WO2020201243A1

WO2020201243A1 - Method for updating a road map based on a network of contributors

Info

Publication number: WO2020201243A1
Application number: PCT/EP2020/059033
Authority: WO
Inventors: Willy Vigneau
Original assignee: Continental Automotive Gmbh
Priority date: 2019-04-02
Filing date: 2020-03-31
Publication date: 2020-10-08
Also published as: FR3094786B1; FR3094786A1

Abstract

The invention relates to a method for updating a road map based on a plurality of vehicles referred to as "contributors" and connected to at least one data processing server via a communication network, each contributing vehicle comprising a geolocation module, a processor and a communication module. The method comprises in particular the steps of calculating, using the at least one data processing server, a first weighting coefficient of a vehicle track according to the number of satellites used to generate the track, a second weighting coefficient of the received track according to at least one reference track stored in the at least one data processing server, and a third weighting coefficient of the received track by applying a mathematical function to the first calculated weighting coefficient and to the second calculated weighting coefficient, of weighting the received track with the third calculated weighting coefficient, of updating the at least one reference track corresponding to the section of the vehicle route based on the weighted track, and of updating a road map based on the updated reference track.

Description

DESCRIPTION

TITLE: Method for updating a road map from a network of

contributors

[Technical area]

[0001] The invention relates to updating a road map and more particularly to a method for updating a road map from a network of contributors. The invention aims in particular to improve road maps used in driver assistance systems of motor vehicles.

[State of the prior art]

[0002] Nowadays, a motor vehicle comprises a driving assistance module allowing for example the display of a road map and in particular a route on a road map, commonly referred to as routing, or else the maintenance of the vehicle in its lane. In particular, such maps are generally used to carry out the correspondence of information related to the roads crossed, or as an illustration for the calculation and display of routes.

[0003] In the case of routing, it is particularly important that the road map does not include errors and that it is up to date. Indeed, it is necessary to know precisely the topology of the maps, that is to say the connections between the various road axes, in particular road crossings or the direction of the roads.

[0004] This is particularly essential in the case of the display of a route in an autonomous or semi-autonomous vehicle. By the term "semi-autonomous" is meant a vehicle which is partly autonomous but which is not fully autonomous. In fact, driving this type of vehicle requires great precision and reliability, in particular with regard to the geolocation of each road, each intersection and even each direction of traffic. In other words, in this case, it is necessary for the map to be precise and for the data supplied by it to be precisely georeferenced. To this end, it is in particular necessary for the card to be intact, that is to say for the user to be certain of the information it provides.

[0005] In known manner, the road map can be generated and / or updated by means of specific equipment or by means of a participatory approach of a network of contributors. The use of specific equipment, such as for example a LIDAR system, requires the integration into the vehicle of complex and expensive equipment, which presents a first drawback. In addition, updating the road map is complex and tedious since it requires the permanent start-up of such equipment and passage through all the places in the map, which does not allow a rapid update of the map, in particular in order to indicate new routes or roads closed for example for works.

[0006] In the case of an integration of the road map by a participatory approach, the information related to the road network, that is to say the geolocation of the roads, the authorized speed and the traffic signs for example, are provided by a community of voluntary contributors, whose track on a journey is recorded and sent in order to implement a database. The term “trace” is understood to mean a succession of geographic coordinates obtained by geolocation by satellite (for example via the GPS system) and sent periodically by the engine control computer of the vehicle on an external network, for example on a cloud designating a virtual storage space.

[0007] The participatory approach is based on the concept of "tags", that is to say that the contributors identify a specific point of the road network, for example a parking lot, the presence of a road, a one-way street, and sends the identification to the external network along with geolocation data. Such an approach has the advantage of being economical because the cards are filled in by volunteers and not by means of expensive specific equipment.

[0008] However, in the case of a database implementation using a participatory approach, it is necessary to ensure the qualitative aspect of the map. As such, it is necessary to check the reliability of the information provided by voluntary users. Indeed, the equipment mounted in vehicles is often inexpensive and limited. For example, a vehicle equipped with a geolocation system, such as a GPS system, of poor quality or having approximate accuracy, will not allow sending and storing accurate information. In addition, such vehicles are most often not equipped with additional sensors making it possible to confirm information. In addition, there is a risk that some information may be transmitted by malicious contributors, that is, contributors who are able to deliberately send false information to the community in order to distort the road map.

[0009] In the state of the art, to date there is no method making it possible to verify the reliability of the information sent by contributors or to validate said contributors, since no particular skill is required on the part of contributors. Indeed, the participatory approach is based on the simple notion of volunteering. It is known, for example, to weight information transmitted by a contributor as a function of the number of people who have taken the same route, but such a method is too limited and generally does not make it possible to really verify the veracity of information sent. on the network.

[Disclosure of the invention]

[0010] The aim of the invention is therefore to remedy at least in part these drawbacks by proposing a simple and inexpensive solution making it possible to verify the reliability of the information transmitted by a contributor, with a view to generating an accurate and reliable database. , which allows a driver to assist in driving a vehicle, in particular the display of an accurate and reliable road map that can be used by any type of vehicle, including an autonomous vehicle, without risking use bad data. More specifically, the invention relates to a method of controlling the quality and integrity of information sent by a contributor to a participatory network for the generation of road maps.

To this end, the invention relates first of all to a method for updating a road map from a plurality of so-called "contributor" vehicles, connected to at least one data processing server by a communication network, each contributing vehicle comprising a geolocation module, a computer and a communication module, said method comprising the steps of:

at. reception, by the at least one data processing server, of a trace comprising a series of successive geographical positions obtained by the geolocation module of a contributing vehicle, each geographical position of the trace being associated with a number of satellites used to determine said geographical position,

b. calculation, by the at least one data processing server of a first weighting coefficient of each point of the trace received as a function of the number of satellites transmitted, of a second weighting coefficient of each point of the trace received in function of at least one reference trace stored in the at least one data processing server, and of a third weighting coefficient of each point of the trace received by applying a mathematical function to the first calculated weighting coefficient and the second calculated weighting coefficient,

vs. weighting of each point of the track received with the third calculated weighting coefficient, d. updating of at least one reference track corresponding to the section of the journey of the vehicle from the weighted track and,

e. updating a road map from the updated reference track.

[0012] Such a method of updating a road map using a participatory approach advantageously makes it possible to judge the quality of the track sent by a contributing vehicle as a function of various parameters in order to make it as relevant as possible. In particular, the method according to the invention makes it possible to refine the quality of the reference trace based on the distance of the received trace from this reference trace as well as on the quality of the geolocation, which depends in particular on the number satellites used to generate the track in the vehicle.

[0013] According to another aspect of the invention, the method comprises, prior to the reception step, the steps of:

reception, by the geolocation module, of a plurality of signals sent by a plurality of satellites,

determination, by the geolocation module, from the plurality of signals received, of a series of geographical positions of the vehicle on a section of the vehicle path, called "track",

determination, by the geolocation module, from the plurality of signals received, of the number of satellites used to determine said trace at each geographical position of the series,

transmission, by the geolocation module, to the computer, of the track and the number of determined satellites,

sending, by the communication module, to at least one data processing server of a communication network, in particular an external one, of said trace and of the number of satellites transmitted to the computer.

[0014] Advantageously, the method comprises a step of weighting by the at least one server of each point of the track received with a fourth weighting coefficient based on additional information relating to the satellites and sent by the vehicle computer in order to further improve the relevance of contributions.

[0015] According to one aspect of the invention, the fourth weighting coefficient is based on the quality of the measurements made on the geolocation signals received from the satellites, in particular their power or the geometry (dilution of the precision of the signals or Dilution of Precision or DOP in English). [0016] Preferably, the quality of the measurements comprises the position of the satellites in the sky, also called the ephemeris of the satellites.

[0017] More preferably, the quality of the measurements comprises the distribution of the satellites.

[0018] More preferably, the quality of the measurements comprises the distance between the measured coordinate point and each satellite that has taken the measurement.

[0019] More preferably, the quality of the measurements comprises at least one characteristic of the atmosphere, in particular of the ionosphere, for example received from an external server over a wireless communication link. For example, waves passing through the atmosphere, especially the ionosphere, can be electrically disturbed in a thunderstorm, making information associated with satellites or signals erroneous.

[0020] Advantageously, the method comprises a step of weighting by the server of each point of the trace received with a fifth weighting coefficient based on the contributor, for example on his number of previous contributions, on the quality of his contributions. previous ones, etc.

[0021] Advantageously, the method comprises a step of weighting by the server of each point of the track received with a sixth weighting coefficient based on the use of sensors on board the vehicle. For example, a sensor used can be a camera whose images will allow the computer to identify objects in the environment of the path section in order to assess the consistency of the corresponding track.

[0022] Preferably, the third weighting coefficient corresponds to the average, the median or the standard deviation of the first weighting coefficient and of the second weighting coefficient.

[0023] In one embodiment, the method comprises a step of sending the updated reference track to at least one contributing vehicle, preferably to all of the contributing vehicles, the updating of the road map from the updated reference trace then being produced by each of the vehicles having received said reference trace.

In one embodiment, the updating of the road map from the updated reference track is performed by the data processing server and the method comprises a step of making available, by the server of data processing, for the contributing vehicles, of the updated road map. Advantageously, the method can comprise a step of displaying the updated road map on a screen of the motor vehicle, the display of a journey to be made by the vehicle on the updated road map, maintaining of the vehicle in its traffic lane using the updated road map or any other appropriate service provided from the updated road map.

[0026] According to one aspect of the invention, the method comprises a preliminary step of creating the road map from a plurality of contributing vehicles.

[0027] The invention also relates to a vehicle, in particular an automobile, comprising a geolocation module, a computer and a communication module, said vehicle being configured for:

- receive, via the geolocation module, a plurality of signals sent by a plurality of satellites,

- Determine, via the geolocation module, from the plurality of signals received, a series of geographical positions of the vehicle on a section of the vehicle path, called "trace",

- determining, via the geolocation module, from the plurality of signals received, the number of satellites used to determine said trace,

- send, via the communication module, to at least one data processing server of a network, in particular an external communication network, of said trace and of the number of satellites determined by the geolocation module.

[0028] According to one aspect of the invention, the vehicle is configured to determine the position of the satellites in the sky, also referred to as the satellite ephemeris.

[0029] According to one aspect of the invention, the vehicle is configured to determine the distribution of the satellites.

[0030] According to one aspect of the invention, the vehicle is configured to determine the distance between the measured coordinate point and each satellite that has taken the measurement.

According to one aspect of the invention, the vehicle is configured to receive over a wireless communication link, for example from a data processing server, data on the quality of the atmosphere, in particular on the quality. of the ionosphere.

The invention also relates to a data processing server for updating a road map from a plurality of so-called "contributor" vehicles, connected to said data processing server by a communication network, each contributing vehicle comprising a geolocation module, a computer and a communication module, said server being characterized in that it is configured for: receiving, from at least one contributing vehicle, a series of geographic positions of the vehicle on a section of the vehicle's path, called a “track”, determined from a plurality of signals sent by a plurality of satellites, as well as the number of satellites used to determine said trace,

- calculate a first weighting coefficient of each point of the received trace as a function of the number of satellites transmitted, a second weighting coefficient of each point of the received trace as a function of at least one reference trace stored in said processing server data, and a third weighting coefficient of each point of the trace received by applying a mathematical function to the first calculated weighting coefficient and to the calculated second weighting coefficient,

- weight each point of the track received with the third calculated weighting coefficient,

- update at least one reference track corresponding to the section of the vehicle's journey from the weighted track and,

- update a road map from the updated reference track.

The invention also relates to a road map updating system, said system comprising at least one data processing server, as presented above, a plurality of so-called "contributor" vehicles, and a network of communication, connecting the plurality of contributing vehicles to at least one data processing server, each contributing vehicle comprising a geolocation module, a computer and a communication module.

[Description of the drawings]

[0034] Other features and advantages of the invention will become apparent on reading the description which follows. This is purely illustrative and should be read in conjunction with the accompanying drawings in which:

[Fig. 1]: Figure 1 functionally illustrates an embodiment of the system according to the invention;

[Fig. 2]: Figure 2 schematically illustrates an example of vehicle, server and satellites according to the invention;

[Fig. 3]: Figure 3 shows schematically a reference trace of a vehicle;

[Fig. 4]: FIG. 4 represents a set of traces received with respect to each point of the reference trace of FIG. 3;

[Fig. 5]: FIG. 5 represents an example of implementation of the method according to the invention. [Description of the embodiments]

The invention will now be described in its application to the creation and updating of a road map to allow driving assistance, for example intended to be displayed on a screen located in the passenger compartment. of a motor vehicle to allow navigation of said vehicle.

[0036] According to the invention, the road map is filled in using a participatory approach of a network of contributing vehicles.

By the term "contributor" is meant a vehicle capable of providing information related to the road network when the latter makes a trip. In other words, a set of contributing vehicles identifies data relating to the different roads on which they travel and enters a database comprising all the information related to the road network, in particular the geolocation of each road, their direction of movement, the signs. signage or the presence of parking lots for example.

FIG. 1 shows an example of a system 1 according to the invention for creating and updating a road map.

This system 1 comprises a plurality of contributors in the form of a plurality of vehicles 10 connected via a communication network 15 to a data processing server 20.

As a variant, the data processing server 20 could just as well be integrated into one or more of the contributing vehicles 10 or else into each vehicle 10 of the plurality of vehicles 10, for example in a network of the " ad hoc network ”.

The example described below presents the case of a single data processing server 20 for the sake of clarity, however it goes without saying that the system 1 could just as easily include a plurality of data servers 20, for example of the “cloud” type (“cloud” in English) performing the same functions or complementary to the functions to be performed in order to implement the invention.

[0042] Vehicle 10

Referring to Figure 2, each vehicle 10 contributor to the system 1 comprises a geolocation module 110, a computer 120 and a communication module 130. Each vehicle 10 can further include a display screen (not shown) , for example in order to display the road map updated by the data processing server 20.

[0044] Location module 110 The geolocation module 1 10 is configured to receive a plurality of signals sent by a plurality of satellites 30 and to determine the position of the vehicle 10 from the signals received in the form of a coordinate point comprising at least the geographic coordinates of the vehicle 10. The geolocation module 110 may for example be of the GPS, GLONASS or GALILEO type. Since the operation of such a geolocation module 110 is known per se, it will not be described in more detail here.

Temporarily, the geolocation module 110 makes it possible to define a series of coordinate points of the vehicle 10 on a path section of said vehicle 10 when the latter is in motion. Such a series of geographic positions is referred to as a “trace”. The track taken into account can be a journey between two nodes of a trajectory, for example between two crossings of roads 2, or on a journey made over a predetermined period. In other words, it is not necessarily the complete trace of a route from a starting point to an ending point, but at least a section of a path. According to the invention, by determining or sending the trace is meant the determination and sending of each coordinate point of such a trace. For example, a trace can include a few points or dozens of coordinate points. The assumption is made that the geographic coordinates of a coordinate point are determined by taking noise into account. Such noise is a known parameter which corresponds to a positioning error margin included for example within a radius of the order of five meters around the actual position of the vehicle 10. The trace determined by the geolocation module 110 corresponds thus to an average of the noise sent by each satellite 30.

The geolocation module 110 is also configured to determine the number of satellites 30 having sent the signals for a coordinate point. Indeed, depending on the position of the vehicle 10 on the road 2 and the position of the satellites 30 in the sky, a greater or lesser number of satellites 30 communicate with the geolocation module 110 and send signals. In general, at least four satellites 30 are necessary to determine a geographical position by triangulation, for example, however, the geolocation module 110 can also receive signals, for example from ten satellites 30, which increases the reliability of the positioning. . This information on the number of satellites 30 is considered unique for each point of a given track and is provided with each point of the track when available. This information varies in particular with the masking of the vehicle due for example to buildings. Other information can be collected and provided with each trace, such as, for example, power or geometry (dilution signal precision or Dilution of Precision (DOP) of satellite signals, as will be described below.

The geolocation module 1 10 is configured to communicate with the computer 120 of the vehicle 10, for example by a CAN bus type network, in order to transmit to said computer 120 the traces it determines, in particular, for each trace, the geographical coordinates of each point of the trace and preferably the number of satellites 30 which sent the signals which made it possible to generate said trace.

[0049] Calculator 120

The computer 120 is configured to communicate with the data processing server 20 via the communication module 130 and the communication network 15. The computer 120 includes a memory in which instructions are stored,

In particular, the computer 120 is configured by the instructions to receive the geolocation module 110, for example via a CAN interface, each trace and the number of satellites 30 having made it possible to determine said trace and to send these data to the server for data processing 20 via the communication module 130 and the communication network 15.

In one embodiment, the computer 120 is configured by the instructions to receive, via the communication network 15 and the communication module 110, reference traces from the data processing server 20 relating to an area in which vehicle 10 is traveling or could be traveling, and to generate or update a road map from the reference traces received, in particular traces representative of the journey made by vehicle 10.

In another embodiment, the computer 120 is configured by the instructions to receive the reference road map sent by the data processing server 20, for example spontaneously sent by the data processing server 20 after each update. up-to-date (“push” type sending), or else by requesting it from the data processing server 20 (“pull” type sending).

[0054] In one embodiment, the computer 120 is configured by the instructions for controlling the display of the updated or received road map as well as, preferably, the position of the vehicle 10 on said road map. As a variant or in addition, the road map may or may not be displayed but used for other driving assistance functions, such as for example keeping the vehicle in its lane. It will be noted here that it is possible that vehicles 10 contributors contribute to the system 1 by sending their tracks without using the road map.

[0056] Communication module 130

The communication module 130 is configured to exchange signals over a wireless communication link with the communication network 15 so that the computer 120 communicates with the data processing server 20. To this end, the communication module 130 may for example comprise a radio circuit and an antenna (not shown), in a manner known per se.

[0058] Communication network 15

The communication network 15 can be a terrestrial (3G, 4G, 5G, Wimax, ...) or satellite communication network.

[0060] Data processing server 20

The data processing server 20 is configured to receive the traces sent by each contributing vehicle 10 as well as the number of satellites 30 used to determine each trace. Optionally, the data processing server 20 is configured to receive and / or determine other indicators such as, for example, additional information supplied by the satellites 30 if necessary, in particular on the quality of measurement (position of the satellites 30, distance from each satellite 30, ephemeris of satellites 30, quality of the atmosphere, etc.), information on the reliability of the contributing vehicles 10 or information generated from sensors, as will be described below.

A camera can for example record images of road 2 and the computer 120 can then be configured to analyze these images in order to validate the consistency of the objects detected on the images (presence of a bridge, of a crossing, placement on the next roadway if the cameras of different vehicles each see a dotted line or one a dotted line and the other a solid line, etc.). This information makes it possible to weight each point of the traces received according to the relevance of the information received.

More particularly, this information makes it possible first of all to refine a given trace with data received from the camera: for example to refine the lateral location according to the line information or to refine the longitudinal location with a bridge. This is particularly useful for the detection of intersections which give an indication of the end of road sections. This information also makes it possible to detect a false track if the objects seen are not consistent with those seen by another vehicle or with an object / road reference database. This will result in a exclusion of the trace, or a low weighting of the trace if there is any doubt about the coherence, or a refinement (for example a translation) of the trace.

[0064] In one embodiment, the data processing server 20 is located in a cloud designating a virtual storage and computing space, to which all of the contributing vehicles can connect. The data processing server 20 is in particular connected to a database 25 which can be implemented in the data processing server 20 or outside the data processing server 20.

The server 20 comprises a processor and a memory (not illustrated), said memory comprising instructions.

The processor of the data processing server 20 is configured by the instructions to weight each point of each trace received in order either to generate a reference trace and store it in the database 25, or to update a existing reference trace already stored in the database 25. As illustrated in FIG. 3, this reference trace To corresponds to an average journey portion carried out by the vehicle or vehicles 10 having sent traces on the corresponding journey section of road 2. The weighting advantageously makes it possible to refine the reference trace To when it has been generated from several traces so as to obtain a trace closer to the average journey made on an existing road 2 and thus model a road map precise.

In particular, the processor of the data processing server 20 is configured by the instructions to calculate a first weighting coefficient of each point of the received trace, as a function of the number of satellites 30 which have made it possible to generate said trace. According to an exemplary embodiment, such a first weighting coefficient is between 0 and 1. A weighting coefficient equal to 1 means that a value is not lowered. Likewise, a weighting coefficient equal to 0.5 means that a value is divided by two. Finally, a weighting coefficient of 0 means that the value is not taken into account.

[0068] By way of example, for a given trace:

when the number of satellites 30 which made it possible to determine the received trace is less than or equal to three, then the first weighting coefficient is equal to 0; when the number of satellites 30 having made it possible to determine the received trace is equal to four, then the first weighting coefficient is equal to 0.4;

when the number of satellites 30 having made it possible to determine the received trace is equal to five, then the first weighting coefficient is equal to 0.5; when the number of satellites 30 which made it possible to determine the received trace is equal to six, then the first weighting coefficient is equal to 0.6;

when the number of satellites 30 having made it possible to determine the received trace is equal to seven, then the first weighting coefficient is equal to 0.7;

when the number of satellites 30 having made it possible to determine the received trace is equal to eight, then the first weighting coefficient is equal to 0.8;

when the number of satellites 30 which made it possible to determine the received trace is equal to nine, then the first weighting coefficient is equal to 0.9;

when the number of satellites 30 having made it possible to determine the received trace is greater than or equal to ten, then the first weighting coefficient is equal to 1.

Of course, any other choice of values is possible. In particular, a weighting coefficient of 0 can be attributed when the number of satellites 30 which have made it possible to determine the received trace is less than or equal to three, while a weighting coefficient of 1 can be attributed when the number of satellites 30 having made it possible to determine the received trace is greater than or equal to four.

The processor of the data processing server 20 is further configured by the instructions to calculate a second weighting coefficient of each point of the trace received as a function of the reference trace To stored in the data processing server 20 (if applicable), in particular an estimate of the distance between the received trace and the stored reference trace To. As shown in FIG. 4 by way of example, when the trace (the average of the noise represented by a sinusoid) T by received the data processing server 20 corresponds to a portion of the trajectory located a distance from the reference trace To less than a threshold, for example two meters, then the second weighting coefficient can be equal to 1 and when the trace T received by the data processing server 20 corresponds to a portion of the trajectory located a distance from the reference trace To greater than the threshold, then the second weighting coefficient is equal to 0. In the absence of a reference trace stored in the database 25, the second weighting coefficient is preferably equal to 1.

The processor of the data processing server 20 is also configured by the instructions to calculate a third weighting coefficient of each point of the trace received by the application of a mathematical function to the first weighting coefficient and to the second coefficient weighting, calculated previously, in order to refine the precision of the reference trace. By way of example, the data processing server 20 can be configured to calculate the third weighting coefficient in realizing the average, the median or the standard deviation of the first weighting coefficient and the second weighting coefficient.

The processor of the data processing server 20 is configured by the instructions to apply the third weighting coefficient to each point of the received trace, sent by the computer 120, so as to weight each point of the received trace as a function of of the various aforementioned parameters. Such a weighting advantageously makes it possible to take into account the coherence of the trace received both according to the number of satellites 30 having made it possible to obtain said trace and with respect to the stored reference trace, representative of the previous passages of another vehicle. 10 contributor.

The processor of the data processing server 20 is configured by the instructions to update a reference trace stored in the database from a weighted trace corresponding to the same section of the path, for example by replacing the reference trace stored by the average of said stored reference trace and the weighted trace. Such an update makes it possible to refine the reference trace so that a vehicle 10 subsequently benefits from a refined reference trace.

The processor of the data processing server 20 is configured by the instructions to send each contributing vehicle 10 the updated reference track in order to update its road map or to send the updated road map in order to it is for example displayed or used for routing or any other driving assistance function of the vehicle using such a road map.

Optionally, the processor of the data processing server 20 can be configured by the instructions to weight each point of the traces received with other weighting coefficients and thus make it possible to improve the reliability of the contributions and therefore of the road map.

For example, the data processing server 20 can be configured to weight each point of the traces received with a fourth weighting coefficient based on additional information supplied by the satellites 30 if necessary.

By way of example, the data processing server 20 can be configured to weight each point of the traces received as a function of the quality of the measurements made on the geolocation signals received from the satellites 30. More specifically, the quality of the measurement may include the position of the satellites 30 and the distance between the measured coordinate point and each satellite 30 having taken the measurement. The quality of the measurement can also include the ephemeris of the satellites 30, that is to say the position of the satellites 30 in the sky as well as their distribution.

The quality of the measurement can also include the quality of the signals received which depends on the quality of the atmosphere and in particular of the ionosphere. In fact, to go from a satellite 30 to a vehicle 10, the waves pass through the ionosphere in particular, however, in the event of an ionospheric storm (causing electrical disturbances), the information centralization network may receive erroneous information from the does electrical activity. Information on the ephemeris and / or on the conditions in the ionosphere, coming for example from an external source, makes it possible to filter the quality of the information sent by weighting for example the data sent by one of the satellites 30 or 1. '' all the data over a given duration (in the event of an ionospheric storm, the information may be weighted to 0 over a time slot corresponding to the duration of the storm so as not to be taken into account), the aim being to exclude bad contributions.

The quality of the measurement can also include the power of the signals received or their geometry (dilution of the precision of the signals or Dilution of Precision or DOP in English).

For example again, the processor of the data processing server 30 can be configured by the instructions to weight the information received by a vehicle 10 with a fifth weighting coefficient based on the contributing vehicle 10. For example, when the vehicle 10 is identified as having previously given information recognized as reliable for previous tracks then the fifth weighting coefficient may be equal to 1. Conversely, when a vehicle 10 is new in the system 1 or if this vehicle 10 has previously provided erroneous information to the data processing server 20, unintentionally, for example if its location module 110 is faulty, then the fifth weighting coefficient may be equal to 0.5. On the other hand, when a vehicle 10 has previously supplied the data processing server 20 with repeatedly erroneous or very erroneous information, then the fifth weighting coefficient may be equal to 0.

For example again, the processor of the data processing server 20 can be configured by the instructions to weight the information received by a vehicle 10 with a sixth weighting coefficient based on the use of additional sensors such as, by example, a camera. A camera can for example record images of road 2 and the computer 120 can then be configured to analyze these images in order to validate the consistency of the objects detected on the images (presence of a bridge, a crossing, placement on the next roadway if the cameras of different vehicles each see a dotted line or one a dotted line and the other a solid line, etc.). This information makes it possible to weight each point of the traces received according to the relevance of the information received.

More particularly, this information makes it possible first of all to refine a given trace with data received from the camera: for example to refine the lateral location according to the line information or to refine the longitudinal location with a bridge. This is particularly useful for detecting intersections which give an indication of the end of road sections. This information also makes it possible to detect a false track if the objects seen are not consistent with those seen by another vehicle or with an object / road reference database. This will result in an exclusion of the trace, or a low weighting of the trace if there is any doubt about the coherence, or a refinement (eg translation) of the trace.

The processor of the data processing server 20 can also, optionally, be configured by the instructions to correct the traces received in order to improve their reliability. For example, the reliability of the contributing vehicles (fourth weighting coefficient) can be calculated by applying a function to the other coefficients, depending on the options used, for example by calculating their average.

The processor of the data processing server 20 can be configured by the instructions to filter the traces before adding them to the reference trace stored in a memory area of the database 25. For example, in the case where a trace received from a reliable vehicle 10 is far from the reference trace stored in the server or if the vehicle 10 is new, unreliable or even unreliable, the data processing server 20 can store the traces sent by said vehicle 10 in order to verify their relevance or reliability later. This can in particular make it possible to detect a new route 2 which would not correspond to an existing route 2 of the road map when several vehicles 10 use it and thus integrate said traces subsequently while then increasing the reliability rate of the contributing vehicles 10 concerned.

Likewise, for a trace located at a distance less than a predetermined distance threshold (for example 10 m), the data processing server 20 can be configured to recalculate the average of the various weighting coefficients used or to keep the trace without taking it into account when generating the updated map.

An example of implementation of the method according to the invention will now be described with reference to FIG. 5. For the sake of clarity, the updating of a map is described. road from data sent by a contributing vehicle 10 but it goes without saying that the method applies to all of the contributing vehicles 10 of the system 1.

As a prerequisite, it is considered that a reference road map, stored in the database 25, has been generated beforehand and that it comprises a reference trace corresponding to the section of the route traveled by the vehicle 10 in the 'example described, this reference trace having been previously generated from one or more traces sent by one or more contributing vehicles.

First, when the vehicle 10 is traveling on a road 2, its geolocation module 110 receives in a step E1 a plurality of signals sent by the plurality of satellites 30 of the satellite navigation system.

Then, the geolocation module 1 10 determines in a step E2, from the plurality of signals received, the trace corresponding to the positions of the vehicle 10 on a section of the route that it has just performed as well as the number of satellites 30 used to determine said trace at each of its points.

The geolocation module 110 then transmits to the computer 120 in a step E3 the trace and the number of satellites 30 determined so that the computer 120 sends them to the data processing server 20 in a step E4.

On receipt (step E5), by the data processing server 20, of the trace and of the number of satellites 30 transmitted, the data processing server 20 calculates in a step E6 the first weighting coefficient, the second weighting coefficient and the third weighting coefficient for each point of the received trace then weights each of the points of the received trace with said third weighting coefficient calculated in a step E7.

Optionally, the data processing server 20 can calculate the fourth, the fifth and / or the sixth coefficient for the received trace and weight each point of this trace with the result obtained in a step E8.

Then, in a step E9, the data processing server 20 updates, in the database 25, the reference track corresponding to the section of the route traveled by the vehicle 10 from the weighted track. This update can for example correspond, for each point of the reference trace to calculate the weighted average between said point (which has its own weighting, a priori strong) and the corresponding points of the new traces with their own weighting. This can be done point to point or globally on all the points of a track.

When no vehicle 10 has traveled on the section of the route, the trace sent by the first contributing vehicle 10 and weighted by the data processing server 20 is stored as a reference trace in the database 25. When the weighted trace appears far from the reference trace, that is to say that it would vary the reference trace significantly, the weighted trace can be stored in a specific memory area of the database 25. Also , if the weighted traces which are subsequently received are also far from the reference trace but close to each other, they can be averaged and become the new reference trace. This scenario can for example occur when a route 2 is modified and a new route is accessible to vehicles 10, whether the old route is still taken or not.

Finally, the data processing server 20 updates the reference road map from the updated reference track and makes the new reference road map available to contributing vehicles 10 in a step E10a or else sends the new updated reference track to the contributing vehicles 10 which, on receipt, update the existing road map stored in a memory area of the vehicle 10 in a step E10b.

The traces and the road map thus generated can thus be used in the vehicle 10 to guide the driver or for driving assistance applications (lane keeping or other) or even to detect a malfunction on an item of equipment. of the vehicle 10. In the latter case, the road map can for example be correlated with the images of a camera of the vehicle in order to detect a malfunction of said camera.

The invention has the advantage of giving a weight indicating its relevance to each point of a trace received by the data processing server 20 so that each reference trace reflects as closely as possible the reality of the trajectory of the 10 vehicles on the corresponding route section. In particular, the use of a coefficient on the reliability of the vehicle 10 contributing to the received trace and / or the non-consideration of a weighted trace when it too far from the reference trace can make it possible to reduce the risk of malicious contributor vehicles sending erroneous traces to corrupt the participatory road map.

Claims

[Claim 1] Method for updating a road map from at least one so-called “contributor” vehicle, connected to at least one data processing server by a communication network, a contributing vehicle comprising a data module. geolocation, a computer and a communication module, said method comprising the steps of:

a) Reception (E5), by the at least one data processing server, of a track comprising a series of successive geographical positions obtained by the geolocation module of a contributing vehicle for a particular section of the route, each position geographical trace being associated with a number of satellites used to determine said geographical position,

b) Calculation (E6), by the at least one data processing server of a first weighting coefficient of the trace received as a function of the number of satellites transmitted, of a second weighting coefficient of the trace received as a function a distance between the received trace and at least one reference trace corresponding to said path section stored in the at least one data processing server, the at least one reference trace corresponding to an average path calculated from traces transmitted beforehand by at least one contributing vehicle for the section of the journey, and a third weighting coefficient of the trace received by applying a mathematical function to the first calculated weighting coefficient and to the calculated second weighting coefficient,

c) weighting (E7) of each geographical position of the received trace with the third calculated weighting coefficient, each geographical position of the received trace being further weighted (E8) with a coefficient representative of a coherence between objects detected by a camera of the vehicle and objects stored in a database,

d) updating (E9) of at least one reference track corresponding to the section of the vehicle's journey from the weighted track and,

e) updating (E10a, E10b) of a road map from at least one updated reference track.

[Claim 2] Method according to the preceding claim, in which the fourth weighting coefficient is based on the quality of the measurements carried out on the geolocation signals received from the satellites.

[Claim 3] Method according to the preceding claim, in which the quality of the measurements comprises the position of the satellites and / or their distribution and / or the distance between the point of coordinates measured and each satellite having taken the measurement.

[Claim 4] A method according to any one of claims 2 and 3, wherein the quality of the measurements includes at least one characteristic of the atmosphere.

[Claim 5] Method according to one of the preceding claims, further comprising a step of weighting by the at least one server of the trace received with a fifth weighting coefficient representative of the reliability of information transmitted beforehand by the contributor. .

[Claim 6] A method according to one of the preceding claims, wherein the third weighting coefficient corresponds to the mean, the median or the standard deviation of the first weighting coefficient and the second weighting coefficient.

[Claim 7] Data processing server for updating a road map from at least one so-called “contributor” vehicle, connected to said data processing server by a communication network, a contributing vehicle comprising a geolocation module (1 10), a computer (120) and a communication module (130), said server being characterized in that it is configured for:

a) Receive (E5), from at least one contributing vehicle, a series of geographic positions of the vehicle on a section of the vehicle's path, called a “trace”, determined from a plurality of signals sent by a plurality of satellites , as well as the number of satellites used to determine said trace,

b) calculate (E6) a first weighting coefficient of the received trace as a function of the number of satellites transmitted, a second weighting coefficient of the received trace as a function of a distance between the received trace and at least one corresponding reference trace to said path section stored in said data processing server, the at least one reference track corresponding to an average path calculated from traces previously transmitted by at least one contributing vehicle for the path section, and a third weighting coefficient of the trace received by applying a mathematical function to the first calculated weighting coefficient and to the second calculated weighting coefficient,

c) weighting (E7) each geographical position of the received trace with the third calculated weighting coefficient, each geographical position of the received trace being furthermore weighted with a coefficient representative of a coherence between objects detected by a vehicle camera and objects stored in a database,

d) updating (E9) the at least one reference trace corresponding to the section of the path of the vehicle from the weighted geographical positions of the received trace, the updating comprising the calculation of an average between geographical positions weighted of the received trace and the corresponding points of the at least one reference trace and,

e) update (E10a, E10b) a road map from at least one updated reference track.

[Claim 8] A road map update system, said system comprising at least one data processing server, according to the preceding claim, a plurality of so-called "contributor" vehicles, and a communication network, connecting the plurality of contributing vehicles. at least one data processing server, each contributing vehicle comprising a geolocation module, a camera, a computer and a communication module.