EP3961599A1

EP3961599A1 - Driving assist method and system

Info

Publication number: EP3961599A1
Application number: EP20193564.0A
Authority: EP
Inventors: Balázs DEVAY
Original assignee: Unify Patente GmbH and Co KG
Current assignee: Unify Patente GmbH and Co KG
Priority date: 2020-08-31
Filing date: 2020-08-31
Publication date: 2022-03-02

Abstract

The invention relates to a driving assist method (200) when a vehicle (104), called secondary vehicle, approaches a slower vehicle (102), called primary vehicle, rolling in front said secondary vehicle (104), said method (100;200) comprising at least one iteration of a phase (110), called warning phase, comprising the following steps:-sending (112), from said secondary vehicle (104) to said primary vehicle (102), at least a signal, called warning signal, relative to the approaching of said secondary vehicle (104), and-issuing (114), in said primary vehicle (102), at least one instruction, called warning instruction, as a function of said warning signal received.The invention also relates to a driving assist system comprising means configured to carry out the steps of a driving assist method according to the invention

Description

Field of the invention

The present invention relates to a driving assist method and system especially when a faster vehicle approaches a slower vehicle in front of said faster vehicle.
The field of the invention is the field of driving assist methods and systems for vehicles.

Background

On road, it is common situation that a faster vehicle approaches a slower vehicle in front of said faster vehicle and rolling on the same line. What happens usually is that the driver of the faster vehicle decreases the distance between the two vehicles to indicate to the driver of the primary vehicle his intention to overtake said slower vehicle. Sometimes, the driver of the faster vehicle also uses the headlight or the horn of his vehicle. This is obviously an unsafe situation for the faster vehicle because the distance between the two vehicles is too small. This is also an unsafe situation for the slower vehicle because the behaviour of the faster vehicle may distract the driver of the slower vehicle's driver.
Some vehicles are equipped with adaptive cruise control (ACC) system to avoid such situations and keep a safe distance between vehicles by using sensors, for example RADAR or LIDAR, to determine the speed, distance and/or position of the slower vehicle and adjusting the faster vehicle's speed if necessary. But, even with these vehicles the aforementioned situation usually happens because the faster vehicle's driver overrides the ACC setting and decreases the distance between the two vehicles.
A purpose of the present invention is to overcome at least one of the aforementioned drawbacks.
Another purpose of the invention is to propose a driving assist method for preventing, or at least signalling, dangerous situations happening when a faster vehicle approaches a slower vehicle ahead.
A further purpose of the invention is to propose a method for assisting drivers when a faster vehicle approaches a slower vehicle ahead.

Summary of the invention

The invention makes it possible to achieve at least one of the aforementioned aims by a driving assist method when a vehicle (104), called secondary vehicle, approaches a slower vehicle, called primary vehicle, rolling in front of said secondary vehicle, said method comprising at least one iteration of a phase, called warning phase, comprising the following steps:

sending, from said secondary vehicle to said primary vehicle, at least a signal, called warning signal, relative to said secondary vehicle, and
issuing, in said primary vehicle, at least one instruction, called warning instruction, as a function of said warning signal received.

Thus, the present invention makes it possible to inform a primary vehicle that a secondary vehicle, that is rolling faster than said primary vehicle, is approaching. Knowing that, the primary vehicle has the possibility and time to adapt/modify its behavior, for example to speed up or to skip lane, before the second vehicle is too close to the primary vehicle. Thus, the method according to the invention may avoid that the secondary vehicle approaches the primary vehicle too much, so that the distance between the vehicles becomes too small and risky.
Plus, the method according to the invention, makes it possible to inform the primary vehicle well before the secondary vehicle uses horn or headlights, thus avoiding the driver of the primary vehicle being surprised by the use of the horn or the headlight of the secondary vehicle, when it happens.
Thus, the method according the invention makes it possible to assist the driver of the primary vehicle, and the driver of the secondary vehicle, in order to avoid, or at least to diminish, risks when said primary vehicle is approached by the secondary faster vehicle.
In some embodiments, the warning phase may be triggered manually by the driver of the secondary vehicle.
In this case, the driver triggers the sending of the warning signal by manually activating a mechanical or tactile knob, or by entering a vocal command through a vocal assistant equipping said secondary vehicle.
In some embodiments, the warning phase may be triggered automatically by a controller arranged in the secondary vehicle. The triggering of the warning phase may optionally be subject to confirmation of the driver of the secondary vehicle.
In this case, the controller of the secondary vehicle may be connected to at least one sensor, such as a LIDAR or a RADAR or a camera, etc. used to detect the slower primary vehicle in the front of the secondary vehicle, i.e. on the same lane as the secondary vehicle. When the controller, in cooperation with the at least one sensor, detects that there is a primary slower vehicle in front of the secondary vehicle, it may trigger the warning phase. The driver of the secondary vehicle may be invited to confirm the sending of the warning signal.
In other words, the triggering of the warning phase may be conditional to the fact that the distance between the primary and the secondary vehicles decreases below a threshold value. The threshold value may be fixed or adjustable. The threshold value may be provided/adjusted by the driver of the secondary vehicle, or entered in the secondary vehicle as a factory setting, etc.
In a non-limitative embodiment, when the secondary vehicle is equipped with a cruise control system, such as an adaptive cruise control or an autocruise or a tempomat, the warning phase may be conditional to said cruise control system being deactivated or overridden, or activated.
Indeed, when the secondary vehicle is equipped with an autocruise system, or a tempomat, regulating the speed of the vehicle to a given fixed value, then the warning phase may be conditional to said autocruise system being activated. Indeed, when the tempomat is activated, it means that the primary vehicle will continue to roll at the same speed and the driver of the secondary vehicle does not intend to slow down and intends to overtake the primary vehicle. Thus, it is possible to anticipate the overtaking of the primary vehicle by the second vehicle without deactivating or overtaking on the tempomat.
When the secondary vehicle is equipped with an adaptive cruise system to keep a predetermined distance between said secondary vehicle and a vehicle in front of said secondary vehicle, then the warning phase may be conditional to said adaptive cruise system being deactivated or overtaken. Indeed, when the adaptive auto cruise system is deactivated or overtaken, that means that the driver of the secondary vehicle intends to decrease the distance between the two vehicles in order the overtake the primary vehicle. Thus, it is possible to anticipate the overtaking of the primary vehicle by the secondary vehicle.
According to some embodiments of the method of the present invention, at least one warning instruction comprises a driving instruction for the primary vehicle.
In the present application, a driving instruction for a vehicle is an instruction for modifying the state of the vehicle, such as a speed of the vehicle, a position of the vehicle, etc.
At least one driving instruction may be is issued to the attention of the driver of the primary vehicle, through an audio and/or a visual interface in said primary vehicle, so that the driver of said vehicle can adopt or not said driving instruction.
Alternatively, or in addition, at least one driving instruction may be automatically issued to a controller of said primary vehicle, or to an automated driving system of said primary vehicle, such as a cruise control system in said primary vehicle.
For example, a driving instruction generated in the primary vehicle may be "speed up". This driving instruction may be displayed, or read, to the user in the primary vehicle. Alternatively, or in addition, the driving instruction may be sent to a cruise control system that may automatically increase the speed of the vehicle.
According to non-limitative examples, at least one driving instruction may be or may comprise an instruction for:

increasing the speed of the primary vehicle;
changing the lane of the primary vehicle.

According to an advantageous feature, for at least one driving instruction, the issuance of said driving instruction may be conditional to whether said driving instruction is authorised or not, depending on at least one of the following parameters:

a speed of said primary vehicle, and/or
the presence of surrounding vehicle(s).

At least one of these parameters may be provided by a controller of the vehicle, or at least one sensor installed in the primary vehicle.
For example, a sensor such as a LIDAR or a RADAR or a camera or a computer vision, etc., may be arranged on one side of the primary vehicle, to detect if there is a vehicle in the lane next to the primary vehicle. Thus, it is possible to determine if a driving instruction asking for "changing lane" is authorized or not, by interrogating such a sensor.
In a similar way, a sensor such as a LIDAR or a RADAR or a camera or a computer vision for instance, may be arranged in the front of the vehicle, to detect if there is a vehicle in front of the primary vehicle. Thus, it is possible to determine if a driving instruction asking for "speeding up" is authorized or not by interrogating such a sensor.
Similarly, a velocity sensor arranged in the vehicle may measure the current speed of the vehicle, said measured speed value may be compared to a speed limit provided for example by a GPS system, in order to determine if a driving instruction asking for "speeding up" is authorized or not.
All these conditions may be carried out by a calculator configured to that end. The calculator may be an individual and additional calculator dedicated to that end, or a calculator already installed in the vehicle, such as the calculator of the vehicle.
II some embodiments, the step of issuing at least a warning instruction may comprise delivering, through and audio and/or visual interface in said vehicle, at least one of the following information:

an information relative to the approaching of the secondary vehicle, and in particular the warning signal received from the secondary vehicle,
a speed of said secondary vehicle,
a distance between said secondary vehicle and said primary vehicle.

Thus the driver of the of the primary vehicle is advised that a secondary vehicle, faster than the primary vehicle is approaching the primary vehicle and may prepare himself to receive solicitations from the secondary vehicle, or to carry out a driving instruction in order to let the secondary vehicle to overtake the primary vehicle.
In a preferred non-limitative embodiment, the method according to the invention may also comprise, after a warning phase, a phase, called response phase, comprising the following steps:

sending, from the primary vehicle to the secondary vehicle, at least a signal, called response signal, in response to the warning signal; and
issuing, in said secondary vehicle, at least one instruction, called response instruction, as a function of said response signal received.

Indeed, it may be beneficial to indicate to the secondary vehicle a response to the warning signal, to assist the driver of the secondary vehicle.
In some embodiments, the response instruction may be, or may comprise, at least an information comprised in the response signal sent by the primary vehicle.
The response signal may comprise information relating to the expected or planned behavior of the primary vehicle, pursuant to the receiving of the warning signal.
The response signal may be a message entered by the driver of the primary vehicle, through a manual interface, or a voice assistant, etc. The response signal may be a message automatically generated by the primary vehicle, and in particular by a controller of the primary vehicle.
For example, when the primary vehicle plans to change lane in response to the warning signal, then the response signal sent to the secondary vehicle may be a signal indicating the following message: "Planning changing lane: please hold on". This response signal may be issued in the secondary vehicle, in the form of a voice message or a visual message.
In another example, when the primary vehicle cannot change lane or speed up because of a heavy load, the response signal may represent the following message: "Overtaking not possible because of heavy load". This response signal may be issued in the secondary vehicle, in the form of a voice message or a visual message.
In yet another example, when the primary vehicle speeds up, the response signal may indicate: "Vehicle speeding up". Then a response instruction may be issued in the secondary vehicle, in the form of a voice message or a visual message, such as "keep the same speed".
The method according to the invention may be used to assist drivers when there are several slower primary vehicles in front the faster secondary vehicle.
In this case, the method according to the invention, may be carried out individually for each primary vehicle in the front of the faster secondary vehicle.
The method according to the invention may be carried out starting from the primary vehicle ahead of all primary vehicles.
According to another aspect of the same invention, it is proposed a driving assist system comprising means arranged for carrying out the steps of the method according to the invention.
In a non-limitative embodiment, such a system may comprise:

arranged in the secondary vehicle:
- at least one sensor, for example a lidar or a radar or a camera or a computer vision, etc., for detecting a slower vehicle rolling in front of said secondary vehicle;
- at least a communication module, said secondary communication module, for sending a warning signal to the primary vehicle.
arranged in the primary vehicle:
- at least a communication module, said primary communication module, for receiving a warning signal sent by the secondary vehicle;
- at least a means for issuing an instruction, called warning instruction, in said primary vehicle.

For example, the means for issuing an instruction in the primary vehicle may comprise a visual interface for displaying the instruction as a visual information.
The means for issuing an instruction in the primary vehicle may comprise, in addition or in a variant, an audio interface for generating the instruction in the form of an audio signal in said primary vehicle.
According to an advantageous but non-limitative embodiment, the means for issuing an instruction in the primary vehicle may comprise a calculator for generating a driving instruction that is emitted to the user and/or sent to a calculator of the vehicle, or to an automated driving system of the vehicle, especially when such a system is activated. For example, when the driving instruction generated in the primary vehicle is "speed up", the instruction may be sent to a cruise control system that may automatically increase the speed of the vehicle.
Such a calculator may be connected to at least a sensor, in the primary vehicle, in order to determine if a driving instruction is authorized or not before emitting said driving instruction.
For example, the calculator may be connected, directly or indirectly, to a sensor such as a LIDAR or a RADAR for instance, arranged on one side of the primary vehicle, to detect if there is a vehicle in the lane next to the primary vehicle, in order to determine if a driving instruction asking for "changing lane" is authorized or not. In a variant or in addition, the calculator may be connected, directly or indirectly, to a sensor such as a LIDAR or a RADAR for instance, arranged in the front of the vehicle, to detect if there is a vehicle in front of the primary vehicle, in order to determine if a driving instruction asking for "speeding up" is authorized or not.
In some embodiments, the driving assist system according to the invention may comprise, arranged in the primary vehicle, a user interface for entering a response signal to be sent to the secondary vehicle.
Such a user interface may comprise a voice assistant, a microphone, a camera, a tactile interface, or manual actuation means such as a button, a knob, a turn-knob, etc.
In this case, the primary communication module may be configured to send the response signal to the secondary vehicle, and the secondary communication module may be configured to receive said response signal.
In some embodiments, the driving assist system according to the invention may comprise, arranged in the secondary vehicle, at least a means for issuing, in said secondary vehicle, an instruction, called secondary instruction.
The secondary instruction may be at least one information contained in the response signal received from the primary vehicle, or another instruction deducted from the response signal.
For example, the means for issuing the secondary instruction may comprise a visual interface for displaying the instruction as a visual information. The means for issuing the secondary instruction in the secondary vehicle may comprise, in addition or in a variant, an audio interface for generating the instruction in the form of an audio signal in said primary vehicle.
According to an advantageous but non-limitative embodiment, the means for issuing the secondary instruction in the primary vehicle may comprise a calculator for generating a driving instruction that is emitted to the user and/or sent to a calculator of the secondary vehicle, or to an automated driving system of the secondary vehicle, especially when such a system is activated in the secondary vehicle.
For example, when the primary vehicle cannot change it's behavior, the response signal sent to the secondary vehicle may be an audio signal indicating "Overtaking is not possible". In this case, the instruction issued in the secondary vehicle may be an audio signal indicating "Overtaking is not possible". In addition or in a variant, the instruction issued in the secondary vehicle may be a visual warning signal displayed on a visual interface in the secondary vehicle asking for "slowing down" the secondary vehicle. In addition or in a variant, the instruction issued in the secondary vehicle may be a driving instruction sent to a calculator of the secondary vehicle, or to a cruise control system of the secondary vehicle, making the secondary vehicle slow down.
The communication modules in the vehicles may be adapted to communicate through any vehicle-to-vehicle communication channel, such as ETSI, ITS, C-ITS, ITS-G5.
The present invention may be implemented in any vehicle.
The present invention may be implemented in manned vehicle.
The present invention may be implemented in autonomous vehicles, or in unmanned vehicles.
The present invention may be implemented in an automated driving system of a vehicle, such as a speed regulator, an adaptive cruise control, etc.
The vehicle may:

be arranged to implement the steps of the method according to the present invention, and/or comprise the components of the system according to the present invention, so that the vehicle may be a primary vehicle in the sense of present invention; or
be arranged to implement the steps of the method according to the present invention, and/or comprise the components of the system according to the present invention, so that the vehicle may be a secondary vehicle in the sense of present invention; or
be arranged to implement all the steps of the method according to the present invention, and/or comprise all the components of the system according to the present invention, so that the vehicle may be a primary vehicle in the sense of present invention and a secondary vehicle in the sense of present invention, one at a time and depending on the situation.

Description of the figures and embodiments

Other advantages and characteristics will become apparent on examination of the detailed description of an embodiment which is in no way limitative, and the attached figures, where:

Figures 1 and 2 are diagrammatic representations of non-limitative examples of a method according to the invention; and
Figure 3 is a schematic representation of a non-limitative example of a system according to the invention.

It is well understood that the embodiments that will be described below are in no way limitative. In particular, it is possible to imagine variants of the invention comprising only a selection of the characteristics described hereinafter, in isolation from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention with respect to the state of the prior art, without going beyond the ambit of the present invention as defined in the claims. Such a selection comprises at least one, preferably functional, characteristic without structural details, or with only a part of the structural details if this part alone is sufficient to confer a technical advantage or to differentiate the invention with respect to the prior art.
In the figures, elements common to several figures retain the same reference.
FIGURE 1 is a schematic representation of a first non-limitative example of a method according to the invention.
The method 100, shown in FIGURE 1, is used to assist drivers in a situation where a primary vehicle 102 is approached by a secondary vehicle 104, rolling faster than the primary vehicle 102, on the same lane 106 as the primary vehicle 102. Since the secondary vehicle 104 is driving faster than the primary vehicle 102, one can easily understand that the distance 108 between the two vehicles 102,104 decreases progressively.
The method 100 comprises a warning phase 110 that is triggered either manually by a driver of the secondary vehicle 104, or automatically by a controller in the secondary vehicle. In this second case, a confirmation may be requested from the driver of the secondary vehicle 104 before actually triggering the warning phase 100.
The secondary vehicle 104 may be equipped with sensor(s), such as LIDAR or RADAR sensor(s), to detect the primary vehicle 102, more particularly to detect that the distance 108 to the primary vehicle 102 decreases. This information may be signalled to the driver, and/or to the controller, in the secondary vehicle 104, so as to trigger the warning phase 100 either manually or automatically.
The triggering of the warning phase 110 may also be conditional to functioning of an autocruise system in the secondary vehicle 104. For example, if a tempomat is activated in the secondary vehicle, it seems likely that the distance 108 between the vehicles 102 and 104 will continue to decrease: in this case the warning phase 110 may be triggered as long as the autocruise system is active. According to another example, if an adaptive cruise system is activated in the secondary vehicle 104, it seems likely that the distance 108 between the vehicles 102 and 104 will note decrease and will be maintained at an acceptable value by the adaptive cruise system: in this case the warning phase 110 may not be triggered as long as the adaptive auto cruise system is not deactivated, or overtaken, by the driver of the second vehicle.
In other words, the triggering of the warning phase 110 may be conditional to the fact that the distance 108 between the two vehicles 102 and 104 decreases below a threshold value. This threshold value may be fixed. In variants, this threshold value may be adjustable, or provided, by the driver of the secondary vehicle. The threshold value may also be entered in the secondary vehicle 104 as a factory setting.
The warning phase 110 comprises a step 112 sending a warning signal to the primary vehicle 102 from the secondary vehicle 104. The purpose of the warning signal is to indicate to the primary vehicle 102 the presence of a faster secondary vehicle 104 behind.
The warning signal may of any kind.
The warning signal may comprise information/data relating to:

the presence of the secondary vehicle 104; and/or
the speed of the secondary vehicle 104, and/or
the measured distance 108 between the two vehicles 102 and 104.

The warning signal may also comprise information/data regarding the intention of the secondary vehicle's driver, for example the indication that the secondary vehicle's wishes to overtake the primary vehicle 102, and optionally the reason why the second vehicle wishes to overtake, such as for example "medical reason", "emergency", "ongoing child birth", "official vehicle", etc..
The warning phase 110 comprises a step 114 of issuing a warning instruction in the primary vehicle 102.
For example, the step 114 of issuing a warning instruction may comprise a step 116 of delivering information to the driver of the primary vehicle 102, in the form of:

an audio signal read to the driver of the primary vehicle 102 through an audio system of the primary vehicle 102, and/or
a visual signal displayed on a display screen in the primary vehicle 102.

The delivered information may correspond to at least one part of the content of the warning signal. The delivered information may be an audio and/or visual message deducted from the warning signal. For example, the information delivered to the driver of the primary vehicle may be an audio message indicating:
"Warning, approaching faster vehicle may want to overtake"
The driver of the primary vehicle 102 may then decide to speed up or to change line.
In addition, or as an alternative, the step 114 of issuing a warning instruction may comprise a step 118 of generating, and delivering, a driving instruction that may help the driver of the primary vehicle 102 to avoid a dangerous situation.
The driving instruction may be increasing the speed of the primary vehicle 102 in order to keep a safe distance with the secondary vehicle 104, or changing the lane of the primary vehicle 102 in order to clear the lane of the secondary vehicle 104 so that the latter can overtake the primary vehicle 102.
Before issuing a driving instruction, step 118 may test said driving instruction before issuing it. For example, a sensor such as a LIDAR or a RADAR for instance, arranged on one side of the primary vehicle, may be interrogated to detect if there is a vehicle in the lane next to the primary vehicle 102. If the next lane is free, then a driving instruction for skipping lane may be issued. Similarly, a sensor such as a LIDAR or a RADAR for instance, arranged in the front of the vehicle, may be interrogated to detect if there is a vehicle in front of the primary vehicle 102: if there is no vehicle in the front, and if the speed limitation is not reached, a driving instruction for speeding up the primary vehicle may be issued.
The generation, the testing and the issuance of each driving instruction may be carried out by a calculator configured to that end. The calculator may be an additional calculator dedicated to that end, or a calculator already installed in the vehicle, such as the calculator of the vehicle.
The driving instruction may be delivered to the driver of the primary vehicle 102, for example in the form of an audio and/or visual message. Alternatively, or in addition, the driving instruction may be delivered automatically to a calculator, or to an automated driving system, or even to an auto cruise system, of the primary vehicle 102.
The warning signal may be sent to the primary vehicle through any communication channel such as ETSI, ITS, C-ITS, ITS-G5.
The warning signal may be in the form of a radiofrequency signal.
FIGURE 2 is a schematic representation of another non-limitative example of a method according to the invention.
The method 200, shown in FIGURE 2, is used to assist drivers in the same configuration as the one depicted for FIGURE 1.
The method 200 of the FIGURE 2 comprises the warning phase 110 of the method 100 of FIGURE 1.
In addition, the method of the FIGURE 2, comprises a response phase 210, carried out after at least one warning phase 110.
The response phase 210 may be triggered either manually by the driver of the primary vehicle 102, or automatically by a controller arranged in the primary vehicle 102. In this second case, a confirmation may be requested from the driver of the primary vehicle 102 before actually triggering the response phase 210.
The response phase 210 comprises a step 212 sending, from the primary vehicle 102 to the secondary vehicle 104, a response signal in response to the warning signal received from said secondary vehicle 104. The purpose of the response signal is to indicate to the secondary vehicle the intention of the primary vehicle 102 in response to the warning signal, so that the secondary vehicle's driver is fully informed to adapt his/her behaviour in accordance.
The response signal may be of any kind.
The response signal may comprise information/data relating to:

a driving instruction that has been triggered in the primary vehicle 102, indicating for example that the primary vehicle is speeding up or changing lane in order to let the secondary vehicle 104 to overtake the primary vehicle;
a message from the driver of the primary vehicle 102 indicating that overtaking is not possible, and optionally an explanation thereof;
a message inviting the driver of the secondary vehicle 104 to be patient,
etc.

The response phase 210 may comprise a step 214 for issuing a response instruction in the secondary vehicle 104, as a function of the response signal.
For example, the step 214 for issuing a response instruction in the secondary vehicle 104 may comprise a step 216 of delivering information to the driver of the secondary vehicle 104, in the form of an audio signal read to the driver of the secondary vehicle 104 through an audio system of the secondary vehicle 104, and/or in the form of a visual signal displayed on a display screen in the secondary vehicle 104. The delivered information may correspond to at least one part of the content of the response signal. The delivered information may be an audio and/or visual message deducted from the response signal. For example, the information delivered to the driver of the secondary vehicle 104 may be and audio message indicating:
"Primary vehicle is about to change lane" or
The driver of the secondary vehicle 104 may then decide to keep the speed of the secondary vehicle unchanged because he/she knows that the primary vehicle will free the lane.
In addition, or as an alternative, the step 214 for issuing a response instruction may comprise a step 218 for issuing a driving instruction that may help the user of the secondary vehicle 104 to avoid dangerous situation.
The driving instruction may be:

decreasing the speed of the secondary vehicle 104 in order to keep a safe distance with the primary vehicle 102, especially when the primary vehicle 102 cannot speed up or change lane;
activating an adaptive autocruise system in the secondary vehicle 104, in order to adapt the behavior of the secondary vehicle 104 to the behavior of the primary vehicle 102;
keeping the same speed, especially when the primary vehicle 102 is about to clear the lane or is about to speed up;
emergency breaking because of extremely dangerous situation ahead.

The issuance of a driving instruction in the secondary vehicle 104 may be carried out by a calculator, arrange in the secondary vehicle 104 and configured to that end. The calculator may be a calculator dedicated to that end, or a calculator already installed in the secondary vehicle 104, such as the calculator of the secondary vehicle 104.
The driving instruction may be delivered to the driver of the secondary vehicle 104, for example in the form of an audio and/or visual message. Alternatively, the driving instruction may be delivered automatically to a calculator, or to an automated driving system, or even to an autocruise system, of the secondary vehicle 104.
The response signal may be sent to the secondary vehicle 104 through any communication channel such as ETSI, ITS, C-ITS, ITS-G5.
The response signal may be in the form of a radiofrequency signal.
Each of the methods 100 and 200 of the FIGURES 1 and 2 has been exemplified in a situation comprising only one primary vehicle in front of the secondary vehicle. Of, course each of the methods 100 and 200 may be used to assist drivers in a situation where several primary vehicles are in front of a secondary vehicle. In such a situation, each method 100 or 200 is carried out individually for each primary vehicle in the front of the faster secondary vehicle, for example starting from the primary vehicle ahead of all primary vehicles.
FIGURE 3 is a schematic representation of a non-limitative example of a system according to the invention.
The system 300 of FIGURE 3 may be used to carry out a method according to the invention, and in particular any one of the methods 100 and 200 of the FIGURES 1 and 2.
The system 300 comprises, arranged in the primary vehicle 102:

at least a communication module 302, said primary communication module, for communicating with the secondary vehicle 104;
at least a means for issuing an instruction in said primary vehicle, such as:
- ▪ an audio interface, for example a loudspeaker 304, for emitting an instruction in the form of an audio signal;
- ▪ a visual interface such as a light or a screen 306, for emitting an instruction in the form of a visual signal; and
- ▪ a calculator 308 configured to generate, test and emit a driving instruction to the attention of the driver of the primary vehicle 102, or to an automated driving system of the vehicle. In some embodiments, this calculator may be a calculator already equipping the primary vehicle 102.

Optionally, the system 300 may also comprise, arranged in the primary vehicle 102 at least one sensor 310, such as LIDAR or RADAR sensor, to detect the presence of surrounding vehicles. In one embodiment, this at least one sensor may be a sensor already equipping the primary vehicle 102.
The system 300 comprises, arranged in the secondary vehicle 104:

at least one sensor 312, such as LIDAR or RADAR sensor, to detect the presence of a primary vehicle 102 in front of the secondary vehicle 104: in some embodiments, this at least one sensor 314 may be a sensor already equipping the secondary vehicle 104; and
at least a communication module 314, said secondary communication module, for communicating with the primary vehicle 102;

system

at least a means for issuing an instruction in said secondary vehicle, such as:
- ▪ an audio interface, for example a loudspeaker 316, for emitting an instruction in the form of an audio signal;
- ▪ a visual interface such as a light, or a screen 318, for emitting an instruction in the form of a visual signal;
- ▪ a calculator 320 configured to generate, test and emit a driving instruction to the attention of the driver of the secondary vehicle 104, or to an automated driving system of the secondary vehicle 104. In one embodiment, this calculator may be a calculator already equipping the secondary vehicle 104.

Of course, the invention is not limited to the examples detailed above.

Claims

A driving assist method (100;200) when a vehicle (104), called secondary vehicle, approaches a slower vehicle (102), called primary vehicle, rolling in front of said secondary vehicle (104), said method (100;200) comprising at least one iteration of a phase (110), called warning phase, comprising the following steps:
- sending (112), from said secondary vehicle (104) to said primary vehicle (102), at least a signal, called warning signal, relative to said secondary vehicle (104), and

- issuing (114), in said primary vehicle (102), at least one instruction, called warning instruction, as a function of said warning signal received.
The method (100;200) according to claim 1, characterized in that the warning phase (110) may be triggered:
- manually by the driver of the secondary vehicle (104); or

- automatically by a controller (320) arranged in said secondary vehicle (104).
The method (100;200) according to any one of the preceding claims, characterized in that said secondary vehicle (104) is equipped with a cruise control system, the warning phase (102) being conditional to said cruise control system being deactivated or overridden, or activated.
The method (100;200) according to any one of the preceding claims, characterized in that at least one warning instruction comprises a driving instruction for the primary vehicle (102).
The method (100;200) according to claim 4, characterized in that at least one driving instruction:
- is issued to the attention of the driver of the primary vehicle (102), through an audio (304) and/or a visual (306) interface in said primary vehicle (102), so that the driver of said primary vehicle (102) can adopt or not said driving instruction;

- automatically issued to a controller of said primary vehicle (102), or to an automated driving system of said primary vehicle.
The method (100;200) according to any one of the claims 4 or 5, characterized in that at least one driving instruction comprises, or is, an instruction for:
- increasing the speed of the primary vehicle (102);

- changing the lane of the primary vehicle (102).
The method (100;200) according to any one of the claims 4 to 6, characterized in that, for at least one driving instruction, the issuance of said driving instruction is conditional to whether said driving instruction is authorised or not, depending on at least one of the following parameters:
- a speed of said primary vehicle (102), and/or

- the presence of surrounding vehicle(s).
The method (100;200) according to any one of the preceding claims, characterized in that the step (114) of issuing at least one warning instruction comprises delivering (116), through and audio (304) and/or visual (306) interface in said primary vehicle (102), at least one of the following information:
- an information relative to the approaching of the secondary vehicle (104), and in particular the warning signal received from the secondary vehicle (104),

- a speed of said secondary vehicle (104),

- a distance between said secondary vehicle (104) and said primary vehicle (102).
The method (200) according to any one of the preceding claims, characterized in that it also comprises, after a warning phase (110), a phase (210), called response phase, comprising the following steps:
- sending (212), from the primary vehicle (102) to the secondary vehicle (104), at least a signal, called response signal, in response to the warning signal; and

- issuing (214), in said secondary vehicle (104), at least one instruction, called response instruction, as a function of said response signal received.
The method (100;200) according to any one of the preceding claims, characterized in that, when there are several slower primary vehicles in front of the faster secondary vehicle, said method (100;200) is carried out individually for each primary vehicle in the front of the faster secondary vehicle.
A driving assist system (300) comprising means (302-320) arranged for carrying out the steps of the method (100;200) according any one of the preceding claims.