Method and device for controlling the speed of a vehicle comprising a predictive cruise control system

Abstract

The present invention relates to a method and a device for controlling the speed of a vehicle equipped with a predictive cruise control system, called a PCC system, and a display system connected in communication to the PCC system. For this purpose, data representative of a maximum authorized speed limit on a portion of road are received. The maximum authorized speed limit is assigned as the set speed of the PCC system. Graphic content (34) is displayed on a display device (20) of the display system to indicate an option for canceling the assignment for a determined period of time from the assignment. The speed of the vehicle is controlled via the PCC system as a function of the set speed. Figure for abstract: Figure 3

Description

Title of the invention: Method and device for controlling the speed of a vehicle comprising a predictive cruise control system Technical field

[0001] The invention relates to methods and devices for controlling the speed of a vehicle, in particular but not exclusively a motor vehicle. The invention also relates to a method and a device for controlling a predictive cruise control system, known as a PCC system (from the English "Predictive Cruise Control"). The invention also relates to a method and a device for controlling the set speed of a PCC system. Technological background

[0002] Some contemporary vehicles have at least one or more systems configured to determine the regulatory speed that applies to the portion of road being used. The regulatory speed corresponds, for example, to the maximum speed authorized on this portion of road or to the recommended speed.

[0003] A system for determining the regulatory speed is in the form of an ISA system (from the English "Intelligent Speed Adaptation" or in French "adaptation intelligente de la vitesse"), an SLI system (from the English "Speed Limitation Information" or in French "Information de la limitation de vitesse") or an AISA system (from the English "Anticipated Intelligent Speed Adaptation" or in French "adaptation intelligent et avertiée de la vitesse") which each correspond to an AD AS system (from the English "Advanced Driver-Assistance System" or in French "Système d'aide à la conduite avance") comprising means for assisting the driver of the vehicle to avoid exceeding a limited speed.

[0004] A first example of a system for determining the regulatory speed comprises a camera on board the vehicle, the on-board camera having in its field of vision the road in front of the vehicle. Such a system is configured to recognize the 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(s).

[0005] A second example of a system for determining the regulatory speed takes the form of an on-board navigation system based on map data stored locally or downloaded as the vehicle moves. The map 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 GPS system "Satellite Geolocation") and mapping data, the system is able to provide the regulatory speed for the section of road traveled.

[0006] When the maximum authorized speed on a portion of road is determined from the mapping data, this information can be anticipated by the vehicle, that is to say that the vehicle is able to determine the maximum authorized speeds on the portions of road that it will take when the vehicle follows a route or when the vehicle is traveling on a road and is approaching a portion of this road with a maximum authorized speed different from the maximum authorized speed of the current portion of road on which the vehicle is located at a current time.

[0007] The information relating to the maximum authorized speed is used by modern cruise control systems to assign this maximum authorized speed, automatically or after explicit validation by the driver of the vehicle, to the set speed of the cruise control system. Such cruise control systems are called predictive cruise control systems, known as PCC systems (from the English "Predictive Cruise Control" or in French "predictive speed regulation") or P-ACC systems (from the English "Predictive Adaptive Cruise Control" or in French "adaptive and predictive speed regulation").

[0008] When the information relating to the maximum authorized speed comes from the mapping data, the PCC system is able to propose to the driver of the vehicle to use this maximum authorized speed as a set speed before taking the portion of road with which the maximum authorized speed is associated. The proposal to change the set speed can thus be submitted for validation by the driver so that the change is made while allowing a change of set speed when the vehicle reaches the portion of road with the new speed limit.

[0009] When the information relating to the maximum authorized speed comes from reading a traffic sign, if the proposal to change the set speed is subject to validation by the driver, the change will occur too late for the speed control to maintain the speed of the vehicle at the maximum authorized speed as soon as the traffic sign is crossed, which represents a danger for the vehicle and its passengers and a failure to comply with the regulations.

[0010] When the information relating to the maximum authorized speed comes from reading a traffic sign, if the change of set speed is automatic without validation by the driver, the vehicle will respect the speed limit from the start of the sign or as soon as possible after crossing the sign. However, this can degrade the user experience with the PCC system, especially when the driver does not want this change in set speed. The driver will then have to manually return to the desired set speed, which requires several actions on the part of the driver via the PCC system's set speed control unit, for example via a steering wheel control lever. Summary of the present invention

[0011] An object of the present invention is to solve at least one of the problems of the technological background described above.

[0012] Another object of the present invention is for example to improve speed control by a PCC system.

[0013] According to a first aspect, the present invention relates to a method for controlling the speed of a vehicle, the vehicle having a predictive speed control system, called a PCC system, and a display system connected in communication to the PCC system, the method being implemented by at least one processor, the method comprising the following steps: - reception of data representative of a maximum authorized speed limit on a section of road; - assignment of the maximum authorized speed limit as the PCC system set speed; - control of display of graphical content on a display device of the display system, the graphical content being representative of an option to cancel the assignment for a determined period from the assignment; - vehicle speed control via the PCC system according to the set speed.

[0014] The display of graphic content offering the driver the option of canceling a change in speed instruction implemented to adapt the speed instruction to a maximum authorized speed limit detected by reading a traffic sign indicating this speed limit offers the driver the possibility of canceling this change while implementing the change automatically and quickly so that the vehicle complies with this speed limit as quickly as possible and without delay via its predictive cruise control system.

[0015] The graphic content being representative of a cancellation option, the validation of the cancellation corresponds to a validation of a positive action which corresponds to the current mode of interaction of a user with the vehicle, in particular in the context of speed regulation systems where a driver may be required to validate a proposal to change the speed setting so that the change of setting speed control is implemented. This brings consistency and coherence to the way the vehicle user interacts with the cruise control system.

[0016] According to a variant, the method further comprises the following steps: - receiving control data representative of a request to cancel the assignment from a human-machine interaction system of the vehicle; - assigning a new speed value as the PCC system setpoint speed to replace the maximum speed limit allowed upon receipt of control data when the control data is received before a specified time period.

[0017] According to another variant, the human-machine interaction system belongs to a set of systems comprising: - a vehicle speed control system; - a PCC system setpoint speed control system; - a voice control system; and - a touch interface system for the display screen.

[0018] According to a further variant, the new speed value corresponds to a speed value assigned as the set speed prior to the assignment of the maximum authorized speed limit as the set speed.

[0019] According to an additional variant, the graphic content is displayed on the display device for a duration corresponding to the determined duration.

[0020] According to another variant, the assignment of the maximum authorized speed limit as the set speed is implemented at a time instant when the vehicle crosses the traffic sign.

[0021] According to an additional variant, the determined duration is between 5 and 7 seconds.

[0022] According to another variant, the method further comprises the following steps: - receiving image data representative of at least one image of a traffic sign representative of the maximum authorized speed limit on the section of road from a camera on board the vehicle; - determination of said maximum authorized speed limit from image data.

[0023] According to a second aspect, the present invention relates to a device for controlling the speed of a vehicle, the device comprising a memory associated with a processor configured for implementing the steps of the method according to the first aspect of the present invention.

[0024] 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.

[0025] According to a fourth aspect, the present invention relates to a computer program which comprises instructions adapted for executing the steps of the method according to the first aspect of the present invention, in particular when the computer program is executed by at least one processor.

[0026] Such a computer program may 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.

[0027] 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 carrying out the steps of the method according to the first aspect of the present invention.

[0028] On the one hand, the recording medium may 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 microelectronic circuit type ROM memory, or a magnetic recording means or a hard disk.

[0029] Furthermore, this recording medium may 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 means. The computer program according to the present invention may in particular be downloaded from an Internet-type network.

[0030] Alternatively, the recording medium may be an integrated circuit in which the computer program is incorporated, the integrated circuit being adapted to perform or to be used in performing the method in question. Brief description of the figures

[0031] Other characteristics and advantages of the present invention will emerge from the description of the particular and non-limiting exemplary embodiments of the present invention below, with reference to the appended figures 1 to 5, in which:

[0032] [Fig.l] schematically illustrates a vehicle traveling in a road environment, according to a particular exemplary embodiment of the present invention;

[0033] [Fig.2] schematically illustrates a display device of the vehicle of [Fig.l], according to a first particular and non-limiting exemplary embodiment of the present invention;

[0034] [Fig.3] schematically illustrates the display device of the vehicle of [Fig.l], according to a second particular and non-limiting exemplary embodiment of the present invention;

[0035] [Fig.4] illustrates a device configured to control the speed of the vehicle of [Fig.l], according to a particular and non-limiting exemplary embodiment of the present invention.

[0036] [Fig.5] illustrates a flowchart of the different steps of a method for controlling the speed of the vehicle of [Fig.l], according to a particular and non-limiting exemplary embodiment of the present invention. Description of examples of implementation

[0037] A method and a device for controlling the speed of a vehicle will now be described in the following with joint reference to Figures 1 to 5. The same elements are identified with the same reference signs throughout the description which follows.

[0038] The terms "first(s)", "second(s)" (or "first(s)", "second(s)"), etc. are used in this document by arbitrary convention to enable different elements (such as operations, means, etc.) implemented in the embodiments described below to be identified and distinguished. Such elements may be distinct or correspond to a single element, depending on the embodiment.

[0039] According to a particular and non-limiting example of embodiment of the present invention, the control of the speed of a vehicle is for example implemented by one or more computers of the vehicle, for example via one or more processors of the computer controlling a predictive speed regulation system, called PCC system, of the vehicle.

[0040] For this purpose, image data of one or more images of a traffic sign indicating a maximum authorized speed limit on a portion of road to which the vehicle is approaching are received from an on-board camera of the vehicle. The maximum authorized speed limit indicated by the display panel is determined by analyzing the image data. This maximum authorized speed limit is used as a speed setpoint of the PCC system of the vehicle, i.e. the maximum authorized speed limit value is assigned to the speed setpoint parameter of the PCC system. The computer then controls the display of a graphic content so that this graphic content is displayed on a display device of the vehicle (for example a screen arranged in the passenger compartment of the vehicle).This graphical content is representative of an option to cancel the assignment for a specified period of time from the assignment to indicate to the driver that he has the option to cancel the assignment of the maximum authorized speed limit as the PCC system set speed value. The vehicle speed is controlled according to the set speed value.

[0041] A PCC system corresponds to a speed regulation system, for example of the ACC type (from the English “Adaptive Cruise Control” or in French “Regulation adaptive speed"), for which the set speed can be automatically adapted based in particular on the speed limits applicable on the sections of road used by the vehicle. These speed limits are obtained, for example, from a system for reading and recognizing traffic signs on board the vehicle and / or from a navigation system based on map data including the speed limits applicable to the different sections of road, knowing the geographical position of the vehicle.

[0042] [Fig. 1] schematically illustrates an environment 1 in which a vehicle 10 moves, according to a particular and non-limiting exemplary embodiment of the present invention.

[0043] [Fig.l] illustrates a road environment 1 in which the vehicle 10 travels. The road environment 1 corresponds for example to an urban environment or to a non-urban environment comprising a departmental or national road, a two-lane road or a motorway.

[0044] According to the example of [Fig.l], the vehicle 10 is traveling on a road comprising 2 successive road portions 110 and 111. The vehicle 10 is traveling on a first road portion 110 with which a first maximum authorized speed limit is associated and the vehicle 10 is approaching a second road portion 111 with which a second maximum authorized speed limit is associated different from the first maximum authorized speed limit. The first road portion 110 is downstream of the second road portion 111 in a direction of travel of the vehicle 10.

[0045] The vehicle 10 corresponds for example to a vehicle with a thermal engine, with an electric motor(s) or even a hybrid vehicle with a thermal engine and one or more electric motors. The vehicle 10 thus corresponds for example to a land vehicle, for example a car, a truck, a bus. Finally, the vehicle 10 corresponds to an autonomous vehicle or not, that is to say a vehicle traveling according to a determined level of autonomy or under the total supervision of the driver.

[0046] The vehicle 10 has a system for detecting road signs, and more particularly speed limit signs applicable on roads. Such a road sign 11 is illustrated in [Fig. 1] and corresponds to an example in which the maximum speed authorized on the second portion of road 111 to which the vehicle 10 is approaching is 110 km / h.

[0047] The maximum authorized speed limit is for example equal to 130 km / h. Of course, the maximum authorized speed limits applicable to the first portion of road 110 and to the second portion of road 111 may be different, for example 50, 80, 90, 110 km / h for the first portion of road 110 and 30, 50, 70, 80 or 90 km / h for the second portion of road 111.

[0048] According to a particular and non-limiting exemplary embodiment of the invention, the traffic sign 11 indicates a temporary maximum authorized speed limit, i.e. limited in time. According to this exemplary embodiment, the traffic sign 11 corresponds for example to a construction site sign associated with the presence of a construction site on the second portion of road 111 resulting in a reduction of the speed limit on this second portion of road 111 for the duration of the work. In such a case, the mapping data does not always include such temporary information.

[0049] The road sign detection system is configured for the detection and recognition of the signs. For this purpose, it comprises a computer controlling the system and at least one camera configured for the acquisition of images of the scene located in front of the vehicle 10 according to the direction of travel of the vehicle 10. The camera corresponds for example to a front camera 101 (also called a windshield camera). Such a camera 101 is arranged in the passenger compartment of the vehicle 10 under the windshield and at the top and in the middle of this windshield. Such a front camera 101 has a field of vision corresponding to the space located in front of the vehicle 10 according to the direction of travel of the vehicle 10. Such a camera 101 is thus configured for the acquisition of image data representative of the real scene located in front of the vehicle 10, according to the direction of travel of the vehicle 10.

[0050] The camera 101 comprises for example the following elements: - a photosensitive sensor corresponding for example to a matrix of photoreceptors associated for example with a Bayer filter; - an optical assembly arranged in front of the sensor with respect to the scene to be acquired by the sensor, the optical assembly comprising for example an arrangement of one or more lenses; and - optionally one or more calculators associated with memory and configured for processing images acquired by the sensor.

[0051] One or more image analysis and processing methods known to those skilled in the art are applied to the image data received from the camera 101 to detect and recognize the traffic sign 11 in the received image(s), making it possible to obtain the speed value indicated on the traffic sign 11 and corresponding to the maximum authorized speed limit applicable on the second portion of road 111.

[0052] The vehicle 10 further includes a display system, which comprises a computer and one or more display devices controlled by the computer. The computer corresponds for example to an IVI (In-Vehicle Infotainment) computer. The display system comprises for example a screen called a handset or dashboard of the vehicle 10 arranged in the dashboard in a space provided behind the steering wheel according to the point of view of a driver of the vehicle 10 seated in the driver's seat. The display system comprises for example furthermore a display screen arranged in a central space of the dashboard. The display screen(s) of the display system correspond for example each to an LCD type screen (from the English "Liquid Crystal Display" or in French "Display à cristals liquide"), for example of the TFT type (from the English "Thin-Film Transistor" or in French "Transistor en film mince"), or OLED (from the English "Organic Light-Emitting Diode" or in French "Diode électroluminescente biologique"). This or these screen(s) are for example furthermore equipped with a touch interface.

[0053] The vehicle computers, in particular the computer controlling the PCC system and the IVI computer, form for example a multiplexed architecture for the realization of different services useful for the proper functioning of the vehicle and for assisting the driver and / or the passengers of the vehicle in the control of the vehicle 10 via the control of the system(s) embedded in the vehicle 10. The computers communicate and exchange data between themselves via one or more computer buses, for example a communication bus of the CAN (Controller Area Network) type, CAN FD (Controller Area Network Flexible Data-Rate), FlexRay (according to the ISO 17458 standard), LIN (Local Interconnect Network) or Ethernet (according to the ISO / IEC 802-3 standard).

[0054] A process for controlling the speed of the vehicle 10 is advantageously implemented by one or more processors of one or more computers, for example the computer of the PCC system connected in communication to the computer of the traffic sign recognition system (these computers being able to correspond to the same and unique computer).

[0055] In a first operation of the process, data representative of the maximum speed limit authorized on a portion of road are received.

[0056] According to a first example of implementation, this data is received from a navigation system of the vehicle 10, this data being included in the mapping data of the navigation system.

[0057] According to a second example of implementation, this data is received from a system for detecting and recognizing traffic signs of the vehicle 10.

[0058] According to this second exemplary embodiment, image data representative of at least one image of a traffic sign representative of a maximum authorized speed limit on a portion of road are received from an on-board camera. in vehicle 10, for example camera 101.

[0059] The image data corresponds to the data associated with each pixel of an image, the data being for example coded in a color space of the RGB type (from the English “Red, Green, Blue” or in French “Rouge, vert, bleu”).

[0060] This image data is received via one or more data buses connecting the camera 101 to the computer processing this image data.

[0061] According to the second example of implementation, the maximum speed limit authorized on the second portion of road 111 indicated on the traffic sign is determined from the image data received or obtained in the first operation. The determination of the applicable speed limit by recognition of the traffic sign 11 implements one or more image processing methods known to those skilled in the art, such as described in the document “Detection and recognition of vertical signage by image analysis”, by Philippe Foucher, published in July 2010.

[0062] In a second operation of the process, the maximum permitted speed limit received in the first operation, i.e. 110 km / h according to the example of [Fig.l], is assigned as the set speed of the PCC system.

[0063] The PCC system thus uses the maximum authorized speed limit value obtained in the first operation to use it as the set speed, replacing the previous set speed, which corresponded for example to the maximum authorized speed limit on the first section of road 110 for example equal to 130 km / h.

[0064] The set speed of the PCC system corresponds to a parameter of the PCC system used by the PCC system to automatically regulate the speed of the vehicle 10 with the objective that the speed of the vehicle 10 corresponds to the set speed. The set speed thus corresponds to the target speed to be reached for the PCC system by acting on the acceleration (and deceleration of the vehicle 10) to maintain the speed of the vehicle 10, when possible, at the set speed. In the case of an adaptive regulation system of the P-ACC type, the speed of the vehicle 10 may be lower than the set speed when the vehicle 10 follows another vehicle, the PCC system possibly reducing the speed of the vehicle 10 to maintain a determined distance between the vehicle 10 and the vehicle in front of it, according to a parameter called TIV (Inter-Vehicle Time) or DIV (Inter-Vehicle Distance).When the vehicle in front of vehicle 10 is at a distance greater than the DIV or is no longer in the path of vehicle 10, then the PCC system automatically controls the acceleration of vehicle 10 so that the speed of vehicle 10 becomes equal to (or close to) the set speed.

[0065] Assigning the maximum authorized speed limit as the set speed of the PCC system is implemented in such a way that the speed of the vehicle 10 complies with the maximum authorized speed limit when the vehicle 10 crosses the traffic sign 11 or as soon as possible after crossing the traffic sign 11.

[0066] According to an alternative embodiment, the assignment of the maximum authorized speed limit as the set speed is implemented at a time instant when the vehicle crosses the traffic sign 11, i.e. when the vehicle 10 passes the traffic sign 11.

[0067] When the previous set speed of the PCC system is higher than the maximum authorized speed limit deduced from the traffic sign 11 or obtained from the mapping data, this results in a reduction in the speed of the vehicle 10 under the control of the PCC system, which then controls the deceleration of the vehicle 10 to reach the set speed.

[0068] The automatic assignment of the maximum authorized speed limit as the set speed of the PCC system allows the vehicle 10 to comply with the speed limit as soon as possible after crossing the sign 11, the recognition of the sign 11 being implemented before the vehicle 10 crosses this sign 11 or when the vehicle 10 crosses the sign, depending on the acquisition field of the camera 101, in particular the acquisition distance.

[0069] In a third operation of the process, the display of graphical content is controlled by the computer so that the graphical content is displayed on a display device (for example the dashboard instrument cluster) of the vehicle 10. Such graphical content is representative of an option to cancel the assignment of the maximum authorized speed limit as the set speed of the PCC system left to the driver of the vehicle 10 for a determined duration from the assignment.

[0070] The determined duration during which the driver can cancel the assignment is for example between 5 and 7 seconds, for example equal to 5, 6 or 7 seconds.

[0071] The display of the graphic content on the display device is for example triggered by the assignment of the maximum permitted speed limit as the set speed of the PCC system or the display of the graphic content is synchronized with the assignment.

[0072] A display control of graphic content or any graphic object (text, pictogram, icon, etc.) comprises a rendering of the graphic content or the graphic object, such rendering corresponding to a set of operations performed by one or more processors on the pixels of one or more images of the graphic content to be displayed on the display device. For example, the rendering consists of associating with a set of pixels of an image pixel data (for example data of colors expressed in an RGB type space (from the English “Red, Green, Blue” or in French “rouge, vert, bleu”) associated with each object or graphic content.

[0073] The display control of the graphic content thus comprises the transmission of control signals to the touch screen to modify the values associated with the pixels of the display device at the location intended to display the graphic content (or any graphic object).

[0074] [Fig.3] illustrates the result of displaying graphic content according to a particular exemplary implementation of the invention.

[0075] [Fig.2] illustrates the content 200 displayed on the display device 20 before the display control of the graphical content illustrated in [Fig.3], according to an exemplary embodiment.

[0076] The content 200 displayed on the display device 20 of [Fig.2] corresponds to the content displayed on the display device before the maximum authorized speed limit signaled by the traffic sign 11 is used as the set speed of the PCC system.

[0077] The content 200 comprises for example a first pictogram 21 representing the maximum authorized speed on the current portion of road on which the vehicle 10 is traveling, for example the first portion of road 110. This first pictogram 21 takes for example the form of a speed limit sign indicating the maximum authorized speed equal to 130 km / h according to the example of [Fig.2].

[0078] The value of the speed limit indicated by this first pictogram 21 is for example obtained from mapping data and / or from the system for detecting and recognizing traffic signs of the vehicle 10.

[0079] The content 200 further comprises a second pictogram 22 representing the set speed obtained from the maximum authorized speed indicated by the first pictogram 21.

[0080] The content 200 also comprises a third pictogram 23 representative of the active state of the PCC system to indicate to the driver of the vehicle 10 that the PCC system is active and that the speed of the vehicle 10 is automatically regulated according to the set speed indicated by the second pictogram 22.

[0081] The arrangement of the first, second and third pictograms 21, 22, 23 on the display device 20 is arbitrary. The first pictogram 21 is for example displayed on the right of the display device, the third pictogram 23 on the left and the second pictogram 22 in the center of the display device, between the first pictogram 21 and the second pictogram 22.

[0082] [Fig. 3] illustrates the content 300 displayed on the display device 20 following the detection and recognition of the traffic sign 11 and the assignment of the maximum authorized speed limit as the set speed of the PCC system, in replacement of the set speed illustrated in [Fig.2].

[0083] The content 300 comprises for example a first pictogram 31 representing the maximum authorized speed on the second portion of road 111 that the vehicle 10 will take once the traffic sign 11 has passed. This first pictogram 31 is similar to the first pictogram 21 and replaces it, this first pictogram 31 taking for example the form of a speed limit traffic sign indicating the maximum authorized speed equal to 110 km / h signaled by the traffic sign 11.

[0084] The value of the speed limit indicated by this first pictogram 31 is obtained or determined via the system for detecting and recognizing traffic signs of the vehicle 10 or obtained from the navigation system via the mapping data.

[0085] The content 300 further comprises a second pictogram 32 replacing the second pictogram 22 and representing the set speed obtained from the maximum authorized speed indicated by the first pictogram 31, i.e. a set speed equal to 110 km / h.

[0086] The content 300 also includes the third pictogram 23, as does the content 200, which is representative of the active state of the PCC system to indicate to the driver of the vehicle 10 that the PCC system is active and that the speed of the vehicle 10 is automatically regulated according to the set speed indicated by the second pictogram 32.

[0087] The arrangement of the first, second and third pictograms 31, 32, 23 on the display device 20 is arbitrary and identical to that of the first, second and third pictograms 21, 22, 23.

[0088] The content 300 further advantageously comprises a graphic content 34 which indicates to the driver the possibility of canceling the assignment of the maximum authorized speed limit obtained from the traffic sign 11.

[0089] The graphic content 34 comprises for example one or more graphic objects illustrating the cancellation option.

[0090] The graphic content 34 corresponds, for example, to text signaling to the driver the possibility of returning to the previous speed setting and canceling the last change of set speed. This text is, for example, further accompanied by a specific pictogram illustrating this option.

[0091] According to another example, the graphic content 34 corresponds to an animation, for example a graphic animation representing the first pictogram 21 transforming into the first pictogram 31, or vice versa.

[0092] According to yet another example, the graphical content comprises a plurality of graphical objects, for example a back arrow directed to a representation of a sign representing the speed limit preceding the speed limit indicated by road sign 11, i.e. the speed limit corresponding to the first section of road.

[0093] The graphic content 34 is for example displayed for the determined duration during which the driver can cancel the assignment of the maximum authorized speed limit indicated by the traffic sign 11 as the set speed, that is to say the graphic content 34 is displayed for a duration of between 5 and 7 seconds, for example equal to 5, 6 or 7 seconds.

[0094] The graphic content 34 is for example displayed in an area of the display device 20 located under the display area of the first and second pictograms 31, 32.

[0095] In a fourth operation of the process, the speed of the vehicle 10 is controlled by the PCC system according to the set speed.

[0096] The set speed corresponds to the maximum authorized speed limit indicated by the traffic sign 11 (i.e. 110 km / h according to the example of figures 1 and 3) when the driver has not performed any action to validate or activate the cancellation option indicated by the graphic content 34 within the time limit, i.e. before the expiry of the determined duration.

[0097] The set speed corresponds to a new maximum speed limit authorized when the driver has carried out a determined action to validate or activate the cancellation option indicated by the graphic content 34 within the time limit, i.e. before the expiry of the determined duration.

[0098] For this purpose, the process then comprises the following operations: - receiving control data representative of a request to cancel the assignment signaled by the graphic content 34, the request being received from a human-machine interaction system of the vehicle within the given time limit, i.e. before the end of the determined duration or while the graphic content 34 is displayed on the display device 20; and - assignment of a new speed value as the PCC system setpoint speed to replace the maximum authorized speed limit indicated by traffic sign 11, this assignment being implemented upon receipt of the control data when the control data is received before the end of the determined duration.

[0099] Unless otherwise instructed by the driver, the new set speed value corresponds to the speed value assigned as the set speed prior to the assignment of the maximum authorized speed limit indicated by the traffic sign 11 as the set speed. According to the example of [Fig. 2], the new set speed value becomes the one set while the vehicle 10 was driving on the first section of road 110, that is, 130 km / h.

[0100] The human-machine interaction system through which the driver validates or activates the cancellation option corresponds for example to: - a speed control system of the vehicle 10, the request being issued by pressing for example the accelerator pedal of the vehicle 10; or - a PCC system set speed control system, for example a lever or control member on the steering wheel (for example by pressing an “OK” button or by pressing once on a “-” control or on the “+” control provided to manually adjust the set speed (in increments of 1 or 2 km / h each time the “-” control or on the “+” control is pressed); - a voice control system, for example by saying a voice command such as “cancel the last set speed change”; and - a touch interface system for the display screen, for example by making a touch press at the location where the graphic content 34 is displayed.

[0101] Such a process offers the driver of the vehicle 10 the possibility of canceling an automatic set speed change via a positive action during a cancellation phase provided for this purpose. This offers the driver the possibility of refusing the last set speed change and returning to the previous set speed by a simple acknowledgment command or activation of the cancellation option.

[0102] [Fig.4] schematically illustrates a device 4 configured for controlling the vehicle speed and / or the control of the set speed of the PCC system of a vehicle, for example the vehicle 10, according to particular and non-limiting exemplary embodiments of the present invention. The device 4 corresponds for example to a device on board the vehicle 10, for example a computer.

[0103] The device 4 is for example configured for the implementation of the operations described with regard to figures 1 to 3 and / or the steps of the method described with regard to [Fig.5]. Examples of such a device 4 include, but are not limited to, on-board electronic equipment such as an on-board computer of a vehicle, an electronic calculator such as an ECU (“Electronic Control Unit”), a smartphone, a tablet, a laptop. The elements of the device 4, individually or in combination, can be integrated into a single integrated circuit, into several integrated circuits, and / or into discrete components. The device 4 can be produced in the form of electronic circuits or software (or computer) modules or even a combination of electronic circuits and software modules.

[0104] 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 may 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 may comprise volatile and / or non-volatile memory, such as EEPROM, ROM, PROM, RAM, DRAM, SRAM, flash, magnetic or optical disk.

[0105] The computer code of the embedded software(s) comprising the instructions to be loaded and executed by the processor is for example stored in the 4L memory.

[0106] According to various particular and non-limiting embodiments, 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.

[0107] According to a particular and non-limiting exemplary embodiment, the device 4 comprises a block 42 of interface elements for communicating with external devices. The interface elements of the block 42 comprise one or more of the following interfaces: - RF radio frequency interface, for example Wi-Fi® type (according to IEEE 802.11), for example in the 2.4 or 5 GHz frequency bands, or Bluetooth® type (according to IEEE 802.15.1), in the 2.4 GHz frequency band, or Sigfox type using UBN (Ultra Narrow Band) radio technology, or LoRa in the 868 MHz frequency band, LTE (LTE) “Long-Term Evolution” or in French “Long-Term Evolution”), 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 “High Definition Multimedia Interface” in French); - LIN interface (from the English “Local Interconnect Network”).

[0108] According to another particular and non-limiting exemplary 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 wired network of the CAN type (from the English "Controller Area Network" or in French "Réseau de contrôles"), CAN FD (from the English "Controller Area Network Flexible Data-Rate" or in French "Réseau de contrôles à débit de données flexible"), FlexRay (standardized by the ISO 17458 standard) or Ethernet (standardized by the ISO / IEC 802-3 standard).

[0109] According to a particular and non-limiting exemplary embodiment, the device 4 can provide output signals to one or more external devices, such as a display screen 440, touch-sensitive or not, one or more speakers 450 and / or other peripherals 460 (projection system) via output interfaces 44, 45 and 46 respectively. According to a variant, one or other of the external devices is integrated into the device 4.

[0110] [Fig. 5] illustrates a flowchart of the different steps of a method for controlling the speed of a vehicle, for example the vehicle 10, according to a particular and non-limiting exemplary 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 [Fig. 4],

[0111] In a first step 51, data representative of a maximum speed limit authorized on a portion of road are received.

[0112] In a second step 52, the maximum authorized speed limit is assigned as the set speed of the PCC system.

[0113] In a third step 53, the display of graphical content is controlled to display this graphical content on a display device of the vehicle display system, the graphical content being representative of an option to cancel the assignment for a determined duration from the assignment.

[0114] In a fourth step 54, the speed of the vehicle is controlled via the PCC system according to the set speed.

[0115] According to a variant, the variants and examples of the operations described in relation to one of figures 1 to 3 apply to the steps of the method of [Fig.5].

[0116] Of course, the present invention is not limited to the exemplary embodiments described above but extends to a method for displaying graphic content, to a method for controlling a set speed or to a method for controlling a PCC system which would include secondary steps without thereby departing from the scope of the present invention. The same would apply to a device configured for implementing such a method.

[0117] The present invention also relates to a vehicle, for example an automobile or more generally an autonomous land-based motor vehicle, comprising the device 4 of [Fig.4].

Claims

Claims

1. Method for controlling the speed of a vehicle (10), said vehicle (10) having a predictive cruise control system, called a PCC system, and a display system connected in communication to said PCC system, said method being implemented by at least one processor, said method comprising the following steps: - receiving (51) data representative of a maximum authorized speed limit on a portion of road (111); - assigning (52) said maximum authorized speed limit as a set speed for said PCC system; - controlling the display (53) of graphic content (34) on a display device (20) of said display system, said graphic content (34) being representative of an option to cancel said assignment (52) for a determined period from said assignment; - controlling (54) the speed of said vehicle (10) via said PCC system as a function of said set speed.

2. A method according to claim 1, further comprising the following steps: - receiving control data representative of a request to cancel said assignment from a human-machine interaction system of said vehicle (10); - assigning a new speed value as a set speed of said PCC system in replacement of said maximum speed limit authorized upon receipt of said control data when said control data is received before an end of said determined duration.

3. Method according to claim 2, wherein said human-machine interaction system belongs to a set of systems comprising: - a speed control system of said vehicle (10); - a set speed control system of said PCC system; - a voice control system; and - a touch interface system of said display screen (20).

4. A method according to claim 2 or 3, wherein said new speed value corresponds to a speed value assigned as a set speed prior to said assignment of said maximum authorized speed limit as a set speed.

5. Method according to one of claims 1 to 4, wherein said content graphic is displayed on said display device (20) for a duration corresponding to said determined duration.

6. Method according to one of claims 1 to 5, for which said assignment (52) of said maximum authorized speed limit as a set speed is implemented at a time instant of crossing of said traffic sign (11) by said vehicle (10).

7. Method according to one of claims 1 to 6, for which said determined duration is between 5 and 7 seconds.

8. Method according to one of claims 1 to 7, further comprising the following steps: - receiving image data representative of at least one image of a traffic sign (11) representative of the maximum authorized speed limit on the portion of road (111) from a camera (101) on board said vehicle (10); - determining said maximum authorized speed limit from the image data.

9. Device (4) for controlling the speed of a vehicle, said device (4) comprising a memory (41) associated with at least one processor (40) configured for implementing the steps of the method according to any one of claims 1 to 8.

10. Vehicle (10) comprising the device (4) according to claim 9.

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