Method for controlling a vehicle during road widening

Abstract

Method for controlling a vehicle during a road widening. Method for controlling a motor vehicle (1), comprising: - observing a road (6) on which the vehicle is traveling with an observation device (5) mounted in the vehicle, then - detecting a left edge (6G) and a right edge (6D) of the road, then - detecting a widening (7) of the road in front of the vehicle, then - defining two virtual lanes (11), based on the left and right edges (6D) of the road, then - transmitting the two virtual lanes to a vehicle trajectory planning module. Figure for the abstract: Figure 4

Description

Title of the invention: Method for controlling a vehicle during road widening. Technical field of the invention

[0001] The invention relates to a method for controlling a motor vehicle, in particular an autonomous motor vehicle. The invention also relates to a motor vehicle comprising hardware and software configured to implement such a control method. Prior art

[0002] Motor vehicles are known to include observation means configured to observe a scene around the vehicle and actuators configured to control the direction and speed of the vehicle based on the previously observed scene. The observation means are generally capable of recognizing lane markings separating traffic lanes. Such vehicles further include computing means capable of calculating a trajectory based on the previously detected lane markings. The actuators are controlled to follow this trajectory.

[0003] Among the situations that may arise when using such a vehicle is the case of a road widening. A widening can be characterized by an increasing distance between the two lane markings of the lane in which the vehicle is traveling. A widening generally occurs before the lane in which the vehicle is traveling splits into two separate lanes. Such a situation is commonly referred to by the English term "lane split." A road widening therefore corresponds to a transition zone before the road presents an additional lane, clearly identified by lane markings. Alternatively, a widening may also occur for other reasons, for example, the creation of a parking space, which is not always marked.An expansion may also be planned due to a particular type of terrain, or even for no specifically identified reason.

[0004] During road widening, it has been observed that the trajectory of such a vehicle is sometimes hesitant: the vehicle generally positions itself in the center of the widened section, or even oscillates around a center line. Such behavior causes concern among vehicle users, who then wish to regain manual control of the vehicle's direction. In even more serious cases, the vehicle is unable, on its own, to avoid an obstacle such as a median strip or a traffic island. positioned between the two traffic lanes at the end of a road widening zone, and a driver must regain control of the vehicle. Presentation of the invention

[0005] The object of the invention is to provide a method of controlling a motor vehicle which remedies the above disadvantages and improves the control methods known in the prior art.

[0006] More specifically, a first object of the invention is a method of controlling a motor vehicle allowing the vehicle to be guided in a reassuring and reliable manner when a road has a widening. Summary of the invention

[0007] The invention relates to a method for controlling a motor vehicle, the method comprising: - observation of a road on which the vehicle is traveling using an observation device mounted in the vehicle, then - the detection of a left and a right edge of the road, then - the detection of a road widening in front of the vehicle, then - the definition of a first virtual lane, the first virtual lane comprising a right edge and a left edge, the right and left edges of the first virtual lane being defined in relation to the right edge of the road, and - the definition of a second virtual lane, the second virtual lane comprising a right edge and a left edge, the right and left edges of the second virtual lane being defined in relation to the left edge of the road and then - the transmission of the first virtual lane and the second virtual lane previously defined to a vehicle trajectory planning module.

[0008] Said detection of road widening in front of the vehicle may include: - estimating the road width at least at one position in front of the vehicle based on the previously detected left and right edges of the road, then comparing the road width with a predefined threshold, including a predefined threshold based on a previously detected road type, and / or - estimating the road width in at least a first position and a second position in front of the vehicle based on the previously detected left and right edges of the road, then comparing the road width in the first position with the road width in the second position.

[0009] The definition of the first virtual path may include: - defining the width of the first virtual lane, then - the definition of the left edge of the first virtual lane as a function of the right edge of the road and as a function of the width of the first virtual lane.

[0010] The definition of the second virtual lane may include: - the definition of a width of the second virtual lane, then - the definition of the right edge of the second virtual lane as a function of the left edge of the road and as a function of the width of the second virtual lane.

[0011] The width of the first virtual lane can be defined according to a width of the road upstream of the widening and / or according to a predefined width according to a previously detected road type.

[0012] The width of the second virtual lane can be defined according to a width of the road upstream of the widening and / or according to a predefined width according to a previously detected road type.

[0013] The definition of the left edge of the first virtual lane may include a left offset from the right edge of the road, said left offset being defined according to the width of the first virtual lane.

[0014] The definition of the right edge of the second virtual lane may include a right offset from the left edge of the road, said right offset being defined according to the width of the second virtual lane.

[0015] The first virtual path and the second virtual path can each comprise a first portion followed by a second portion, the first portion of the first virtual path being coincident with the first portion of the second virtual path, the second portion of the first virtual path diverging from the second portion of the second virtual path.

[0016] The control process may then include: - a step of determining the vehicle's trajectory by the vehicle trajectory planning module, the trajectory being determined either to follow the first virtual lane, or to follow the second virtual lane, then - automatic control of a vehicle steering system to follow the previously determined trajectory.

[0017] The invention also relates to a motor vehicle comprising an observation means embedded in the vehicle and hardware and software means configured to implement the control method as defined above.

[0018] The invention also relates to a computer program product comprising program code instructions recorded on a computer-readable medium to implement the steps of the control process as defined above when said program is running on a computer.

[0019] The invention also relates to a computer-readable data storage medium on which a computer program comprising program code instructions for implementing the control process as defined previously. Presentation of the figures

[0020] These objects, features and advantages of the present invention will be described in detail in the following description of a particular embodiment, given by way of non-limiting example, with reference to the accompanying figures, among which:

[0021] Fig. 1 is a schematic view of a motor vehicle according to one embodiment of the invention.

[0022] Fig. 2 is a schematic top view of the vehicle travelling on a road with a widening.

[0023] Fig. 3 is a synoptic diagram of a method for controlling the motor vehicle according to an embodiment of the invention.

[0024] Fig. 4 is a schematic top view of the vehicle in the configuration of Fig. 2, and of two virtual lanes defined during the implementation of the control method.

[0025] Fig. 5 is a schematic top view of the vehicle in a second configuration, and of two virtual lanes defined during the implementation of the control method. Detailed description

[0026] Figure 1 schematically illustrates a motor vehicle 1 according to an embodiment of the invention. The vehicle 1 can be of any type. For example, it can be a passenger car, a commercial vehicle, a truck, or a bus. The vehicle 1 comprises at least two steering wheels 2 and a control device 3 for the orientation of the steering wheels 2. The control device 3 includes, in particular, an actuator, for example, an electric motor. The actuator is mechanically linked to the steering wheels 2, for example, by means of a rack and pinion and tie rods, so as to control the orientation of the steering wheels 2. The control device 3 forms a physical means capable of autonomously controlling the vehicle's trajectory, that is, independently of any action by a driver on a steering wheel.Vehicle 1 can therefore be a Level 2 vehicle or higher, according to the SAE (Society of Automotive Engineers) definition of autonomy levels. Vehicle 1 also includes an observation system 5 for monitoring its surroundings. This observation system 5 is specifically designed to observe the scene in front of the vehicle, for example, over a range of a few meters to several tens of meters, or even a hundred meters. The observation system 5 may include radar, lidar, and / or cameras. These various devices can provide complementary data. or redundant so as to improve the reliability of scene observation in front of the vehicle. The observation means 5 is specifically configured to detect the left and right edges of a road on which vehicle 1 is traveling. Finally, vehicle 1 includes an electronic control unit 4. The control device 3 and the observation means 5 are connected to the electronic control unit 4, for example by electrical cable harnesses.

[0027] The longitudinal axis X is defined as the axis along which the vehicle 1 moves in a straight line. The X axis is oriented towards the front of the vehicle. Left and right are defined from the point of view of a vehicle user seated in the vehicle and facing the direction in which the vehicle is moving forward.

[0028] The electronic control unit 4 comprises a memory 41, a microprocessor 42, and an input / output interface 43 adapted to receive data from other equipment of the vehicle 1, in particular from the observation means 5, and to transmit data to other equipment of the vehicle 1, in particular the control device 3. The memory 41 of the electronic control unit is a data storage medium on which a computer program is stored, comprising program code instructions for implementing a control method according to an embodiment of the invention. The microprocessor 42 is capable of executing this method. In particular, the electronic control unit 4 is capable of sending control commands to the control device 3 via its input / output interface 43 so as to control the vehicle's trajectory.The electronic control unit 4 can be integrated into a single computer on board the vehicle 1, or distributed across several computers on board the vehicle 1. In this second scenario, the different computers are connected, for example via a data bus, in order to exchange digital information.

[0029] Figure 2 illustrates, from a top view, vehicle 1 on a road 6, i.e., a drivable surface, on which vehicle 1 is traveling. Road 6 has a left edge 6G and a right edge 6D. The left edge 6G and / or the right edge 6D correspond to physical boundaries of the road. Depending on the type of road considered, the edges 6G and 6D may, for example, correspond to painted markings on the ground, for example, white or yellow, to boundaries of a drivable surface such as boundaries separating an asphalt surface from unasphalted surfaces, or to barriers. Road 6 has a widening 7 in front of vehicle 1. The widening 7 is an area of ​​road 6 in which the width L1 separating the left edge 6G and the right edge 6D increases with the direction of travel of the vehicle. The width L1 is measured perpendicular to the X axis.In this particular case, the widening 7 corresponds to a transitional zone of the route 6 before it includes two traffic lanes 8G, 8D side-by-side. The two traffic lanes 8G and 8D can be separated from each other by a separation element 9, such as a painted lane line, a central reservation, or any other obstacle. The separation element 9 is positioned further forward relative to the widening 7.

[0030] When vehicle 1 moves forward, it must therefore choose between the left lane 8G or the right lane 8D in order to avoid colliding with or crossing the separation element 9. To this end, a control method according to an embodiment of the invention is implemented. This method will now be described with reference to Figures 3 and 4.

[0031] In a first step El, the observation means 5 observes the road 6 on which the vehicle 1 is traveling. The observation means 5 then emits digital signals which are received by the electronic control unit 4.

[0032] Next, in a second step E2, the left edge 6G and the right edge 6D of route 6 are detected. The edges 6G, 6D can be modeled by a set of points in space whose coordinates are determined. Alternatively or in addition, the edges 6G, 6D can be modeled by mathematical functions, for example, clothoid or polynomial functions.

[0033] Next, in a third step E3, a widening of the road 6 in front of the vehicle is detected, i.e., the presence of the widening 7 described earlier is detected. To detect the widening 7, in a first substep E31, the width L1 of the road can be estimated at at least one position in front of the vehicle based on the left edge 6G and the right edge 6D. Then, in a second substep E32, the width L1 is compared with a predefined threshold. The predefined threshold can be a fixed value stored in memory 4L. If the width L1 is greater than or equal to the predefined threshold, then a widening is detected.

[0034] Advantageously, it is possible to record several width thresholds, each threshold being associated with a particular road type. In this case, the third step E3 also includes a substep E33 for detecting the type of road on which the vehicle is traveling. Road type detection can be performed based on data provided by the observation means 5 and / or by combining vehicle geolocation with map data. Step E33 is then executed before step E32. During step E32, the road width L1 is compared with the threshold corresponding to the previously detected road type. This embodiment allows for more precise detection of the presence of a widening. For example, a highway lane usually has a width of 3.50 m.When a vehicle is travelling on a motorway, for example, one can conclude that there is a widening if the width of the lane becomes greater than or equal to 3.85m.

[0035] Preferably, during the third step El, the width L1 of the road can be detected at several positions in front of the vehicle, and the comparison of the width with the predefined threshold(s) for each of the detected widths can be repeated. This improves the reliability of the widening detection.

[0036] Alternatively, or in addition to the method described above, the widening 7 can be detected simply by comparing the width L1 of the road at different positions more or less distant from the vehicle. A widening can thus be detected if the road width at a first position is strictly less than the road width at a second position, the second position being further from the vehicle 1 than the first position. This second method therefore comprises a first substep E34 of estimating the width L of the road at at least two positions in front of the vehicle, followed by a second substep E35 of comparing the road width at the first position with the road width at the second position. For example, the presence of a widening can be confirmed if the road width at the second position is greater than or equal to 110% of the road width at the first position.This threshold can be modified by parameter settings. This second method has the advantage of being independent of any predefined threshold. Advantageously, this second method is also implemented by comparing the road width at a greater number of positions in front of the vehicle, in order to improve the reliability of widening detection.

[0037] Next, in a fourth step E4 following the third step E3, a first virtual lane 11 is defined. The first virtual lane 11 does not correspond to a physically marked traffic lane on the road 6 in front of the vehicle. The first virtual lane 11 does not result from the prior detection, by the observation means 5, of an actual traffic lane. On the contrary, the first virtual lane 11 is defined digitally in the memory 41 of the electronic control unit 4, in particular on the basis of the previously detected edges 6G and 6D.

[0038] The virtual lane 11 can be defined by a set of numerical characteristics, preferably presented according to a codified standard. In particular, with reference to [Fig. 4], the first virtual lane 11 comprises a right edge 11D and a left edge 1IG. As with the edges 6G and 6D, the edges 1IG and 11D can be defined as a set of points in space, and / or by mathematical functions, for example, clothoid or polynomial functions. The right edge 11D and the left edge 1IG of the first virtual lane are defined in terms of the right edge 6D of the lane 6. In contrast, the right edge 11D and the left edge 1IG of the first virtual lane are not defined in terms of the left edge 6G of the lane 6.

[0039] The fourth step E4 may include a first substep E41 for defining the right edge 11D of the first virtual lane 11. The right edge 11D may be defined as being identical to the right edge 6D of the lane 6 already detected. Alternatively, the right edge 11D could be slightly offset relative to the right edge 6D and / or be smoothed relative to the right edge 6D.

[0040] Next, in a second substep E42, a width LD of the first virtual lane IL is defined. By analogy with the third step E3, the width LD can be defined as a function of the width of the road 6 upstream of the widening 7, i.e., behind the widening 7, this width being detected by the observation means 5. Alternatively or in addition, the width LD can be defined as a function of a previously detected type of the road 6. The type of the road 6 can be detected by the observation means 5 or by a geolocation means associated with mapping data. Assuming that the observation means 5 could detect the width of the traffic lane 8D downstream of the widening 7, then the width LD could be defined as being equal to the width of the traffic lane 8D.In any event, the width LD of the first virtual lane 11 is less than or equal to the width L1 of the road 6 in front of the vehicle for any longitudinal position.

[0041] Next, in a third substep E43, the left edge 1 IG of the first virtual lane 11 is defined. The left edge 1 IG is also defined in terms of the right edge 6D of the road and in terms of the width L1 of the first virtual lane 11. The left edge 1 IG is not defined in terms of the left edge 6G of the road 6. In particular, the left edge 1 IG can be defined by a left offset of the right edge 6D of the road, said left offset being defined in terms of the width LD of the first virtual lane 11. Advantageously, the left edge 1 IG can be defined such that the distance separating the left edge 1 IG from the right edge 11D is equal to the predefined width LD, at every point.

[0042] In a fifth step E5, also subsequent to the third step E3, a second virtual lane 12 is defined. The second virtual lane 12 can be defined in the same way as the first virtual lane 11, but this time with reference to the left edge 6G instead of the right edge 6D of the route 6. The second virtual lane 12 also includes a right edge 12D and a left edge 12G and a width LG. The right edge 12D and the left edge 12G are therefore defined with respect to the left edge 6G of the route 6, and not with respect to the right edge 6D. The method for defining the second virtual lane 12 can be analogous to the method for defining the first virtual lane 11. In particular, the fifth step E5 can also include substeps E51, E52, and E53, which are transposed from the substeps E41, E42, and E43 described previously.

[0043] The fifth step E5 can be executed simultaneously with the fourth step E4, or just before the fourth step E4, or even just after the fourth step E4. The terms "first" and "second" thus do not confer any preference relationship between the two steps E4 and E5.

[0044] Finally, the first virtual lane 11 and the second virtual lane 12 are therefore defined in front of the vehicle 1 over a distance that can correspond to the ability of the observation means 5 to reliably detect the right edge 6D or respectively the left edge 6G of the road 6.

[0045] Next, in a sixth step E6, the two virtual lanes 11, 12 are used by a vehicle trajectory planning module.

[0046] The sixth step E6 may include a first substep E61 in which the definitions of the virtual lanes 11, 12 are transmitted to the vehicle trajectory planning module. The virtual lanes 11, 12 can be transmitted to the vehicle trajectory planning module in exactly the same way as if these two lanes resulted from the detection of actual traffic lanes. Thus, the trajectory planning module can operate in the ordinary manner. The implementation of the invention makes it possible to avoid modifying the part of the computer program corresponding to the trajectory planning module.

[0047] The sixth step E6 may then include a second substep E62 in which the planning module selects one virtual lane from among the two virtual lanes 11, 12. This selection can be made in the same way as if these two virtual lanes were actually marked on the road 6. To choose between the two virtual lanes 11, 12, the trajectory planning module may query an on-board navigation system in the vehicle and / or consult data provided by an on-board navigation system in the vehicle. If the vehicle does not have a navigation system or if it lacks instructions, the right-hand virtual lane could be automatically selected when the vehicle is traveling in a country where traffic laws mandate driving on the right-hand side of the road by default.Conversely, the virtual left lane could be automatically selected when the vehicle is travelling in a country where the motoring legislation mandates driving on the left side of the road by default.

[0048] Next, the sixth step E6 may include, in a third substep E63, the determination of a trajectory to be followed by the vehicle 1 to follow either the first virtual lane 11 or the second virtual lane 12. For example, the trajectory may be defined so that the vehicle 1 positions itself in the center of the first virtual lane 11 or in the center of the second virtual lane 12.

[0049] Following the sixth step E6, the control method includes a seventh step E7 of automatic control of the vehicle steering system, in particular of the control device 3, to orient the steering wheels so that the vehicle 1 follows the trajectory determined in substep E63.

[0050] As can be seen in [Fig. 4], the first virtual lane 11 and the second virtual lane 12 each comprise a first portion 111, 121 followed by a second portion 112, 122. The first portions 111, 121 are located upstream of the widening 7. The first portion 111 of the first virtual lane 11 is substantially coincident with the first portion 121 of the second virtual lane 12. The second portions 112, 122 are located at the widening 7. The second portion 112 of the first virtual lane 11 diverges from the second portion 122 of the second virtual lane 12. The first virtual lane 11 and the second virtual lane 12 may also each comprise a third portion 113, 123 extending respectively into the actual traffic lanes 8G, 8D.

[0051] Finally, thanks to the invention, smooth and safe vehicle trajectory control is achieved. The vehicle's trajectory is free of jolts or changes of direction that could alarm vehicle users or even endanger them.

[0052] Figure 5 now illustrates a second use case of the invention. To describe this second use case, the same references will be used as for the description of the first use case above. According to the configuration of Figure 5, the road splits not into two parallel traffic lanes 8G, 8D, but into two substantially perpendicular traffic lanes 8G, 8D. To use traffic lane 8G, the vehicle must continue straight ahead. To use traffic lane 8D, the vehicle must turn right. The intersection between the two traffic lanes 8G and 8D locally forms a widening 7 that can be detected by the observation means 5. The first virtual lane 11 can then be defined in terms of the right edge 6D of the road 6, which has an angle of approximately 90°. Thus, the first virtual lane 11 will also have an angle of approximately 90°.A smoothing algorithm can nevertheless be implemented to increase the radius of curvature of the first virtual lane while maintaining the first virtual lane 11 within the boundaries of route 6. The second virtual lane 12 can be defined based on the left edge 6G of route 6, and thus be a straight lane. The invention can also be adapted for other use cases where a route 6 splits into two traffic lanes, the two traffic lanes forming any angle between them.

Claims

Demands

1. A method for controlling a motor vehicle (1), characterized in that it comprises: - observing a road (6) on which the vehicle is traveling with an observation means (5) mounted in the vehicle, then - detecting a left edge (6G) and a right edge (6D) of the road, then - detecting a widening (7) of the road in front of the vehicle, then - defining a first virtual lane (11), the first virtual lane comprising a right edge (11D) and a left edge (11IG), the right and left edges of the first virtual lane being defined as a function of the right edge (6D) of the road, and - defining a second virtual lane (12), the second virtual lane comprising a right edge (12D) and a left edge (12G),the right and left edges of the second virtual lane being defined in relation to the left edge (6G) of the road, then - the transmission of the first virtual lane (11) and the second virtual lane (12) previously defined to a vehicle trajectory planning module.

2. A control method according to the preceding claim, characterized in that said detection of the road widening (7) in front of the vehicle comprises: - estimating a road width (Ll) in at least one position in front of the vehicle as a function of the previously detected left edge (6G) and right edge (6D) of the road, then comparing the road width (Ll) with a predefined threshold, in particular a predefined threshold based on a previously detected road type, and / or - estimating a road width (Ll) in at least a first and a second position in front of the vehicle as a function of the previously detected left edge (6G) and right edge (6D) of the road, then comparing the road width in the first position with the road width in the second position.

3. A control method according to any one of the preceding claims, characterized in that the definition of the first virtual lane (11) comprises: - the definition of a width (LD) of the first virtual lane, then - the definition of the left edge (1 IG) of the first virtual lane as a function of the right edge (6D) of the road and as a function of the width (LD) of the first virtual lane, and / or in that the definition of the second virtual lane (12) comprises: - the definition of a width (LG) of the second virtual lane (12), then - the definition of the right edge (12D) of the second virtual lane as a function of the left edge (6G) of the road and as a function of the width (LG) of the second virtual lane.

4. Control method according to the preceding claim, characterized in that: - the width (LD) of the first virtual lane (11) is defined as a function of a road width (6) upstream of the widening (7) and / or as a function of a predefined width according to a previously detected road type, and / or in that: - the width (LG) of the second virtual lane (12) is defined as a function of a road width (6) upstream of the widening (7) and / or as a function of a predefined width according to a previously detected road type.

5. Control method according to claim 3 or 4, characterized in that: - the definition of the left edge (1 IG) of the first virtual lane (11) includes a left offset of the right edge (6D) of the road, said left offset being defined as a function of the width (LD) of the first virtual lane, and / or in that - the definition of the right edge (12D) of the second virtual lane (12) includes a right offset of the left edge (6G) of the road, said right offset being defined as a function of the width (LG) of the second virtual lane.

6. A control method according to any one of the preceding claims, characterized in that the first virtual channel and the second virtual channel each comprise a first portion followed by a second portion, the first portion of the first virtual channel being confused with the first portion of the second virtual track, the second portion of the first virtual track diverging from the second portion of the second virtual track.

7. A control method according to any one of the preceding claims, characterized in that it subsequently comprises: - a step of determining the trajectory of the vehicle by the vehicle trajectory planning module, the trajectory being determined either to follow the first virtual lane or to follow the second virtual lane, and then - the automatic control of a vehicle steering system to follow the previously determined trajectory.

8. Motor vehicle comprising an observation means on-board in the vehicle and hardware and software means configured to implement the control method according to any one of the preceding claims.

9. Product computer program comprising program code instructions recorded on a computer-readable medium to implement the steps of the control process according to any one of claims 1 to 7 when said program is running on a computer.

10. A computer-readable data recording medium on which is recorded a computer program comprising program code instructions for implementing the control method according to any one of claims 1 to 7.

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