Method for pairing a measurement module mounted in a motor vehicle wheel
10787047 ยท 2020-09-29
Assignee
Inventors
- Nicolas Guinart (Toulouse, FR)
- Antoine Richard (Lacroix-Falgarde, FR)
- Sylvain GODET (Saint-Cezert, FR)
Cpc classification
B60T8/171
PERFORMING OPERATIONS; TRANSPORTING
B60C23/0437
PERFORMING OPERATIONS; TRANSPORTING
B60C23/0416
PERFORMING OPERATIONS; TRANSPORTING
B60C23/0489
PERFORMING OPERATIONS; TRANSPORTING
International classification
B60C23/00
PERFORMING OPERATIONS; TRANSPORTING
G01B21/22
PHYSICS
Abstract
A method for pairing a measurement module with a wheel of a motor vehicle. The method is implemented by a computer and includes, for each received measured signal, determining the power of the measured signal, determining the angular orientation of each wheel and identifying, in a plurality of tables, a row and column pair including the determined power and the angular orientation of each wheel. The pairing being performed when, for a number of determined columns of each table higher than a first minimum threshold, the number of row and column pairs identified in one table is lower than a predetermined maximum threshold and the number of row and column pairs identified in the other tables is higher than a second minimum threshold.
Claims
1. A method for pairing a measurement module with a wheel of a motor vehicle comprising a plurality of wheels, said method being implemented by an on-board computer in said vehicle, said measurement module being installed in one of the wheels of the vehicle and being able to emit, to the computer, at least one measured signal taking the form of at least one pulse received by the computer in the form of a frame of varying power, over at least one interval of a power range divided into K consecutive intervals of the same width, as a function of the position of the measurement module with respect to the computer, the vehicle comprising a plurality of wheel anti-lock modules, each wheel anti-lock module, installed facing a wheel, being able to deliver, to the computer, an orientation signal representative of an angular orientation of said wheel, varying over the angular orientation range divided into M consecutive intervals of the same width, said pairing method comprising: for each frame of a measured signal received by the computer, the computer: determining at least one value of the power of said received measured signal, determining, at the time of reception of the measured signal, the angular orientation of each wheel on the basis of the orientation signal received from each wheel anti-lock module, for each determined power value, identifying, in a plurality of predetermined tables, each divided into K rows and M columns respectively associating the power of the measured signal with the angular orientation of each of the wheels, at least one row and column pair per table, each row and column pair respectively comprising said determined power value and the value of the angular orientation determined for each of the wheels, a final step of pairing the measurement module with one of the wheels of the vehicle when, after the number of columns determined for each table has reached a first minimum threshold, the number of row and column pairs identified in one of the tables for one of the wheels is lower than a maximum threshold and the number of row and column pairs identified in each of the other tables for the other wheels is higher than a second minimum threshold.
2. The pairing method as claimed in claim 1, wherein the duration of the measured signal is less than 500 ms.
3. The pairing method as claimed in claim 2, wherein the emitted measured signal takes the form of a pulse train.
4. The pairing method as claimed in claim 3, wherein, for a given measurement module, when, after the number of columns of each table has reached the first minimum threshold, the number of row and column pairs identified in one of the tables is lower than the maximum threshold and the number of row and column pairs identified for each of the other tables is higher than the second minimum threshold and contained within one and the same interval of predetermined width, of the order of 5%, of the total number of row and column pairs of the table.
5. The pairing method as claimed in claim 2, wherein, for a given measurement module, when, after the number of columns of each table has reached the first minimum threshold, the number of row and column pairs identified in one of the tables is lower than the maximum threshold and the number of row and column pairs identified for each of the other tables is higher than the second minimum threshold and contained within one and the same interval of predetermined width, of the order of 5%, of the total number of row and column pairs of the table.
6. The pairing method as claimed in claim 1, wherein the first minimum threshold for the number of columns determined for each table is of the order of 30%.
7. The pairing method as claimed in claim 1, wherein the maximum threshold for the number of pairs determined for a table is of the order of 30%.
8. The pairing method as claimed in claim 1, wherein the second minimum threshold for the number of pairs determined for the other tables is of the order of 90%.
9. The pairing method as claimed in claim 1, wherein, for a given measurement module, when, after the number of columns of each table has reached the first minimum threshold, the number of row and column pairs identified in one of the tables is lower than the maximum threshold and the number of row and column pairs identified for each of the other tables is higher than the second minimum threshold and contained within one and the same interval of predetermined width, of the order of 5%, of the total number of row and column pairs of the table.
10. The pairing method as claimed in claim 1, comprising a preliminary step of evaluating the power range of the measured signal emitted by the measurement module and of determining the width of the K intervals of each table.
11. The pairing method as claimed in claim 1, wherein the emitted measured signal takes the form of a pulse train.
12. A computer for a motor vehicle, said vehicle comprising a plurality of wheels, each wheel comprising a measurement module, each measurement module being able to emit, to said computer, at least one measured signal taking the form of at least one pulse received by the computer in the form of a frame of varying power, over at least one interval of a power range divided into K consecutive intervals of the same width, as a function of the position of the measurement module with respect to the computer, the vehicle comprising a plurality of wheel anti-lock modules, each wheel anti-lock module, installed facing a wheel, being able to deliver, to the computer, an orientation signal representative of the angular orientation of said wheel, varying over an angular orientation range divided into M consecutive intervals of the same width, said computer being configured, for each measurement module, so as to: for each frame of a received measured signal: determine at least one value of the power of said received measured signal, determine, at the time of reception of the measured signal, the angular orientation of each wheel on the basis of the orientation signal received from each wheel anti-lock module, for each determined power value, identify, in a plurality of predetermined tables, each divided into K rows and M columns respectively associating the power of the measured signal as a function of the angular orientation of each of the wheels, one row and column pair per table, each row and column pair respectively comprising said determined power value and the value of the angular orientation determined for each of the wheels, detect that the number of columns determined for each table has reached a first minimum threshold, detect that the number of row and column pairs identified in one of the tables is lower than a maximum threshold and that the number of row and column pairs identified in the other tables is higher than a second minimum threshold, pair the measurement module with one of the wheels when, after the number of columns determined for each table has reached the first minimum threshold, the number of row and column pairs identified in one of the tables for one of the wheels is lower than the maximum threshold and the number of row and column pairs identified in each of the other tables for the other wheels is higher than the second minimum threshold.
13. The computer as claimed in claim 12, configured so as to perform pairing when, when more than 30% of the columns of each table have been determined, the number of row and column pairs identified in a table is less than 30% of the total number of row and column pairs of the table and the number of row and column pairs identified in each of the other tables is higher than 90% of the total number of row and column pairs of each of the tables.
14. A motor vehicle comprising: a computer as claimed in claim 13, a plurality of wheels, each wheel comprising a measurement module, each measurement module being able to emit, to said computer, at least one measured signal taking the form of at least one pulse received by the computer in the form of a frame of varying power, over at least one interval of a power range divided into K consecutive intervals of the same width, as a function of the position of the measurement module with respect to the computer, and a plurality of wheel anti-lock modules, each wheel anti-lock module, installed facing a wheel, being able to deliver, to the computer, an orientation signal representative of the angular orientation of said wheel, varying over an angular orientation range divided into M consecutive intervals of the same width.
15. A motor vehicle comprising: a computer as claimed in claim 12, a plurality of wheels, each wheel comprising a measurement module, each measurement module being able to emit, to said computer, at least one measured signal taking the form of at least one pulse received by the computer in the form of a frame of varying power, over at least one interval of a power range divided into K-consecutive intervals of the same width, as a function of the position of the measurement module with respect to the computer, and a plurality of wheel anti-lock modules, each wheel anti-lock module, installed facing a wheel, being able to deliver, to the computer, an orientation signal representative of the angular orientation of said wheel, varying over an angular orientation range divided into M consecutive intervals of the same width.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Other features and advantages of aspects of the invention will emerge during the following description, given with reference to the appended figures, which are given by way of nonlimiting example and in which identical references are given to similar objects.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
(14) The pairing method according to an aspect of the invention is presented primarily for the purpose of implementation in a motor vehicle. However, any implementation in a different context, in particular in any type of vehicle comprising a plurality of wheels and a plurality of measurement modules that need to be paired (that is to say associated) is also targeted by an aspect of the invention.
(15) With reference to
(16) In this example, with reference to
(17) The measurement module 20 is configured so as to periodically emit, for example every 10 to 30 seconds (for example every 16 seconds), a measured signal S.sub.m, in which there is coded a message containing characteristics of the wheel 5, such as for example its pressure or its temperature. Such a measured signal S.sub.m also comprises an identifier for distinguishing the measured signal S.sub.m emitted by each measurement module 20.
(18) The emitted measured signal S.sub.m preferably takes the form of a pulse train (or burst), comprising for example between three and twelve pulses, making it possible to fragment the coded message between said pulses. This pulse train may for example take the form, as is known, of a series of segments. By way of example, a pulse train may comprise nine pulses, each having a duration of 3 ms and spaced apart from one another by 30 ms (that is to say a total duration of 267 ms).
(19) The computer 10 receives a pulse train emitted by a measurement module 20 in the form of frames, each received frame corresponding to an emitted pulse.
(20) Using, upon emission, a pulse train in which the message is fragmented allows the computer 10, upon reception, firstly to distinguish the measured signals S.sub.m from other signals that are emitted continuously and secondly to measure the power P of each measured signal S.sub.m received over a longer time interval than if the measurement module 20 were to send a non-fragmented message (that is to say a single pulse) in the measured signal S.sub.m, thus making it possible to measure a more significant variation in power P during the duration of said time interval.
(21) Furthermore, the computer 10 measures at least one power P value per frame, but is advantageously able to measure several of them per frame through sampling, for example at least three.
(22) The duration of a measured signal S.sub.m may be intentionally limited, for example below 500 ms, preferably below 300 ms, so as to greatly reduce the risks of collision between the measured signals S.sub.m emitted by the various measurement modules 20 of the vehicle 1.
(23) To limit the duration of an emitted pulse train and therefore of a train of received frames, it is possible for example to reduce the number of pulses, the duration of the pulses and/or the time interval between two pulses.
(24) With reference to
(25) Furthermore, the anti-lock module 30 delivers, for each wheel 5, a continuous signal to the computer 10, denoted orientation signal S.sub.o. Such an orientation signal S.sub.o indicates the angular orientation (between 0 and 360) of the wheel 5 facing which the anti-lock module 30 is installed. Specifically, when the vehicle 1 is moving, each wheel 5 turns at a speed different from the other wheels 5, as described above and illustrated in
(26) The computer 10 is therefore able, at a given time, to measure both the received power P of the measured signal S.sub.m emitted by each measurement module 20 and the angular orientation of each wheel 5 facing each anti-lock module 30.
(27) Preferably, with the measurement module 20 emitting a measured signal S.sub.m for a predetermined time interval, the computer 10 is configured so as to measure the power P of the received measured signal S.sub.m and determine, on the basis of each orientation signal S.sub.o received from each wheel 5, the angular orientation value of each of the wheels 5 corresponding to the measured power P.
(28) In other words, the computer 10 is able, for each measurement module 20, to determine a plurality of received measured signal S.sub.m power P measurements associated with a plurality of angular orientation measurements from the four anti-lock modules 30.
(29) The computer 10 is also configured so as to correlate the power P of the measured signal S.sub.m received from each measurement module 20 as a function of the angular orientation of each of the wheels 5 for a plurality of positions of each wheel 5, that is to say for a plurality of angular orientations of each of the wheels 5, typically obtained for a plurality of wheel 5 revolutions, so as to associate each wheel 5 with a measurement module 20, as will be explained hereinafter.
(30) An aspect of the invention will now be described in terms of the implementation thereof with reference to
(31) First of all, with reference to
(32) With reference to
(33) The angular orientation range of the wheels 5 may be expressed in degrees and be contained within the interval [0; 360], or else be expressed as a number of teeth of a disk mounted on each wheel 5 measured by the anti-lock module 30 in a manner known per se.
(34) To determine the power P range of the measured signal S.sub.m received from the measurement modules 20, the computer 10 may for example determine beforehand, in an initialization phase (that is to say before proceeding with pairing), the maximum power P and the minimum power P of the measured signals S.sub.m received during one or more wheel 5 revolutions. As a variant, the table T may be defined in advance and stored in a memory zone of the computer 10.
(35) Preferably and by way of example, such a table T comprises between eight and twenty-four rows, preferably sixteen rows, and between eight and thirty-two columns, preferably sixteen columns.
(36) This table T makes it possible to classify a power P of a received measured signal S.sub.m and angular orientation pair (P, ) of a wheel 5 in a cell of the table T by associating it with a row and column pair (k, m) of the table T.
(37) To associate each measurement module 20 with the wheel 5 in which it is installed, the computer 10 will carry out, preferably simultaneously, for at least three measurement modules 20, a series of four successive steps E1 to E4 that will be repeated several times for each measurement module 20 with each of the wheels 5.
(38) For the sake of clarity, the method will be described hereinafter in steps E1 to E4 thereof for a given measurement module 20.
(39) First of all, the computer 10 receives, in a step E1, in the form of a train of frames, a measured signal S.sub.m emitted by the measurement module 20 in the form of a pulse train.
(40) In parallel, in a step E2, the computer 10 receives the orientation signal S.sub.o representing the angular orientation , sent by each anti-lock module 30 of each wheel 5 of the vehicle 1.
(41) In a step E3, the computer 10 determines the power P of the measured signal S.sub.m during the time interval over which it is received and correlates it, for each wheel 5 of the vehicle 1, with the angular orientation given by the orientation signal S.sub.o received in step E2.
(42) Preferably, each frame of the received measured signal S.sub.m is sampled by the computer 10, which then associates the value of the power P of each sample (for example three samples per frame) with an angular orientation value for each wheel 5, thus forming power P and angular orientation value pairs (P, ) for each of the wheels 5.
(43) In a step E4, the computer 10 then identifies, in each table T of a plurality of tables T (a table T corresponding to one of the four wheels 5), a row and column pair (k, m) for each power P and angular orientation pair (P, ) determined in step E3.
(44) Steps E1 to E4 are repeated upon each emission of a measured signal S.sub.m by the measurement module 20 so as to be able to evaluate the power P of the measured signal S.sub.m over a significant portion of the angular orientation range and thus determine a large number of power P and angular orientation pairs (P, ) for each wheel 5.
(45) The power P of the measured signal S.sub.m is preferably evaluated over at least 30% of each angular orientation range of each wheel 5 (that is to say over 30% of the columns of each table T), this value statistically making it possible to associate enough power P and angular orientation value pairs (P, ) of each table T to allow the measurement module 20 to be paired with a wheel 5.
(46) In the illustrative (but nonlimiting) example of
(47) Steps E1 to E4 are repeated several times until the computer 10 determines, in a step E5, that a decision criterion is met so as to associate a given measurement module 20 with a given wheel 5.
(48) Preferably, this decision criterion is a minimum number of angular orientations of each wheel 5 covered over the range of each table T, as described above.
(49) In practice, the computer 10 will determine that a measurement module 20 is installed in a given wheel 5 when, after the number of columns of each table T has reached a first minimum threshold, for example 30% of the total number of columns of each table T, the number of row and column pairs (k, m) identified in a table T for said wheel 5 is lower than a maximum threshold, for example between 30% and 50%, preferably 30%, that is to say seventy-six to one hundred and twenty-eight pairs (k, m) for a table T of sixteen rows by sixteen columns, and the number of row and column pairs (k, m) identified in the other tables T for the other wheels 5 is lower than a second minimum threshold, for example 90% of all of the row and column pairs (k, m) of each table T.
(50) As a variant, the computer 10 may also determine that a measurement module 20 is not installed in a given wheel 5 when, after the determined number of columns of each table T has reached the first minimum threshold, the number of row and column pairs (k, m) identified for said wheel 5 is higher than the second minimum threshold, or even higher than 70%, for example higher than 90%, and the number of row and column pairs (k, m) identified for another wheel 5 is lower than the maximum threshold.
(51) Pairing may also be performed for a given measurement module 20 when, after the number of columns of each table T has reached the first minimum threshold, the number of row and column pairs (k, m) identified in one of the tables T is lower than the maximum threshold and the number of row and column pairs (k, m) identified for each of the other tables T is higher than the second minimum threshold and contained within one and the same interval of predetermined width, for example 5%, of the total number of row and column pairs (k, m) of the table T. Such proximity between the numbers of row and column pairs (k, m) identified for the other tables T advantageously makes it possible to increase the first minimum threshold (for example from 30% to 40%) while at the same time lowering the maximum threshold (for example from 90% to 70%).
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(53) Each graph illustrates the evolution of the power P of the measured signal S.sub.m received by the computer 10 as a function of the angular orientation of a given wheel 5 for a plurality of measured signals S.sub.m sent over the course of several wheel 5 revolutions.
(54) In this example, the four wheels 5 are denoted as follows: FL, meaning front left, FR, meaning front right, RL, meaning rear left, RR, meaning rear right.
(55) The power P of the measured signals S.sub.m received by the computer 10 and emitted by each of the measurement modules 20 (FL.sub.20, FR.sub.20, RL.sub.20 and RR.sub.20) are described as a function of the angular orientations given by each anti-lock module 30 (FL.sub.30, FR.sub.30, RL.sub.30 and RR.sub.30).
(56) It is thus deduced that a measurement module 20 is associated with the wheel 5 in which it is installed when the evolution of the power P of the received measured signals S.sub.m as a function of the angular orientation is substantially identical over the course of the received measured signals S.sub.m (cases FL.sub.20/FL.sub.30, FR.sub.20/FR.sub.30, RR.sub.2/RR.sub.30 and RL.sub.20/RL.sub.30 in
(57) Likewise, it is deduced that a measurement module 20 is not associated with a wheel 5 when the evolution of the power P of the received signals as a function of the angular orientation differs over the course of the received measured signals S.sub.m, that is to say that the graphs are not superimposed over the course of the measured signals S.sub.m (all of the other cases in
(58) In this example, the computer 10 determines the number of pairs (k, m) identified over sixteen tables T (four tables T per measurement module 20).
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(60) This table T includes ten rows and ten columns corresponding respectively to a number of ten intervals representative of the power P range of the measured signal S.sub.m received by the computer 10, and to a number of ten intervals representative of the angular orientation range of the wheel 5.
(61) In this example, the table T (FL.sub.20/FL.sub.30) comprises, after a plurality of measured signals S.sub.m, sent after a plurality of wheel 5 revolutions, covering a plurality of angular orientations , twenty-nine determined pairs (k, m) out of a hundred possible pairs (k, m).
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(63) In this example illustrating the power P of the measured signal S.sub.m received by the computer 10 and emitted by the measurement module 20 of the front-left FL.sub.20 wheel 5, plotted as a function of the angular orientation of the front-right FR.sub.30 wheel 5, it is noted that the power P graphs obtained for several measured signals S.sub.m are not superimposed. The computer 10 therefore deduces from this, by combining these results with the results of the other wheels 5, that the measurement module 20 of the front-left FL.sub.20 wheel 5 is not associated with the front-right FR.sub.30 wheel 5.
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(65) In this example, it is observed that the percentage of pairs (k, m) determined for the front-right FR.sub.30 wheel 5 increases very quickly above 30% for more than two received measured signals S.sub.m and tends toward a limit close to 90% for more than fifteen received measured signals S.sub.m, whereas the percentage of pairs (k, m) determined for the front-left FL.sub.30 wheel 5 never exceeds 30% regardless of the number N.sub.s of received measured signals S.sub.m.
(66) The method has been described for a vehicle 1 comprising four wheels 5, but it goes without saying that the vehicle 1 could equally comprise more or fewer wheels 5. Likewise, the example describes a table T comprising a set of ten rows and ten columns corresponding respectively to a number K of ten intervals representative of the power P range of the measured signal S.sub.m received by the computer 10, and to a number M of ten intervals representative of the angular orientation range of the wheel 5. However, it goes without saying that the table T could comprise a different number K of intervals representative of the power P range of the measured signal S.sub.m received by the computer 10, and a different number M of intervals representative of the angular orientation range of the wheel 5.
(67) The method according to an aspect of the invention is therefore able to converge very quickly and advantageously requires only little processing capability of the computer 10, such that the measurement modules 20 are able to be paired with their respective wheels 5 quickly and efficiently. In addition, the method described in this document does not require the presence of an acceleration sensor in the measurement module 20 of each wheel 5, thereby making the architecture of the computer 10 less complex and limiting costs.