FR3065933A1 - SYSTEM FOR POSITIONING AN AUTONOMOUS VEHICLE ON A CIRCULATION PATH - Google Patents

Abstract

The subject of the invention is a method for the autonomous driving of a motor vehicle on the traffic lane. The vehicle is initially maintained in a centered position of the track. The method describes the steps (2, 3, 4) of changing from the centered lateral position instruction to an off-centered position instruction, under the condition of a torque being exerted by the driver (2). The torque condition includes torque and time thresholds. A man-machine communication interface enables the driver to be alerted to these steps for changing the position setpoint. The method further comprises a step of taking back control (5) of the pipe if the torque is exerted beyond a certain duration.

Description

Holder (s): PEUGEOT CITROËN AUTOMOBILES SA Société anonyme.

O Extension request (s):

® Agent (s): PEUGEOT CITROËN AUTOMOBILES SA Public limited company.

(54) SYSTEM FOR POSITIONING A SELF-CONTAINED VEHICLE ON A TRACK.

FR 3 065 933 - A1 (57) The subject of the invention is a method of autonomous driving of a motor vehicle on the traffic lane. The vehicle is initially kept in a centered position on the track. The method describes the steps (2, 3, 4) of changing the set lateral position setpoint towards an off-center position setpoint, under the condition of torque exerted by the driver (2).

The torque condition includes torque and time thresholds. A man-machine communication interface allows the driver to be alerted of these position setpoint change steps. The method further comprises a step of taking back in hand (5) of the pipe if the torque is exerted beyond a certain duration.

POSITIONING SYSTEM OF A SELF-CONTAINED VEHICLE ON A TRACK

TRAFFIC

The invention relates to the field of autonomous driving of a motor vehicle on a traffic lane, more particularly to methods of autonomous control of the lateral dynamics of a motor vehicle.

Patent document US Pat. No. 5,765,116 discloses a driver assistance system for an autonomous vehicle. A sensor system associated with a processor makes it possible to determine the position of the vehicle relative to the lane marking lines. The assistance system also includes an electric motor intended to apply a torque to the steering mechanism, whether to assist or to oppose the torque exerted by the driver on the steering wheel.

This state-of-the-art document is interesting in that it provides an assistance system making it possible to keep the vehicle at a certain safety distance from the lane marking lines. However, this system does not allow programming of a lateral repositioning of the vehicle on the taxiway, while maintaining the autonomous driving mode.

Within the framework of automated level 2 OICA driving (acronym for "International Organization of Automobile Manufacturers"), the driver can delegate all or part of the operational driving tasks to autonomous vehicle controls, such as acceleration, braking or handling the steering wheel. However, there is no time limit to notify the driver when the vehicle ceases to control the steering independently. The driver therefore remains responsible for driving.

In the case of OICA level 3 automated driving, the driver no longer performs operational tasks, but only those of a tactical level, such as changing gears, overtaking another vehicle, or positioning on the way. The driver is authorized not to hold the steering wheel to perform other tasks in parallel. If necessary or if the driver wishes, he has a certain period of time to take control of the vehicle. This process, called "Give Back" and meaning "Takeover", is signaled by an alert. Part of the driving responsibility lies with the autonomous driving system.

Driving in autonomous mode involves positioning the vehicle in the center of the lane. If the driver wishes to position himself on one side of the track, for comfort when overtaking another vehicle or for personal preference, he exerts a slight torque on the steering wheel to shift. The autonomous driving mode remains activated. If the torque exerted is above a certain limit, the autonomous driving mode is deactivated.

This has the drawback that the driver has to keep his hands on the steering wheel and continuously exert a slight torque if he wishes to stay offset from the center of the lane permanently, without deactivating the autonomous mode. Otherwise, if it exerts a torque above a certain threshold, the autonomous driving mode is deactivated, and the driver must resume control of the vehicle. Consequently, it is not possible to benefit from autonomous driving in the event of long repositioning of the vehicle on the track.

The object of the invention is to overcome at least one drawback of the above-mentioned state of the art. More particularly, the invention aims to provide a method for autonomous driving of a motor vehicle which makes it easier to drive in the off center position on a traffic lane.

The subject of the invention is a method of autonomous driving of a motor vehicle on a traffic lane, comprising the following step: controlling the direction of the vehicle so as to maintain said vehicle in accordance with a central position setpoint on the lane traffic; remarkable in that it further comprises the following step: controlling the direction of the vehicle so as to maintain said vehicle in accordance with an off-center position instruction on the taxiway, provided that a torque is exerted by the driver on the steering wheel so as to move the vehicle from a central position to said position.

By central position on the track means a neutral or reference position, close to a perfectly central position, and giving enough space to allow a lateral shift of the vehicle in at least one direction.

According to an advantageous embodiment of the invention, the condition of the couple comprises the exercise of said couple during a period greater than or equal to a value t ₂ .

According to an advantageous embodiment of the invention, the value t ₂ is between 3 and 5 seconds, preferably between 3.5 and 4.5 seconds. It is advantageously of the order of 4 seconds.

According to an advantageous embodiment of the invention, the condition of the couple comprises the exercise of said couple during a period less than or equal to a value t3.

According to an advantageous embodiment of the invention, the value t3 is between 5 and 7 seconds, preferably between 5.5 and 6.5 seconds. It is advantageously of the order of 6 seconds.

According to an advantageous embodiment of the invention, the method further comprises the step of deactivating the steering of the vehicle when the torque exerted by the driver on the steering wheel so as to move the vehicle towards said position is maintained for a period greater than or equal to the value t3.

According to an advantageous embodiment of the invention, said method further comprises the step of transmitting a signal to the driver when the torque exerted by the driver on the steering wheel so as to move the vehicle towards the off center position is maintained during a period greater than or equal to a value ti, said signal expressing a passage in progress from the control of the direction of the vehicle according to the central position setpoint to the control of the direction of the vehicle according to the offset position setpoint.

According to an advantageous embodiment of the invention, when the torque exerted by the driver on the steering wheel so as to move the vehicle towards the off-center lateral position is for a period less than the value ti, the vehicle begins to return and stabilize around the central position.

According to an advantageous embodiment of the invention, the value ti is less than the value t ₂ .

Advantageously, the value ti is between 1 and 3 seconds, preferably between 1.5 and 2.5 seconds. It is advantageously of the order of seconds.

According to an advantageous embodiment of the invention, the signal sent to the driver is a visual signal expressing the lateral side of the shift and / or the imminent nature of a change of position setpoint, by a flashing effect and / or by means of 'a cursor.

The invention also relates to a motor vehicle comprising an electrically controlled steering, an autonomous driving system with a man-machine interface and a computer connected to said interface and to said direction, remarkable in that the computer is configured to execute the method described above according to the invention.

The measures of the invention are advantageous in that they make it possible to continue to benefit from the autonomous driving mode in a lateral position different from that set by default in the system which generally corresponds to a central lateral position of the taxiway.

This characteristic therefore allows driving adapted to different situations, in particular when the driver wishes to shift in the event of a long overtaking maneuver or personal driving preference. The temporal logic of the process makes it possible to propose to the driver to lock the new position of the vehicle, while leaving the possibility of deactivating the autonomous driving mode and regaining control of the driving.

The method also provides alerts sent to the driver in order to communicate the various stages of the method and to optionally signal the imminent change in the control of the direction.

This process can be implemented as part of an autonomous driving level 2 and 3 according to OICA regulations.

Other characteristics and advantages of the present invention will be better understood from the description and the drawings, among which:

- Figure 1 illustrates the positioning of the vehicle on the taxiway;

- Figure 2 is a diagram representing the different stages of the process;

- Figure 3 is a view of the communication interface according to a version;

- Figure 4 is a view of the communication interface according to another version;

- Figure 5 shows the functional logic of the recovery phase.

FIG. 1 illustrates the positioning of the vehicle 10 on the track. Autonomous vehicle controls act to stabilize the vehicle in the center of the lane. The vehicle can however be shifted following the application to the steering wheel of a torque greater than a certain threshold. The position of the vehicle must however remain within a safety band, the limits of which are located at a given distance from the edges of the taxiway. This distance is preferably between 70 and 80cm.

FIG. 2 is a diagram representing the stages of the process of the invention as well as their temporal logic. When the driver applies to the steering wheel a torque exceeding a predefined threshold, the vehicle 10 starts to move and is offset from its current position. If this torque is applied for a period less than a value ti, it is a point shift, followed by a return to the center of the track, under the autonomous controls of the vehicle 10. This step is designated under the name of “punctual override” 2, the term “override” signifying that the piloting of the vehicle by the driver has temporary priority over autonomous piloting.

If this torque is maintained for a period greater than ti, the driver is alerted of an imminent change in the setpoint from a centered lateral position to an off-centered lateral position. This step is designated by the name of “transient state” 3. In a preferred embodiment of the invention, ti is equal to 2 seconds.

When the action time of the hands at the wheel is greater than a duration t2, equal to 4 seconds in a preferred embodiment of the invention, the locking 4 of the current position of the vehicle is activated. The lateral direction control acts according to an offset lateral position setpoint. This locking of the new position is expressed on the man-machine communication interface (HMI).

On the other hand, if the torque is maintained beyond a duration t ₃ , equal to 6 seconds in a preferred embodiment of the invention, the autonomous driving mode is deactivated, and a recovery phase 5 is launched. The driver resumes manual control of the vehicle's steering functions at the end of this recovery phase 5.

FIG. 3 is a view of the man-machine communication interface (HMI) according to a version of “loading gauge” or even of a cursor. This gauge is represented by three bars of equal dimensions, arranged horizontally at the bottom of the screen. The vehicle is initially positioned in the center of track 1 and is under the control of autonomous controls. This state 1 is expressed by a visual signal on the interface, which here corresponds to a fully filled central bar.

When the torque exerted on the steering wheel is greater than a torque threshold, the central bar, previously filled, is "unloaded". Its condition is similar to the rest of the bars on the gauge. This visual representation materializes the fact that the vehicle is removed from its central position, and that it is performing a temporary overtaking maneuver, known as a "punctual override" 2.

When the vehicle enters transient state 3 following the occasional Override, the interface signals the imminent change in the lateral position setpoint. This message is visually illustrated by a side bar which gradually fills between 2 and 4 s (in this case half filled), on the side of the track where the vehicle is shifted.

The final change in the lateral position setpoint 4 is illustrated by the complete loading of the bar corresponding to the actual position of the vehicle relative to the center of the track. Autonomous driving operates in this new locked position.

FIG. 4 is a view of the man-machine communication interface according to a version of "ghost vehicle". For maximum safety, the driver continuously monitors the system through an interactive communication interface: the dashboard allows information from external sensors to be displayed, facilitating decision-making. The man-machine interface allows the driver to communicate various graduated alerts, linked to the transitions of the autonomous driving system as well as to the external driving environment, to guarantee its responsiveness and program a manual intervention if necessary.

In initial state 1, the vehicle is shown in the center of the lane. The edges of it are illustrated by side bands.

When a specific Override 2 maneuver is performed, the initial image of the vehicle is shifted on the track in the direction of the actual movement of the vehicle, resulting from the torque exerted on the steering wheel and exceeding a threshold value. A transparent, vehicle-like image appears simultaneously where the vehicle was before the start of the One-time Override maneuver. This image is called "ghost image", and is fixed. It is likely to disappear if the driver ceases to exert torque according to the conditions provided by the process (Figure 2) and the vehicle stabilizes around its initial central position.

When the vehicle enters transient state 3, the interface signals the imminent change in the lateral position setpoint, by the flashing of the ghost image, the vehicle always being represented by an opaque and fixed image. This visual message prepares its disappearance from the screen, and corresponds to the transition of the setpoint from a central position to an off-center position.

When the setpoint change is made 4, the ghost image disappears, and the vehicle is represented by an opaque image, its location on the screen corresponding to the actual position of the vehicle relative to the center of the lane. Autonomous driving operates in this new locked position.

FIG. 5 represents the functional logic of the recovery phase, according to an implementation mode compatible with the method of the invention. As long as the steering wheel operation does not exceed a period t3 (2, 3, 4), the interface visually signals to the driver that autonomous driving is activated by a written message "You are on control" meaning "You are in control " When the maneuver on the steering wheel lasts beyond a period t3, a recovery phase 5 is launched, and is signaled by an alert mechanism on the interface, in the form of a countdown and d 'a written message "Take control >> meaning" Take orders >>. This mode of implementation is possible thanks to the compatibility of the temporal logics of each of the phases of override and recovery. Thus, a need for a long override, linked for example to a flow of motorcycles between two lanes, is not immediately interpreted as a request for recovery. The process of the invention can therefore be implemented within the framework of level 3 of the OICA regulations.

Claims (10)

Claims 1. Method for autonomous driving of a motor vehicle (10) on a traffic lane, comprising the following step: - control (1) of the vehicle direction so as to maintain said vehicle in accordance with a central position instruction on the taxiway; characterized in that the method further comprises the following step: - control (4) of the direction of the vehicle so as to maintain said vehicle according to an off-center position instruction on the taxiway, provided that a torque is exerted by the driver on the steering wheel so as to move (2) the vehicle to said position. 2. Method according to claim 1, characterized in that the condition of the torque comprises the exercise of said couple during a period greater than or equal to a value t ₂ . 3. Method according to claim 2, characterized in that the value t ₂ is between 3 and 5 seconds, preferably between 3.5 and 4.5 seconds. 4. Method according to one of claims 1 to 3, characterized in that the condition of the couple includes the exercise of said couple during a period less than or equal to a value t3. 5. Method according to claim 4, characterized in that the value t3 is between 5 and 7 seconds, preferably between 5.5 and 6.5 seconds. 6. Method according to claim 5, characterized in that said method further comprises the following step (5): - deactivation of the vehicle's steering when the torque exerted by the driver on the steering wheel so as to move the vehicle to said position is maintained for a period greater than or equal to the value Î3- 7. Method according to one of claims 1 to 6, characterized in that said method further comprises the following step (3): - emission of a signal to the driver when the torque exerted by the driver on the steering wheel so as to move the vehicle to the off-center position is maintained for a period greater than or equal to a value ti, said signal expressing a passage during the command of the vehicle direction according to the central position command to the command of the vehicle direction according to the off-center position command. 8. Method according to claim 7, characterized in that the value ti is between 1 and 3 seconds, preferably between 1.5 and 2.5 seconds. 9. Method according to one of claims 7 and 8, characterized in that the signal sent to the driver is a visual signal expressing the lateral side of the shift and / or the imminent nature of a change of position setpoint, by an effect flashing and / or by means of a cursor. 10. Motor vehicle (1) comprising an electrically controlled steering, an autonomous driving system with a man-machine interface and a computer connected to said interface and to said direction, characterized in that the computer is configured to carry out the method according to one of claims 1 to 9. 1/3