wheel when V 1 =V 2 , of a rotationally mobile state of the wheel when V 1 ≠V 2 .