FR3123616A1 - Method and device for determining a risk of collision between vehicles configured to communicate in V2X - Google Patents

Abstract

The present invention relates to a method and a device for determining a risk of collision between a first vehicle (10) and a second vehicle (11). To this end, the first vehicle (10) receives from the second vehicle (11) a message according to a vehicle-type wireless communication mode to any V2X. This message includes second information representative of the location of the second vehicle (11). The first vehicle (11) determines its location by obtaining first information representative of its position. A level representing the risk of collision between the first vehicle (10) and the second vehicle (11) is determined by the first vehicle (10) from the first information and the second information. If this level is greater than a first threshold value, then the automatic emergency braking system of the first vehicle is activated. Figure for abstract: Figure 1

Description

Method and device for determining a risk of collision between vehicles configured to communicate in V2X

The present invention relates to methods and devices for determining a risk of collision between vehicles. The present invention also relates to a method and a device for vehicle trajectory prediction and collision prediction. The present invention also relates to a method and a device for communication between vehicles.

Technology background

Road safety is an important issue for our societies. With the increase in the number of users, whether vehicles, pedestrians or even cyclists, on the road networks around the world, the risks of accidents and incidents caused by these same users have never been as important.

To improve road safety, some contemporary vehicles are equipped with driving assistance functions or systems, known as ADAS (from the English "Advanced Driver-Assistance System" or in French "Advanced Driving Assistance System") . ADAS systems, for example, implement methods based on the detection of surrounding obstacles using peripheral sensors on board a vehicle such as cameras, radars, or even lidars (from the English "Light Detection And Ranging" , or “Detection and estimation of distance by light” in French).

The detection of an object on the traffic lane by one or more of these on-board sensors leads, for example, to the generation of an alert in the passenger compartment of the vehicle or an automatic action by the vehicle to avoid collision with the detected object.

However, these systems have certain limitations. For example, for an object to be detected by one or more of these sensors, the object must be within the sensor's field of view. Depending on the geometry of the road or the visibility conditions, the detection of the object may arrive late, which limits the reaction capacity of the driver or the vehicle.

Summary of the present invention

An object of the present invention is to solve at least one of the problems or limitations of the technological background described above.

An object of the present invention is thus to improve the detection of obstacles on a road.

Another object of the present invention is to improve the prediction of a risk of collision in order to avoid the collision between a vehicle and an object, in particular another vehicle.

Finally, another object of the present invention is to improve the safety of a vehicle and its passages, as well as that of other road users.

According to a first aspect, the present invention relates to a method for determining a risk of collision between vehicles, the method being implemented by a first vehicle, the method comprising the following steps:

- reception of at least one message transmitted by a second vehicle according to a vehicle-to-everything communication mode, called V2X, the at least one message comprising a second piece of information representing the location of the second vehicle;

- Obtaining first information representative of the location of the first vehicle from a receiver of a satellite positioning system on board the first vehicle;

- determination of a level of risk of collision between the first vehicle and the second vehicle according to the first information and the second information;

- activation of an automatic emergency braking system of the first vehicle when the level is greater than a first threshold value.

According to a variant, the method further comprises the following steps when the level is below the first threshold value:

- determination of a first trajectory over a determined time interval from the first information and first dynamic parameters of the first vehicle;

- determination of a geographical zone of destination for the first vehicle according to the first trajectory of the first vehicle, a margin of error on the location of the first vehicle and a width of the first vehicle;

- determination of the presence or absence of the second vehicle in the geographical area of destination according to a third piece of information representative of the location of the second vehicle.

According to another variant:

- The third information corresponds to the second information when the second vehicle is stationary;

- the third information corresponds to a final position of a second trajectory of the second vehicle determined over the time interval determined from the second information and second dynamic parameters of the second vehicle, the second dynamic parameters being included in the at least a message.

According to an additional variant, the first trajectory and the second trajectory are predicted by implementing a method of kinematic modeling of a bicycle over a time horizon determined from a current instant.

According to yet another variant, when the second vehicle is present in the geographical area of destination, the method further comprises the following steps:

- determination of a time remaining before collision, called TTC, between the first vehicle and the second vehicle, said TTC being determined as a function of the first trajectory of the first vehicle, of a projection point corresponding to a projection of the location of the second vehicle represented by the third information on the first trajectory and a speed of the first vehicle;

- comparison of the TTC with a set of second threshold values comprising at least one second threshold value;

- activation of the automatic emergency braking system of the first vehicle when the TTC is lower than at least a second threshold value of the set of second threshold values.

According to an additional variant, the method further comprises a step of rendering an alert when the automatic emergency braking system of the first vehicle is activated.

According to another variant, the at least one message is of the cooperative warning message type, called CAM message, or of the decentralized environmental notification message type, called DENM message.

According to a second aspect, the present invention relates to a device for determining a risk of collision between vehicles, the device comprising a memory associated with a processor configured for the implementation of the steps of the method according to the first aspect of the present invention.

According to a third aspect, the present invention relates to a vehicle, for example of the automobile type, comprising a device as described above according to the second aspect of the present invention.

According to a fourth aspect, the present invention relates to a computer program which comprises instructions adapted for the execution of the steps of the method according to the first aspect of the present invention, this in particular when the computer program is executed by at least one processor.

Such a computer program can use any programming language, and be in the form of source code, object code, or intermediate code between source code and object code, such as in a partially compiled form, or in any other desirable form.

According to a fifth aspect, the present invention relates to a computer-readable recording medium on which is recorded a computer program comprising instructions for the execution of the steps of the method according to the first aspect of the present invention.

On the one hand, the recording medium can be any entity or device capable of storing the program. For example, the medium may comprise a storage means, such as a ROM memory, a CD-ROM or a ROM memory of the microelectronic circuit type, or even a magnetic recording means or a hard disk.

On the other hand, this recording medium can also be a transmissible medium such as an electrical or optical signal, such a signal being able to be conveyed via an electrical or optical cable, by conventional or hertzian radio or by self-directed laser beam or by other ways. The computer program according to the present invention can in particular be downloaded from an Internet-type network.

Alternatively, the recording medium may be an integrated circuit in which the computer program is incorporated, the integrated circuit being adapted to execute or to be used in the execution of the method in question.

Brief description of figures

Other characteristics and advantages of the present invention will emerge from the description of the particular and non-limiting examples of embodiments of the present invention below, with reference to the appended FIGS. 1 to 5, in which:

schematically illustrates an environment comprising a first vehicle and a second vehicle, according to a particular and non-limiting embodiment of the present invention;

schematically illustrates a process for determining a risk of collision between the first vehicle and the second vehicle of the , according to a particular and non-limiting embodiment of the present invention;

schematically illustrates a geographical area of destination of the first vehicle of the , according to a particular and non-limiting embodiment of the present invention;

schematically illustrates a device configured to determine a risk of collision between the first vehicle and the second vehicle of the , according to a particular and non-limiting embodiment of the present invention;

illustrates a flowchart of the different steps of a method for determining a risk of collision between the first vehicle and the second vehicle of the , according to a particular and non-limiting embodiment of the present invention.

Description of the examples of realization

A method and a device for determining a risk of collision between vehicles will now be described in the following with reference jointly to FIGS. 1 to 5. The same elements are identified with the same reference signs throughout the description. who will follow.

According to a particular and non-limiting embodiment of the present invention, a first vehicle receives from a second vehicle one or more messages according to a vehicle-to-everything type wireless communication mode, called V2X (from the English "Vehicle to Everything” or in French “Véhicule vers tout”). This or these messages each correspond for example to a cooperative warning message, called CAM message (from the English "Cooperative Awareness Message" or in French "Cooperative warning message"), or to a decentralized environmental notification message, said DENM message (from the English “Decentralized Environmental Notification Message” or in French “Message de notification Environnementaleelocée”). This or these message(s) advantageously each comprise a second piece of information representative of the location of the second vehicle at the time of transmission of the message by the second vehicle. The first vehicle also determines its location by obtaining first information representative of its position or its location, for example from a receiver of a GPS-type satellite positioning system (from the English “Global Positioning System” or in French "Global Positioning System") for example, this receiver being embedded in the first vehicle. A level representing the risk of collision between the first vehicle and the second vehicle is determined by the first vehicle from the first location information of the first vehicle and the second location information of the second vehicle. If this level is greater than a first threshold value, then the automatic emergency braking system of the first vehicle is activated or triggered, for example automatically.

The use of the V2X communication system allows the first vehicle to obtain information on the presence of other vehicles in its environment, independently of their visibility from the first vehicle. The first vehicle can thus determine the risk of collision with this or these other vehicles from information received according to this V2X communication mode and activate the actions necessary to avoid the collision. The safety of the first vehicle as well as that of the other vehicles is thus improved.

Other particular aspects and embodiments of the invention are described below.

The schematically illustrates an environment 1 comprising a first vehicle 10 and a second vehicle 11, according to a particular and non-limiting embodiment of the present invention.

The illustrates an environment 1 corresponding for example to a road environment in which a first vehicle 10 and a second vehicle 11 are traveling. The first vehicle 10 and the second vehicle 11 are traveling for example on the same portion of road illustrated with dotted lines on the .

The first vehicle 10 and the second vehicle 11 travel for example in the opposite direction or in the same direction. The second vehicle 11 corresponds for example to an immobile or stationary vehicle or according to another example to a mobile or moving vehicle.

The first vehicle 10 corresponds for example to a vehicle with a combustion engine, with electric motor(s) or else a hybrid vehicle with a combustion engine and one or more electric motors. The first vehicle 10 thus corresponds for example to a land vehicle, for example an automobile, a truck, a bus, a motorcycle. Finally, the first vehicle 10 corresponds to an autonomous vehicle or not, that is to say a vehicle circulating according to a determined level of autonomy or under the total supervision of the driver.

The second vehicle 11 also corresponds to a vehicle with a heat engine, electric motor(s) or even a hybrid vehicle with a heat engine and one or more electric motors, corresponding for example to a land vehicle, for example an automobile , a truck, a bus, a motorcycle, autonomous or not.

The first vehicle 10 advantageously embeds a satellite geolocation system configured to determine the current position of the first vehicle 10, the first vehicle 10 for this purpose embeds a receiver of a GPS or Galileo type system, for example in communication with a computer of the embedded system of the first vehicle 10.

The second vehicle 11 also carries a satellite geolocation system configured to determine the current position of the second vehicle 11, the second vehicle 11 carrying for this purpose a receiver of a GPS or Galileo type system for example in communication with a computer of the embedded system of the second vehicle 11.

The first vehicle 10 and the second vehicle 11 each also embed a communication system or device configured to communicate with each other directly or via an infrastructure of a wireless communication network.

The mobile communication infrastructure allowing wireless data communication between the first vehicle 10 and the second vehicle 11 comprises for example one or more communication equipment 101 of the relay antenna type (cellular network) or roadside unit, called UBR. In a mode of communication using such a network architecture, the data is for example transmitted by the second vehicle 11 to the first vehicle 10 (and vice versa from the first vehicle 10 to the second vehicle 11) via a relay antenna or UBR 101, the exchanged data transiting for example by one or more remote devices (for example a server) of the “cloud” (or “cloud” in French) 100, the communication equipment 101 being for example connected to the “cloud” 100 via a wired link.

The communication system of the first vehicle 10 (respectively of the second vehicle 11) comprises for example one or more communication antennas connected to a telematics control unit, called TCU (from the English "Telematic Control Unit"), itself connected to one or more computers of the on-board system of the first vehicle 10 (respectively of the second vehicle 11). The antenna(s), the TCU unit and the computer(s) form, for example, a multiplexed architecture for performing various useful services for the correct operation of the vehicle and for assisting the driver and/or the passengers of the vehicle in controlling the first vehicle 10 (respectively of the second vehicle 11), for example in the control of one or more ADAS systems on board the first vehicle 10 (respectively of the second vehicle 11). The computer or computers and the TCU communicate and exchange data with each other via one or more computer buses, for example a communication bus of the CAN data bus type (from the English “Controller Area Network”). or in French "Network of controllers"), CAN FD (from English "Controller Area Network Flexible Data-Rate" or in French "Network of controllers with flexible data rate"), FlexRay (according to the ISO 17458 standard) or Ethernet (according to ISO/IEC 802-3 standard).

Each communication system or device can be likened to a node of a network, for example an ad hoc wireless network.

The first vehicle 10 and the second vehicles 11 advantageously communicate using the V2X communication system, for example based on the 3GPP LTE-V or IEEE 802.11p standards of ITS G5. In such a V2X communication system, each vehicle embeds a node to allow communication from vehicle to vehicle V2V (from the English “vehicle-to-vehicle”), from vehicle to infrastructure V2I (from the English “vehicle-to- -infrastructure”) and/or vehicle-to-pedestrian V2P, the pedestrians being equipped with mobile devices (for example a smart phone (“Smartphone”)) configured to communicate with vehicles.

The communication equipment 101 corresponding for example to an antenna of a cellular network of the 4G or 5G LTE type or to a UBR ("Roadside Unit") is for example assimilated to a node of the network, in addition to the nodes equipping vehicles 10 and 11.

According to a particular embodiment, the set of nodes (that is to say the communication devices associated with the vehicles 10 and 11 and the antenna or UBR 101) of the network forms, for example, an ad hoc wireless network ( also called WANET (from the English "Wireless Ad Hoc Network") or MANET (from the English "Mobile Ad Hoc Network"), corresponding to a decentralized wireless network. The ad hoc wireless network advantageously corresponds to a vehicular ad hoc network (or VANET, standing for “Vehicular Ad hoc NETwork”) or to an intelligent vehicular ad hoc network (or InVANET, standing for “Intelligent Vehicular Ad hoc NETwork”), also known as the “GeoNetworking” network. In such a network, 2 or more vehicles each carrying a node can communicate with each other in the context of V2V vehicle-to-vehicle communication; each vehicle can communicate with the infrastructure set up as part of a V2I vehicle-to-infrastructure communication; each vehicle can communicate with one or more pedestrians equipped with mobile devices (for example a smart phone (“Smartphone”)) as part of a V2P vehicle-to-pedestrian communication (“vehicle-to- walker”).

According to an exemplary embodiment, the first vehicle 10 and the second vehicle 11 communicate and exchange data according to a V2V type communication mode, for example according to a direct communication mode.

A direct communication mode is for example compliant with:

- ITS G5 in Europe or DSRC (Dedicated Short Range Communications) in the United States of America, both of which are based on the IEEE 802.11p standard; Where

- LTE-V Mode 4 (from English “Long-Term Evolution – Vehicle Mode 4” or in French “Evolution à long terme –véhicle Mode 4”) which allows V2V communications, also called “sidelink” communications (or in French "side link")) based on a direct communication interface of LTE called PC5; such technology is described for example in the article entitled "Analytical Models of the Performance of C-V2X Mode 4 Vehicular Communications", written by Manuel Gonzalez-Martin, Miguel Sepulcre, Rafael Molina-Masegosa and Javier Gozalvez, and published in 2018 .

The first vehicle 10 (via for example one or more processors of one or more on-board computers in the first vehicle 10) is thus configured for the implementation of a process for determining a risk of collision as described next of the and/or for the implementation of a method for determining a risk of collision as described with regard to the .

An example of a computer embodiment is described below with regard to the .

The schematically illustrates a process for determining a risk of collision implemented by the first vehicle 10, according to a particular and non-limiting embodiment of the present invention.

The process described below is for example implemented by one or more processors of one or more computers of the on-board system of the first vehicle 10.

In a first operation 21, the first vehicle 10 obtains a set of data 201 comprising first information representing its position or its location. This first information is for example received from the GPS receiver on board the first vehicle 10.

According to a variant embodiment, this set of data 201 also comprises a set of dynamic parameters of the first vehicle 10, called first dynamic parameters. These first dynamic parameters include, for example, one or more information on the speed of the first vehicle 10, one or more information on the direction of movement of the first vehicle 10, one or more steering wheel angle measurements or even one or more curvature information. These first parameters are advantageously obtained from devices or sensors on board the first vehicle 10, for example the steering wheel angle sensor (CAV), an odometric system, an inertial unit.

In this first operation, the first vehicle 10 also receives one or more messages 202 transmitted by the second vehicle 11 according to the V2X communication mode.

The message(s) 202 are for example transmitted in a more particular way according to a V2V communication mode, directly between the vehicles 10 and 11 or indirectly via the infrastructure of the wireless network, that is to say via including the antenna or UBR 101.

Each message received corresponds for example to a cooperative warning message, called CAM message (from the English “Cooperative Awareness Message” or in French “Cooperative Warning Message”), as defined in the technical specification ETSI TS 102 637 -2 v1.2.1 from March 2011.

A CAM message includes for example an identifier of the sender of the message (for example the second vehicle 11), position or location information (called second information) of the sender (for example the second vehicle 11) obtained from the receiver GPS embedded in the second vehicle 11 and a set of dynamic parameters (called second dynamic parameters) of the transmitter (for example the second vehicle 11). The second dynamic parameters include for example the speed of the second vehicle, the direction of movement, steering wheel angle measurements or even curvature information. These second parameters are advantageously obtained from devices or sensors on board the second vehicle 11, for example the steering wheel angle sensor (CAV), an odometer system, an inertial unit.

According to another example, each message received corresponds to a decentralized environmental notification message, known as DENM message (from the English "Decentralized Environmental Notification Message" or in French "Message de notification Environnementaleelocée"), as defined in the technical specification ETSI TS 102 637-3 v1.1.1 of September 2010.

A DENM message includes for example the identifier of the sender of the message (for example the second vehicle 11) and the second position or location information of the sender (for example the second vehicle 11) obtained from the GPS receiver on board in the second vehicle 11.

According to a variant, the set of messages received comprises one or more CAM messages and one or more DENM messages.

In this first operation 21, the first vehicle 10 determines a collision risk level between the first vehicle 10 and the second vehicle 11 according to the first location information of the first vehicle 10 and the second location information of the second vehicle 11 .

The first information and the second information are representative of the location of respectively the first vehicle 10 and the second vehicle 11 at the same time instant corresponding for example to a current instant, corresponding for example to the instant of reception of the message CAM or DENM carrying the second information.

The collision risk level corresponds for example to a probability of a possible collision between the first vehicle 10 and the second vehicle 11. This probability is for example calculated or determined by evaluating the intersection between two confidence ellipses of the positions of the first vehicle 10 and of the second vehicle 11. This probability is for example calculated using the Monte Carlo method, according to the following equation:

With p _v1 (x,y) the probability (normal distribution) with respect to the first position of the first vehicle V1 10 and p _v2 (x,y) the probability (normal distribution) with respect to the first position of the second vehicle V2 11 .

The level of risk of collision is compared with a first threshold value which depends for example on the type of the road and on the type of the second vehicle.

This first threshold value is for example equal to 0.7 or 0.8.

When the result of the comparison indicates that the collision risk level is greater than the first threshold value, then the process continues with operation 210.

When the result of the comparison indicates that the collision risk level is lower than the first threshold value, then the process continues with operation 22.

In a second operation 22, when the collision risk level is greater than the first threshold value, that is to say when the probability is high that a collision between the first vehicle 10 and the second vehicle 11 will take place, one or more actions to prevent the collision are triggered.

For example, the computer in charge of implementing the process transmits a request to one or more computers each in charge of controlling a particular ADAS system of the first vehicle 10.

For example and advantageously, the determination of a collision risk level greater than the first threshold value automatically triggers the emergency braking system of the first vehicle 10.

According to a variant embodiment, the determination of a collision risk level greater than the first threshold value triggers the generation and rendering of one or more alert messages intended for the driver of the first vehicle 10.

According to another variant embodiment, the activation of the emergency braking system of the first vehicle 10 causes the transmission of one or more alert messages to vehicles near the first vehicle 10 according to the V2X communication mode to alert them. that the emergency braking system is activated.

In a third operation 23, when the collision risk level is lower than the first threshold value, that is to say when there is uncertainty about the fact that a collision between the first vehicle 10 and the second vehicle 11 takes place, the first vehicle 10 determines its geographical destination area, known by the acronym GDA (Geographical Destination Area). This GDA of the first vehicle 10 is advantageously determined or calculated from the first current location information of the first vehicle 10 and the first dynamic parameters of the first vehicle 10 obtained at the current instant. For the determination of this GDA, it is assumed that the first vehicle 10 retains the first dynamic parameters for a determined duration (called time horizon) which depends for example on the type of road on which the first vehicle 10 is traveling and/or on the current speed of the first vehicle 10. The time horizon is for example inversely proportional to the speed. For example, this time horizon is equal to 10 seconds. According to other examples, the time horizon is equal to 5, 15 or 20 seconds.

The determination of the GDA also takes into account the errors or uncertainties associated with the measurement of the position of the first vehicle 10 (for example the errors associated with the GPS system). The determination of the GDA also takes as an input parameter the width of the first vehicle 10.

Such a GDA zone is known to those skilled in the art and described for example in the document entitled "Vehicle to Pedestrian Communications for Protection of Vulnerable road Users", by José Javier Anaya, Pierre Merdrignac, Oyunchimeg Shagdar, Fawzi Nashashibi and José E. Naranjo, published on May 19, 2014 in the HAL archive.

The determination of the GDA is based on the determination of the trajectory of the first vehicle 10 over the time horizon from the first current position information of the first vehicle 10 and the first dynamic parameters of the first vehicle 10. The determination of such a trajectory is for example obtained by using any dynamic trajectory modeling method such as the method known as the kinematic modeling method of a bicycle (standing for “Bicycle Kinematic Model”). Such a method is for example described in the document entitled “Kinematic and Dynamic Controller Design for Autonomous Driving of Car-like Mobile Robot”, by Kiwon Yeom, published on July 7, 2020 in “International Journal of Mechanical Engineering and Robotics Research”, volume 9, Number 7.

The trajectory of the first vehicle 10 predicted over a time horizon for example equal to 10 seconds corresponds for example to an arc of a circle of radius R and centered at a point of coordinates (x _c ,y _c ), with:

With (x _D ,y _D ) the current position of the first vehicle 10, 'l' the width of the first vehicle 10, θ the direction of the first vehicle 10 and δ the measurement of the steering wheel angle.

The geographical area to GDA destination obtained is illustrated by the , according to a particular and non-limiting embodiment of the present invention.

The thus illustrates a GDA 30 delimited by solid lines with the trajectory 301 of the first vehicle 10 predicted over the determined time horizon, as explained above. The position 31 of the second vehicle 11 illustrated by a square corresponds to the final position of the second vehicle 11 at the end of the time period corresponding to the time horizon. Finally, the gray ellipse 33 corresponds to the projection of the position 31 of the second vehicle on the first trajectory 301 predicted for the first vehicle 10.

The first vehicle 10 rotates around an instantaneous axis of rotation around a point 32 corresponding to the instantaneous center of rotation, or ICR (standing for “Instantaneous Center of Rotation”).

The GDA zone 30 is for example defined by two distances corresponding to the minimum radius of curvature 322 and the maximum radius of curvature 323, both having point 32 as their origin. 322 thus form the GDA zone 30 of the first vehicle 10.

In this third operation 23, it is determined whether the second vehicle 11 is located in the GDA zone 30 at the end of the time period corresponding to the time horizon.

When the second vehicle 11 is stationary, the position of the second vehicle at the end of the time horizon corresponds to its position defined by the second information.

When the second vehicle 11 is mobile, the position of the second vehicle at the end of the time horizon corresponds to the last point of the trajectory. To determine this point, the trajectory of the second vehicle 11 is predicted according to the same method as that used to predict the first trajectory 301 of the first vehicle 10, for example according to the kinematic modeling method of a bicycle, from the second information location and second dynamic parameters of the second vehicle 11 transmitted by the second vehicle 11 to the first vehicle 10 in the CAM message(s) according to the V2X communication mode.

The presence or absence of the second vehicle 11 in the GDA zone is advantageously determined by comparing the distance 'd' 321 between the point 32 and the final position 31 of the second vehicle with the minimum radius of curvature 322 'R _min 'd' one hand and the maximum radius of curvature 323 'R _max ' on the other hand. Thus if this distance 'd' 321 is between 'R _min '322 and 'R _max '322, then the second vehicle 11 is detected as being present in the GDA zone 30, otherwise the second vehicle 11 is absent from the GDA zone 30.

When it is determined that the second vehicle 11 is absent from the GDA zone 30, then the process goes to the fourth operation 24 and ends without additional action for the first vehicle 10, the risk of collision being judged as normal or low and requiring no activation of a safety system such as the emergency braking system for example.

When it is determined that the second vehicle 11 is present in the GDA zone 30, then the process goes to the fifth operation 25.

In a fifth operation 25, the time remaining before collision, called TTC (from the English “Time To Collision”), between the first vehicle 10 and the second vehicle 11 is determined or calculated from the first predicted trajectory 301 for the first vehicle 10 and the projection point 33 of the final position 31 of the second vehicle 11 on the first trajectory 301 of the first vehicle 10, knowing the speed of the first vehicle 10.

This time remaining before collision TTC is advantageously at a set of second threshold values comprising one or more threshold values to determine the level of risk of collision as well as the action or actions to be implemented to avoid the collision between the first vehicle 10 and the second vehicle 11.

The set of second threshold values comprises for example the following threshold values: 5 s and 20 s, or 5 s and 10 s, or 10 s and 20 s.

For example, if TTC is less than 5 s (TTC <= 5 s) then the collision risk is determined to be critical. If TTC is between 5 s and 20 s (5s < TTC <= 20 s) then the collision risk is determined to be very high (or considerable). If TTC is greater than 20 s (TTC > 20 s) then the risk is considered normal or reasonable.

In a sixth operation 26, one or more actions are implemented, for example automatically, by the first vehicle 10 according to the result of the comparison between the TTC and the second threshold value or values.

An action corresponds for example to the activation of an ADAS system of the first vehicle 10.

For example, if TTC is less than 5 s (TTC <= 5 s) then the automatic emergency braking system of the first vehicle 10 is implemented. According to a variant, an alert is also generated and rendered (for example display of a message on a screen or rendering of a sound via one or more loudspeakers) in the passenger compartment of the first vehicle 10 to alert the driver and /or passengers.

If TTC is between 5 s and 20 s (5s <TTC <= 20 s) then the automatic emergency braking system of the first vehicle 10 is implemented with a braking intensity lower than that of the case where TTC is less than 5s (TTC <= 5s).

Finally, if TTC is greater than 20 s (TTC > 20 s) then no action is implemented.

The schematically illustrates a device 4 configured to determine a level of risk of collision between vehicles, for example between the first vehicle 10 and the second vehicle 11, according to a particular and non-limiting embodiment of the present invention. The device 4 corresponds for example to a device on board the vehicle 10, for example a computer.

The device 4 is for example configured for the implementation of the operations described with regard to FIGS. 1, 2, and 3 and/or of the steps of the method described with regard to the . Examples of such a device 4 include, but are not limited to, on-board electronic equipment such as a vehicle's on-board computer, an electronic computer such as an ECU ("Electronic Control Unit"), a telephone smart phone, tablet, laptop. The elements of device 4, individually or in combination, can be integrated in a single integrated circuit, in several integrated circuits, and/or in discrete components. The device 4 can be made in the form of electronic circuits or software (or computer) modules or else a combination of electronic circuits and software modules.

The device 4 comprises one (or more) processor(s) 40 configured to execute instructions for carrying out the steps of the method and/or for executing the instructions of the software or software embedded in the device 4. The processor 40 can include integrated memory, an input/output interface, and various circuits known to those skilled in the art. The device 4 further comprises at least one memory 41 corresponding for example to a volatile and/or non-volatile memory and/or comprises a memory storage device which can comprise volatile and/or non-volatile memory, such as EEPROM, ROM , PROM, RAM, DRAM, SRAM, flash, magnetic or optical disk.

The computer code of the on-board software or software comprising the instructions to be loaded and executed by the processor is for example stored on the memory 41.

According to various particular and non-limiting examples of embodiment, the device 4 is coupled in communication with other similar devices or systems and/or with communication devices, for example a TCU (from the English “Telematic Control Unit” or in French "Telematic Control Unit"), for example via a communication bus or through dedicated input/output ports.

According to a particular and non-limiting embodiment, the device 4 comprises a block 42 of interface elements for communicating with external devices, for example a remote server or the “cloud”, other nodes of the ad hoc network. Block 42 interface elements include one or more of the following interfaces:

- RF radio frequency interface, for example of the Wi-Fi® type (according to IEEE 802.11), for example in the 2.4 or 5 GHz frequency bands, or of the Bluetooth® type (according to IEEE 802.15.1), in the band frequency at 2.4 GHz, or of the Sigfox type using UBN radio technology (Ultra Narrow Band, in French ultra narrow band), or LoRa in the 868 MHz frequency band, LTE (from English " Long-Term Evolution” or in French “Evolution à long terme”), LTE-Advanced (or in French LTE-advanced);

- USB interface (from the English "Universal Serial Bus" or "Universal Serial Bus" in French);

- HDMI interface (from the English “High Definition Multimedia Interface”, or “Interface Multimedia Haute Definition” in French);

- LIN interface (from English “Local Interconnect Network”, or in French “Réseau interconnecté local”).

Data are for example loaded to the device 4 via the block 42 interface using a Wi-Fi® network such as according to IEEE 802.11, an ITS G5 network based on IEEE 802.11p or a mobile network such as a 4G network (or 5G) based on the LTE (Long Term Evolution) standard defined by the 3GPP consortium, in particular an LTE-V2X network.

According to another particular and non-limiting example of embodiment, the device 4 comprises a communication interface 43 which makes it possible to establish communication with other devices (such as other computers of the on-board system) via a communication channel 430. The communication interface 43 corresponds for example to a transmitter configured to transmit and receive information and/or data via the communication channel 430. The communication interface 43 corresponds for example to a CAN-type wired network (of the 'English "Controller Area Network" or in French "Réseau de Contrôleurs"), CAN FD (from English "Controller Area Network Flexible Data-Rate" or in French "Réseau de Contrôleurs à Flow de Data Flexible"), FlexRay ( standardized by ISO 17458) or Ethernet (standardized by ISO/IEC 802-3).

According to a particular and non-limiting example of embodiment, the device 4 can supply output signals to one or more external devices, such as a display screen, touch-sensitive or not, one or more loudspeakers and/or other devices (projection system) through respective output interfaces.

The illustrates a flowchart of the different steps of a method for determining a risk of collision between vehicles, for example between the first vehicle 10 and the second vehicle 11, according to a particular and non-limiting example embodiment of the present invention. The method is for example implemented by a device on board the vehicle 10 or by the device 4 of the .

In a first step 51, one or more messages transmitted by a second vehicle are received according to a vehicle-to-everything communication mode, called V2X, the at least one message comprising a second piece of information representing the location of the second vehicle.

In a second step 52, first information representing the location of the first vehicle is obtained from a receiver of a satellite positioning system on board the first vehicle.

In a third step 53, a collision risk level between the first vehicle and the second vehicle is determined according to the first information and the second information.

In a fourth step 54, an automatic emergency braking system of the first vehicle is activated when the level is above a first threshold value.

According to a variant, the variants and examples of the operations described in relation to FIGS. 1 to 3 apply to the steps of the method of .

Of course, the present invention is not limited to the embodiments described above but extends to a method for predicting a collision between two vehicles which would include secondary steps without departing from the scope of the present invention. . The same would apply to a device configured for the implementation of such a method.

The present invention also relates to a vehicle, for example automobile or more generally an autonomous land motor vehicle, comprising the device 4 of the .

Claims (10)

A method of determining a risk of collision between vehicles, said method being implemented by a first vehicle (10), said method comprising the following steps:
- reception (51) of at least one message (202) sent by a second vehicle (11) according to a vehicle-to-everything communication mode, called V2X, said at least one message comprising a second piece of information representing the location of said second vehicle ( 11);
- Obtaining (52) first information representative of location of said first vehicle (10) from a receiver of a satellite positioning system on board said first vehicle (10);
- determination (53) of a level of risk of collision between said first vehicle (10) and said second vehicle (11) according to said first information and said second information;
- activation (54) of an automatic emergency braking system of said first vehicle (10) when said level is greater than a first threshold value. A method according to claim 1, further comprising the following steps when said level is below said first threshold value:
- determination of a first trajectory (301) over a determined time interval from said first information and first dynamic parameters of said first vehicle (10);
- determination of a geographic zone of destination (30) for said first vehicle (10) as a function of said first trajectory (301) of said first vehicle (10), of a margin of error on the location of said first vehicle and of a width of said first vehicle;
- determination of the presence or absence of said second vehicle (11) in said geographical area of destination (30) according to a third piece of information representative of the location of said second vehicle (11). Method according to claim 2, for which:
- said third information corresponds to said second information when said second vehicle (11) is stationary;
- said third piece of information corresponds to a final position of a second trajectory of said second vehicle (11) determined over said time interval determined from said second piece of information and second dynamic parameters of said second vehicle (11), said second dynamic parameters being included in said at least one message (202). Method according to claim 3, for which said first trajectory and said second trajectory are predicted by implementing a method of kinematic modeling of a bicycle over said determined time interval. Method according to one of Claims 2 to 4, for which, when said second vehicle (11) is present in said geographical area of destination (30), said method further comprises the following steps:
- determination of a time remaining before collision, called TTC, between said first vehicle (10) and said second vehicle (11), said TTC being determined as a function of said first trajectory (301) of said first vehicle, of a point of projection (33) corresponding to a projection of the location (33) of the second vehicle (11) represented by said third information on said first trajectory (301) and of a speed of said first vehicle (10);
- comparison of said TTC with a set of second threshold values comprising at least one second threshold value;
- activation of said automatic emergency braking system of said first vehicle (10) when said TTC is lower than at least a second threshold value of said set of second threshold values. Method according to one of claims 1 to 5, further comprising a step of rendering an alert when said automatic emergency braking system of said first vehicle (10) is activated. Method according to one of claims 1 to 6, for which said at least one message is of the cooperative warning message type, called CAM message, or of the decentralized environmental notification message type, called DENM message. Computer program comprising instructions for implementing the method according to any one of the preceding claims, when these instructions are executed by a processor. Device (4) for determining a risk of collision between vehicles, said device (4) comprising a memory (41) associated with at least one processor (40) configured for the implementation of the steps of the method according to any of claims 1 to 7. Vehicle (10) comprising the device (4) according to claim 9.