FR3058515A1 - DEVICE AND METHOD FOR LOCATING A VEHICLE - Google Patents

Abstract

The invention relates to a location device adapted to be installed in a vehicle, the location device comprising a sensor (11) and an electronic processing unit programmed to: - map data (DT1) representative of a road environment of the vehicle, obtained by means of said sensor, with data (D1) relating to the positioning of at least one remarkable element situated in this road environment, pre-recorded in a storage unit (13) of the electronic processing unit, - determining a reliability level (NF1) of this remarkable element as a function of the result of said mapping, and for - determining a position (POSV) of the vehicle using the result of said matching only if the reliability level (NF1) the corresponding remarkable element is greater than a given reliability threshold (SF1). The invention also relates to an associated method of localization.

Description

Holder (s): VALEO SCHALTER UND SENSOREN GMBH Simplified joint-stock company.

Extension request (s)

Agent (s): VALEO COMFORT AND DRIVING ASSISTANCE.

154) DEVICE AND METHOD FOR LOCATING A VEHICLE.

FR 3 058 515 - A1 (57) The invention relates to a location device suitable for being installed in a vehicle, the location device comprising a sensor (11) and an electronic processing unit programmed for:

- to match data (DT1) representative of a road environment of the vehicle, obtained by means of said sensor, with data (D1) relating to the positioning of at least one remarkable element located in this road environment, prerecorded in a unit storage (13) of the electronic processing unit,

- determine a level of reliability (NF1) of this remarkable element as a function of the result of said mapping, and for

- determining a position (POSV) of the vehicle using the result of said matching only if the reliability level (NF1) of the corresponding remarkable element is greater than a given reliability threshold (SF1).

The invention also relates to an associated localization method.

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Device and method for locating a vehicle

Technical field to which the invention relates

The present invention relates to a location device adapted to be installed in a vehicle.

It relates more particularly to a location device for determining a position of this vehicle along a network of traffic lanes.

The invention also relates to a localization method implemented in such a device.

It can be applied particularly advantageously in a motor vehicle.

Technological background

More and more motor vehicles are equipped with a GPS and / or GMS type localization device (according to the acronyms of "Global Positioning System" and "Global System for Mobile communication"), making it possible to determine a position of the vehicle along a network of traffic lanes.

It is also known, to determine such a position, to match:

- data, prerecorded in a vehicle storage unit, relating to the positioning of remarkable elements, such as traffic lights or road signs, located on this network of traffic lanes, with

- an image captured by a front camera equipping the vehicle, then determining the position of the vehicle as a function of this mapping.

However, when one of the remarkable elements of the road environment of the vehicle has been moved, during road works for example, said data representative of its positioning, stored in the storage unit of the location device, can no longer correspond faithfully to the real position of this remarkable element. The above-mentioned mapping can then lead to an erroneous, or at least imprecise, determination of the position of the vehicle.

In addition, one of the remarkable elements located in the road environment of the vehicle can be partially masked, for example by plants, passers-by, or other vehicles. This element then lends itself poorly to such a mapping, the accuracy of which it risks degrading.

Object of the invention

In this context, the invention provides a location device suitable for being installed in a vehicle, the location device comprising:

- a sensor, and

- an electronic processing unit comprising a storage unit in which are stored data relating to the positioning of remarkable elements located on or near a network of traffic lanes, characterized in that the processing unit is programmed for :

E1) for at least one of said remarkable elements located in a road environment of the vehicle:

- to match the data relating to the positioning of this remarkable element, supplied by the storage unit, with data representative of the road environment of the vehicle obtained by means of said sensor, and

- determine a level of reliability of this remarkable element, according to the result of said matching, and for

E2) determining a position of the vehicle using the result of said mapping only if said level of reliability is greater than a given reliability threshold.

Thanks to the invention, the position of the vehicle is determined on the basis of those of the remarkable elements effectively making it possible to carry out such a mapping in a reliable and precise manner.

One of the remarkable things:

- for which the data stored in the storage unit of the localization device is not reliable, for example because this element has been moved, or

- for which the captured data do not allow a reliable matching, for example because this element is partially hidden, will not be taken into account in the vehicle location process.

The position of the vehicle is thus determined in an advantageously robust manner with respect to possible errors or faults in updating said cartographic data, as well as with respect to possible faults in the captured data caused for example by noise. or measurement errors.

The accuracy with which this position is determined is also improved.

These properties are particularly advantageous when the vehicle is of the autonomous type, that is to say when it is adapted to perform maneuvers or movements without the intervention of its driver, or at least with reduced intervention of the latter. Indeed, during such autonomous operation of the vehicle, it must be able to determine its position with high precision and reliability.

Other non-limiting and advantageous characteristics of the location device according to the invention are as follows:

- said storage unit contains, for each of said remarkable elements, an indication of a category of remarkable elements to which this remarkable element belongs, and, for at least one of the categories of remarkable elements, descriptive, representative data common characteristics specific to the remarkable elements belonging to this category;

- the processing unit is programmed to, in step E1), carry out said matching as a function, moreover, of descriptive data associated with the category to which belongs said remarkable element matched;

- the processing unit is also programmed for, the matching of step E1) having been carried out for several of said remarkable elements located in the road environment of the vehicle, determining that the category, to which one belongs at least one of said remarkable elements matched, is reliable, depending at least on the level of reliability of this remarkable element, and for determining the position of the vehicle using, for each of said matches, the corresponding result, only if the associated remarkable element belongs to one of the reliable categories of remarkable elements;

- the processing unit is programmed to determine the level of reliability of the remarkable element put in correspondence by testing to what extent the data relating to the positioning of this remarkable element, stored in the storage unit of the localization device, allow to report data representative of the road environment of the vehicle, obtained by means of said sensor;

- the processing unit is programmed to test to what extent the data, relating to the positioning of the remarkable element put in correspondence, make it possible to account for said data representative of the road environment of the vehicle, taking account of a position previous vehicle and a vehicle movement model;

the processing unit is programmed to determine a plurality of potential positions that the vehicle could occupy, distributed around an average potential position, this average potential position being determined as a function of the previous position of the vehicle and of a speed of moving vehicle;

- The processing unit is programmed to carry out the mapping of said data representative of the road environment of the vehicle, with the data relating to the positioning of said remarkable element, on the basis of said potential positions that the vehicle could occupy.

It can also be provided that the processing unit is programmed to carry out said mapping, by means of the following steps, executed for each of said potential positions:

- Determine, as a function of this potential position and of the data relating to the positioning of the remarkable element matched, stored in the storage unit, an expected datum representative of a position that said remarkable element would occupy relative to the vehicle if the vehicle was positioned at this potential position,

- compare said expected data with said data representative of the road environment of the vehicle, and

- Determine, for said remarkable element, a likelihood level associated with this potential position of the vehicle, according to the result of said comparison.

Other optional features of the location device according to the invention are as follows:

- the processing unit is programmed to determine the level of reliability of said remarkable element matched as a function of the likelihood levels associated respectively with the potential positions of the vehicle, and which have been determined for this remarkable element;

- the processing unit is programmed to determine, for each of said remarkable elements, the corresponding level of reliability, by summing the likelihood levels which are associated with the potential positions of the vehicle and which have been determined for this remarkable element;

the processing unit is programmed to, in step E2), determine the position of the vehicle as a function of said potential positions, and, for each of said potential positions, using the corresponding likelihood level only if the reliability level of the remarkable element, for which the likelihood level of this potential position has been determined, is greater than said reliability threshold.

the processing unit is programmed to determine, for each of said potential positions, an overall likelihood level equal to the sum of all the likelihood levels associated with this potential position, and which have been obtained respectively for each of the elements remarkable, the reliability level of which is greater than the corresponding reliability threshold, and for determining the position of the vehicle as a function of the overall likelihood levels respectively associated with each of said potential positions.

- the processing unit is programmed to determine that the position of the vehicle is equal to that of said potential positions which, among said potential positions, has the greatest overall likelihood level;

the processing unit is programmed to determine that the position of the vehicle is equal to a weighted average of said potential positions each assigned a weighting coefficient which is determined as a function of the overall likelihood level of this potential position;

- the processing unit is also programmed to, in step E2), determine an orientation of the vehicle as a function of said mapping.

The invention also provides a method of locating a vehicle, implemented in a locating device which equips the vehicle and which comprises:

- a sensor adapted to capture data representative of a road environment of said vehicle, and

- an electronic processing unit comprising a storage unit in which data relating to the positioning of remarkable elements located on or near a network of traffic lanes are stored, the method comprising the following steps, executed by the electronic processing unit:

E1) for at least one of said remarkable elements located in a road environment of the vehicle:

- matching of the data relating to the positioning of this remarkable element, supplied by the storage unit, with data representative of the road environment of the vehicle obtained by means of said sensor, and

- determination of a level of reliability of this remarkable element, according to the result of said matching,

E2) determination of a position of the vehicle using the result of said mapping only if said level of reliability is greater than a given reliability threshold.

The optional features which have been presented above in terms of device can also be applied to the process which has just been described.

Detailed description of an exemplary embodiment

The description which follows with reference to the appended drawings, given by way of nonlimiting examples, will make it clear what the invention consists of and how it can be carried out.

In the accompanying drawings:

- Figure 1 shows schematically, seen from the side, a vehicle equipped with a location device in accordance with the teachings of the invention,

FIG. 2 schematically represents an image of the road environment of the vehicle of FIG. 1, captured by means of an image sensor of the location device which equips this vehicle,

FIGS. 3A and 3B each schematically represent an image, respectively of a first type of remarkable element and of a second type of remarkable element capable of being located in the road environment of the vehicle,

FIG. 4 schematically represents a localization method implemented in the localization device of FIG. 1, and

- Figure 5 schematically shows a previous position of the vehicle of Figure 1, as well as a plurality of potential positions that the vehicle could occupy.

FIG. 1 schematically represents a vehicle 1, here a motor vehicle such as a car, a truck, or even a bus, located on a traffic lane 3. The vehicle 1 can be a vehicle whose movements are controlled manually by a driver, or an autonomous vehicle.

The vehicle 1 comprises a location device 10 which comprises a sensor 11, making it possible to capture data relating to a road environment 2 of vehicle 1, in particular data relating to the positions of elements of this environment relative to vehicle 1.

The sensor 11 can be produced by means, in particular:

- an image sensor, such as a front, rear or side camera,

- radar,

- an ultrasonic detector,

- or a lidar (according to the acronym "Light Detection and Ranging"), such as a laser rangefinder (or laser scanner).

The road environment 2 of the vehicle designates all the objects, grounds, roads, reliefs, plants, and constructions located near the vehicle 1, as well as those possibly distant from the vehicle 1 but visible or at least detectable therefrom , such as a particularly tall distant building.

The sensor 11 is more specifically adapted to capture data representative of a part of the road environment of the vehicle located in a detection field of the sensor.

In the embodiment described below, the sensor 11 is produced by means of an image sensor, in this case a video camera.

The detection field of the sensor 11 corresponds in this case to the field of vision CH of the image sensor.

The image sensor 11 is here adapted to be placed in the vehicle 1 so that its field of vision CH includes a part of the road environment 2 located opposite the vehicle 1.

Optionally, the location device can include one or more additional sensors as described above. Thus, the location device can for example include the above-mentioned image sensor 11 as well as a lidar.

The location device 10 also comprises an electronic processing unit 12 comprising in particular a processor performing logical operations, for example a microprocessor, and a storage unit 13, produced for example by means of a hard disk or non-volatile memory. - rewritable volatile.

The electronic processing unit 12 is connected to the sensor 11, and is adapted to receive the data captured by this sensor 11, or at least data representative thereof.

Cartographic data, representative of a network of traffic lanes on which the vehicle 1 travels, is stored in the storage unit 13.

This cartographic data notably includes data relating to the positioning of remarkable elements, detectable by means of said sensor, located on this network of traffic lanes or near this network of traffic lanes.

The expression “remarkable element” designates an element which can be identified and efficiently identified by means of the data captured by the sensor 11, such as for example a road signaling element such as a traffic sign, a traffic light, in particular a traffic light, or a line of marking on the ground. Such a remarkable element can also correspond to a barrier or a parapet bordering a traffic lane, to a building facade, to an element of urban furniture, or to a relief having a specific shape.

Here, said cartographic data further comprises, for each of said remarkable elements, an indication of a category of remarkable elements to which this remarkable element belongs.

Such a category corresponds, for example, to remarkable elements of the “three-color traffic light” type, or of the “speed limit sign” type, or of the “duty to turn right sign” type.

The storage unit also comprises, for at least one of these categories of remarkable elements, here for each of them, descriptive data, representative of common characteristics specific to the remarkable elements belonging to this category.

These descriptive data are representative of characteristics specific to this category, and common to the various remarkable elements which form part of it. They can be representative of a shape or texture common to these elements, or include a typical image of an element belonging to this category.

FIGS. 3A and 3B show two such images: one, IM1, representative of a remarkable element of the “tricolor light” type (FIG. 3A), and the other, IM2, representative of a remarkable element of the “ speed limit indication sign >>.

This descriptive data may also include data representative of the positioning, relative to each other, of characteristic points, such as angular points, or points having a high brightness or contrast, of a remarkable element typical of this category.

FIG. 2 schematically represents, for an example of road configuration, an IMG image of the road environment 2 of the vehicle 1 captured by the image sensor.

Several remarkable elements located in this road environment are visible in this IMG image, in particular a three-color light ER1, a road sign ER2, a line of markings on the ground ER3, and a building facade ER4.

According to a particularly remarkable characteristic of the location device 10, the processing unit 12 is programmed to execute the following steps of the location process shown diagrammatically in FIG. 4:

E1) for at least one of said remarkable elements ER1, ..., ERi, ...,

ERN located in the road 2 environment of vehicle 1:

- matching (operations MC1, MCi, MCN in FIG. 4) the data relating to the positioning of this remarkable element ER1, ERi, ERN, supplied by the storage unit 13, with data representative of the road environment 2 of vehicle 1 obtained by means of said sensor 11, and

- determine a level of reliability NF1, NFi, NFN of this remarkable element ER1, ERi, ERN, as a function of the result of said mapping, and for

E2) determining a POSV position of the vehicle 1 using the result of said mapping only if said level of reliability NF1,

NFi, NFN is above a given reliability threshold SF1, SFi, SFN.

Thanks to this arrangement, the POSV position of the vehicle 1 is determined based on that, or those of the remarkable elements effectively making it possible to carry out such a mapping in a reliable and precise manner.

So one of the remarkable things:

- for which the data stored in the storage unit of the localization device is not reliable, for example because this element has been moved, or

- for which the captured data does not allow a reliable matching, for example because this element is partially hidden, is not taken into account in determining the position of the vehicle.

The precision and reliability with which the POSV position of the vehicle is determined are then advantageously improved.

It will be noted that the data relating to the positioning of the remarkable elements ER1, ..., ERi, ..., ERN mentioned above are present in the storage unit 13 before the execution of steps E1) and E2), for example because 'they were recorded there before the location device 10 was put into service.

Here, the processing unit 12 is programmed more precisely for, in step E1), carrying out said mapping, and determining the level of reliability NF1, ..., NFi, ..., associated NFN, for each remarkable elements

ER1E Ri, ..., ERN located in the road 2 environment of vehicle 1.

The number of remarkable elements ER1, ..., ERi, ..., ERN which are located in the road environment 2 of vehicle 1 and which are included in the detection field of the sensor, is noted N. These remarkable elements are referenced here by the index i, between 1 and N.

The location method, the main steps of which are shown in FIG. 4, includes the steps E1) and E2) mentioned above. This method is implemented in the location device 10 described above.

Steps E1) and E2) are now described in more detail.

Step E1)

In the embodiment of the location method described here, step E1) comprises a processing step E10) of data captured DCAPT by the sensor 11, prior to the mapping E11) in itself, as shown schematically in Figure 4.

The processing step E10) of the DCAPT captured data includes:

a detection of the remarkable elements present in the detection field of the sensor 11, comprising an identification of the category to which each of the remarkable elements detected belongs, and

- a determination, for each remarkable element ER1, ..., ERi, ..., ERN detected, of processed data DT1, ..., DTi, ..., DTN concisely representing this remarkable element.

It will be recalled that the detection field of the sensor here corresponds to the field of vision CH of the image sensor 11, and that the data captured DCAPT is representative of an image of the road environment 2 of the vehicle captured by it.

The remarkable elements mentioned above are detected by analysis of this image, by means of a shape recognition algorithm, for example.

The processed data DT1, ..., DTi, ..., DTN representing one of these remarkable elements can include in particular:

- a position of the remarkable element, in the captured image,

- a position of the remarkable element relative to the vehicle, deduced from the captured image,

- positions of points characteristic of this remarkable element (angular point, very bright and / or contrasting point, point presenting particular properties with respect to a change of scale of the image),

- part of the captured image (i.e. a sub-image), in which this remarkable element is visible.

When the location device comprises several sensors (for example several cameras), provision may be made, during processing step E10), to

- process the data captured by each of these sensors, then

- Determining said processed data DT1, ..., DTi, ..., DTN by merging the results obtained during the processing of data respectively from the different sensors.

The data supplied by the storage unit 13 of the location device 10 here includes, for each remarkable element ER1, ..., ERi, ..., ERN located in the road environment 2 of the vehicle 1, reference data D1, ..., Di, ..., DN relating to this remarkable element.

The reference data D1, ..., Di, ..., DN relating to one of these remarkable elements include:

- the data relating to the positioning of this remarkable element, and, here,

- the descriptive data (which have been described previously), corresponding to the category to which this remarkable element belongs (for example a characteristic image of a three-color light, if the remarkable element is a three-color light).

During the next step E11), for each remarkable element ER1, ..., ERi, ..., ERN located in the road environment 2 of the vehicle 1, the reference data D1, ..., Di, ..., DN relative to this element are mapped MC1, ..., MCi, ..., MCN, individually, with the processed data DT1, ..., DTi, ..., DTN corresponding to this element .

As previously indicated, during the mapping step E11), a level of reliability NF1, ..., NFi, ..., NFN is determined for each of the remarkable elements.

This level of reliability is determined here by testing to what extent the reference data D1, ..., Di, ..., DN relating to this remarkable element make it possible to account for the data captured.

This test can be carried out using a known method of statistical test of comparison or of adequacy between the captured data and the reference data.

The level of reliability is determined more precisely here by testing to what extent the data relating to the positioning of this remarkable element (included in said reference data D1, ..., Dl, ..., DN) allow, taking into account of a previous position POSP of the vehicle 1 (FIG. 5) and of a movement model of the vehicle, to report on the data captured DCAPT.

The method therefore includes a determination of a plurality of potential positions POS1, ..., POSj, ... POSM, which the vehicle 1 could occupy (FIG. 5).

These potential positions POS1, ..., POSj, ... POSM are distributed around a potential average position <POSj> which is determined as a function of the previous position POSP of the vehicle 1 and of the speed vector of the vehicle 1.

The average potential position <POSj> of the vehicle is determined in accordance with the vehicle displacement model, for example by integrating over time, from an instant corresponding to the previous POSP position, to a subsequent instant corresponding to this average position < POSj>, the vehicle speed vector. The vehicle displacement model can correspond for example to a kinematic displacement model in which the vehicle is assimilated in a simplified manner to a two-wheeled vehicle, generally called “bicycle model”, or to a kinematic displacement model taking into account the geometry of the front axle of the vehicle, such as the kinematic model known as the “Ackermann model”.

The number of potential positions POS1, ..., POSj, ... POSM thus determined is noted M. These potential positions are referenced here by the index j, between 1 and M.

For each of the remarkable elements ER1, ..., ERi, ..., ERN, the associated matching operation MC1, ..., MCi, ..., MON is then carried out by means of the following steps, executed for each of said potential positions POS1, ..., POSj, ... POSM:

a) determination, as a function of said potential position and of the data relating to the positioning of the remarkable element stored in the storage unit 13, of an expected datum, representative of a position that said remarkable element would occupy relative to the vehicle if the vehicle was positioned at this potential position POS1, ..., POSj, ... POSM,

b) comparison of said expected data with said DCAPT captured data, and

c) determination, for said remarkable element ER1, ..., ERi, ... ERN, of a likelihood level NVij associated with this potential position POS1, ..., POSj, ... POSM of the vehicle, as a function of the result of said comparison.

The likelihood level carrying the reference NVij is that associated with the potential position POSj, and is determined by comparing, for the remarkable element ERi, the data captured with the data prerecorded in the storage unit 13.

The expected data determined during step a) can, as here, include expected perceptual data, of the same type as the processed data DT1, ..., DTi, ... DTN relating to this remarkable element.

These expected perceptual data correspond to an estimate of the processed data which would be obtained if the vehicle were positioned at this potential position POS1, ..., POSj, ... POSM.

During step b), the expected data determined in step a) are more particularly compared, here, with the processed data DT1, ..., DTi, ..., DTN relating to the remarkable element considered. .

When the processed data DT1, ..., DTi, ..., DTN include the positions of characteristic points of the remarkable element, this comparison is for example carried out in:

- calculating, for each characteristic point, a difference between the position of this point as indicated by the processed data, and the expected position of this point, as indicated by the expected data mentioned above, then by

- summing the differences thus determined to obtain an overall difference between predictions and observation, for this remarkable element.

The comparison carried out in step b) can also be carried out, more simply, by calculating a difference between:

- on the one hand, the position that the remarkable element in question would occupy, relative to the vehicle, if the vehicle was positioned at one of the potential positions, determined as a function of the data relating to the positioning of this remarkable element stored in the storage unit 13 of the device, and,

- on the other hand, a position of this remarkable element relative to the vehicle, deduced from the captured data.

Here, in step c), the likelihood level NVij, associated respectively with each of the potential positions of the vehicle, is determined so as to be greater than the above-mentioned overall deviation is small. In other words, the likelihood level is all the greater since the expected data, determined for this potential position, are close to the processed data resulting from the captured data. For example, the likelihood level NVij can for example be inversely proportional to the overall difference between data, mentioned above.

In the embodiment of the location method described here, the level of reliability NFi associated with the remarkable element ERi is determined as a function of the likelihood levels NVi1, ..., NVij, ..., NViM, associated respectively with the positions potential POS1, ..., POSi ..., POSM of the vehicle, and which were determined during the matching MCi based on this remarkable element ERi.

This level of reliability NFi is determined more precisely, here, by summing the likelihood levels determined for this remarkable element ER], for all of the potential positions POS1, ..., POSi ..., POSM of the vehicle, in accordance with the following formula F1:

NFi = NVij (Fl).

As a variant, this level of reliability NFi could for example be equal to the level of likelihood NFij, which, among the levels of likelihood determined for this remarkable element ERi, is the greatest.

Step E2)

In step E2), the processing unit 12 tests here, for each of the remarkable elements ER1, ..., ERi, ..., ERN having been the subject of a mapping, if the level of reliability NF1, ..., NFi, ..., NFN of this remarkable element is higher than the reliability threshold SF1, ..., SFi, ..., SFN.

When the reliability level NF1, NFi, NFN of this remarkable element is greater than the corresponding reliability threshold SF1, SFi, SFN, this remarkable element is considered to be reliable. Otherwise, it is considered unreliable.

Among the N remarkable elements which have been the subject of a mapping, a number N '(less than or equal to N) of reliable remarkable elements, ERF1, ... ERFi', ... ERFN 'are thus selected. . These remarkable reliable elements are referenced here by the index i ’, between 1 and N’.

Here, the value of the reliability threshold to be used is determined directly by the category to which the remarkable element that is the subject of this reliability test belongs.

Thus, if the remarkable element is a first three-color traffic light of the road environment of the vehicle, or a second three-color traffic light of this environment, the value of the reliability threshold used for this element will be that associated with the category d 'remarkable elements' tricolor traffic light'.

The value of the reliability threshold to be used for a given category of remarkable elements can for example be determined during tests preliminary to the putting into service of the locating device 10, by comparing the reliability levels obtained in road situations for which it has been shown that a remarkable element of this category is reliable, and those obtained in other configurations for which the remarkable elements of this category are manifestly unreliable.

The value of the reliability threshold to be used for a given category of remarkable elements can also be determined according to values usually recommended for a statistical adequacy test (such as the reliability test carried out here), for example those recommended for the adequacy test called "chi-square" (also called "chi-square", or χ ² ).

In alternative embodiments (not shown), instead of testing the reliability of said remarkable elements by considering them individually, in isolation from one another (as described above), one could test their reliability by rather considering all of the elements of the same category, located in the road environment of the vehicle.

It is for example possible in this case, for each of the categories, at least one remarkable element of which is located in the road environment of the vehicle, to determine whether this category is reliable, or not reliable, as a function of the reliability levels of the elements remarkable belonging to this category.

The processing unit can for example be programmed to determine that such a category is reliable provided that the level of reliability of each of its elements is greater than the reliability threshold associated with this category.

As a variant, the processing unit could also be programmed to determine that such a category is reliable, provided that an average of the reliability levels of its remarkable elements is greater than the reliability threshold associated with this category.

In the embodiment, mentioned above, for which the reliability levels are determined directly category by category, and not item by item, a category is considered to be reliable if a level of reliability is greater than the corresponding reliability threshold.

In the context of these alternative embodiments, a remarkable element is ultimately considered reliable when it belongs to a reliable category of remarkable elements.

Whatever the embodiment considered, the POSV position of the vehicle 1 is then determined, as a function of the results of the matches carried out for the remarkable reliable elements ERF1, ... ERFi ’, ... ERFN’.

For this, the processing unit 12 here firstly determines, for each potential position POSj, a global likelihood level NGVj, as a function of the likelihood levels NVi'j associated with this potential position POSj, and which have been obtained for each of the remarkable elements reliable ERFi '.

The overall likelihood level NGVj of the potential position POSj is for example determined in accordance with the formula F2 below, that is to say by summing, for all of the remarkable remarkable elements, the likelihood levels NVi'j associated with this potential position POSj:

NGVj = Σίΐϊ'NVi'j (F2).

The processing unit 12 then determines the position POSV of the vehicle 1 as a function of the potential positions POS1, ..., POSj, ...., POSM thereof and the overall likelihood levels NGV1, ..., NGVj , ... Corresponding NGVM.

The position POSV of vehicle 1 is determined more particularly by calculating a weighted average of said potential positions POS1, POSj, POSM, each assigned a weighting coefficient which is determined as a function of the overall likelihood level NGV1, NGVj, ... NGVM of this potential position.

The weighting coefficients associated respectively with each of the potential positions of the vehicle can in particular be equal each to the overall likelihood level of this potential position. In this case, the position of the vehicle is determined in accordance with the following formula F3:

POSV = POSj x NGVj] / [Zff NGVj] (F3).

As a variant, instead of being determined by a weighted average calculation, the position POSV of the vehicle could for example be determined as being equal to that of said potential positions POS1, POSj,

POSM which (among these potential positions) has the highest overall likelihood level.

Optionally, a final reliability level, associated with the POSV position of the vehicle 1 thus determined, is calculated in step E2), as a function of the reliability levels of the remarkable elements present in the road environment 2 of the vehicle 1.

The final level of reliability NFPOS is for example equal to the sum of the levels of reliability of the remarkable remarkable elements:

NFPOS = Σν = ϊ NFi '(F4).

According to another optional characteristic, step E2) can include the calculation of a determination uncertainty, linked to the precision with which the POSV position of the vehicle 1 is obtained. This uncertainty of determination can for example be equal to the standard deviation of all of the potential positions of the vehicle, each assigned a weighting coefficient equal for example to the overall likelihood level of this potential position.

According to a particularly remarkable optional feature, the location method can, as here, include a determination of an orientation of the vehicle 1 relative to its road environment 2, in addition to the determination of its POSV position described above.

The data captured DCAPT by the sensor 11 are in fact sensitive to the orientation of the vehicle 1. Here, for example, the position of a remarkable element in the image captured by the image sensor clearly depends on the orientation of the vehicle 1 with respect to its road environment 2. This dependence of the data captured DCAPT with the orientation of vehicle 1 allows a determination of this orientation.

For this, provision may be made, for example, to determine, in step E1), not only potential positions of the vehicle 1, but also potential orientations OR 1, ... ORk, ..., ORP thereof.

In a manner comparable to what has been described above, a likelihood level NVijk is then calculated for each pair formed by one of the positions POSj and one of the potential orientations ORk, during the mapping based on the remarkable element ERi.

The level of reliability of the remarkable element ERi can then be determined as a function of these likelihood levels, for example by summing these likelihood levels for all of the potential positions and orientations of the vehicle.

The optional characteristics of step E2) relating to the determination of the vehicle POSV position, which have been described above, can then also apply to the determination of its orientation.

In other embodiments, the reliability levels of the remarkable elements located in the road environment 2 of the vehicle 1 could be determined differently from what has been described above.

For example, in an alternative embodiment, it can be provided that the correspondence of the captured data DCAPT, with the reference data supplied by the storage unit 13, is carried out by calculating the values of the correlation function of the captured image, with an image representative of the remarkable element concerned, supplied by the storage unit 13. The level of reliability of this remarkable element can then be equal, for example, to the maximum value of this correlation function, while the shift between images, for which this correlation function is maximum, provides information on the position of the vehicle.

Claims (15)

1. Locating device (10) adapted to be installed in a vehicle (1), the locating device comprising: - a sensor (11), and - an electronic processing unit (12) comprising a storage unit (13) in which data relating to the positioning of remarkable elements located on or near a network of traffic lanes are stored, characterized in that l the processing unit (12) is programmed for: E1) for at least one of said remarkable elements (ER1, ERi, ERN) located in a road environment (2) of the vehicle (1): - matching (MC1, MCi, MCN) the data relating to the positioning of this remarkable element (ER1, ERi, ERN), supplied by the storage unit (13), with data representative of the road environment (2 ) of the vehicle (1) obtained by means of said sensor (11), and - determine a level of reliability (NF1, NFi, NFN) of this remarkable element (ER1, ERi, ERN), depending on the result of said mapping, and for E2) determining a position (POSV) of the vehicle (1) using the result of said mapping only if said reliability level (NF1, NFi, NFN) is greater than a given reliability threshold (SF1, SFi, SFN) . 2. Locating device (10) according to claim 1, in which the storage unit (13) contains: - for each of said remarkable elements (ER1, ..., ERi, ..., ERN), an indication of a category of remarkable elements to which this remarkable element belongs, and - for at least one of the categories of remarkable elements, descriptive data, representative of common characteristics specific to the remarkable elements belonging to this category. 3. Locating device (10) according to claim 2, in which the processing unit (12) is programmed to, in step E1), carry out said mapping according, moreover, to descriptive data associated with the category to which the said remarkable element that is matched belongs. 4. Locating device (10) according to one of claims 2 and 3, in which the processing unit (12) is also programmed for, the mapping of step E1) having been carried out for several of said remarkable elements located in the road environment of the vehicle: - determine that the category, to which belongs at least one of said remarkable elements matched, is reliable, depending at least on the level of reliability of this remarkable element, and for - determine the position of the vehicle using, for each of said matches, the corresponding result, only if the associated remarkable element belongs to one of the reliable categories of remarkable elements. 5. Locating device (10) according to one of claims 1 to 4, in which the processing unit (12) is programmed to determine the level of reliability (NF1, ..., NFi, ..., NFN ) of the remarkable element (ER1, ..., ERi, ..., ERN) matched by testing to what extent the data relating to the positioning of this remarkable element, stored in the storage unit (13) of the location device, make it possible to account for data representative of the road environment (2) of the vehicle (1), obtained by means of said sensor (11). 6. Locating device (10) according to claim 5, in which the processing unit (12) is programmed to test to what extent the data relating to the positioning of the remarkable element (ER1, ..., ERi, ..., ERN) matched, make it possible to account for said data representative of the road environment (2) of the vehicle (1), taking into account a previous position (POSP) of the vehicle (1) and of a vehicle displacement model (1). 7. Locating device (10) according to claim 6, in which the processing unit (12) is programmed for: - determine a plurality of potential positions (POS1, POSj, POSM) that the vehicle (1) could occupy, distributed around an average potential position (<POSj>), this average potential position (<POSj>) being determined as a function of the previous position (POSP) of the vehicle (1) and of a speed of movement of the vehicle (1), and for - carrying out the mapping of said data representative of the road environment (2) of the vehicle (1), with the data relating to the positioning of said remarkable element (ER1, ERi, ..., ERN), on the basis of said potential positions that the vehicle could occupy (1). 8. Locating device (10) according to claim 7, in which the processing unit (12) is programmed to carry out said mapping, by means of the following steps, executed for each of said potential positions (POS1, ... , POSj, ..., POSM): - determine, as a function of this potential position (POSj) and of the data relating to the positioning of the remarkable element (ERi) matched, stored in the storage unit (13), an expected datum representative of a position qu occupy said remarkable element (ERi) relative to the vehicle (1) if the vehicle (1) was positioned at this potential position (POSj), - compare said expected data with said data representative of the road environment (2) of the vehicle (1), and - determining, for said remarkable element (ERi), a likelihood level (NVjj) associated with this potential position (POSj) of the vehicle (1), as a function of the result of said comparison. 9. Locating device (10) according to claim 8, in which the processing unit (12) is programmed to determine the level of reliability (NFi) of said remarkable element (ER1, ..., ERi, ..., ERN) mapped according to the likelihood levels (NV, i, ..., NV, j, ..., NV, m) associated respectively with the potential positions (POS1, ..., POSj, ..., POSM) of the vehicle, and which have been determined for this remarkable element (ERi). 10. Locating device (10) according to one of claims 8 and 9, in which the processing unit (12) is programmed to, in step E2), determine the position (POSV) of the vehicle (1) as a function of said potential positions (POS1, ..., POSj, ..., POSM), and, for each of said potential positions, using the likelihood level (NVn, ..., NVjj, ..., NVnm) corresponding only if the reliability level of the remarkable element, for which the likelihood level of this potential position has been determined, is greater than said reliability threshold. 11. Locating device (10) according to claim 10, in which the processing unit (12) is programmed for, the matching of step E1) having been carried out for several of said remarkable elements located in the environment. road vehicle: - determine, for each of said potential positions (POS1, ..., POSj, ..., POSM), a global likelihood level (NGVj) equal to the sum of all the likelihood levels (NV-q,. .., NV ^, ..., NV _Nj ) associated with this potential position (POSj), and which have been obtained respectively for each of the remarkable elements (ERF1, ..., ERFi ', ..., ERFNj whose reliability level is above the corresponding reliability threshold, and for - determine the position (POSV) of the vehicle (1) as a function of the global likelihood levels (NGVj) respectively associated with each of said potential positions (POS1, ..., POSj, ..., POSM). 12. Locating device (10) according to claim 11, wherein the processing unit (12) is programmed to determine that the position (POSV) of the vehicle (1) is equal to that of said potential positions (POS1, .. ., POSj, ..., POSM) which, among said potential positions, has the highest overall likelihood level (NGV _1; ..., NGVj, ..., NGV _M ). 13. Locating device (10) according to claim 11, in which the processing unit (12) is programmed to determine that the position (POSV) of the vehicle (1) is equal to a weighted average of said potential positions (POS1, POSj, ..., POSM) each assigned a weighting coefficient which is determined as a function of the global likelihood level (NGVj) of this potential position (POSj). 14. Locating device (10) according to one of claims 1 to 13, in which the processing unit (12) is also programmed to, in step E2), determine an orientation of the vehicle (1) by based on said mapping. 15. A method of locating (10) a vehicle (1), implemented in a locating device (10) which equips the vehicle (1) and which comprises: - a sensor (11) adapted to capture data representative of a road environment (2) of said vehicle (1), and - an electronic processing unit (12) comprising a storage unit (13) in which data relating to the positioning of remarkable elements located on or near a network of traffic lanes are stored, the method comprising the steps following, executed by the electronic processing unit (12): E1) for at least one of said remarkable elements (ER1, ..., ERi, ..., ERN) located in a road environment (2) of the vehicle (1): - matching (MC1, ..., MCi, ..., MCN) of the data relating to the positioning of this remarkable element (ER1, ..., ERi, ..., ERN), provided by the unit of storage (13), with data representative of the road environment (2) of the vehicle (1) obtained by means of said sensor (11), and - determination of a level of reliability (NF1, ..., NFi, ..., NFN) of this remarkable element (ER1, ..., ERi, ..., ERN), according to the result of said setting in correspondence, and for E2) determination of a position (POSV) of the vehicle (1) using the result of said mapping only if said level of reliability (NF1, ..., NFi, ..., NFN) is greater than a threshold reliability (SF1, ..., SFi, ..., SFN) given. IM1