FR3147990A1 - Checking the activation of a lane change assistance function - Google Patents

Abstract

The invention relates to a method for controlling a lane change assistance function of a vehicle. Following receipt (200) of a command to activate a lane change assistance function towards a destination lane, the method comprises detecting (201), on the basis of data from at least one sensor, at least one vehicle, and assigning (202) said at least one detected vehicle to a lane. Furthermore, driver data is received (203) from a driver monitoring system. A decision (205) whether or not to allow activation of the lane change assistance function is made based on the driver data and the assignment of said at least one detected vehicle to the lane. FIG. 2

Description

Checking the activation of a lane change assistance function

The present invention belongs to the field of assistance with driving a motor vehicle, in particular assistance with lateral driving of the vehicle.

It is particularly advantageous in the context of a change of traffic lane.

“Vehicle” means any type of vehicle such as a motor vehicle, moped, motorcycle, storage robot in a warehouse, etc.

“Autonomous driving” of an “autonomous vehicle” means any method capable of assisting the driving of the vehicle. The method may consist of partially or totally steering the vehicle or providing any type of assistance to a natural person driving the vehicle. Thus, “autonomous driving” covers all levels 1 to 5 of the OICA scale, for International Organisation of Motor Vehicle Manufacturers.

Driving assistance can intervene at different levels of autonomy: from autonomous driving without driver intervention to manual driving assistance.

Driving assistance systems, such as ADAS for example, for “Advanced Driver-Assistance Systems” in English, make it possible to assist the driver of the vehicle or even to fully control certain parameters of the vehicle’s driving, such as the longitudinal trajectory, speed in particular, and the lateral trajectory, turning or changing lanes in particular.

These systems improve driving comfort and safety by using data from vehicle sensors, such as radar or lidar data, and/or geolocation devices.

A driver assistance function helps to assist the lateral movement of the vehicle when changing lanes. Such a function is called semi-automated lane change, or SALC, or “Semi-Automated Lane Change” in English.

Such a function can be activated when the driver triggers a turn indicator, or TI, for "Turn Indicator" in English. It thus indicates the destination lane in order to change lanes, from a current lane to the destination lane adjacent to it.

The function uses vehicle sensor data to assist with lane changes, including accepting or refusing activation of the SALC function, and then, if accepted, assisting with controlling the vehicle's lateral trajectory.

In particular, sensors such as radars may be arranged at the rear of the vehicle to detect other vehicles traveling behind the vehicle, in the same direction of travel.

The vehicles thus detected are then assigned to a traffic lane, for example, a right, left or central lane, depending on the number of traffic lanes on the road on which the vehicle is traveling.

Lanes can be identified by a front-facing camera and then extrapolated to the rear of the vehicle based on vehicle movement data.

However, any sensor has limitations and/or is likely to make detection errors, particularly when traffic conditions, such as weather conditions in particular, deteriorate, or depending on the trajectory of the road, particularly at the rear of the vehicle in the event of a sharp turn or yaw.

Errors can lead to the following situations, among others:
- failure to detect a vehicle located in the adjacent destination lane or error in the lane assigned to a detected vehicle, for example if the detected vehicle is assigned to a lane adjacent to the destination lane, while it is traveling in the destination lane. Such a situation is called a "false negative", i.e. a vehicle present in the destination lane is not detected or is not assigned as such. The activation of the SALC function can then be validated without taking this vehicle into account, which can cause a dangerous situation or even a collision;
- detection of a "phantom" object or vehicle, in particular by reflection of radar waves on road barriers, in the destination lane, or error whereby a detected vehicle is mistakenly assigned to the destination lane, while it is traveling on another lane. Such a situation is then a "false positive", i.e. a vehicle is detected and assigned to the destination lane by mistake. In this case, the change of traffic lane may be refused, which prevents the driver from changing lanes when a safe lane change could be implemented.

There is therefore a need to improve driving comfort and/or safety in the context of a vehicle's lane change assistance function.

The present invention improves the situation.

For this purpose, a first aspect of the invention relates to a method for controlling a lane change assistance function of a vehicle, called an ego-vehicle, the method comprising:
- receiving a command to activate the lane change assistance function, for a change from a current lane to a destination lane;
- detection, on the basis of sensor data, of at least one vehicle in a rear position relative to said ego-vehicle, and assignment of each detected vehicle to a traffic lane;
- receiving driver data from a driver monitoring module;
- decision whether or not to authorize the activation of the lane change assistance function, based on the driver data and the assignment of said at least one detected vehicle to a traffic lane.

Thus, the invention makes it possible to exploit driver data representative of driver behavior, in particular of their vigilance, or of a driver's fitness level, to authorize or not the activation of the lane change assistance function to change lanes to the destination lane. The driver data thus makes it possible to strengthen the interpretation of sensor data, and thus make it possible to improve safety and/or driving comfort when changing lanes.

According to embodiments, the driver data may include an indication of a driver's mirror consultation, and the decision whether to allow activation of the lane change assist feature may depend on the driver's mirror consultation indication.

Such an indication makes it possible to condition the activation of the lane change assistance function in certain driving situations, in the event of vigilance by the driver who consults the rear-view mirror. The safety associated with changing lanes is thus improved. In addition, the decision to authorize or not may depend on a comparison of a duration of consultation of the rear-view mirror with a given threshold duration. The activation of the lane change assistance function may in particular be conditioned by consultation of the rear-view mirror for a consultation duration longer than the given threshold duration.

Additionally, the decision whether or not to allow the activation of the lane change function may include comparing the driver data and the assignment of said at least one vehicle to the lane, with conditions of at least one predefined decision-making rule, and at least one predefined decision-making rule may include a condition dependent on the indication of consultation of the rearview mirror by the driver.

The use of predefined decision-making rules helps to address driving situations identified as potentially problematic or dangerous.

Additionally, said at least one vehicle can be detected with a given detection probability, at least one predefined decision-making rule can include a condition relating to a comparison between the detection probability of the vehicle and a detection threshold value.

This makes it possible to take into account the uncertainty about the detection of a vehicle. Such uncertainty can in particular be compensated by greater vigilance of the driver which can be evaluated from the driver data.

Additionally or alternatively, said at least one detected vehicle may be assigned to the traffic lane with a given assignment probability, at least one predefined decision-making rule may include a condition relating to a comparison between the assignment probability of the vehicle and an assignment threshold value.

This makes it possible to take into account the uncertainty of assigning the traffic lane to the detected vehicle, in order to compensate for such uncertainty in particular based on the driver's vigilance which is indicated by the driver data received from the driver monitoring system.

Additionally or alternatively, at least one predefined decision-making rule may comprise a first condition relating to a first comparison between a distance separating the ego-vehicle from said at least one detected vehicle assigned to the destination lane, and a first longitudinal distance threshold value, and may comprise a second condition relating to a second comparison of said distance with a second longitudinal distance threshold value, the second longitudinal distance threshold value being less than the first longitudinal distance threshold value.

Thus, it is possible, by comparing with two distance threshold values, to classify the distance to the vehicle detected behind into at least three distance intervals, and to make a decision based on the interval in which the vehicle detected behind is located.

In addition, the decision-making rule comprising the first and second conditions may authorise the activation of the lane change assistance function if the rear-view mirror consultation indication indicates that the driver is consulting the rear-view mirror and if said distance is between the second longitudinal distance threshold value and the first longitudinal distance threshold value.

Thus, when the detected vehicle is in the destination lane at an intermediate distance from the ego-vehicle, activation of the lane change assistance function may still be permitted if it is determined that the driver is exercising vigilance, i.e. when checking his rear-view mirror.

According to embodiments, the method may further comprise identifying a vehicle type for the at least one detected vehicle. The vehicle detection threshold, the vehicle assignment threshold, the first longitudinal distance threshold value and/or the second longitudinal distance threshold value may be determined based on the vehicle type identified for the at least one detected vehicle.

Thus, the decision-making rules are adapted to the type of vehicle detected, which improves the accuracy of decision-making and the safety associated with lane changing.

A second aspect of the invention relates to a computer program comprising instructions for implementing the method according to the first aspect of the invention, when these instructions are executed by a processor.

A third aspect of the invention relates to a module for controlling a lane change assistance function of a vehicle, called an ego-vehicle, comprising:
- an interface capable of receiving a command to activate a lane change assistance function, for a change from a current lane to a destination lane;
- a processor capable of detecting, on the basis of sensor data, at least one vehicle in a rear position relative to said ego-vehicle, and of assigning each detected vehicle to a traffic lane;
- another interface capable of receiving driver data from a driver monitoring module.
The processor is further able to decide whether or not to authorize the activation of the lane change assistance function, based on the driver data and the assignment of each detected vehicle to a lane.

Other characteristics and advantages of the invention will appear on examining the detailed description below, and the attached drawings in which:

illustrates a vehicle according to one embodiment of the invention;

is a diagram illustrating the steps of a method for controlling a lane change function of a vehicle, according to embodiments of the invention;

illustrates a first driving situation of a vehicle according to embodiments of the invention;

illustrates a second driving situation of a vehicle according to embodiments of the invention;

illustrates a third driving situation of a vehicle according to embodiments of the invention;

illustrates the structure of a device for controlling a lane change assistance function of a vehicle, according to embodiments of the invention.

There presents a vehicle 100, or ego-vehicle 100, according to one embodiment of the invention.

The ego-vehicle 100 comprises a control device 101. The control device 101 may be an ECU type element, for “Electronic Control Unit” in English, in charge of the centralized control of the vehicle 100. The control device 101 may comprise several modules in charge of piloting or communicating with different elements of the motor vehicle.

The vehicle 100 may further comprise a human-machine interface, HMI, 102 capable of allowing the control device 101, and other entities of the vehicle 100, to exchange information with the driver or with passengers of the vehicle 100.

No restriction is attached to the HMI 102, which comprises any element capable of receiving a command from the user, whether this command relates to the piloting of the vehicle or to the control of interior equipment, or to transmit information to the user. For this purpose, the HMI 102 may comprise a screen, such as a touch screen, a set of one or more buttons, a speaker, a microphone, a dashboard capable of displaying one or more luminous pictograms of predefined shapes, a steering wheel vibration system, etc.

Preferably, the HMI 102 is capable of transmitting visual and/or audio data to the driver of the vehicle. In addition, the driver or passengers can also enter information via the HMI 102, for transmission to the ECU control device 101, via a button, a touch command, a voice command, or any other type of user input.

The vehicle 100 may further comprise a turn signal activation interface 106 capable of receiving a turn signal activation command, so as to transmit such a command to the ECU 101 which is thus capable of controlling a lighting/signaling device to trigger a turn signal. Such an interface 106 for receiving a turn signal activation command may be capable of receiving a right turn signal activation command and a left turn signal activation command. It may for example be a rotary lever, operable by the user in one direction or another direction in order to generate a right or left turn signal activation command.

The ego-vehicle 100 may comprise a driving assistance module 104, also called ADAS, for “ Advanced Driver Assistance Systems ” in English, capable of carrying out at least one driving assistance function, on the basis in particular of data from sensors 103.1 and 103.2 of the vehicle 100, and possibly other sensors not shown in the figure. .

No restrictions are attached to the vehicle 100, in particular to the level of driving autonomy permitted by the vehicle. The ADAS module 104 can assist the driver in steering the vehicle, in particular for determining or maintaining the speed or acceleration, or can ensure autonomous steering of the vehicle, without the driver's contribution. Driving assistance thus also covers automatic steering of the vehicle.

According to the invention, the ADAS module 104 is at least capable of performing a semi-automated lane change function, also called SALC function for “Semi Automated Lane Change”.

Such a function can use data from at least one first sensor 103.1 arranged at the rear of the vehicle and capable of detecting one or more vehicles traveling behind the vehicle 100, in particular traveling in the same direction of travel. The first sensor 103.1 can be of the radar type, or can be a camera facing the rear of the vehicle. In the following, it is considered, for illustrative purposes only, that the first sensor 103.1 is a radar.

The vehicle 100 may further comprise at least one second sensor 103.2 capable of identifying traffic lanes of the road on which the vehicle 100 is traveling, for example the traffic lanes in front of the vehicle 100. The sensor 103.2 may be a camera facing the front of the vehicle 100 associated with an analysis module capable of detecting the traffic lanes, of identifying a current traffic lane and one or more adjacent lanes, from the sensor images by the camera.

Thus, activation of the SALC function is conditioned by the detection of at least one other vehicle traveling on the same road, on the detection of traffic lanes, and on the assignment of a traffic lane to each vehicle thus detected.

The sensor 103.1 may also be capable of acquiring position and speed data from at least one other vehicle traveling on the road. For example, for each other vehicle, the sensor 103.1 is capable of determining:
- the distance between said other vehicle and vehicle 100;
- the speed of the other vehicle.

The vehicle 100 may further comprise a driver monitoring system 105, also called DMS for “Driver Monitoring System” in English, and which may in particular comprise a camera oriented towards the driver inside the vehicle, in particular towards the driver’s face, as well as an analysis module capable of analyzing the images captured by the camera of the DMS 105.

There is a diagram illustrating the steps of a method for controlling a lane change assistance function of the vehicle 100, in particular for controlling the SALC function described above. Such a method may be implemented in the ADAS module 104 described above, or alternatively in the ECU 101. Alternatively, some steps are implemented in the ECU 101 and other steps are implemented in the ADAS module 104. In the following, the example of an implementation in the ADAS module 104 is detailed, for illustrative purposes only.

In a step 200, a command to activate the SALC function is received by the ADAS module 104. Such a command may come from a driver command on the HMI 102. Alternatively, such an activation command may be generated automatically by the ECU module 101 upon receipt of a signal from the turn signal activation interface 106. The command makes it possible to identify a destination lane, which is the adjacent lane to the right of the current lane if the right turn signals are activated, and which is the adjacent lane to the left of the current lane if the left turn signals are activated.

At a step 201, the ADAS module 104 detects at least one other vehicle traveling on the same road as the vehicle 100, in the same direction of travel, and behind the vehicle 100, on the basis of data from the first sensor 103.1.

In a step 202, the ADAS module 104 assigns each vehicle detected in step 201 to a traffic lane. Step 202 may comprise a prior identification of the traffic lanes based on the data from the second sensor 103.2 for example. Such identification of the traffic lanes may in particular be implemented continuously, for use by other driving assistance functions implemented by the ADAS module 104 in particular.

Thus, each detected vehicle can be assigned to the current lane of vehicle 100 or to one of the other lanes, including the destination lane.

As detailed in the following, uncertainties may be associated with steps 201 to 202, due to limitations of the sensors 103.1 and 103.2, and/or due to weather conditions. The detection of a vehicle in step 201 may also comprise the evaluation of a detection probability Pdet, which may be a value between 0 and 1, being strictly greater than 0, 1 indicating a total level of certainty, while 0 indicates a total uncertainty on the detected vehicle. The detection probability Pdet thus indicates the reliability associated with the detection of a vehicle. Several methods for evaluating such a probability Pdet are known and are not detailed further in the present description.

Similarly, the assignment of a detected vehicle to a traffic lane in step 202 may also comprise the evaluation of a probability of assignment to a Pass lane, which may be a value between 0 and 1, being strictly greater than 0, 1 indicating a total level of certainty, while 0 indicates a total uncertainty on the traffic lane assigned to the detected vehicle. Several methods of evaluating such a Pass probability are known and are not detailed further in the present description.

In a step 203, which can be implemented in parallel with steps 201 and 202, or before step 201, or after step 202, but before step 204 described below, the ADAS module 104 obtains driver data from the DMS 105. No restriction is attached to the driver data, which includes any descriptive data of the driver's behavior, in particular the driver's face, and/or a physical or physiological state of the driver. Preferably, the driver data identifies whether or not the driver is looking at the rearview mirror. More specifically, the driver data can identify a position of the driver's gaze. Obtaining such data is known per se and is not described further in the present description. They can in particular be obtained by the module for analyzing the images acquired by the camera of the DMS 105.

At a step 204, the ADAS module 104 determines a decision whether or not to authorize the SALC function, based on the data obtained at steps 201 to 203, namely, based on:
- the assignment of a traffic lane to at least one detected vehicle;
- driver data from the DMS 105 system.

Thus, taking into account driver data in the decision-making process relating to the authorisation of the activation of the SALC function makes it possible to improve the decision-making process for activating the SALC function, since the data from sensors are reinforced by driver behaviour data. In particular, the activation of the SALC function may be authorised when the driver data indicate that the driver is consulting the rear-view mirror. Conversely, the activation of the SALC function may be refused in the event of uncertainty about the detected vehicle or the lane assignment, when the driver data indicate that the driver is not consulting the rear-view mirror.

The following general decision-making rule may be applied by the ADAS module 104: activation of the SALC function is permitted only if no vehicle is detected with certainty in the destination lane at a distance from the vehicle 100 less than a threshold longitudinal distance value Dmin. The vehicle is detected with certainty in the destination lane, if the vehicle is detected with a high detection probability Pdet, greater than a given detection probability threshold, and is assigned to the destination lane with a high assignment probability Pass, greater than a given assignment probability threshold. The threshold longitudinal distance value Dmin may be fixed or may be preferentially calculated as a function of the speed Vego of the vehicle 100, and the speed of the vehicle Varr detected in the destination lane. In particular, the higher the speed Varr of the vehicle detected in the destination lane, the greater the threshold longitudinal distance value Dmin.

When Varr is less than Vego – Vseuil1, the threshold distance value Dmin can be equal to a minimum distance pMinDist. Vseuil1 is a first predetermined speed threshold, which can depend on Vego, and which can be equal to 10km/h for example.

When Varr is between Vego –Vseuil 1 and Vego, the threshold distance value Dmin varies linearly as a function of Varr, between pMinDist and Vego*TgMin, TgMin being a minimum duration, which may depend on Vego.

When Varr is between Vego and Vego + Vthreshold 2, the threshold distance value can vary linearly with Varr, between Vego*TgMin and a pSupDist value greater than Vego*TgMin. pSupDist can depend on Vego.

When Varr is greater than Vego + Vseuil 2, Dmin can vary beyond pSupDist, for example depending on the square of Varr.

Other rules for calculating Dmin can be applied according to the invention.

According to the invention, decision-making rules, implemented by the ADAS module 104 and also taking into account the driver data, are given below, it being understood that this set of rules is not exhaustive, and that the decision to authorize or not the SALC function, may include other decision-making rules comprising other conditions, not described in the present application.

Each decision-making rule detailed in the following comprises a decision-making, namely allow or deny, corresponding to a set of at least one condition. If all the conditions of the decision-making rule are met, then the decision-making of the rule is applied. The decision-making rules are preferably mutually exclusive, such that two conflicting decisions cannot be made for the same detected vehicle. If two vehicles are detected, the decision-making rules are applied independently to both vehicles, and in the event of a conflict in the decision-making, i.e. if a rule for a first vehicle leads to an acceptance, and another rule for the second vehicle leads to a refusal, the ADAS module 104 may refuse the activation of the SALC function.

A first decision-making rule can be applied by the ADAS 104 module: refuse activation of the SALC function (decision-making) if the driver data indicate that the driver is not looking at the rear-view mirror (first condition) and if there is uncertainty about the presence of a vehicle detected at the rear (second condition). There is uncertainty about the presence of a vehicle detected at the rear if the vehicle's detection probability Pdet is lower than a first detection threshold value Pds1. The first decision-making rule makes it possible to avoid activating the SALC function in the event of uncertainty about the detection, with the driver data indicating that the driver has not looked at the rear-view mirror. This avoids any risk-taking when the data from the sensors is unreliable and is not compensated for by the driver's vigilance.

A second decision-making rule may be applied by the ADAS module 104: refuse the activation of the SALC function (decision-making) if the driver data indicate that the driver is not looking at the rear-view mirror (first condition), and if a vehicle is assigned to a lane other than the destination lane with an uncertainty on the assignment of the lane to the vehicle (second condition), i.e. with a certainty on the assignment of the lane to the vehicle lower than a given threshold. In particular, the uncertainty may correspond to a probability of assignment Pass of the vehicle lower than a predetermined assignment threshold value Pas1, or may correspond to a lateral position of the vehicle too close to the destination lane, for example at a lateral distance lower than a first given lateral distance threshold value Dlat1.

There illustrates a first driving situation in which the second decision rule can be applied.

In the first driving situation, the vehicle 100 is traveling on a road 300 comprising a right lane 301, a central lane 302, and a left lane 303. The current lane of the vehicle 100 is the right lane 301. The driver of the vehicle has activated his right turn signals and the destination lane is therefore the central lane 302. In the first situation, a first vehicle 310.1 or a second vehicle 310.2 is detected behind the vehicle 100. The first vehicle 310.1 may be assigned to the current lane 301, but with a low degree of certainty due to its proximity to the destination lane 302. Similarly, the second vehicle 310.2 may be assigned to the left lane 303, but with a low degree of certainty due to its proximity to the destination lane 302. Thus, if at least one detected vehicle is at a distance from the destination lane 302 that is less than the first value lateral distance threshold Dlat1, the application of the second rule by the ADAS 104 module implies the refusal of activation of the SALC function if the driver data indicate that the driver is not consulting the rearview mirror.

Referring again to the , a third decision-making rule may be applied by the ADAS module 104: authorizing the activation of the SALC function (decision-making) if the driver data indicates that the driver is consulting the rearview mirror (first condition), and if there is uncertainty about the presence of a vehicle detected at the rear of the ego-vehicle 100 (second condition). There is uncertainty about the presence of a vehicle detected at the rear if, for each detected vehicle, the detection probability Pdet is less than a second detection threshold value Pds2, the second detection threshold value Pds2 preferably being greater than the first detection threshold value Pds1 of the first decision-making rule. The third rule may include the additional condition that the driver turns the steering wheel at least partially towards the destination lane to authorize the activation of the SALC function.

The ADAS module 104 may further apply the following fourth decision-making rule: authorize the activation of the SALC function (decision-making) if the driver data indicates that the driver is consulting the rearview mirror (first condition) and if a vehicle is detected and assigned to the destination lane (second condition), at a distance from the vehicle 100 less than the threshold distance value Dmin (third condition), called the first threshold longitudinal distance value Dmin, but greater than a second threshold longitudinal distance value Dmin' (fourth condition), Dmin' being less than Dmin. The second threshold longitudinal distance value Dmin' may depend on the speed of the vehicle 100, and on the speed of the vehicle detected in the destination lane. As for Dmin, Dmin' may evolve differently according to different intervals of values of Varr:
- Dmin' is equal to a fixed low value pMinDist' if Varr is less than Vego – Vseuil1, with pMinDist' less than or equal to pMinDist;
- first linear dependence of Dmin' on Varr, with a first coefficient of variation, when Varr is between Vego –Vseuil 1 and Vego. The second threshold distance value Dmin' thus varies between pMinDist' and Vego*TgMin', TgMin' being a minimum duration, which can depend on Vego and which can be less than TgMin;
- second linear dependence of Dmin' to Varr, with a second coefficient of variation, greater than the first coefficient of variation, when Varr is between Vego and Vego + Vseuil 2. The second threshold distance value Dmin' can be between Vego*TgMin and a value pSupDist' greater than Vego*TgMin', t greater than or equal to pSupDist. pSupDist' can depend on Vego;
- dependence of Dmin' on the square of Varr, when Varr is greater than Vego + Vseuil 2: Dmin' can vary beyond pSupDist'.

The ADAS module can apply the fourth rule in the second driving situation illustrated with reference to the .

On the , the vehicle 100 is traveling on a road 320 comprising two traffic lanes, namely a right lane 321, which is the current lane of the vehicle 100, and a left lane 322, which is the destination lane of the vehicle 100 when the driver activates the left turn signals.

A vehicle 330 is detected and assigned to the destination lane 322. In particular, the vehicle 330 can be detected and assigned with certainty to the destination lane 322, that is to say with high detection and assignment probabilities Pdet and Pass, in particular higher than the threshold values Pds1 and Pas1 described above.

The detected vehicle 330 is at a distance 323 from the ego-vehicle 100, the distance 323 being less than a first distance 324 equal to the first longitudinal distance threshold value Dmin, and greater than a second distance 325 equal to the second longitudinal distance threshold value Dmin’.

So, in the second situation of the , the ADAS 104 module can allow the SALC function to be activated if the driver data indicates that the driver is looking at the rearview mirror.

The fourth rule may include the additional condition that the driver turns the steering wheel at least partially towards the destination lane to allow activation of the SALC function.

Referring again to the , the ADAS module 104 can further apply the following fifth decision-making rule: the activation of the SALC function is validated (decision-making) if the driver data indicates that the driver consults the rearview mirror (first condition) and if a vehicle is detected and assigned to the destination lane (second condition), but with an uncertainty on the assignment to the destination lane (third condition). For example, the uncertainty can correspond to an assignment probability Pass lower than the first assignment threshold value Pas1 mentioned above, or to a second assignment threshold value Pas2 different from Pas1. Alternatively or in a complementary manner, the uncertainty can correspond to a lateral distance of the vehicle lower than a second lateral distance threshold value Dlat2 given from a lane adjacent to the destination lane. The second lateral distance threshold value Dlat2 can be equal to the first lateral distance threshold value Dlat1 used in the second rule described above. Alternatively, Dlat1 and Dlat2 are equal.

The ADAS 104 module may apply the fifth rule in a third driving situation illustrated with reference to the .

In the third driving situation of the , the vehicle 100 travels on a road 340 comprising three lanes, namely a right lane 341, which is the current lane of the vehicle 100, a central lane 342 and a left lane 343.

The driver of vehicle 100 indicates a lane change to the destination lane, which is the central lane 342, by activating the left turn signals of vehicle 100.

A vehicle 350.1 or 350.2 is detected and assigned to the center lane 342, which is the destination lane. Both vehicles 350.1 and 350.2 are shown in the , although the third driving situation occurs when one of the vehicles 350.1 and 350.2 is detected and uncertainly assigned to the destination lane.

As indicated on the , the vehicle 350.1 is close to the right lane 341, which is a lane adjacent to the destination lane 342. An uncertainty in the assignment of the vehicle 350.1 to the destination lane 342 is due to the lateral distance between the vehicle 350.1 and the right lane 341 which is less than the second lateral distance threshold value Dlat2. Alternatively or in addition, the uncertainty is due to the probability Pass of assignment of the vehicle 350.1 to the destination lane 342 which is less than the second assignment threshold value Pas2.

As indicated on the , the vehicle 350.2 is close to the left lane 343, which is a lane adjacent to the destination lane 342. An uncertainty in the assignment of the vehicle 350.2 to the destination lane 342 is due to the lateral distance between the vehicle 350.2 and the right lane 341 which is less than the second lateral distance threshold value Dlat2. Alternatively or in addition, the uncertainty is due to the probability Pass of assignment of the vehicle 350.2 to the destination lane 342 which is less than the second assignment threshold value Pas2.

So, in the driving situation of the , vehicle 350.1 or 350.2 is assigned to the destination lane with uncertainty, due to its proximity to an adjacent lane. In this case, the ADAS 104 module can apply the fifth rule and allow the activation of the SALC function if, in addition, the driver data indicates that the driver is consulting the rearview mirror.

The fifth rule may include the additional condition that the driver turns the steering wheel at least partially towards the destination lane 342 to allow activation of the SALC function.

Referring again to the , following the application of one of the decision-making rules whose conditions are met, the ADAS module 104 authorizes or refuses, in step 204, the activation of the SALC function and the change of direction of the vehicle 100.

In case of refusal of the authorization of the SALC function, for example by application of the first decision-making rule or by application of the second decision-making rule, the ADAS module 104 inhibits the activation of the SALC function at a step 205. Furthermore, the ADAS module 104 can transmit a message to the driver via the HMI 102, in order to indicate that the activation of the SALC function is refused.

If the activation of the SALC function is authorized, the ADAS module 104 can display a confirmation request message on the HMI 102, at a step 206, in order to require confirmation from the driver before the effective activation of the SALC function.

If the driver refuses at step 206, the process ends at step 208, without implementing a semi-automated lane change, therefore without executing the SALC function.

If the driver accepts in step 206, the ADAS module 104 implements the SALC function in step 207 in order to assist in changing lanes. During step 207, the ADAS module 104 can verify that the driver has his hands on the steering wheel, based on data from a sensor located on the steering wheel, and, in the event of a negative verification, can transmit a message to the driver to indicate to him to place his hands on the steering wheel, via the HMI 102. In the event that the driver does not place his hands on the steering wheel at the end of a given duration, the SALC function can be interrupted and the vehicle 100 remains in the current lane.

The confirmation request message of step 206 is optional, and, in the event of authorization to activate the SALC function in step 204, the method can proceed directly to step 207 of changing the traffic lane to the destination lane.

According to embodiments, step 201 of detecting a vehicle further comprises identifying a type of vehicle, for example among the following types: car, truck, motorcycle, etc. The threshold values described above can advantageously depend on the type of vehicle. Thus, a threshold value is predefined per type of vehicle detected for each of the following threshold values: first longitudinal distance threshold value Dmin, second longitudinal distance threshold value Dmin', first lateral distance threshold value Dlat1, second lateral distance threshold value Dlat2, first assignment threshold value Pas1, second assignment threshold value Pas2, first detection threshold value Pds1, second detection threshold value Pds2.

In other words, a first longitudinal distance threshold value Dmin1 is defined for cars, a first longitudinal distance threshold value Dmin2 is defined for trucks, a first longitudinal distance threshold value Dmin3 is defined for motorcycles, etc., the values Dmin1, Dmin2 and Dmin3 being different.

According to embodiments, the driver data from the DMS system 105 and obtained in step 203 further comprise an attention indicator and/or a driver drowsiness indicator. The aforementioned threshold values may then depend on the attention indicator and/or the drowsiness indicator. For example, the higher the drowsiness indicator, the higher the threshold values Dmin, Dmin', Dlat1, Dlat2, Pas1, Pas2, Pds1 and/or Pds2.

This makes it possible to take into account a physiological state of the driver, in particular a state of attention/fatigue of the driver, and the safety associated with the control of the SALC function is thus improved.

In embodiments, the “driver looked at the rearview mirror” condition used in the five decision-making rules detailed above may be more restrictive and may require looking at the rearview mirror for a period of time greater than a predefined threshold duration. Alternatively or additionally, the “driver looked at the rearview mirror” condition may be replaced by the condition that the driver looked at the road ahead of the vehicle before looking at the rearview mirror.

According to embodiments, a gaze position of the driver is evaluated by the ADAS module 104 on the basis of the driver data received in step 203, before implementing step 204. For example, a two-dimensional or three-dimensional point corresponding to an intersection of the axes of the driver's eyes can be used as a gaze position. The gaze position thus evaluated is compared with a position of the at least one vehicle detected and assigned to a traffic lane following steps 201 and 202. The threshold values Dlat1, Dlat2, Pas1, Pas2, Pds1 and/or Pds2 used during step 204 for the detected vehicle can then depend on a distance between the driver's gaze position and the position of the detected vehicle. Thus, the lower such a distance, the lower the threshold values Dlat1, Dlat2, Pas1, Pas2, Pds1 and/or Pds2 applied to this vehicle during step 204 can be.

There presents the structure of a control module 400 according to one embodiment of the invention.

The control module 400 may be integrated into, or may be, the ADAS module 104 described above, capable of implementing the steps of the method according to the invention described with reference to the .

Alternatively, the control module 400 may be integrated into, or may be, the ECU control device 101 described above, when the method according to the invention is implemented in the ECU 101 and not in the ADAS module 104. In this case, the ECU 101 authorizes or refuses the activation of the SALC function which is implemented by the ADAS module 104.

The control module 400 comprises a processor 401 configured to communicate in a one-way or two-way manner, via one or more buses or via a direct wired connection, with a memory 402 such as a “ Random Access Memory ” type memory, RAM, or a “ Read Only Memory ” type memory, ROM, or any other type of memory (Flash, EEPROM, etc.). Alternatively, the memory 402 comprises several memories of the aforementioned types.

The memory 402 is capable of storing, permanently or temporarily, at least some of the data used and/or resulting from the implementation of the steps of the method according to the invention illustrated with reference to the .

In particular, the memory 402 may be capable of storing the threshold values previously described as well as at least one of the decision-making rules previously described, preferably several of the decision-making rules previously described.

The processor 401 is capable of executing instructions, stored in the memory 402, for implementing the steps of the method according to the invention, described with reference to the . Alternatively, the processor 401 can be replaced by a microcontroller designed and configured to carry out the steps of the method according to the invention, described with reference to the .

The control module 400 comprises a first interface 403 capable of receiving a command to activate a lane change assistance function from a current lane to a destination lane, from the ECU 101 or from the interface 106.

The control module 400 further comprises a second interface 404 capable of receiving data from the first sensor 103.1, from which the control module 400 can detect one or more vehicles located at the rear of the vehicle 100.

The control module 400 comprises a third interface 405, capable of receiving data from the second sensor 103.2, from which the control module 400 is capable of identifying the traffic lanes, and then assigning a traffic lane to each detected vehicle.

The control module 400 further comprises a fourth interface 406 capable of receiving driver data from the DMS system 105.

The control module 400 comprises a fifth interface 407 capable of communicating with the SALC function of the ADAS module 104. When the control module 400 is integrated into the ADAS module 104, it does not comprise a fourth interface 406, since it can itself implement the SALC function.

The control module 400 may further comprise a sixth interface 408 capable of communicating with the HMI 102, for the restitution of messages in particular for the attention of the driver of the vehicle 100.

The present invention is not limited to the embodiments described above as examples; it extends to other variants.

Claims (10)

Method for controlling a lane change assistance function of a vehicle (100), called an ego-vehicle, the method comprising:
- receiving (200) a command to activate a lane change assistance function, for a change from a current lane (301; 321; 341) to a destination lane (302; 322; 342);
- detection (201), on the basis of data from at least one sensor (103.1; 103.2), of at least one vehicle (310.1; 310.2; 330; 350.1; 350.2) in a rearward position relative to said ego-vehicle, and assignment (202) of said at least one detected vehicle to a traffic lane;
- receiving (203) driver data from a driver monitoring system (105);
- decision (205) whether or not to authorize the activation of the lane change assistance function, depending on the driver data and the assignment of the detected vehicle to the lane. The method of claim 1, wherein the driver data comprises an indication of a consultation of a rearview mirror by the driver, and wherein the decision (205) whether or not to authorize the lane change command depends on the indication of consultation of the rearview mirror by the driver. The method of claim 2, wherein the decision (205) whether or not to allow the activation of the lane change assistance function comprises comparing the driver data and the assignment of the detected vehicle to the lane, with conditions of at least one predefined decision-making rule, wherein at least one predefined decision-making rule comprises a condition dependent on the indication of consultation of the rear-view mirror by the driver. Method according to claim 3, wherein said at least one vehicle (310.1; 310.2; 330; 350.1; 350.2) is detected with a given detection probability, wherein at least one predefined decision-making rule comprises a condition relating to a comparison between the detection probability of the detected vehicle and a detection threshold value. Method according to claim 3 or 4, wherein said at least one detected vehicle (310.1; 310.2; 330; 350.1; 350.2) is assigned to the traffic lane (301-303; 321; 322; 341-343) with a given assignment probability, wherein at least one predefined decision-making rule comprises a condition relating to a comparison between the assignment probability of the detected vehicle and an assignment threshold value. Method according to one of claims 3 to 5, wherein at least one predefined decision-making rule comprises a first condition relating to a first comparison between a distance (323) separating the ego-vehicle (100) from said at least one vehicle (310.1; 310.2; 330; 350.1; 350.2) detected and assigned to the destination lane (302; 322. 342), and a first longitudinal distance threshold value (324) and comprises a second condition relating to a second comparison of said distance with a second longitudinal distance threshold value (325), the second longitudinal distance threshold value being less than the first longitudinal distance threshold value. The method of claim 6, wherein the decision-making rule comprising the first and second conditions, authorizes the activation of the lane change assistance function if the rearview mirror consultation indication indicates that the driver is consulting the rearview mirror and if said distance (323) is between the second longitudinal distance threshold value (325) and the first longitudinal distance threshold value (324). A method according to claim 5 and according to claim 6 or 7, further comprising identifying a vehicle type for said at least one detected vehicle (310.1; 310.2; 330; 350.1; 350.2), wherein the vehicle detection threshold value, the vehicle assignment threshold value, the first longitudinal distance threshold value (324) and/or the second longitudinal distance threshold value (325) is determined as a function of the vehicle type identified for said at least one detected vehicle. Computer program comprising instructions for implementing the method according to one of the preceding claims, when these instructions are executed by a processor (401). Control module (400) of a lane change assistance function of a vehicle (100), called ego-vehicle, comprising:
- an interface (403) capable of receiving a command to activate a lane change assistance function, for a change from a current lane to a destination lane;
- a processor (401) capable of detecting, on the basis of data from at least one sensor (103.1; 103.2), at least one vehicle in a rear position relative to said ego-vehicle, and of assigning said at least one detected vehicle to a traffic lane;
- another interface (406) capable of receiving driver data from a driver monitoring system (105);
wherein the processor is further capable of deciding whether or not to authorize the activation of the lane change assistance function, based on the driver data and the assignment of said at least one detected vehicle to the lane.