Automatic vehicle trajectory control method

Abstract

Method for automatically controlling the trajectory of a vehicle. One aspect of the invention relates to a method for automatically controlling the trajectory of a vehicle (200) traveling on a lane (201) with a curve (2010), comprising the following steps: Detection (101) of the presence of a curve (2010) on the lane (201); Activation (102) of a function for controlling the positioning of the vehicle (200) in the lane, resulting in the implementation of at least one step (1031, 1032, 1033) of progressively shifting the vehicle (200) towards a line (2011, 2012) delimiting the lane (201), before and / or during and / or after the curve (2010). Figure to be published with the abbreviation: Figure 2

Description

Title of the invention: Method for automatically controlling the trajectory of a vehicle TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of safety functions in vehicles, and more particularly that of trajectory control functions in vehicles.

[0002] The present invention relates to a method for controlling the trajectory of a vehicle and, in particular, to an automatic method for controlling the trajectory of a vehicle traveling in a road with a curve. The invention also relates to a vehicle and a computer program for implementing the method. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] The lane centering function is a feature that allows a vehicle to be centered in the lane in which it is traveling, without the driver having to apply torque to the steering wheel.

[0004] A current problem with this function is that its scope of application is limited. Indeed, the function must comply with regulatory constraints, resulting in its deactivation for lateral accelerations of the vehicle exceeding 3 m / s².

[0005] Since the lateral acceleration of the vehicle is a function of the speed of the vehicle and the radius of curvature of the traffic lane, the lane centering function often deactivates in turns and the driver must then take back control of the vehicle to control its trajectory.

[0006] There is also an automatic speed regulation function which allows a vehicle to slow down to take a turn at a speed which ensures the comfort of the driver but it is not always possible to slow down the vehicle sufficiently without impacting the safety of the driver or other road users.

[0007] There is therefore a need for a method to automatically control the trajectory of a vehicle in a turn, which limits the risks for the driver and other road users. Summary of the invention

[0008] The invention offers a solution to the problems mentioned above, by allowing automatic control of the vehicle's trajectory in a turn without endangering the driver or other road users.

[0009] A first aspect of the invention relates to a method for automatically controlling the trajectory of a vehicle traveling on a road with a curve, comprising the following steps: • Detection of the presence of a bend in the track; • Activation of a vehicle positioning control function within the lane resulting in the implementation of at least one step of progressively shifting the vehicle towards a line delimiting the lane, before and / or during and / or after the turn.

[0010] Thanks to the invention, a lane positioning control function is activated, and the vehicle is progressively shifted to one side of the lane to reduce its lateral acceleration by adjusting the radius of curvature, while ensuring that the vehicle remains within the lane. This allows the vehicle to move away from the speed limit without having to reduce its speed and without the driver having to take control of the vehicle.

[0011] In addition to the characteristics mentioned in the preceding paragraph, the process according to the invention may have one or more additional characteristics from among the following, considered individually or according to all technically possible combinations.

[0012] According to one embodiment, the step of activating the vehicle positioning control function in the lane is carried out if an estimated lateral acceleration of the vehicle in the turn is greater than a threshold.

[0013] Thus, the vehicle positioning control function in the lane is only activated if the value of the lateral acceleration in the turn would cause the lane centering function to be deactivated.

[0014] According to an embodiment compatible with the previous embodiment, the method according to the invention comprises a first step of shifting the vehicle towards a lane line located outside the curve before the curve, then a second step of shifting the vehicle towards a lane line located inside the curve during the curve, then a third step of shifting the vehicle towards the lane line located outside the curve after the curve.

[0015] Thus, the radius of curvature is increased and the lateral acceleration is decreased while increasing the driver's visibility throughout the turn.

[0016] According to an embodiment compatible with the previous embodiments, the offset step is carried out if no obstacle is detected before and / or in the turn.

[0017] Thus, the shifting step is not carried out if an obstacle making the maneuver dangerous is detected.

[0018] According to an embodiment compatible with the previous embodiments, the shift step is performed if no contextual event is detected after the turn.

[0019] Thus, the shifting step is not carried out if a contextual event, such as the presence of a roundabout or a tollbooth after the turn, making the maneuver dangerous is detected.

[0020] According to an embodiment compatible with the previous embodiments, the method according to the invention includes a step of reducing a sensitivity threshold of a line crossing alert function.

[0021] Thus, reducing the sensitivity threshold of the line crossing alert function makes it possible to reduce the safety margin with respect to the lines delimiting the track.

[0022] According to an embodiment compatible with previous embodiments, the vehicle positioning control function in the lane is activated if a lane centering function is activated.

[0023] According to an embodiment compatible with the previous embodiments, the method according to the invention includes a step of centering the vehicle in the lane after the offset step.

[0024] A second aspect of the invention relates to a vehicle comprising means for implementing the method according to the invention.

[0025] A third aspect of the invention relates to a computer program product comprising instructions which, when the program is executed by a computer, lead the latter to implement the steps of the process according to the invention.

[0026] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0027] The figures are presented for illustrative purposes only and are in no way limiting of the invention. • The [Fig. 1] is a synoptic diagram illustrating the sequence of steps of a process according to the invention. • Fig. 2 shows a schematic representation of a vehicle on which the process according to the invention is applied, as a function of time. DETAILED DESCRIPTION

[0028] Unless otherwise specified, the same element appearing on different figures has a unique reference.

[0029] The invention relates to a method for automatically controlling the trajectory of a vehicle, i.e. without intervention by a driver of the vehicle.

[0030] The sequence of steps of process 100 is illustrated in [Fig.1] and their effects on vehicle 200 as a function of time are illustrated in [Fig.2].

[0031] Vehicle 200 travels on a lane 201 delimited by an outer line 2011 and an inner line 2012.

[0032] The term "outer line delimiting a track" means the line delimiting the track having the highest radius of curvature in the case where the track has a curve.

[0033] By contrast, the term "inner line delimiting a track" means the line delimiting the track with the smallest radius of curvature in the case where the track has a curve.

[0034] A first step 101 of the process 100 consists of detecting the presence of a curve 2010 on track 201.

[0035] The detection is carried out upstream of the turn 2010, that is to say before the vehicle 200 is engaged in the turn 2010.

[0036] Detection is carried out for example by consulting a map showing the route for each road in a set of roads in a given geographical area.

[0037] Knowing the location of vehicle 200, it is then possible to know that lane 201 will soon have a turn 2010.

[0038] A second step 102 of the process 100 consists of activating a vehicle positioning control function 200 in the lane.

[0039] Such activation is carried out automatically.

[0040] The vehicle positioning control function 200 in the lane is for example a function which allows vehicle 200, when a lane following assistance function is activated, to automatically move to one side of the lane to allow for example to let motorcycles pass between lanes, or to move away from a truck that is being overtaken.

[0041] The lane following assistance function is, for example, a lane centering function.

[0042] The second step 102 of the process 100 is carried out, for example, only if an estimated lateral acceleration of the vehicle 200 in the turn 2010 is greater than a threshold.

[0043] The threshold is for example 2.5 m / s2.

[0044] The lateral acceleration A of a vehicle in a turn is calculated as follows:

[0045]

[0046] With V the speed of the vehicle and R the radius of curvature of the turn.

[0047] The radius of curvature of the 2010 bend is obtained for example by consulting a map showing the route for each road in a set of roads in a given geographical area.

[0048] Knowing the location of vehicle 200, it is then possible to know that lane 201 will soon have a curve 2010 and the radius of curvature of this curve 2010.

[0049] Knowing the radius of curvature of the upcoming turn 2010 and the speed of vehicle 200, it is then possible to estimate the lateral acceleration of vehicle 200 in turn 2010.

[0050] Activation of the vehicle positioning control function 200 in the lane allows the implementation of the following steps of the method 100 according to the invention.

[0051] At least one step 1031, 1032, 1033 of progressive shifting of vehicle 200 towards a line 2011, 2012 delimiting the traffic lane 201 is implemented following the activation of the vehicle 200 positioning control function in the lane.

[0052] The offset step 1031, 1032, 1033 is carried out just before vehicle 200 enters turn 2010 and / or while vehicle 200 is travelling in turn 2010 and / or just after vehicle 200 exits turn 2010.

[0053] Vehicle 200 is considered to be travelling in the curve 2010 as soon as the radius of curvature of track 201 becomes non-zero.

[0054] According to an embodiment illustrated in [Fig.2], the method 100 according to the invention comprises a first step 1031 of shifting the vehicle 200 towards the outer line 2011 of the lane 201 just before the entry of the vehicle 200 into the curve 2010, then a second step 1032 of shifting the vehicle 200 towards the inner line 2012 of the lane 201 when the vehicle 200 is in the curve 2010, then a third step 1033 of shifting the vehicle 200 towards the outer line 2011 of the lane 201 just after the exit 200 of the vehicle 200 from the curve 2010.

[0055] On [Fig.2], the first shift step 1031 is implemented between times t0 and t1, the second shift step 1032 is implemented between times t1 and t2, then the third shift step 1033 is implemented between times t2 and t3.

[0056] According to an alternative embodiment, the offset step 1031, 1032, 1033 is only carried out if no obstacle is detected before and / or in the turn 2010 and / or if no contextual event is detected after the turn 2010.

[0057] The obstacle may be another vehicle, or a person or object located on lane 201 before turn 2010 or in turn 2010.

[0058] The contextual event may be the presence of a road feature, for example the presence of a toll plaza, a roundabout, a crossroads, or a hill, the presence of a road or local hazard event, for example the presence of an accident, a traffic jam, roadworks, or an object on the roadway, the presence of a weather event, for example the presence of fog or black ice, the presence of another vehicle nearby which has, for example, triggered an emergency stop function, after the 2010 bend.

[0059] Detection can be carried out by vehicle 200, for example via a sensor on vehicle 200, such as a camera, or by another vehicle that has reported detection information is sent to a shared alert database between a fleet of connected vehicles.

[0060] The method 100 according to the invention may include a step 1030 of reducing a sensitivity threshold of a line crossing warning function.

[0061] The sensitivity threshold goes for example from 0 cm to -30 cm.

[0062] The method 100 according to the invention may include a centering step 104 of the vehicle 200 in lane 201 after stage 1031, 1032, 1033 of offset.

Claims

Demands

1. Method (100) for automatically controlling the trajectory of a vehicle (200) travelling on a lane (201) with a curve (2010), comprising the following steps: • Detection (101) of the presence of a curve (2010) on the lane (201); • Activation (102) of a function for controlling the positioning of the vehicle (200) in the lane resulting in the implementation of at least one step (1031, 1032, 1033) of progressively shifting the vehicle (200) towards a line (2011, 2012) delimiting the lane (201), before and / or during and / or after the curve (2010).

2. Method (100) according to the preceding claim, wherein the step (102) of activating the vehicle (200) lane positioning control function is performed if an estimated lateral acceleration of the vehicle (200) in the turn (2010) is greater than a threshold.

3. A method (100) according to any one of the preceding claims, comprising, a first step (1031) of shifting the vehicle (200) towards a line (2011) of the lane (201) located outside the curve (2010) before the curve (2010), then a second step (1032) of shifting the vehicle (200) towards a line (2012) of the lane (201) located inside the curve (2010) during the curve (2010), then a third step (1033) of shifting the vehicle (200) towards the line (2011) of the lane (201) located outside the curve (2010) after the curve (2010).

4. Method (100) according to any one of the preceding claims, wherein the offset step (1031, 1032, 1033) is performed if no obstacle is detected before and / or in the turn (2010).

5. Method (100) according to any one of the preceding claims, wherein the shift step (1031, 1032, 1033) is performed if no contextual event is detected after the turn (2010).

6. Method (100) according to any one of the preceding claims, comprising a step (1030) of reducing a sensitivity threshold of a lane crossing warning function.

7. Method (100) according to any one of the preceding claims, wherein the vehicle positioning control function (200) in the lane is activated if a lane centering function is activated.

8. Method (100) according to any one of the preceding claims, comprising a step (104) of centering the vehicle (200) in the lane (201) after the step (1031, 1032, 1033) of offsetting.

9. Vehicle (200) comprising means for implementing the method (100) according to any one of the preceding claims.

10. Product computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the steps of the process (100) according to any one of claims 1 to 8.

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