FR3074125A1 - METHOD AND DEVICE FOR ASSISTING AUTOMATED DRIVING OF A VEHICLE IN CASE OF SUBDIVISION IN PARTS OR FUSION OF PARTS OF THE CIRCULATION PATH - Google Patents

Abstract

A method is provided to assist the driver of a vehicle (VA) that can be driven in an automated manner on a taxiway (VC) defined by first (d1) and second (d2) boundaries. This method comprises a step in which in case of detection of a next subdivision of the taxiway (VC) in at least two parts (P1-P2), the vehicle (VA) is automatically driven in an absolute mode consisting of to make it follow a path located at a selected distance (dc) from one of the first (d1) and second (d2) delimitations, then, when the vehicle (VA) is placed on one of the parts (P1-P2 ), it is conducted in an automated manner in a relative mode of following a path relative to the width of the traffic lane, with respect to a median line (Im) equidistant from the first (d1) and second (d2) boundaries.

Description

METHOD AND DEVICE FOR ASSISTING THE AUTOMATED DRIVING OF A VEHICLE IN THE EVENT OF PART DIVISION OR MERGER OF PARTS OF THE ROADWAY

The invention relates to vehicles with automated driving (possibly autonomous), possibly of the automobile type, and more specifically assistance intended to help the drivers of such vehicles to drive the latter.

In what follows, the term “automated driving vehicle” means a vehicle that can be driven in an automated manner (partial or total (without intervention of its driver)) during an automated driving phase. Note that this does not exclude that such a vehicle can also be driven manually (and therefore with the intervention of its driver on the steering wheel and / or pedals) during a manual driving phase.

Certain vehicles with automated driving, generally of the automobile type, include an assistance device responsible for automatically controlling their positioning with respect to the first and second delimitations which define the traffic lane used. This type of assistance device may, for example, be that which is known in English as LPA ("Lane Positionning Assist").

This type of assistance device more precisely controls the automated driving of the vehicle in a so-called relative mode consisting in making it follow between the first and second delimitations of the taxiway a trajectory, relative to the width of the taxiway, which is more or less spaced from the middle line (imaginary), located equidistant from these first and second boundaries, according to the driver's wishes. This trajectory being relative to the width of the taxiway, the spacing relative to the center line is therefore not constant but proportional to this width. This mode of control is problematic when the taxiway is divided into at least two parts or when parts of the taxiway merge.

Indeed, in the first situation (subdivision) the traffic lane widens before at least one intermediate delimitation appears between its neighboring parts, and therefore the assistance device will make the vehicle follow a relative trajectory close to, or identical to, the aforementioned midline. Consequently, the vehicle deviates more and more from the first and second boundaries, occupying substantially the middle of the taxiway.

In the second situation (merger) the part of the traffic lane on which the vehicle travels is suddenly again defined by the first and second boundaries (momentarily widely spaced) while it was defined by one of the first and second delimitations and an intermediate delimitation. The assistance device interprets this as a sudden widening of the lane, and therefore will make the vehicle follow a relative trajectory substantially identical to the center line located at equal distance from the first and second delimitations. As a result, the vehicle "leaves its line" and can suddenly find itself on the path of another vehicle traveling in the part of the lane that adjoins that in which it was traveling, which can be very dangerous.

In the two aforementioned situations, the driver is forced to act on the steering wheel, immediately and generally by exerting an effort, so that his vehicle again follows a correct and non-dangerous trajectory. However, such an intervention can be perceived as a loss of continuity or availability of assistance, which can push the driver to no longer use it and / or to have it checked in an after-sales service.

It has certainly been proposed in the patent document US 2016/272203 to determine in advance the positions of the subdivision and merging zones of the traffic lanes among the cartographic information of a navigation aid device on board the vehicle, in order to adapt the trajectory when the latter arrives in one of the aforementioned zones. Unfortunately, such a solution requires not only that the vehicle has a very precise position detection system, but also that the cartographic information of its navigation aid device be very frequently updated.

The invention therefore aims in particular to improve the situation.

It proposes in particular for this purpose a method, on the one hand, making it possible to assist a driver of a vehicle capable of being driven in an automated manner on a traffic lane defined by first and second delimitations, and, on the other hand , comprising a step in which the vehicle is driven in an automated manner in a so-called relative mode consisting in making it follow on the taxiway a trajectory, relative to the width of the taxiway, relative to a median line situated at equal distance from the first and second boundaries.

This assistance process is characterized by the fact that in its stage:

- in the event of detection of a next subdivision of the taxiway into at least two parts, the vehicle is driven automatically in a so-called absolute mode consisting in making it follow a trajectory located at a chosen distance from one of the first and second boundaries, then, when the vehicle is placed on one of these parts, it is driven again in the relative mode, and

- in the event of vehicle circulation on one of the parts of the traffic lane and detection of a next merger of these parts, the vehicle is driven in absolute mode, then, when the vehicle is placed on the circulation after this merger, it is led again in the relative mode.

Thanks to the invention, the trajectory of the vehicle is automatically adapted so that it does not leave its line as soon as a subdivision or merger zone of its taxiway is detected in the images of its environment (acquired by means on-board image acquisition), without the driver having to intervene on the steering wheel.

The assistance method according to the invention may include other characteristics which can be taken separately or in combination, and in particular:

- in absolute mode, the vehicle can follow a trajectory located at a chosen distance from the delimitation, from the first and second delimitations, which is either located to its right in the case of a traffic lane suitable for vehicles with left-hand drive is on the left in the case of a traffic lane suitable for right-hand drive vehicles. As a variant, the vehicle can be made to follow a trajectory situated at a chosen distance from the delimitation which is closest to it at the time of detection;

- in its stage, a next subdivision of the traffic lane can be detected when the latter gradually widens and at least one intermediate delimitation appears between the first and second delimitations;

- in its stage, we can detect a next merger of the parts of the traffic lane when an intermediate delimitation, which defines a part with one of the first and second delimitations, is interrupted;

- in its stage, while driving in absolute mode, it is possible to determine successive instructions from a vehicle direction control automaton, intended to make the trajectory follow the latter, as a function of successive real positions of the vehicle relative to the traffic lane.

The invention also proposes a device, on the one hand, intended to assist a driver of a vehicle capable of being driven in an automated manner on a traffic lane defined by first and second delimitations, and, on the other hand, comprising control means which control an automated driving of the vehicle in a so-called relative mode consisting in making it follow on the taxiway a trajectory, relative to the width of the taxiway, relative to a median line situated at equal distance from the first and second boundaries.

This assistance device is characterized by the fact:

- that in the event of detection of a next subdivision of the taxiway into at least two parts, its control means control the driving of the vehicle in a so-called absolute mode consisting in making it follow a trajectory situated at a chosen distance of one of the first and second delimitations, then, when the vehicle is placed on one of the parts, its control means again control the driving of the vehicle in the relative mode, and

- that in the event of vehicle circulation on one of the parts of the traffic lane and detection of a next merger of these parts, its control means control the driving of the vehicle in absolute mode, then, when the vehicle is placed on the taxiway after this merger, its control means again control the driving of the vehicle in the relative mode.

The assistance device according to the invention may include other characteristics which can be taken separately or in combination, and in particular:

- in absolute mode, its control means can control the driving of the vehicle so that it follows a trajectory located at a chosen distance from the delimitation, from the first and second delimitations, which is either located to its right in the case of a lane suitable for left-hand drive vehicles is located to the left of it in the case of a lane suitable for right-hand drive vehicles. Alternatively, its control means can control the driving of the vehicle so that it follows a trajectory located at a chosen distance from the delimitation which is closest to it at the time of detection;

- while driving in absolute mode, its control means can determine successive instructions from a vehicle direction control automaton, intended to follow the trajectory by the latter, as a function of successive real positions of the vehicle relative to the traffic lane.

The invention also provides a vehicle, possibly of the automotive type, capable of being driven in an automated manner on a traffic lane defined by first and second delimitations, and comprising an assistance device of the type of that presented above.

Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawing, in which the single figure schematically and functionally illustrates a traffic lane subdivided into two parts and on which an example of a vehicle with automated driving and comprising a computer provided with an exemplary embodiment of an assistance device according to the invention is materialized at three different times.

The object of the invention is in particular to propose an assistance method, and an associated assistance device DA, intended to assist a driver of a VA vehicle with automated driving to drive the latter (VA) on a traffic lane VC which is subdivided into at least two neighboring parts Pj or whose neighboring parts Pj merge.

It is recalled that here the term “automated driving vehicle” means a vehicle which can be driven in an automated manner (partial or total (without intervention of its driver)) during an automated driving phase, under control (partial or total) of an assistance device, and possibly manually (and therefore under the sole control of its driver) during a manual driving phase.

In what follows, it is considered, by way of nonlimiting example, that the vehicle VA is of the automobile type. This is for example a car. However, the invention is not limited to this type of vehicle. It concerns in fact any type of vehicle with automated driving which can circulate on land traffic lanes defined by two delimitations.

There is schematically and functionally shown in the single figure a traffic lane VC subdividing into two parts Pj (j = 1 or 2) and on which is materialized an example of vehicle VA with automated driving at three times tk (k = 1 to 3) different.

This traffic lane VC is defined by first d1 and second d2 delimitations. It is subdivided here, from a given location, into two parts P1 and P2 which are separated by an intermediate delimitation di. The first part P1 is therefore defined by the first delimitation d1 and the intermediate delimitation di, and the second part P2 is defined by the second delimitation d2 and the intermediate delimitation di. It is conceivable that at another given location, distant from the one shown, the two parts Pj merge.

It will be noted that the traffic lane VC could be subdivided into more than two neighboring parts Pj, for example three or four. Similarly, the taxiway VC could include more than two neighboring parts Pj, for example three or four, which merge.

The VA vehicle being automated driving, it comprises in particular a steering wheel VV, means for acquiring images of the environment MA and an assistance device DA according to the invention.

Although it does not appear in the single figure, the VV steering wheel is fixedly secured to a steering column, in order to allow the driver to control it by exerting on it a torque vce with at least one of his hands. This steering column is coupled to a direction control automaton (not shown) controllable by the assistance device DA by means of a setpoint, for example of assistance torque.

This DA assistance device comprises control means MC which are responsible, at least, for controlling the automated driving of the vehicle VA in a so-called absolute mode or else in a so-called relative mode depending on whether it is in an area where the track of traffic VC which it borrows will be subdivided into parts Pj or to parts Pj which will merge or else in a portion (or part Pj) of a lane of traffic VC which should not very soon be subdivided or merge, as we will see later.

The relative mode consists in making the vehicle VA follow on the taxiway VC a trajectory tv1 (or tv3), relative to the width of the taxiway, relative to a median line (imaginary) Im located equidistant from the first d1 and second d2 boundaries. This trajectory, relative to the width of the taxiway VC, is more or less spaced by a deviation Δ from this center line Im as desired by the driver. In the example illustrated without limitation in the single figure, the driver has chosen a non-zero difference Δ (to the right) between the path tv1 (or tv3 (k = 1 or 3)), relative to the width of the lane circulation VC, vehicle VA, and the center line Im. But this difference Δ could be chosen equal to zero (0) or else could be non-zero and to the left of the middle line Im.

The absolute mode consists in making the vehicle VA follow on the taxiway VC a (absolute) trajectory tv2 (k = 2) located at a chosen distance from one of the first d1 and second d2 delimitations.

It will be noted that in the example illustrated without limitation in the single figure, the assistance device DA is installed in a computer CA of the vehicle VA which can possibly perform at least one other function. But it (DA) could include a calculator. Consequently, a DA assistance device can be produced in the form of software modules (or computer modules or even "software >>), or of electrical or electronic circuits or components (or" hardware >>), or even of a combination of electrical or electronic circuits or components and software modules. It will also be noted that the assistance device DA constitutes, for example, what a person skilled in the art calls an ADAS device (“Advanced Driver Assistance System” - assistance system (or assistance) for driving advanced).

As mentioned above, the invention provides an assistance method intended, in particular, to assist the driver of the VA vehicle to drive the latter (VA), and at least as regards the control of his trajectory tvk.

An assistance method according to the invention comprises a step in which the VA vehicle is driven in absolute mode in an automated manner when it is detected that it is traveling in an area where a subdivision or a merger is taking place, and in the relative mode when it is detected that it is circulating in an area where there is no subdivision or merger. It will be understood that this is controlled by the control means MC.

More precisely, in the event of detection of a next subdivision of the taxiway VC into at least two parts Pj, the vehicle VA is driven in absolute mode in an automated manner, then, when the vehicle VA is placed on one of these parts Pj, it is led again in the relative mode. Likewise, in the case of circulation of the vehicle VA on one of the parts Pj of the traffic lane VC and detection of a next fusion of these parts Pj, the vehicle VA is driven in absolute mode, then, when the vehicle VA is placed on the taxiway VC after this merger, it is driven again in the relative mode.

In other words, when the vehicle VA is driven in the relative mode under the control of the control means MC (instant t1 of the single figure) and that a next subdivision of the taxiway is detected

VC, we go from driving in the relative mode to driving in the absolute mode (instant t2 of the single figure). Then, when the vehicle VA is driven in the absolute mode under the control of the control means MC (instant t2) and that it is detected that it has reached one of the parts Pj, driving is passed into the absolute driving mode in relative mode (instant t3 of the single figure). Likewise, when the vehicle VA is driven in the relative mode under the control of the control means MC (instant t3 of the single figure) and that a next fusion of the parts Pj is detected, one passes from driving in the driving mode in absolute mode (instant following t3, not shown in the single figure). Then, when the vehicle VA is driven in the relative mode under the control of the control means MC and that it is detected that it has reached the merged traffic lane VC, driving is changed to the mode relating to the driving in absolute mode.

It will be noted that in the example illustrated without limitation in the single figure, the traffic lane VC is suitable for vehicles driving on the left, and therefore the distance chosen from is that which separates the trajectory tv2 of the vehicle VA from the first delimitation d1 (here the one on the right). But if the taxiway VC was suitable for vehicles driving on the right, the distance chosen from would be that which separates its trajectory tv2 from the second delimitation d2 (here the one on the left). In general, in absolute mode, the vehicle VA is preferably made to follow a trajectory situated at a chosen distance d1 from the delimitation, from among the first d1 and second d2 delimitations, which is either situated to its right in the case of '' a VC traffic lane suitable for left-hand drive vehicles is located to its left in the case of a VC lane suitable for right-hand drive vehicles. It is also possible to have independence from the type of driving (on the right or on the left), and in this case the delimitation d1 or d2 retained in the absolute mode is that which is closest to the vehicle VA at the time of detection (and therefore just before absolute mode is initiated). It is also possible to have a mixture of the two solutions presented above: if the vehicle VA is approximately at equal distance from the two delimitations d1 and d2, the delimitation of the direction of circulation is preferred, and if the vehicle VA is really closer to a d1 or d2 delimitation, we favor (or retain) this last delimitation.

The trajectory of the vehicle VA is therefore automatically adapted so that it does not leave its line as soon as a subdivision or merger zone of its taxiway VC is detected in the images of its environment (on the side of its front part) .

The images of the front environment of the VA vehicle are acquired by MA image acquisition means which are embedded in the latter (VA). They include, for example, at least one digital camera facing the front of the VA vehicle. Each image is then analyzed by environmental analysis means in order to detect (for example by shape recognition) the first d1 and second d2 delimitations and possible intermediate delimitation (s) of the portion. taxiway VC which is located in front of the vehicle VA, and the actual position of the latter (VA) with respect to the detected boundaries. These environmental analysis means can possibly be part of the DA assistance system, but this is not compulsory. Indeed, they can also be responsible for detecting other environmental information than the actual boundaries and positions of the VA vehicle in the acquired images, and in this case, they only provide the control means MC with the information they need (positions of boundaries d1, d2 and di and actual position of the VA vehicle). The boundaries can be modeled by mathematical polynomials, with a point of the VA vehicle as a reference.

For example, in the process step, a next subdivision of the taxiway VC can be detected when the latter (VC) gradually widens and at least one intermediate delimitation di appears between its first d1 and second d2 delimitations. It will be understood that the widening corresponds to a progressive increase in the distance separating locally the first d1 and second d2 delimitations. The detection of this widening can be carried out by the control means MC from the aforementioned information supplied in real time by the environmental analysis means.

Also for example, in the process step, it is possible to detect a next fusion of the parts Pj of the traffic lane VC when an intermediate delimitation di, which defines a part Pj with one of the first d1 and second d2 delimitations, s interrupts. This abrupt interruption of the intermediate delimitation di is interpreted as an abrupt widening of the taxiway VC. The detection of this sudden widening can be carried out by the control means MC from the aforementioned information provided in real time by the environmental analysis means.

It will be noted that in the process step, while driving in absolute mode, we (the control means MC) can (Fri) t determine successive instructions from the direction control automaton of the vehicle VA, intended to make follow the trajectory by the latter (VA), as a function of the successive real positions of the vehicle VA with respect to the traffic lane VC (provided in real time by the environmental analysis means). The use of these real positions advantageously makes it possible to avoid lateral offsets.

Each setpoint can, for example, be determined as follows. The control means MC can first of all determine a reference angle which the steering wheel VV should take so that the vehicle VA follows the determined path tvk, as a function of the information representative of the vehicle VA and of its environment. Then, the control means MC can, for example, determine a assistance torque that the direction control automaton must produce, as a function of the angle of the steering wheel in progress (measured by a sensor coupled to the steering column ) and the reference angle they have just determined. This assistance torque depends on any torque vce applied by the driver to the steering wheel VV, and therefore on the angle of the steering wheel. Finally, the control means MC generate a setpoint representative of this assistance torque, intended for the direction control automaton.

The invention makes it possible to offer continuity in assistance with trajectory control (and in particular correctness of guidance), which avoids the driver having to take back his vehicle in hand, without consequence on the cost of the vehicle and requiring no not the use of cartographic information or digital maps.

Claims (10)

1. Assistance method for a driver of a vehicle (VA) capable of being driven in an automated manner on a traffic lane (VC) defined by first (d1) and second (d2) delimitations, said method comprising a step in which said vehicle (VA) is automatically driven in a so-called relative mode consisting in making it follow on said taxiway (VC) a trajectory, relative to a width of said taxiway (VC), with respect to a center line located equidistant from said first (d1) and second (d2) delimitations, characterized in that in said step i) in the event of detection of a next subdivision of said taxiway (VC) into at least two parts ( Pj), said vehicle (VA) is automatically driven in a so-called absolute mode consisting in making it follow a trajectory located at a chosen distance (from) from one of said first (d1) and second (d2) delimitations, then, when said vehicle (VA) is placed on one of said parts (Pj), it is driven again in said relative mode, and ii) in the case of movement of said vehicle (VA) on one of said parts (Pj ) and of detection of a next fusion of these parts (Pj), said vehicle (VA) is driven in said absolute mode, then, when said vehicle (VA) is placed on said traffic lane (VC) after said fusion, it is led again in said relative mode. 2. Method according to claim 1, characterized in that in said absolute mode, said vehicle (VA) is followed by a trajectory situated at a chosen distance (from) from the delimitation, from among said first (d1) and second (d2) delimitations , which is either located to its right in the case of a taxiway (VC) suitable for left-hand drive vehicles or which is located to its left in the case of a taxiway (VC) suitable for vehicles with left-hand drive right-hand drive. 3. Method according to claim 1 or 2, characterized in that in said step a next subdivision of said traffic lane (VC) is detected when the latter (VC) gradually widens and at least one intermediate delimitation appears ( di) located between said first (d1) and second (d2) boundaries. 4. Method according to one of claims 1 to 3, characterized in that in said step a next fusion of the parts (Pj) of said traffic lane (VC) is detected when an intermediate delimitation (di), which defines a part (Pj) with one of said first (d1) and second (d2) delimitations, is interrupted. 5. Method according to one of claims 1 to 4, characterized in that in said step, while driving in said absolute mode, it determines successive setpoints of a direction control automaton of said vehicle (VA), intended for forward said trajectory by the latter (VA), as a function of successive real positions of said vehicle (VA) relative to said taxiway (VC). 6. Device (DA) for assisting a driver of a vehicle (VA) capable of being driven automatically on a traffic lane (VC) defined by first (d1) and second (d2) delimitations, said device (DA ) comprising control means (MC) controlling an automated driving of said vehicle (VA) in a so-called relative mode consisting in making it follow on said taxiway (VC) a trajectory, relative to a width of the taxiway (VC) ), with respect to a median line located equidistant from said first (d1) and second (d2) delimitations, characterized in that in the event of detection of a next subdivision of said taxiway (VC) into at least two parts (Pj), said control means (MC) control the driving of said vehicle (VA) in a so-called absolute mode consisting in making it follow a trajectory located at a chosen distance (from) from one of said first (d1) and second (d2) deli mitations, then, when said vehicle (VA) is placed on one of said parts (Pj), said control means (MC) again control the driving of said vehicle (VA) in said relative mode, and in that in in case of circulation of said vehicle (VA) on one of said parts (Pj) and detection of a next fusion of these parts (Pj), said control means (MC) control the driving of said vehicle (VA) in said mode absolute, then, when said vehicle (VA) is placed on said taxiway (VC) after said merger, said control means (MC) again control the driving of said vehicle (VA) in said relative mode. 7. Device according to claim 6, characterized in that in said absolute mode said control means (MC) control the driving of said vehicle (VA) so that it follows a trajectory located at a chosen distance (from) of the delimitation, among said first (d1) and second (d2) delimitations, which is either located to its right in the case of a traffic lane (VC) 5 suitable for vehicles driving on the left or located to its left in the case of '' a traffic lane (VC) suitable for right-hand drive vehicles. 8. Device according to one of claims 6 and 7, characterized in that, while driving in said absolute mode, said control means îo (MC) determine successive setpoints of a direction control automaton of said vehicle (VA ), intended to follow said trajectory by the latter (VA), as a function of successive real positions of said vehicle (VA) relative to said taxiway (VC). 9. Vehicle (VA) capable of being driven automatically on a traffic lane (VC) defined by first (d1) and second (d2) delimitations, characterized in that it comprises an assistance device (DA) ) according to one of claims 6 to 8. 10. Vehicle according to claim 9, characterized in that it is of the automobile type.