MANAGEMENT OF EXIT RAMPS BY AN AUTONOMOUS VEHICLE FOR PERFORMING LANE CHANGE MANEUVERS

Description

[0001] The present invention claims priority from French application 2205791 filed on 15.06.2022. technical field

[0002] The present invention relates to the field of autonomous vehicles, particularly self-driving cars. The invention specifically relates to a method for autonomously driving a motor vehicle on roadways using a computer system embedded in the vehicle. The invention also relates to a device implementing such a method, as well as a vehicle incorporating such a device. Prior art

[0003] It is known that some current vehicle driver assistance systems provide features that enable autonomous or semi-autonomous vehicle guidance in certain specific driving environments (e.g., highways, expressways, urban areas, etc.). To comply with traffic regulations, which stipulate that a motor vehicle must position itself as far to the right as possible on the roadway, some systems initiate lane-change maneuvers to move into the adjacent right-hand lane when it is free. However, this automatic repositioning into the free right-hand lane proves detrimental in the context of autonomous driving on divided highways, particularly at exit ramps.Indeed, in a situation where a vehicle is approaching an exit ramp on a divided highway, a driver assistance system that initiates a lane change maneuver into the adjacent right-hand lane, if it is free, risks leading the vehicle into the exit ramp. The driver would then be forced to take over immediately, possibly requiring a sudden maneuver to exit the ramp. Such a situation would undoubtedly cause stress and discomfort, jeopardizing driving safety.

[0004] In particular, document WO 2019 / 166714 A1 describes a method assisting the driver of a vehicle and comprising a step in which environmental data is analyzed to determine a speed limit variation temporally correlated with a variation in the number of traffic lanes, and in the presence of such a determination the vehicle is considered to be located near a mandatory passage zone and an alert is generated requiring the driver to take back control of driving during the crossing of this mandatory passage zone or for the control means to implement an automated driving strategy specific to this crossing. Summary of the invention

[0005] The invention aims to address this problem. Specifically, the invention provides a method and device that ensure safe and comfortable autonomous driving when exiting a dual carriageway. In particular, the invention aims to provide a method and device that minimize the risk of a motor vehicle's driver assistance system inappropriately initiating the vehicle onto a dual carriageway exit ramp.

[0006] To achieve these goals, the invention relates, according to a first aspect, to a method for the autonomous driving of a motor vehicle on the traffic lanes of a road by means of a computer device embedded in the vehicle, the method comprising the steps of: to acquire data characterizing the vehicle's driving environment generated by means of a detection device of a vehicle driver assistance system; to determine, based on the data characterizing the vehicle's driving environment, whether the driving environment contains a first road sign indicating a speed limit of 90 km / h which is located upstream and at a distance less than a first pre-established threshold value of at least a second road sign indicating a first speed limit value lower than 90 km / h; and, when it is established that this is the case, determine, based on data characterizing the vehicle's driving environment, whether a guardrail is located to the right of the vehicle at a lateral distance greater than a value separated by twice the width of a traffic lane of the road by a second pre-established threshold value; and, when it is established that this is the case, cause the vehicle to perform a maneuver during which it leaves the current traffic lane to join the adjacent traffic lane on the right; or, when it is established that this is not the case, cause the vehicle to remain in the current traffic lane.

[0007] According to another variant, the first threshold value can be between ten meters and thirty meters.

[0008] According to yet another variant, the second threshold value can be less than fifty centimeters.

[0009] According to a second aspect, the invention relates to an autonomous driving device for a motor vehicle on the traffic lanes of a road, the device comprising at least one information processing unit, including at least one processor, and a data storage medium configured to implement a method as described above.

[0010] According to a third aspect, the invention relates to a program comprising program code instructions for the execution of the steps of a process as described above when said program is executed by at least one processor.

[0011] According to a fourth aspect, the invention relates to a medium usable in a computer, on which a program as described above is recorded.

[0012] According to a fifth aspect, the invention relates to a motor vehicle comprising a device as described above. Brief description of the figures

[0013] Other features and advantages of the invention will become apparent upon examination of the detailed description below, and the accompanying drawings, in which: [ Fig. 1 ] is a diagram of a vehicle according to the invention implementing a method according to the invention; [ Fig. 2 ] is a functional diagram of a device according to the invention; and [ Fig. 3 ] is a flowchart of the steps of a process according to the invention. Detailed description of the invention

[0014] There figure 1This schematically illustrates a motor vehicle 1 according to the invention in a driving environment in which the method according to the invention is implemented. As seen in the figure, the vehicle 1 is traveling on a multi-lane road 2, in particular a divided highway, preferably a motorway, and is approaching an exit ramp 3 on the road 2. In this context, the vehicle 1 according to the invention is equipped with a driver assistance system and an autonomous driving device according to the invention which implements the method according to the invention described below to manage the guidance of the vehicle safely and comfortably as it approaches the exit ramp 3.

[0015] The autonomous driving device 100 according to the invention, installed on board vehicle 1 according to the invention, is illustrated in the figure 2. This is a computer device, which includes at least one information processing unit 101, comprising one or more processors, a data storage medium 102, on which is recorded in particular a program which includes program code instructions for the execution of the steps of the process according to the invention described below, and an input and output interface 103 enabling the reception and transmission of data.

[0016] According to one embodiment of the invention, the device 100 according to the invention is housed on one or more computers, electronic control units, or other telematics units of the vehicle 1. According to the preferred embodiment, that illustrated in the figure 2The device 100 according to the invention is housed on an independent computer and interacts, via its input / output interface 103 and by means of a wired communication network of the vehicle 1 (e.g., CAN, Ethernet) – represented in the figure by the double-headed arrow – with a computer of the vehicle's driver assistance system 200. In another embodiment, the device 100 according to the invention is an integral part of a computer of the vehicle's driver assistance system 200. Thus, regardless of the embodiment, the device 100 according to the invention is always able to interact, via its input / output interface 103, not only with the driver assistance system 200 of the vehicle 1, but also, via this system, with any other device that conventionally equips and / or interacts with the driver assistance system 200.

[0017] According to the invention, the driver assistance system 200 of vehicle 1 comprises at least one detection device (e.g., lidar, radar, camera, ultrasonic sensor, etc.), which it uses to perceive the driving environment around the vehicle, and one or more dedicated computers and / or processors, which, based on raw data generated by the detection device, can control the operation of certain vehicle components that govern its movement (e.g., electronic power steering, electronic stability control, ABS, cruise control, etc.). Thus, by interacting with or being an integral part of such a driver assistance system, the device 100 according to the invention is notably able to determine the location and nature of road signs or other elements of the road infrastructure, such as guardrails, that are present in the driving environment of vehicle 1.Furthermore, these means also allow the device 100 according to the invention to autonomously manage the guidance of vehicle 1, in particular to cause the execution of lane change maneuvers or, on the contrary, to keep vehicle 1 on the same lane.

[0018] According to the invention, all the elements described above contribute to enabling the device 100 according to the invention to implement a method of autonomous driving of a motor vehicle on the traffic lanes of a road, as described below in connection with the Figures 1 And 3 .

[0019] According to a first step 201 of the method according to the invention, the device 100 according to the invention acquires data characterizing the driving environment of the vehicle generated by means of a detection device of the driving assistance system 200 of the vehicle 1. To do this, the device 100 according to the invention interacts with the driving assistance system 200, which conventionally determines a model of the driving environment, i.e. the data characterizing the driving environment, using raw data generated by means of its detection device.To generate such data, when the detection device providing the raw data is a camera mounted on the vehicle to capture images of the driving environment, the driver assistance system 200 processes the images generated by the camera to locate and categorize moving or static objects in the driving environment. Thus, at the end of this first step 201 of the method according to the invention, the device 100 according to the invention holds data that identifies and locates static objects, including elements of road infrastructure (e.g., road signs, road markings, guardrails), or moving objects, for example, other vehicles, that are present in the driving environment of vehicle 1.

[0020] Next, according to a second step 202 of the method according to the invention, the device 100 according to the invention advantageously determines, based on data characterizing the vehicle's driving environment acquired during the preceding step of the method, whether the driving environment contains a first speed limit sign of 90 km / h located upstream and at a distance less than a pre-established threshold value, for example, less than 50 meters, from at least a second speed limit sign of a value lower than 90 km / h. Indeed, on a divided highway, exit ramps are characterized by the presence of a sequence of decreasing speed limit signs spaced a few tens of meters apart, which invariably begins with a first speed limit sign of 90 km / h.Thus, by determining whether the presence of a first speed limit sign of 90 km / h followed at a relatively short distance by a second speed limit sign of less than 90 km / h, the device 100 according to the invention is able to identify and locate an exit ramp from a divided highway.

[0021] And, when it has established during the previous step that the driving environment does indeed contain a first traffic sign indicating a speed limit of 90 km / h which is located upstream and at a distance less than a pre-established threshold value of at least a second traffic sign indicating a speed limit value less than 90 km / h, which means the presence of an exit ramp, the device 100 according to the invention carries out the following steps of the method according to the invention described below.

[0022] According to a third step 203 of the method according to the invention, the device 100 according to the invention advantageously determines, based on data characterizing the vehicle's driving environment, whether a guardrail is located to the right of the vehicle at a lateral distance greater than a value separated by twice the width of a traffic lane of road 2 by a second predetermined threshold value, for example, less than 50 centimeters. To do this, the device 100 according to the invention determines, for example, the width of the traffic lanes of road 2 from detected road markings. Alternatively, the width of a traffic lane is predetermined and recorded on the data storage medium 102 at the time of vehicle design.In other words, the device 100 according to the invention seeks at this stage to determine the lateral positioning of the vehicle on the roadway in order to determine, taking into account the presence of the exit ramp, whether a lane change maneuver to the adjacent lane on the right can be performed. Advantageously, it determines this by observing the lateral distance between the vehicle 1 and a guardrail located on its right side. Thus, referring to the... figure 1 , the lane adjacent to the right of the vehicle is the exit ramp and the guardrail (not shown) is necessarily at a lateral distance from vehicle 1 which is less than twice the width of a traffic lane of the roadway.

[0023] Then, when it has established during the third step 203 of the process that a safety barrier is indeed located to the right of the vehicle at a lateral distance greater than a value separated by twice the width of a traffic lane of the road by a second pre-established threshold value, the device 100 according to the invention carries out a fourth and final step 204a of the process according to the invention during which it causes the vehicle to perform a maneuver during which it leaves the current traffic lane to join the traffic lane adjacent to the right, by interacting for this purpose with the driving assistance system 200 of the vehicle 1.On the contrary, when it established during the third step 203 of the process that a guardrail is located to the right of the vehicle at a distance less than a value separated by twice the width of a traffic lane by a second pre-established threshold value, as illustrated on the . figure 1 The device 100 according to the invention advantageously performs a fourth and final step 204b of the method according to the invention, during which it keeps the vehicle in the current traffic lane. In other words, the device 100 according to the invention prevents, in this case, a lane change maneuver to the adjacent lane on the right, thus preventing the vehicle 1 from improperly entering the exit ramp 3.

[0024] Therefore, thanks to the method and device according to the invention described above, a solution is provided to enable safe and comfortable autonomous driving when passing through an exit ramp of a divided highway.

Claims

1. Method for autonomous driving of a motor vehicle (1) on the traffic lanes of a road (2) by means of a computer device (100) on board the vehicle, and comprising the steps of: • acquiring (201) data characterising the driving environment of the vehicle generated by means of a device for detecting a driver assistance system (200) of the vehicle; • determine (202), based on the data characterising the driving environment of the vehicle, whether the driving environment contains a first road sign indicating a speed limit of 90 km / h which is located upstream and at a distance less than a first pre-established threshold value of at least one second road sign indicating a first speed limit value of less than 90 km / h; wherein, when this is established, the method comprises the following additional steps: • determine (203), on the basis of the data characterising the driving environment of the vehicle, whether a safety slide is located to the right of the vehicle at a lateral distance greater than a value separated by twice the width of a highway taxiway (2) by a second pre-established threshold value; and, where it is established that this is the case, • cause (204a) the vehicle to perform a manoeuvre in which it leaves the current taxiway to join the adjacent taxiway to the right; or, where it is determined that this is not the case, • causing (204 b) the vehicle to remain on the current taxiway.

2. The method according to claim 1, wherein the first threshold value is between ten metres and thirty metres.

3. The method according to claim 1, wherein the second threshold value is less than fifty centimetres.

4. Device (100) for autonomous driving of a motor vehicle on the lanes of a highway, wherein the device comprises at least one information processing unit (101), comprising at least one processor, and a data storage medium (102) configured to implement a method according to any one of the previous claims.

5. Computer Plan comprising plan code instructions for executing the steps of a method according to any one of claims 1 to 3 when said plan is executed by at least one processor.

6. Medium usable in a computer, wherein a plan according to claim 5 is recorded therein.

7. Motor vehicle, characterised in that it comprises a device (100) according to claim 4.