Method for locating a vehicle, associated electronic locating device and computer program product

Abstract

Method for locating a vehicle, electronic locating device and associated computer program product The present invention relates to a method for locating a vehicle (10), in particular a railway vehicle, moving on a track (13). The method comprises the following steps: measuring, at successive times, a speed of the vehicle and an inclination (α) of the track in at least one direction to obtain a data set at each time, the set of data sets forming an instantaneous profile of the track, comparing the instantaneous profile with a plurality of signatures, and identifying signatures corresponding to the instantaneous profile and defining a section of the track profile, each signature comprising: a speed measurement, a measurement of the inclination of the track in a direction, and a position, and determining a position of the vehicle as a function of the position of the at least one identified signature. Figure for abstract: Figure 1

Description

Title of the invention: Method for locating a vehicle, associated electronic locating device and computer program product

[0001] The invention relates to a method for locating a vehicle.

[0002] The invention also relates to an electronic device for locating a vehicle, and to a computer program product adapted to implement the locating method.

[0003] The invention relates to the field of locating a vehicle in motion on a railway track.

[0004] Document DE 10 2012 209311 discloses a method for locating a railway vehicle. The method comprises generating a plurality of hypotheses of the vehicle's position. Then, the method comprises, at a characteristic instant, a measurement of an inclination of the track on which the vehicle is traveling, a measurement of the vehicle's speed and a measurement of the vehicle's acceleration. From the measurements obtained at the characteristic instant, the method comprises calculating the probability of each hypothesis being true using a Bayesian network. The method further comprises applying particle filter(s) to the probabilities to obtain the vehicle's position.

[0005] However, such a localization method is complex to implement.

[0006] The object of the invention is therefore to propose a method for locating a vehicle that is simpler to implement.

[0007] To this end, the present invention relates to a method for locating a vehicle, in particular a railway vehicle, moving on a track, the method being implemented by an electronic locating device and comprising the following steps: - measurement, at successive times, of a vehicle speed and an inclination of the track in at least one direction to obtain a data set at each time, the set of data sets forming an instantaneous profile of the track, - comparison of the instantaneous profile with a plurality of signatures, and identification of signatures corresponding to the instantaneous profile and defining a section of the track profile, the plurality of signatures defining a track profile over time, each signature comprising: at least one speed measurement, at least one track inclination measurement in at least one direction, and at least one position, and - determination of a position of the vehicle based on the position of at least one identified signature.

[0008] According to particular embodiments, the method comprises one or more of the following characteristics, taken in isolation or in all technically possible combinations: - the plurality of signatures is generated from a machine traveling on the track, each signature comprising, for a time specific to the signature: a measurement of the speed of the machine, a measurement of the inclination of the track and a measurement of the position of the machine, - each inclination measurement is chosen from a group comprising: a vehicle roll angle and a vehicle pitch angle, - the method further comprises a resampling step during which, if the speed measurements of the instantaneous profile differ from the speed measurements of the signatures by more than a first predefined value, at least one data set is deleted from the instantaneous profile and / or at least one additional data set is added to the instantaneous profile, each additional data set comprising a speed measurement and an inclination measurement, at an additional instant between two measurement instants for which the instantaneous profile comprises a data set, - the method further comprises a step of updating the plurality of signatures, by adding, to the plurality of signatures, a newly generated signature comprising: a data set of the instantaneous profile, and the determined position, - the method further comprises the following steps: • reception of a position of the vehicle, called received position, and • calculation of an improved position of the vehicle by data fusion between at least the determined position and the received position, and - the method further comprises the following steps: • reception of a position of the vehicle, called received position; and • selection of signature(s) from among the plurality of signatures of which the position differs from the received position by at most one second value, • second step of comparing at least one of the inclination measurements of the instantaneous profile, to the inclination measurement of each selected signature, and • detection of anomaly(ies) if, during the second comparison step, at least one difference between two compared inclination measurements is greater than a third value.

[0009] The present invention also relates to an electronic location device.

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

[0016]

[0017] of a vehicle, in particular a railway vehicle, moving on a track, the electronic location device comprising: - at least one sensor configured to measure, at successive times, a speed of the vehicle and an inclination of the track in at least one direction to obtain a data set at each time, the set of data sets forming an instantaneous profile of the track, - a comparison module configured to compare the instantaneous profile to a plurality of signatures, the plurality of signatures defining a profile of the track over time, each signature comprising: at least one speed measurement, at least one measurement of the track inclination in at least one direction, and at least one position, and to identify the signature(s) corresponding to the instantaneous profile and defining a section of the track profile, and - a determination module configured to determine a position of the vehicle from the position of the at least one identified signature. According to a particular embodiment, the electronic location device comprises the characteristic according to which the plurality of signatures is included in a database remote from the vehicle, the device further comprising on-board communication means capable of exchanging data between the vehicle and the database. The present invention also relates to a computer program product comprising software instructions suitable for, when implemented by computer, implementing at least the steps of comparison, identification and determination of a location method as defined above. Other characteristics and advantages of the invention will appear on reading the following description of embodiments of the invention, given by way of example only and with reference to the appended drawings in which: [Fig.l] [Fig.l] is a partial schematic representation of a railway vehicle comprising an electronic location device according to the invention, the device communicating with a database; [Fig.2] [Fig.2] is a graphical representation of changes in vehicle roll measurements and cant of a section of track over time; and [Fig.3] [Fig.3] is a flowchart of an example of implementation of a localization method according to the invention. An example of a portion of a vehicle 10 is illustrated in [Fig.l]. For example, the vehicle 10 is a railway vehicle, such as a train, a subway or a tram. The vehicle 10 is moving on a track 13. When the vehicle 10 is a railway vehicle, the track 13 typically comprises rails 15.

[0018] The vehicle 10 comprises on-board communication means 20, an electronic location device 25 capable of locating the vehicle 10, and optionally an external positioning device 30 configured to obtain a position Lr, / ., of the vehicle 10, called the received position, by means external to the vehicle 10 not shown, and to transmit the received position Lr, / ., to the location device 25.

[0019] The on-board communication means 20 are connected to the location device 25 and configured to exchange signals with remote communication means 32, themselves connected to a remote database 35. The remote communication means 32 and the database 35 are for example located in a centralized station such as a server room, several kilometers away from the vehicle 10. Such a database 35 is then able to exchange signals, via the remote communication means 32, with a plurality of vehicles 10.

[0020] Alternatively, the database 35 is included within the vehicle 10, and is directly connected to the electronic location device 25.

[0021] As a further variant, a part of the database 35 comprising the data corresponding to the route planned by the vehicle 10 is loaded into the location device 25 prior to the movement of the vehicle 10.

[0022] The data contained in the database 35 will be detailed below.

[0023] The location device 25 comprises a set of sensor(s) 40, a computer 45 capable of processing quantities measured by the set of sensor(s) 40, and optionally an audible or luminous warning device 46.

[0024] Optionally, the on-board communication means 20 are included in the location device 25.

[0025] The set of sensor(s) 40 is capable of measuring at successive instants f, a speed V of the vehicle 10 and at least one inclination of the track 13 in at least one direction. For this purpose, the set of sensor(s) 40 comprises for example a first angular sensor 50, a second angular sensor 55, a speed sensor 60 and optionally a time sensor 65 and an altitude sensor 70.

[0026] The first angular sensor 50 is configured to measure a pitch angle α of the vehicle 10. The vehicle 10 being in contact with the track 13 via the rails 15, the pitch angle α of the vehicle 10 is representative of a slope of the track 13. In other words, the pitch angle α characterizes a variation in altitude of the vehicle 10 as it advances on the track 13. Thus, when the track 13 has a slope, the pitch angle α is positive. Conversely, when the track 13 has a descent, the pitch angle α is negative.

[0027] The second angular sensor 55 is configured to measure a roll angle [3 of the vehicle 10. In a manner analogous to the pitch angle a, the roll angle [3 is represented indicative of a cant of the track 13. The term cant is understood here in the sense of an angle defined around a longitudinal axis X along which the track 13 extends. The vehicle 10 is suitable for traveling along the longitudinal axis X. By convention, for a passenger of the vehicle 10 looking in the direction of travel of the vehicle 10, when the vehicle 10 leans to the left, the associated roll angle [3 is positive. Still by convention, for this same passenger, when the vehicle 10 leans to the right, the associated roll angle [3 is negative. It follows that when the vehicle 10 leans neither to the left nor to the right, the roll angle [3 is substantially zero.

[0028] It is noted that for a railway vehicle, when the rails 15 are such that the vehicle 10 makes a turn to the left, the roll angle [3 is positive. Similarly, when the rails 15 are such that the vehicle 10 makes a turn to the right, the roll angle [3 is negative.

[0029] The unit of measurement of the pitch angles a and roll angles [3 is for example the degree, noted °.

[0030] The first 50 and second 55 angular sensors are for example included in a two-axis inclinometer, integrated into the vehicle 10.

[0031] The speed sensor 60 is configured to measure the speed V of the vehicle 10 along the longitudinal axis X. Alternatively, the speed sensor 60 receives the speed V of the vehicle 10 from an on-board computer not shown and included in the vehicle 10. The unit of measurement of the speed V of the vehicle 10 is for example the kilometer / hour.

[0032] The time sensor 65, or stopwatch, is configured to measure the elapsed time. More specifically, the stopwatch 65 is configured to measure each measurement instant f, at which the set of sensor(s) 40 performs a measurement.

[0033] The altitude sensor 70, or altimeter, is configured to measure an altitude of the vehicle 10 above sea level. The altitude sensor 70 is known per se and is, for example, suitable for measuring the altitude of the vehicle 10 from ambient air pressure measurements. The unit of altitude H is, for example, the meter.

[0034] At each measurement instant f, the set of sensor(s) 40 is configured to measure the pitch angle a, the roll angle [3, the speed V, and optionally the measurement instant f, and the altitude H. A duration between two measurement instants f is for example equal to five seconds or fifteen seconds. Thus, the acquisition frequency of each sensor 50, 55, 60, 65, 70 is preferably equal, so that at each measurement instant f, each sensor 50, 55, 60, 65, 70 performs a measurement simultaneously.

[0035] The set of sensor(s) 40 is configured to form, for each measurement instant f, a set of measurements, and to form an instantaneous profile of the channel 13 by concatenation of the successive sets of measurements. The set of sensor(s) 40 is further configured to send to the computer 45, the instantaneous profile of the channel 13. A example of instantaneous track profile is shown in the following table 1:

[0036] [Tables 1] V (km / h) 280 281 279 280 a(°) 1.1 1.0 1.0 0.9 P (°) 2.1 2.3 2.5 1.9 ti(s) ti ti+5 t[+10 ti+15 H (m) 112 114 115 115

[0037] where ti denotes an arbitrarily chosen measurement time.

[0038] The instantaneous profile of the track 13 is a set of data measured at successive times and characterizing a temporal evolution of the data of the track 13 traveled by the vehicle 10 between a first measurement time ti and a last measurement time.

[0039] Alternatively, the set of sensor(s) 40 is configured to send each data set to the computer 45. The computer 45 is then configured to generate the instantaneous profile of the channel 13 by concatenating the received data sets.

[0040] The computer 45 comprises a processor 75 and a memory 80. The memory 80 is suitable for storing software modules, or software bricks, intended to be executed by the processor 75. In addition, the computer 45 comprises a plurality of communication ports, in particular ports of the universal serial bus (USB) type, or even Ethernet ports, via which the computer 45 is connected to the set of sensor(s) 40 and to the on-board communication means 20, by connectors. The computer 45 is configured to exchange data with equipment external to the vehicle 10 via the on-board communication means 20.

[0041] The memory 80 comprises a comparison software module 85, a determination software module 90, and optionally an update software module 95, a calculation software module 100, a selection software module 105, and a detection software module 110.

[0042] The comparison module 85 is configured to compare the instantaneous profile, received from the set of sensor(s) 40, to a plurality of signatures received from the database 35 via the on-board communication means 20. These communication means can be supported by general public networks, or private networks. They can use GSM-R technologies, or even FRMCS.

[0043] The plurality of signatures defines a profile of the track 13 over time. More specifically, each signature comprises data characteristic of the track 13. In particular, each signature is specific to a position expressed by a longitude L and a latitude X. Each signature comprises a slope a' and a superelevation [3' of the track 13 at the aforementioned position. For example, each signature corresponds to measurements made by a machine not shown having traveled on track 13 before vehicle 10 and whose position L, X at each instant was known. Thus, the slope a' and the superelevation [3' are respectively measurements of the pitch and roll angle of the machine, acquired at a respective instant t'; of the signature. In addition, each signature includes a speed V' of the machine at the instant t'; of the signature, the instant t'; of the signature, and the altitude H' of the machine at the instant t'; of the signature.

[0044] An example of a time profile of a section of track 13 is presented in the following table:

[0045] [Tables2] V' (km / h) 140 139 139 137 137 139 140 141 a' (°) 1.0 1.2 1.1 1.0 0.9 0.8 0.9 1.0 13' (°) 2.1 2.3 2.4 2.4 2.5 2.1 1.9 1.7 t'i(s) t'o t'o+5 t'o+10 10+15 t'o+20 1o+25 t'o+30 t 0+35 H' (m) 112 113 113 114 114 115 115 115 L(°) -1.1511 -1.1511 -1.1510 -1.1510 -1.1510 -1.1510 -1.1510 -1.1509

[0046] where t'o is an arbitrarily chosen instant.

[0047] The comparison module 85 is therefore configured to compare the measurements of each of the instantaneous profile of the channel 13 and the signatures. For this purpose, the comparison module 85 is for example configured to generate a likelihood indicator between the instantaneous profile and a part of the signatures of the database 35.

[0048] The likelihood indicator characterizes similarities between the instantaneous profile and a part of the signatures. Thus, the higher the likelihood indicator, the more the instantaneous profile corresponds to the part of the signatures.

[0049] More particularly, in one example the comparison module 85 is configured to calculate an integral of each measurement with respect to time. [Fig. 2] graphically represents an example of temporal evolutions of the roll angle [3 by circles connected by solid lines, and of the slope [3' by crosses connected by dotted lines. Thus, as visible in [Fig. 2], the data to be integrated are discrete. Thus each integral is for example obtained using a method of rectangles, trapezoids or Runge-Kutta of order four. Consequently, the comparison module 85 is configured to generate the likelihood indicator from the difference(s) between the integrals of the instantaneous profile and those of the signatures.

[0050] The comparison module 85 is further configured to identify, among the plurality of signatures, those corresponding to the instantaneous profile. For this purpose, the comparison module 85 is for example configured to apply an operational search algorithm on the likelihood indicator by varying the chosen signatures, the algorithm providing a set of signatures, called identified signatures, maximizing the likelihood indicator with the instantaneous profile. Thus, the identified signatures are specific to the section traveled by the vehicle 10, and for which the instantaneous profile is measured.

[0051] As an optional addition, the comparison module 85 is configured to, prior to the comparison, perform a resampling of the data sets of the instantaneous profile. The comparison module 85 is configured to, if the speeds of the instantaneous profile differ from those of the signatures by more than a first predefined value, resample the data sets of the instantaneous profile. In other words, the comparison module 85 is configured to, where appropriate, delete one or more data sets of the instantaneous profile and / or add, to the instantaneous profile, one or more additional data sets, corresponding to an additional instant between two measurement instants of the instantaneous profile. The measurements of the additional data set are then obtained for example by averaging the measurements of the data set at the instant preceding the additional instant and the measurements of the data set at the instant following the additional instant in the instantaneous profile.The comparison module 85 is then configured to adapt the speed measurements of the instantaneous profile so that they correspond to the speeds V of the signatures.

[0052] In the example of [Fig.2] and of tables 1 and 2, the speeds V' of the signatures of the database 35 are two times lower than those of the vehicle 10 contained in the instantaneous profile of the track. Thus, in [Fig.2], the roll angle [3 presents a similar evolution to that of the slope towards [3' of the signatures represented. However, the shape of the curve representing the roll angle [3 is more contracted than that representing the slope |3', because the speeds of the instantaneous profile are greater than those of the signatures represented. The comparison module 85 is then configured to add between each data set of the instantaneous profile of the track 13, an additional data set.More particularly, the additional data set between the first two data sets of the instantaneous profile of track 13 comprises, for example, an additional pitch angle a” equal to 1.05°, an additional roll angle |3” equal to 2.2°, an additional measurement time t”; equal to ti+2.5, an additional altitude H' ' equal to 113 m. The speed V' ' of the additional set is, for example, equal to 140.5 km / h.

[0053] The determination module 90 is configured to determine a position LD, XD of the vehicle 10 from the position L, / . of at least one of the identified signatures. For this, the determination module 90 is configured to determine the longitude LD of the vehicle 10, for example, equal to the average of the longitudes L of the identified signatures, and the latitude XD, for example, equal to the average of the latitudes / . of the identified signatures. In the example of tables Table 1 and Table 2 and of [Fig.2], the determination module 90 is configured to determine a position whose longitude LD is equal to -1.1510 and whose latitude XD is equal to 46.1605. Alternatively, the determined position LD, XD is equal to the position L, / . of the selected signature whose instant t'; is the latest.

[0054] As an optional addition, the update module 95 is configured to update the database 35 from the instantaneous profile of the channel 13 and the determined position LD, XD. The update module 95 is then configured to generate a new signature comprising the determined position LD, XD and one of the data sets of the instantaneous profile or a combination of the data sets of the instantaneous profile. By way of example, the generated signature comprises for example the determined position LD, XD and the data set of the instantaneous profile corresponding to the latest measurement instant h. Thus, in the example of tables Table 1 and Table 2 and of [Fig.2], the generated signature is represented in the following table 3:

[0055] [Tables3] V'” (km / h) 280 a'” (°) 0.9 P'”(°) 1.9 h'” (s) ti+15 H'”(m) 115 Ld(°) -1.1510 M°) 46.1605

[0056] Optionally, the update module 95 is further configured to send the newly generated signature to the database 35, via the on-board communication means 20. The newly generated signature is then included in the database 35.

[0057] As an optional addition, the calculation module 100 is configured to, when the vehicle 10 comprises the external positioning device 30, receive the received position Lr, / ., from said external positioning device 30. The received position Lr, comprises a received longitude Lr and a received latitude Xr. The calculation module 100 is further configured to calculate an improved position of the vehicle 10, comprising an improved longitude La and an improved latitude Xa, from the position determined Ld, Xd by the determination module 90 and the position received Lr, Xr. For this purpose, the calculation module 100 is configured to perform a data fusion between the determined position LD, XD and the position received Lr, Xr.

[0058] Optionally, the calculation module 100 is optionally configured to further replace the longitude LD and the latitude XD determined by the improved longitude La and the improved latitude X., in the signature newly generated by the update module 95.

[0059] As an optional addition, the selection module 105 is configured to, when the vehicle 10 comprises the external positioning device 30, select from the plurality of signatures in the database 35, the signature(s) whose position L, X differs from the received position Lr, X, by at most a second value. In other words, the selection module 105 is configured to select the signatures whose position L, X is within a predefined perimeter around the received position Lr, Xr. For example, the selection module 105 is configured to define a circle around the received position Lr, Xr whose radius is equal to the second value, and to select, from the signatures in the database 35, the signature(s) whose position L, X is included in said circle.

[0060] Optionally, the anomaly detection module 110 is configured to compare each pitch measurement a and roll [3 of the instantaneous profile, with the slopes a' and cant [3' of each signature selected by the selection module 105. The detection module 110 is further configured to detect an anomaly if, when comparing the inclination measurements of the instantaneous profile and that of the selected signatures, at least one difference between two compared inclination measurements is greater than a third value.

[0061] Alternatively, the detection module 110 is configured to calculate an average of the pitch and roll measurements [3] of the instantaneous profile, and an average of the slopes a' and the cants [3' of the selected signatures. The detection module 110 is configured to detect the anomaly if one of the differences between the pitch and slope averages and between the roll and cant averages is greater than the third value, in absolute value.

[0062] The detected anomaly therefore corresponds to a discrepancy between the angles a, [3 measured by the set of sensor(s) 40 and the slopes a' or overhang [3' of the selected signatures. Such a discrepancy is for example due to a landslide, to an error during the constitution of the database 35, or to a calibration error of the first 50 and / or second 55 angular sensor(s). In this, the detection module 110 is configured to detect inconsistencies between the measurements made by the vehicle 10 and those present in the database 35.

[0063] The detection module 110 is further optionally configured to, in the event of detection of an anomaly(ies), send an alarm signal to the warning device 46 of the vehicle 10.

[0064] Optionally, the warning device 46 is configured to then emit an audible signal or light up an indicator light, intended to alert a driver of the vehicle 10.

[0065] Alternatively or as an optional addition, the detection module 110 is configured to send the alarm signal to the database 35, via the on-board communication means 20.

[0066] As an optional addition, the external positioning device 30 is configured to obtain the received position Lr, / ., by communication with systems external to the vehicle 10, not shown. For this purpose, the external positioning device 30 is for example a GNSS (Global Navigation Satellite System) receiver integrated into the on-board computer of the vehicle 10. The external positioning device 30 is then configured to exchange signals with satellites and obtain the received position Lr, / ., of the vehicle 10 according to a technique known per se. The external positioning device 30 can also use satellite-based augmentation systems, also called SBAS (Satellite Based Augmentation System).

[0067] Alternatively, the external positioning device 30 is a GSM (Global System for Mobile Communications) module configured to exchange signals with telephone relay antennas not shown and to deduce the position Lr, / ., of the vehicle 10 from said signals according to a technique known per se.

[0068] As a further variant, the external positioning device 30 is configured to directly receive the position Lr, / ., of the vehicle 10 from a beacon not shown on the track 13 capable of communicating with said device 30. The external positioning device 30 is connected to the computer 45 and is configured to send the received position of the vehicle 10 to the computer 45.

[0069] As a variant, the software modules 85, 90, 95, 100, 105, and 110 of the computer 45 are remoted into the server room where the database 35 is located. Thus, in this variant, the computer 45 is only a relay used to transmit the instantaneous profile to the set of software modules 85, 90, 95, 100, 105, and 110, via the on-board communication means 20.

[0070] The operation of the electronic location device 25 will now be described with reference to [Fig. 3] showing a flowchart of a method implemented by said device 25.

[0071] Prior to the vehicle 10 being put into circulation on track 13, the database 35 is generated from measurements taken by one or more machines traveling on track 13 and acquiring at different successive times t'; measurements of their longitude L, their latitude X, their speed V', the slope a' of track 13 and / or the superelevation [3' of track 13. Optionally, the machine(s) also acquire measurements of the altitude H' of track 13, and the measurement time t';. These measurements are compiled in the form of a plurality of signatures and stored in the database 35, thus forming a profile of track 13 over time.

[0072] Initially, the vehicle 10 is traveling on track 13 and its driver, or an automation system allowing automatic piloting, wishes to determine the position LD, XD of said vehicle 10.

[0073] During a measurement step 210, the set of sensor(s) 40 measures, at successive measurement times f, the speed V, the pitch angle a and / or the roll angle [3 of the vehicle 10. As an optional addition, the set of sensor(s) 40 further measures the altitude H of the vehicle 10 as well as the measurement time f at which the measurements are taken. At each measurement time f, the measurements form a data set. All of the data sets then form an instantaneous profile of the track 13. The instantaneous profile of the track 13 is then sent, by the set of sensor(s) 40, to the computer 45.

[0074] Optionally, during a resampling step 220, if the speed measurements V of the instantaneous profile differ from the speeds V' of the signatures by more than the first value, the comparison software module 85 resamples the instantaneous profile of the channel 13 by adding one or more additional data sets to the instantaneous profile of the channel 13, or by deleting data sets from the instantaneous profile and modifying the speeds V of the instantaneous profile so that they correspond to the speeds V' of the signatures.

[0075] Then, during a comparison step 230, the comparison module 85 compares the instantaneous profile and the signatures of the database 35. For this purpose, the comparison module 85 compares the pitch measurements a with the slopes a', the roll measurements [3 with the cants |3', and optionally the altitude measurements H with the altitudes H' of the track 13. For this purpose, the comparison module 85 calculates, for example, a likelihood indicator between the instantaneous profile and a portion of the plurality of signatures. For this, the comparison module 85 applies an operational search algorithm to the likelihood indicator by varying the signatures of the database.

[0076] Following the application of this algorithm, during an identification step 235, the comparison module 85 identifies, among the plurality of signatures, which correspond to the instantaneous profile of the track, that is to say those which maximize the likelihood indicator. The identified signatures then correspond to the section of the track 13 described by the instantaneous profile.

[0077] During a determination step 240, the determination module 90 determines the position Ld, Xd of the vehicle 10 from the positions L, X of the identified signatures. The determined position LD, XD comprises for example a determined longitude LD equal to the average of the longitudes L of the identified signatures, and a determined latitude XD equal to the average of the latitudes X of the identified signatures.

[0078] As an optional addition, during a reception step 245, the computer 45 receives the received position Lr, X, from the external positioning device 30. The received position includes for example the received longitude Lr and the received latitude Xr.

[0079] Optionally, during a calculation step 250, the calculation module 100 calculates the improved position La, Xa by data fusion between the determined position LD, XD and the received position Lr, Xr. For this, the calculation module 100 calculates the improved longitude La and the improved latitude Xa. For this purpose, the calculation module 100 implements for example the techniques described in the CLUG project, meaning Certifiable Localisation Unit based on GNSS (from the English, Certifiable Localisation Unit with GNSS).

[0080] Optionally, during an update step 260, the update module 95 generates the newly generated signature from the data sets of the instantaneous profile and the determined position LD, XD, as described previously. The update module 95 then sends the newly generated signature to the database 35, via the on-board communication means 20. The newly generated signature is then added to the plurality of signatures of the database 35.

[0081] As an optional addition, during the update step 260, the calculation module 100 replaces the determined position LD, XD with the improved position La, Xa in the newly generated signature.

[0082] Optionally, during a selection step 270, the selection module 105 selects, from among the signatures of the database 35, the signature(s) whose position L, X differs from the received position Lr, Xr by at most the second value. In other words, the selection module 105 calculates a distance between the received position Lr, Xr and the position L, X of each signature and selects the signatures for which said distance is less than the second value.

[0083] As an optional addition, during a second comparison step 280, the detection module 110 compares the inclination measurements a, [3 of the instantaneous profile with the slopes a' and the cants [3' of the selected signatures. More specifically, the detection module 110 compares the pitch measurements a with the slope a' of each selected signature and the roll measurements [3 with the cant [3' of each selected signature.

[0084] If at least two of the compared quantities differ by more than the third value, then, during an optional detection step 290, the detection module 110 detects the anomaly.

[0085] If the anomaly is detected, during an optional sending step 300, the detection module 110 sends the alarm signal to the warning device 46 and / or to the database 35, via the on-board communication means 20.

[0086] Alternatively, the selection step 270, the second comparison step 280, the detection step 290 and the sending step 300, optional, precede, or are carried out in parallel with the calculation steps 250 and update steps 260.

[0087] The location method and the electronic location device 25 simplify, in particular thanks to the first comparison step 230, the determination of the location of the vehicle 10.

[0088] Furthermore, when the database 35 is remote from the vehicle 10, it is able to communicate with several vehicles 10 simultaneously. As a result, when the update module 95 adds the newly generated signature to the database 35, each vehicle 10 benefits simultaneously from this addition.

[0089] Furthermore, when the database 35 is fully or partially included in the vehicle 10, the location device 25 is able to determine the location of the vehicle 10 even when it cannot communicate with any external system, in particular in a tunnel or in an area without network coverage.

[0090] Those skilled in the art will understand that the previously described variants can be combined to form new variants provided that they are technically compatible.

Claims

Claims

1. Method for locating a vehicle (10), in particular a railway vehicle, moving on a track (13), the method being implemented by an electronic locating device (25) and comprising the following steps: - measuring (210), at successive times (h), a speed (V) of the vehicle and an inclination (a, P) of the track in at least one direction to obtain a data set at each time, the set of data sets forming an instantaneous profile of the track, - comparing (230) the instantaneous profile with a plurality of signatures, and identifying (235) signatures corresponding to the instantaneous profile and defining a section of the track profile, the plurality of signatures defining a profile of the track over time, each signature comprising: at least one speed measurement (V'), at least one track inclination measurement (a', [3') in at least one direction, and at least one position (L, X),and - determination (240) of a position (LD, XD) of the vehicle as a function of the position (L, X) of the at least one identified signature.,

2. Method according to claim 1, in which the plurality of signatures is generated from a machine traveling on the track (13), each signature comprising, for an instant (t'i) specific to the signature: a speed measurement (V') of the machine, a measurement of inclination (a', P') of the track (13) and a measurement of position (L, X) of the machine.

3. A method according to claim 1 or 2, wherein each tilt measurement (a, P) is selected from a group comprising: a roll angle (P) of the vehicle (10) and a pitch angle (a) of the vehicle (10).

4. Method according to any one of claims 1 to 3, further comprising a resampling step (220) during which, if the velocity measurements (V) of the instantaneous profile differ from the velocity measurements (V') of the signatures by more than a first predefined value, at least one data set is deleted from the instantaneous profile and / or at least one additional data set is added to the instantaneous profile, each additional data set comprising a speed measurement (V”) and an inclination measurement (a”, |3”), at an additional time (t”;) between two measurement times (h) for which the instantaneous profile comprises a data set.

5. A method according to any one of claims 1 to 4, wherein the method further comprises a step (260) of updating the plurality of signatures, by adding, to the plurality of signatures, a newly generated signature comprising: a data set of the instantaneous profile, and the determined position (LD, XD).

6. Method according to any one of claims 1 to 5, in which the method further comprises the following steps: - reception (245) of a position (Lr, Xr) of the vehicle (10), called received position, and - calculation (250) of an improved position (La, Xa) of the vehicle (10) by merging data between at least the determined position (LD, XD) and the received position (Lr, Xr).

7. Method according to any one of claims 1 to 6, further comprising the following steps: - reception (245) of a position (Lr, Xr) of the vehicle, called received position, - selection (270) of signature(s) from the plurality of signatures whose position (L, X) differs from the received position (Lr, Xr) by at most a second value, - second step of comparison (280) of at least one of the inclination measurements (a, |3) of the instantaneous profile, with the inclination measurement (a', |3') of each selected signature, and - detection (290) of anomaly(ies) if, during the second comparison step (280), at least one difference between two inclination measurements (a, [3; a', |3') compared is greater than a third value.

8. Electronic location device (25) for a vehicle (10), in particular a railway vehicle, moving on a track (13), the electronic location device (25) comprising: - at least one sensor (50, 55, 60) configured to measure, at successive instants (f), a speed (V) of the vehicle (10) and an inclination (a, |3) of the track (13) in at least one direction to obtain a data set at each instant (h), the set of data sets forming an instantaneous profile of the track (13), - a comparison module (85) configured to compare the instantaneous profile with a plurality of signatures, the plurality of signatures defining a profile of the track over time, each signature comprising: at least one speed measurement (V'), at least one inclination measurement (a', [3') of the track (13) in at least one direction, and at least one position (L, X), and to identify the signature(s) corresponding to the instantaneous profile and defining a section of the profile of the track (13), and - a determination module (90) configured to determine a position (LD, XD) of the vehicle (10) from the position (L, X) of the at least one identified signature.

9. Device (25) according to claim 8, in which the plurality of signatures is included in a database (35) remote from the vehicle (10), the device (25) further comprising on-board communication means (20) capable of exchanging data between the vehicle (10) and the database (35).

10. Computer program product comprising software instructions suitable for, when implemented by computer, implementing at least the steps of comparison (230), identification (235) and determination (240) of a location method according to claim 1.

Images