FR3120340A1 - Method and device for determining a regulatory speed on a portion of road for a vehicle - Google Patents

Abstract

The invention relates to a method and a device for determining a regulatory speed applicable on the portion of road on which a vehicle (10) is traveling. To this end, the vehicle (10) transmits via a wireless link a request to a remote data processing device (101). The request includes the current position of the vehicle (10), such a position being for example determined by the vehicle (10) via an on-board geolocation system of the GPS type. The vehicle receives in return from the remote data processing device (101) a first regulatory speed that the remote data processing device has determined from mapping data and the current position of the vehicle (10) included in the request. Figure for abstract: Figure 1

Description

Method and device for determining a regulatory speed on a portion of road for a vehicle

The invention relates to methods and devices for determining the regulatory speed for vehicles, in particular for motor vehicles. The invention also relates to a method and a device for communication between a vehicle and a remote device, in particular for determining the regulatory speed.

Technology background

Contemporary vehicles, for some of them, have at least one or more systems configured to determine what is the regulatory speed that applies on the portion of road taken. The legal speed corresponds for example to the maximum speed authorized on this section of road or to the recommended speed.

A first example of a regulatory speed determination system takes the form of an ADAS system (from the English "Advanced Driver-Assistance System" or in French "Advanced Driving Assistance System") comprising an on-board camera in the vehicle, the on-board camera having the road in front of the vehicle in its field of vision. Such a system is configured to recognize road signs from the image data received from the camera, the regulatory speed applicable on the portion of road taken being determined from the recognized sign or signs.

However, such a system is sometimes insufficient to achieve a high level of performance, in particular because speed limit signs are not present for all roads. Indeed, the regulatory speed is sometimes "implicit", that is to say that it is associated with the type of road, without this being indicated by a sign. In other cases, the multiplicity of speed limit signs of the "30 zone" type and/or entrance to agglomeration also leads to a lack of detection and/or identification by the system of the correct regulatory speed.

A second example of a regulatory speed determination system takes the form of an on-board navigation system based on map data stored locally or downloaded as the vehicle moves. The mapping data includes in particular information on the regulatory speed. From the position of the vehicle obtained for example by GPS (from the English "Global Positioning System" or in French "Système Mondial de Positioning") and from the mapping data, the system is able to provide the regulatory speed for the portion of road traveled.

However, such a system is susceptible to error, especially when the mapping data is not up to date. Moreover, such a system requires a large storage space and/or a large exchange of data to download the updates or the mapping data as the vehicle moves.

An object of the present invention is to solve at least one of the problems of the prior art described above.

An object of the present invention is thus to improve the reliability of the determination of the regulatory speed and/or to reduce the memory footprint and/or to reduce the bandwidth requirements for determining a regulatory speed.

According to a first aspect, the invention relates to a method for determining a regulatory speed on a portion of road for a vehicle traveling on the portion of road, the method comprising the following steps:

- transmission, by the vehicle, of a regulatory speed determination request intended for a remote data processing device via a wireless link, the request comprising at least one item of information representing the position of the vehicle;

- reception, by the vehicle, of data representative of a first regulatory speed on the portion of road associated with the position of the vehicle, the data being determined by the remote data processing device and received from the remote data processing device via the wireless link.

According to a variant, the method further comprises the following steps:

- acquisition of at least one image of the section of road by a camera on board the vehicle;

- data processing of the at least one image for recognition of at least one road sign indicating a legal speed;

- determination of a second regulatory speed from at least one road sign, a level of confidence being associated with the determination.

According to another variant, the method further comprises a step of displaying the regulatory speed on a display screen on board the vehicle, the regulatory speed corresponding to the first regulatory speed when the level of confidence is below a determined threshold ; and the regulation speed corresponding to the second regulation speed when the confidence level is greater than the determined threshold.

According to an additional variant, the request is transmitted if and only if the confidence level is below the determined threshold.

According to yet another variant, the request also comprises at least one item of information representative of a dynamic behavior of the vehicle.

According to an additional variant, the method further comprises a step of determining the first prescribed speed by the remote data processing device from mapping data and from the at least one piece of information representing the position of the vehicle.

According to a second aspect, the invention relates to a device for determining a prescribed speed on a portion of road for a vehicle traveling on the portion of road, 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 invention.

According to a third aspect, the invention relates to a system for determining a regulatory speed on a portion of road for a vehicle traveling on the portion of road, the system comprising the device as described above according to the second aspect of the invention and a remote data processing device in communication with the device as described above according to the second aspect of the invention via a wireless link.

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

According to a fifth aspect, the 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 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 sixth aspect, the 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 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 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 invention will emerge from the description of the non-limiting embodiments of the invention below, with reference to the appended figures 1 to 3, in which:

schematically illustrates a road environment in which a vehicle is traveling, according to a particular embodiment of the present invention;

schematically illustrates a device configured to determine a regulatory speed for the vehicle of the , according to a particular embodiment of the present invention;

illustrates a flowchart of the different steps of a method for determining a legal speed for the vehicle of the , according to a particular embodiment of the present invention.

A method and a device for determining a legal speed on a portion of road for a vehicle traveling on the portion of road will now be described in the following with reference jointly to FIGS. 1 to 3. The same elements are identified with the same reference signs throughout the following description.

According to a particular and non-limiting example of embodiment of the invention, a vehicle transmits via a wireless link a request intended for a remote data processing device, for example a server of the "cloud" (from the English " cloud "). The request is transmitted to request the determination of a regulatory speed applicable on the section of road on which the vehicle is traveling. To this end, the request advantageously comprises the current position of the vehicle, such a position being for example determined by the vehicle via an on-board geolocation system of the GPS type. The vehicle receives in return from the remote data processing device a first regulatory speed that the remote data processing device has determined from mapping data and the current position of the vehicle included in the request.

A legal speed associated with a section of road corresponds for example to a speed limit applicable on this section of road, that is to say the maximum speed authorized on this section of road. According to another example, a regulation speed corresponds to a recommended speed. According to yet another example, a regulation speed corresponds to a mandatory minimum speed to be observed on this portion of road.

Such a method has the advantage that a small volume of data is exchanged between the vehicle and the remote device, that is to say the data of the request and the data representative of the first regulatory speed. In addition, such a method has the advantage of minimizing the requirements in terms of calculation and memory footprint in the vehicle by deporting the determination of the first regulatory speed to the remote device.

schematically illustrates a road environment in which a vehicle 10 moves, according to a particular and non-limiting embodiment of the present invention.

There illustrates a road environment 1 comprising a portion of road on which the vehicle 10 travels. The portion of road is for example located in an urban environment, on a departmental or national road, on a road with two traffic lanes or on a motorway.

The 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 vehicle 10 thus corresponds for example to a land vehicle, for example an automobile, a truck, a bus, a motorcycle. Finally, the 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 vehicle 10 advantageously carries a satellite geolocation system configured to determine the current position of the vehicle 10, the vehicle 10 carrying for this purpose a receiver of a system of the GPS or Galileo type, for example in communication with a computer of the on-board system of the vehicle 10.

The vehicle 10 also advantageously embeds a communication system configured to communicate with one or more remote devices 101 via an infrastructure of a wireless communication network. The remote device 101 advantageously corresponds to a device configured to process data, for example data stored in the memory of the remote device 101 and/or data received from the vehicle 10. The remote device 101 corresponds for example to a "cloud" server 100.

The communication system of the vehicle 10 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 vehicle 10. The antenna(s), the TCU unit and the computer(s) form, for example, a multiplexed architecture for performing various services useful for the proper operation of the vehicle and for assisting the driver and/or passengers of the vehicle in the control of the vehicle 10, for example by displaying regulatory speed information on a display device on board the vehicle 10. The computer(s) and the unit TCU communicate and exchange data between them via a or several computer buses, for example a communication bus of the CAN data bus type (from the English “Controller Area Network” or in French “Réseau de Contrôleurs”), CA N FD (from the English "Controller Area Network Flexible Data-Rate" or in French "Réseau de Contrôleurs à Flow de Data Flexible"), FlexRay (according to the ISO 17458 standard) or Ethernet (according to the ISO/IEC 802- 3).

The mobile communication infrastructure allowing wireless data communication between the vehicle 10 and the remote data processing device 101 comprises, for example, several communication devices 110 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 vehicle 10 to the remote device 101 of the "cloud" 100 via a relay antenna 110 (the antenna 110 being for example connected to the "cloud" 100 via wired connection).

The wireless communication system allowing the exchange of data between the vehicle 10 and the remote device 101 corresponds for example to:

- a V2I vehicle-to-infrastructure communication system, for example based on the 3GPP LTE-V or IEEE 802.11p standards of ITS G5; Or

a communication system of the cellular network type, for example a network of the LTE type (from the English “Long-Term Evolution” or in French “Long-term Evolution”), LTE-Advanced (or in French LTE-advanced) 4G or 5G LTE; Or

- A WiFi type communication system according to IEEE 802.11, for example according to IEEE 802.11n or or IEEE 802.11ac.

A process for determining a regulatory speed associated with the portion of road on which the vehicle 10 is traveling is advantageously implemented by a system comprising the vehicle 10 (that is to say by one or more devices on board the vehicle 10, for example one or more computers) and the remote device 101 connected in communication with the vehicle 10 via a wireless connection or link.

In a first operation, a request is transmitted by the vehicle 10 to the remote device 101 via a wireless link, for example a V2I and/or LTE or LTE-Advanced type link. The request corresponds to a request requesting from the remote device 101 that the latter determines the regulatory speed applicable to the portion of road on which the vehicle 10 is traveling at the moment when the vehicle 10 transmits the request. The request advantageously includes data representative of the current position of the vehicle 10, such data being for example obtained from a satellite geolocation system on board the vehicle 10.

The request also includes, for example, information allowing it to be routed to the remote device 101, for example an identifier of the remote device 101 included in the data frame forming the request.

According to an optional embodiment variant, the request further comprises one or more pieces of information or data representative of the dynamic behavior of the vehicle 10, for example the wheel tops counter, the yaw rate, the speed of the vehicle 10.

In a second operation, the remote device receives the request transmitted by the vehicle 10. Such a reception triggers the determination of one (or more) first regulatory speed from the current position of the vehicle 10 included in the request.

Such a determination comprises for example the implementation of a so-called map-matching method, such a method using mapping data of the road environment 1 and the information of current position of the vehicle 10 included in the request (and optionally the data representative of the dynamic behavior of the vehicle 10). Such a method of map matching is well known to those skilled in the art and is for example described in the article entitled "A map matching method for GPS based real-time vehicle location" (or in French "Une method de corresondance de real-time GPS-based vehicle location map”), published in “The Journal of Navigation” 57, 429-440 in 2004.

Such a method makes it possible to determine on which portion of the road the vehicle is located. The mapping data advantageously includes data on the route of the roads and on the first regulatory speeds associated with each road or portion of road.

In a third operation, the remote device 101 transmits to the vehicle 10 via the wireless link or connection the first regulatory speed information(s) determined in the second operation. The remote device transmits, for example, one or more of the following regulatory first speed information:

- maximum authorized speed; and or

- recommended speed; and or

- Mandatory minimum speed.

In a fourth operation, the vehicle 10 displays the first regulatory speed information(s) received in the third operation, for example in the form of an icon corresponding to the panel indicating the first regulatory speed or in the form of a number corresponding to the regulatory first speed value. Such regulatory first speed information is for example displayed on the dashboard and/or on a display screen of the vehicle 10.

According to a particular and optional embodiment, the process also comprises the following operations.

In a fifth operation implemented before the first operation, the vehicle 10 determines one (or more) second regulatory speed. Such a determination is advantageously implemented by one or more computers of the on-board system from image data of the road in front of the vehicle acquired by a so-called front camera on board the vehicle 10. A front camera corresponds to a camera having in its field of vision the road environment located in front of the vehicle 10 in the direction of travel of the vehicle 10. Such a front camera is for example arranged in the passenger compartment and fixed for example on the windshield, for example behind the rear view mirror.

The image data acquired by the front camera are transmitted to the computer in charge of the road sign recognition system for the recognition of the road signs installed in the road environment 1, for example the sign 111 indicating the start of a restricted area at a maximum speed of 30 km/h.

The recognition is implemented according to any method known to those skilled in the art, for example by processing the images obtained from the front camera by applying a segmentation of each image into objects (for example a segmentation based on the color and/or the associated with the pixels in the image) and comparing each object with a library of positive images (i.e. images representing road signs) and a library of negative images (i.e. i.e. images that do not represent a road sign). According to another example, the recognition is obtained by a so-called machine learning method, for example implemented by a neural network.

The recognition of the road sign 111 thus makes it possible to determine the second regulatory speed, namely 30 km/h according to the particular example of the .

A level of confidence associated with the determination of the second regulation speed is advantageously determined and associated with the second regulation speed. The confidence level is determined using any method known to those skilled in the art.

In a sixth operation implemented before the first operation, the confidence level is compared with a threshold value between 0.8 and 1, for example equal to 0.85, 0.9 or 0.95.

If the level of confidence is greater than the threshold value, then the regulatory speed displayed in the vehicle 10 corresponds to the second regulatory speed determined in the fifth operation.

In this case, the request is not transmitted to the remote device 101, and the first, second and third operations are not implemented.

If the confidence level is lower than the threshold value, then the request is transmitted to the remote device and the regulatory speed displayed in the vehicle 10 corresponds to the first regulatory speed determined by the remote device 101 in the second operation and received by the vehicle 10 as described in the third operation.

In this case, the request is transmitted to the remote device 101, and the first, second and third operations are implemented.

This particular and optional exemplary embodiment makes it possible to reduce the quantity of data exchanged between the vehicle 10 and the “cloud” 100 by transmitting the request only when the confidence level is below a threshold. This particular and optional embodiment also makes it possible to guarantee that the regulatory speed displayed has a high level of confidence, that is to say greater than the set threshold.

schematically illustrates a device 2 configured to determine the regulatory speed applicable to a portion of road on which a vehicle 10 is traveling, according to a particular and non-limiting embodiment of the present invention. The device 2 corresponds for example to a device on board the vehicle 10, for example a computer. According to another example, the device 2 corresponds to a calculation or data processing device, for example the remote device 101.

The device 2 is for example configured for the implementation of the operations described with regard to the and/or the steps of the process described with regard to the . Examples of such a device 2 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 telematics control unit, known as a TCU (Telematic Control Unit), a smartphone, a tablet, a laptop computer, a server, or a combination of several of the devices listed above. The elements of device 2, individually or in combination, can be integrated in a single integrated circuit, in several integrated circuits, and/or in discrete components. The device 2 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 2 comprises one (or more) processor(s) 20 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 2. The processor 20 can include integrated memory, an input/output interface, and various circuits known to those skilled in the art. The device 2 further comprises at least one memory 21 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 21.

According to various particular embodiments, the device 2 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 “Unité Telematics Control"), for example via a communication bus or through dedicated input/output ports.

According to a particular and non-limiting embodiment, the device 2 comprises a block 22 of interface elements for communicating with external devices, for example a remote server or the “cloud”, a TCU unit. Block 22 interface elements include one or more of the following interfaces:

- RF radio frequency interface, for example of the Bluetooth® or Wi-Fi® type, 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 2 via the interface of block 22 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 LTE Advanced according to 3GPP release 10 – version 10) or 5G, in particular an LTE-V2X network.

According to another particular embodiment, the device 2 comprises a communication interface 23 which makes it possible to establish communication with other devices (such as other computers of the on-board system or other servers) via a communication channel 230. The communication interface 23 corresponds for example to a transmitter configured to transmit and receive information and/or data via the communication channel 230. The communication interface 23 corresponds for example to a CAN-type wired network ( from the English "Controller Area Network" or in French "Réseau de Contrôleurs"), CAN FD (from the 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 an additional particular embodiment, the device 2 can provide output signals to one or more external devices, such as a display screen, one or more loudspeakers and/or other peripherals (projection system ) via respectively suitable output interfaces. According to a variant, one or the other of the external devices is integrated into the device 2. The display screen corresponds for example to a screen, touchscreen or not.

illustrates a flowchart of the different steps of a method for determining a prescribed speed on a portion of road for a vehicle traveling on the portion of road, 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 2 of the .

In a first step 31, the vehicle (or one or more computers of the vehicle) transmits a request requiring the determination of at least one regulatory speed, the request being transmitted to a remote data processing device, for example a cloud server via a wireless link or connection. The request advantageously comprises at least one item of information representing the position or location of the vehicle.

In a second step 32, the vehicle (or one or more computers of the vehicle) receives data representative of one (or more) first (s) speed (s) regulation (s) associated with the portion of road associated with the position of the vehicle. These data are advantageously determined by the remote data processing device and are transmitted by the remote data processing device via the wireless link or connection to the vehicle.

The data representative of the first regulatory speed or speeds are for example determined by using map data of the road environment comprising the portion of road on which the vehicle is traveling and the position of the vehicle.

According to another example, the data representative of the first regulatory speed or speeds are determined from a correspondence table, called LUT (from the English “Look-Up Table”) matching a set of regulatory speeds with a set of positions or geographical locations, at each position or interval or set of positions corresponding to one or more regulatory speed values

According to a variant embodiment, the variants and examples of the operations described in relation to the apply to the process steps of the .

Of course, the invention is not limited to the embodiments described above but extends to a method for displaying information representative of regulatory speed which would include secondary steps without thereby departing from the scope of the present invention. The same would apply to a device configured for the implementation of such a method.

The invention also relates to a vehicle, for example an automobile or more generally an autonomous land motor vehicle, comprising the device 2 of the .

The invention also relates to a system comprising the device 2 of the (or a set of devices 2) on board a vehicle and a remote data processing device, for example the remote device 101, the device(s) 2 being connected in wireless communication with the remote data processing device .

Claims (10)

Method for determining a prescribed speed on a portion of road for a vehicle (10) traveling on said portion of road, said method comprising the following steps:
- transmission (31), by said vehicle (10), of a regulatory speed determination request intended for a remote data processing device (101) via a wireless link, said request comprising at least one piece of information representing position of said vehicle (10);
- reception (32), by said vehicle (10), of data representative of a first regulatory speed on the portion of road associated with said position of the vehicle (10), said data being determined by said remote data processing device ( 101) and received from said remote data processing device (101) via said wireless link. A method according to claim 1, further comprising the following steps:
- acquisition of at least one image of said portion of road by a camera on board said vehicle (10);
- Data processing of said at least one image for recognition of at least one road sign (111) indicating a legal speed;
- determination of a second legal speed from said at least one road sign (111), a level of confidence being associated with said determination. Method according to claim 2, further comprising a step of displaying said regulatory speed on a display screen on board said vehicle (10),
said regulatory speed corresponding to said first regulatory speed when said confidence level is below a determined threshold; And
said regulatory speed corresponding to said second regulatory speed when said confidence level is greater than said determined threshold. Method according to claim 3, for which said request is transmitted if and only if said confidence level is lower than said determined threshold. Method according to one of Claims 1 to 4, for which the said request also comprises at least one item of information representing a dynamic behavior of the said vehicle (10). Method according to one of Claims 1 to 5, further comprising a step of determining said first regulatory speed by the remote data processing device (101) from mapping data and said at least one item of information representative of position of said vehicle (10). Device (2) for determining a legal speed on a portion of road for a vehicle traveling on said portion of road, said device (2) comprising a memory (21) associated with at least one processor (20) configured for setting implementing the steps of the method according to any one of claims 1 to 5. System for determining a legal speed on a portion of road for a vehicle traveling on said portion of road, said system comprising the device (2) according to claim 7 and a remote data processing device (101) in communication with said device (2) according to a wireless link. Vehicle (10) comprising the device (2) according to claim 7. Computer program comprising instructions for implementing the method according to one of Claims 1 to 6, when these instructions are executed by a processor.