Method of locating the position of wheels of an automotive vehicle

1. A method of locating the position of wheels ( 1 - 4 ) of a vehicle (V) with r wheels ( 1 - 4 ), each wheel of said r wheels equipped with an electronic apparatus ( 5 - 8 ) that includes at least means of measuring ( 9 ) an angular position of the electronic apparatus and a transmitter ( 10 ) configured to transmit signals containing data representative of operating parameters of the wheel and an identification code of the electronic apparatus, a wheel speed sensor ( 13 - 16 ) positioned on the vehicle (V) in proximity to each one of said wheels ( 1 - 4 ) and configured to generate data representative of the orientation of the one of said wheel wheels ( 1 - 4 ), and, integrated in the vehicle (V), a central monitoring apparatus ( 11 ) with a receiver ( 12 ) configured to receive the signals transmitted from the electronic apparatuses ( 5 - 8 ) and connected to each of the wheel speed sensors ( 13 - 16 ), said method comprising:

at the electronic apparatus ( 5 - 8 ) of a wheel of said wheels, furnishing to the central monitoring apparatus ( 11 ), at successive times t 1 . . . t n , n signals RF 1 . . . RFn transmitted for at least one angular position θ 1 . . . θ n of said electronic apparatus, each of the n signals RF 1 . . . RFn containing the identification code of the electronic apparatus ( 5 - 8 ) and data representative of the angular position θ 1 . . . θ n of transmission; and

at the central monitoring apparatus ( 11 ):

receiving and storing the values β 1 . . . βn measured by each of the r wheel speed sensors ( 13 - 16 ), for each of the successive times δ 1 to t n , and determining compensated values δ 1 to δ n , determined in relation to a fixed unique reference position, by a compensation of each measured value β 1 . . . βn as a function of the data representative of the angular position θ 1 . . . θ n of transmission of the associated signal RF 1 . . . RFn,

calculating, for each series of compensated values δ 1 to δ n associated with a wheel speed sensor ( 13 - 16 ), a characteristic value V n 1 , V n 2 . . . V n r representative of a dispersion of said series of values, and assigning the identification code of the electronic apparatus ( 5 - 8 ) to a position of the wheel ( 1 - 4 ) situated in proximity to the wheel speed sensor ( 13 - 16 ) at an origin of a most clustered series of angular values δ 1 -δ n ,

wherein and said method further comprises, in a preliminary phase:

determining an angular value dmax corresponding to an angular tolerance of precision allowable for the angular position θ i of transmission of each signal RFi,

determining a corresponding compensated value δ max , and then for each electronic apparatus:

upon receipt of each RFi signal furnished by said electronic apparatus, with i≥3, a value is calculated that is representative of the mean (i) of the i compensated values δ 1 to δ i obtained for each of the r wheel speed sensors ( 13 - 16 ),

upon receipt of each RF(i+1) signal, with i≥3, the compensated value δ (i+1) obtained for each of the r wheel speed sensors ( 13 - 16 ) is measured,

for each compensated value δ (i+1) a comparison angular value δ com is calculated, such that: δ com =δ (i+1) −(i), and

the RF(i+1) signal is eliminated when all the calculated values δ com , each of which corresponds to a wheel speed sensor ( 13 - 16 ), are such that: δ com ≥δ max .

2. The method of location as claimed in claim 1 ,

wherein the assigning of the identification code of the electronic apparatus ( 5 - 8 ) to the position of the wheel ( 1 - 4 ) includes, starting with receipt of a third signal RFi, selecting two characteristic values V n 1 , V n 2 of lowest value, with V n 2 >V n 1 , and then when the ratio V n 2 /V n 1 is greater than a predetermined threshold, assigning the identification code to the wheel ( 1 - 4 ) situated in proximity to the wheel speed sensor ( 13 - 16 ) at an origin of a series of angular values having the characteristic value V n 1 ,

wherein only the angular comparison value δ com of the at least one of the two series of compensated values δ 1 to δ i corresponding to the characteristic values V n 1 , V n 2 is calculated, and

wherein the signal Rfi is eliminated when each calculated value δcom is such that: δ com ≥δ max .

3. The method of location as claimed in claim 2 , wherein, upon reception of a signal RFi, with i≥3, coming from an electronic apparatus ( 5 - 8 ):

for determining a new characteristic value of each dispersion, selecting a value δ i such that the angular distance d between the value δ i and the mean (i−1) of the (i−1) compensated values δ 1 −δ i −1 is equal to min(d 1 , d 2 ), where d 1 and d 2 represent two complementary angular sectors delimited by the values δ i and (i−1) situated on a circular circumference, and

calculating characteristic values V i of the dispersion of i angular values such that:

V i =V i-1 ×( i− 1)/ i+d 2 ×( i− 1)/ i 2

with d=min(d 1 , d 2 ).

4. The method of location as claimed in claim 3 , further comprising, for each electronic apparatus ( 5 - 8 ) and after receipt of a first three signals RF 1 -RF 3 furnished by said electronic apparatus:

calculating a maximum angular deviation between the three compensated values δ 1 to δ 3 obtained for each of the r wheel speed sensors ( 13 - 16 ); and

eliminating a group of the first three signals RF 1 -RF 3 , and ordering an overall reinitialization of the location procedure when for all the wheel speed sensors ( 13 - 16 ) a maximum deviation between the three compensated values δ 1 to δ 3 is greater than a predetermined compensated value δ 3 max which is lower in value than the value δ max .

5. The method of location as claimed in claim 3 , further comprising:

incrementing a number of signals RFi eliminated; and

reinitializing the location procedure when the number of signals eliminated exceeds a predetermined threshold.

6. The method of location as claimed in claim 2 , further comprising:

incrementing a number of signals RFi eliminated; and

reinitializing the location procedure when the number of signals eliminated exceeds a predetermined threshold.

7. The method of location as claimed in claim 6 , further comprising, for each electronic apparatus ( 5 - 8 ) and after receipt of a first three signals RF 1 -RF 3 furnished by said electronic apparatus:

calculating a maximum angular deviation between the three compensated values δ 1 to δ 3 obtained for each of the r wheel speed sensors ( 13 - 16 ); and

eliminating a group of the first three signals RF 1 -RF 3 , and ordering an overall reinitialization of the location procedure when for all the wheel speed sensors ( 13 - 16 ) a maximum deviation between the three compensated values δ 1 to δ 3 is greater than a predetermined compensated value δ 3 max which is lower in value than the value δ max .

8. The method of location as claimed in claim 2 , further comprising, for each electronic apparatus ( 5 - 8 ) and after receipt of a first three signals RF 1 -RF 3 furnished by said electronic apparatus:

calculating a maximum angular deviation between the three compensated values δ i to δ 3 obtained for each of the r wheel speed sensors ( 13 - 16 ); and

eliminating a group of the first three signals RF 1 -RF 3 , and ordering an overall reinitialization of the location procedure when for all the wheel speed sensors ( 13 - 16 ) a maximum deviation between the three compensated values δ 1 to δ 3 is greater than a predetermined compensated value δ 3 max which is lower in value than the value δ max .

9. The method of location as claimed in claim 1 , wherein, upon reception of a signal RFi, with i≥3, coming from an electronic apparatus ( 5 - 8 ):

for determining a new characteristic value of each dispersion, selecting a value δ i such that the angular distance d between the value δ i and the mean (i−1) of the (i−1) compensated values δ 1 -δ i −1 is equal to min(d 1 , d 2 ), where d 1 and d 2 represent two complementary angular sectors delimited by the values δ i and (i−1) situated on a circular circumference, and

calculating characteristic values V i of the dispersion of i angular values such that:

V i =V i-1 ×( i− 1)/ i+d 2 ×( i− 1)/ i 2

with d=min(d 1 , d 2 ).

10. The method of location as claimed in claim 9 , further comprising:

transforming the value δ max corresponding to the angular tolerance of precision dmax allowable for the angular position θ i of transmission of each signal RFi, into values Max (V i −V i-1 ) expressed in terms of maximum variation value of variances, and such that, for each characteristic value V i 1 , V i 2 . . . V i r:

Max( V i −V i-1 )=(( i− 1)/ i 2 )×( d max) 2 −( V i-1 )/ i;

transforming each comparison value δ com into a value (V i −V i-1 ) expressed in terms of a variation of variances; and

eliminating the signals RFi when each calculated value (V i −V i-1 ) corresponding to a wheel speed sensor ( 13 - 16 ) is greater than or equal to the corresponding value Max(V i −V i-1 ) calculated for this wheel speed sensor ( 13 - 16 ).

11. The method of location as claimed in claim 10 , further comprising:

incrementing a number of signals RFi eliminated; and

reinitializing the location procedure when the number of signals eliminated exceeds a predetermined threshold.

12. The method of location as claimed in claim 11 , further comprising, for each electronic apparatus ( 5 - 8 ) and after receipt of a first three signals RF 1 -RF 3 furnished by said electronic apparatus:

calculating a maximum angular deviation between the three compensated values δ 1 to δ 3 obtained for each of the r wheel speed sensors ( 13 - 16 ); and

eliminating a group of the first three signals RF 1 -RF 3 , and ordering an overall reinitialization of the location procedure when for all the wheel speed sensors ( 13 - 16 ) a maximum deviation between the three compensated values δ 1 to δ 3 is greater than a predetermined compensated value δ 3 max which is lower in value than the value δ max .

13. The method of location as claimed in claim 10 , further comprising, for each electronic apparatus ( 5 - 8 ) and after receipt of a first three signals RF 1 -RF 3 furnished by said electronic apparatus:

calculating a maximum angular deviation between the three compensated values δ 1 to δ 3 obtained for each of the r wheel speed sensors ( 13 - 16 ); and

eliminating a group of the first three signals RF 1 -RF 3 , and ordering an overall reinitialization of the location procedure when for all the wheel speed sensors ( 13 - 16 ) a maximum deviation between the three compensated values δ 1 to δ 3 is greater than a predetermined compensated value δ 3 max which is lower in value than the value δ max .

14. The method of location as claimed in claim 9 , further comprising:

incrementing a number of signals RFi eliminated; and

reinitializing the location procedure when the number of signals eliminated exceeds a predetermined threshold.

15. The method of location as claimed in claim 14 , further comprising, for each electronic apparatus ( 5 - 8 ) and after receipt of a first three signals RF 1 -RF 3 furnished by said electronic apparatus:

calculating a maximum angular deviation between the three compensated values δ 1 to δ 3 obtained for each of the r wheel speed sensors ( 13 - 16 ); and

eliminating a group of the first three signals RF 1 -RF 3 , and ordering an overall reinitialization of the location procedure when for all the wheel speed sensors ( 13 - 16 ) a maximum deviation between the three compensated values δ i to δ 3 is greater than a predetermined compensated value δ 3 max which is lower in value than the value δ max .

16. The method of location as claimed in claim 9 , further comprising, for each electronic apparatus ( 5 - 8 ) and after receipt of a first three signals RF 1 -RF 3 furnished by said electronic apparatus:

calculating a maximum angular deviation between the three compensated values δ 1 to δ 3 obtained for each of the r wheel speed sensors ( 13 - 16 ); and

eliminating a group of the first three signals RF 1 -RF 3 , and ordering an overall reinitialization of the location procedure when for all the wheel speed sensors ( 13 - 16 ) a maximum deviation between the three compensated values δ 1 to δ 3 is greater than a predetermined compensated value δ 3 max which is lower in value than the value δ max .

17. The method of location as claimed in claim 1 , further comprising:

incrementing a number of signals RFi eliminated; and

reinitializing the location procedure when the number of signals eliminated exceeds a predetermined threshold.

18. The method of location as claimed in claim 17 , further comprising, for each electronic apparatus ( 5 - 8 ) and after receipt of a first three signals RF 1 -RF 3 furnished by said electronic apparatus:

calculating a maximum angular deviation between the three compensated values δ 1 to δ 3 obtained for each of the r wheel speed sensors ( 13 - 16 ); and

eliminating a group of the first three signals RF 1 -RF 3 , and ordering an overall reinitialization of the location procedure when for all the wheel speed sensors ( 13 - 16 ) a maximum deviation between the three compensated values δ 1 to δ 3 is greater than a predetermined compensated value δ 3 max which is lower in value than the value δ max .

19. The method of location as claimed in claim 1 , further comprising, for each electronic apparatus ( 5 - 8 ) and after receipt of a first three signals RF 1 -RF 3 furnished by said electronic apparatus:

calculating a maximum angular deviation between the three compensated values δ 1 to δ 3 obtained for each of the r wheel speed sensors ( 13 - 16 ); and

eliminating a group of the first three signals RF 1 -RF 3 , and ordering an overall reinitialization of the location procedure when for all the wheel speed sensors ( 13 - 16 ) a maximum deviation between the three compensated values δ 1 to δ 3 is greater than a predetermined compensated value δ 3 max which is lower in value than the value δ max .

20. The method of location as claimed in claim 19 further comprising, for each electronic apparatus ( 5 - 8 ) and after receipt of a first two signals RF 1 -RF 2 furnished by said electronic apparatus:

calculating a maximum angular deviation between the two compensated values δ 1 to δ 2 obtained for each of the r wheel speed sensors ( 13 - 16 ),

eliminating the first two signals RF 1 ,RF 2 ,

and ordering an overall reinitialization of the location procedure when for all the wheel speed sensors ( 13 - 16 ) a deviation between the two compensated values δ 1 to δ 2 is greater than a predetermined value δ 2 max which is lower in value than the predetermined compensated value δ 3 max .