RU2800838C2 - Method for calculation of vehicle lateral position - Google Patents

Abstract

FIELD: traffic optimization.

SUBSTANCE: group of inventions is related to a method for calculating the lateral position of a given vehicle in a traffic lane. The method comprises first, second, third and/or fourth stages. At the first stage, the first theoretical lateral position of the given vehicle on the lane is calculated depending on the lateral position on the lane of the vehicles in front of the given vehicle and/or the vehicles following behind the given vehicle. At the second stage, the second theoretical lateral position of the given vehicle on the traffic lane is calculated depending on the position of the vehicles on the traffic lanes adjacent to the specified traffic lane. At the third stage, the third theoretical lateral position of the given vehicle in the lane is calculated depending on the static obstacles found on the sides of the said lane. At the fourth stage, the lateral position of the given vehicle is calculated using the weighted average of the first lateral position, the second lateral position, and the third lateral position.

EFFECT: optimization of safe lateral distances with vehicles or obstacles is achieved.

12 cl, 7 dwg

Description

The field of technology to which the invention belongs

The invention relates to a method for calculating the lateral position of a motor vehicle, in particular an autonomous vehicle. The invention also relates to a motor vehicle, in particular an autonomous vehicle, comprising means for carrying out such a lateral position calculation method.

State of the art

Autonomous vehicles are equipped with vehicle environment tracking and servo steering. In particular, the trackers are configured to identify the lane in which the vehicle is located. The computing device, connected simultaneously with the tracking means and with the steering device, can control the steering device in such a way that the vehicle is kept in the center of the lane. In this regard, lane centering systems are known, also called the English expression "Lane Centering Assist" or LCA. Such systems are regulated by the regulations presented in regulation No. R79 of the United Nations Economic Commission for Europe.

However, known lane alignment systems do not naturally position an autonomous vehicle. The lateral position of the vehicle in the lane does not correspond to the position that the driver would choose if he could control the steering device himself. Thus, the autonomous vehicle does not merge with the traffic flow, and the risks of collision with other vehicles or objects may increase. In particular, known lane alignment systems do not allow the optimization of safe lateral distances with other vehicles or obstacles. In a traffic jam situation, the known systems also do not allow the vehicle to be shifted laterally to leave enough space for a motorcycle or special vehicles that pass along the line of vehicles.

Description of the invention

The invention aims to provide a method for calculating the lateral position of a motor vehicle that overcomes the aforementioned disadvantages and improves the known methods.

In particular, the first object of the invention is a method for calculating a lateral position of a vehicle that is reliable and safe.

The second object of the invention is a solution, which is a method for calculating the lateral position of the vehicle, which facilitates the movement of other road users.

Disclosure of the essence of the invention

The invention relates to a method for calculating the lateral position of a given vehicle in a traffic lane, the method comprising:

- the first step of calculating the first theoretical lateral position of a given vehicle in a specified lane depending on the lateral position in a specified lane of vehicles in front of this vehicle and/or vehicles following behind this vehicle, and/or

- the second step of calculating the second theoretical lateral position of the given vehicle on the specified lane, depending on the position of the vehicles on the lanes adjacent to the specified lane,

- the third step of calculating the third theoretical lateral position of this vehicle on the specified lane depending on the static obstacles detected on the sides of the specified lane,

- the fourth step of calculating the lateral position of the given vehicle using the weighted average of the first lateral position, the second lateral position and the third lateral position.

The first calculation step may comprise a sub-step of calculating the weighted average lateral positions of preceding vehicles and/or vehicles following behind in the indicated lane, wherein the weighting factors of each lateral position are a function of the longitudinal distance separating the given vehicle from the considered vehicle in front and/or from the vehicle under consideration at the rear, and as a function of the speed of the preceding vehicle under consideration and/or the following vehicle under consideration.

The second stage of the calculation may include:

- the sub-step of calculating the theoretical safe corridor on both sides of the dividing line, while the dividing line is located between the lane of the given vehicle and the lane adjacent to the lane of the given vehicle,

- a sub-step of detecting the presence of a vehicle in a safe corridor,

- a sub-step of calculating the second theoretical lateral position depending on the distance separating the given vehicle from the vehicle detected in the specified safe corridor and depending on the speed of the vehicle detected in the specified safe corridor.

The calculation method may comprise a first execution condition for the calculation method, wherein the first execution condition is met:

- if the dividing lines of the traffic lane of this vehicle are detected by this vehicle, and

- if the lane curvature of the given vehicle is less than or equal to a predetermined threshold.

The calculation method may comprise a second execution condition for the first calculation step, wherein the second execution condition is met:

- if at least the first vehicle is detected in front of this vehicle,

- if at least a second vehicle is detected in front of or behind this vehicle, and

- no blinking signal of this vehicle is activated.

The fourth stage of the calculation may include:

- a sub-step of detecting the driving conditions of a given vehicle, and

- a sub-step of calculating a first theoretical lateral position weight, a second theoretical lateral position weight, and a third theoretical lateral position weight depending on the detected driving conditions of the vehicle.

The fourth stage of the calculation may include:

- a sub-step of limiting the deviation between the theoretical lateral position of the given vehicle and the theoretical center line of the lane of the given vehicle, and/or

- a sub-step of limiting the change in time of the theoretical lateral position of the given vehicle.

The calculation method may include:

- the fifth stage of autonomous control of the steering device of this vehicle, in order to make this vehicle take the theoretical lateral position calculated during the fourth stage,

- the sixth stage of displaying on the screen of this vehicle a visual indication of the relative position of this vehicle relative to the theoretical center line of the lane of this vehicle.

The subject of the invention is also a computer program product containing command codes of a program recorded on a computer-readable medium for carrying out the steps of the aforementioned method when said program is running on the computer. The object of the invention is also a computer program product downloadable remotely from a communication network and/or recorded on a data carrier readable by a computer and/or executable by a computer, wherein the software product contains instructions that, when the program is executed by the computer, allow it to carry out the above method.

The subject of the invention is also a computer-readable data recording medium on which a computer program is recorded containing the command codes of the program for implementing the aforementioned method, or a computer-readable recording medium containing instructions that, when the program is executed by the computer, allows it to carry out the aforementioned method.

The subject of the invention is also a data carrier signal containing the aforementioned computer program product.

The subject of the invention is also a steering system comprising a computing device, a steering device controlled by the computing device, and environmental tracking means, wherein the tracking means are connected to the computing device, wherein the computing device is configured to implement the above calculation method.

The object of the invention is also a motor vehicle, in particular, an autonomous vehicle, containing a computing device, a steering device controlled by a computing device, and means for tracking the environment of the vehicle, while the tracking means are connected to a computing device, while the computing device is configured to implement the above calculation method.

Description of drawings

These objects, features and advantages of the present invention will be described in detail in the following description of a particular embodiment, presented as a non-limiting example with reference to the accompanying figures, in which:

Fig. 1 is a schematic view of a motor vehicle according to an embodiment of the invention.

Fig. 2 is a schematic plan view of a three-lane road on which the claimed vehicle and surrounding vehicles travel.

Fig. 3 is a flowchart of a method for calculating a lateral position according to an embodiment of the invention.

Fig. 4 is a schematic plan view of a first example of a driving situation.

Fig. 5 is a schematic plan view of a second example of a driving situation.

Fig. 6 is a schematic plan view of a third example of a driving situation.

Fig. 7 is a schematic plan view of a fourth example of a driving situation.

Implementation of the invention

In FIG. 1 schematically shows a motor vehicle 1 according to an embodiment of the invention. Vehicle 1 can be anything. In particular, it may be a car, commercial vehicle, truck or bus. Vehicle 1 comprises two front wheels 2f, two rear wheels 2r, a steering device 3 connected to two front wheels 2f. The two front wheels 2f are steering wheels. Their orientation is controlled by the steering system. The steering system includes, in particular, the steering device 3 and means for monitoring the environment of the vehicle. These trackers are type 4 ADAS sensors. These sensors can be, for example, ultrasonic sensors, cameras or radars. It is configured to detect objects or other vehicles located around the vehicle 1. According to the presented embodiment, the vehicle contains six sensors 4, of which five radar sensors are located in the four corners of the vehicle and one in front essentially in the middle of the vehicle, and also a camera capable of observing the road, in particular, in front of the vehicle 1. Alternatively, the sensors 4 can be made in a different number and can be located in other places on the vehicle 1.

The steering system also contains a computing device 5 or an electronic control unit. In particular, the computing device 5 includes a memory 51, a microprocessor 52 and an input/output interface 53. Using its interface 53, the computing device is connected to the sensors 4 in order to receive signals from these sensors at the input. The computing device 5 is also connected to the steering device 4 via its interface 53 in order to transmit to the steering device 3 orientation commands for the steered wheels 2f. Finally, the vehicle 1 also includes a dashboard provided with a screen 6. The screen 6 is connected to the computing device 5 and can display information transmitted by the computing device to the user of the vehicle 1. program codes for implementing methods for calculating the lateral position of the vehicle 1 according to an embodiment of the invention. Microprocessor 52 is configured to execute instruction codes stored in memory 51.

Vehicle 1 is an autonomous vehicle. In particular, the steering device 3, which interacts with the computing device 5 and sensors 4, can autonomously control the orientation of the steered wheels 21 of the vehicle. Thus, the vehicle can travel without passengers on board or with passengers not directly in control of the vehicle's trajectory.

Vehicle 1 can move on a road occupied by other vehicles. In particular, in FIG. 2 shows a vehicle 1, also called this vehicle, on a road containing three traffic lanes L1, L2, L3. The term "this" is a purely distinctive term to distinguish the vehicle 1 from the vehicles surrounding the vehicle 1. The three traffic lanes are adjacent to each other. Three traffic lanes are identified and separated by dividing lines D1, D2, D3, D4, eg white or yellow lines, solid or broken. Such dividing lines may be painted onto the pavement and may have a substantially constant width. Vehicles can change lanes or, in other words, change lanes and move through the dividing lines. The direction of movement along the three lanes is shown by the X vector. Other vehicles V1, V2, V3, V4, V5, V6, V7, V8, V9, V10, V11, V12 can also move along the lanes L1, L2, L3. Vehicles V1, V2, V3 and V4 are driving in the left lane L1. Vehicles V5, V6, V7 and V8 are moving in the center lane L2. In particular, vehicles V5 and V6 are located at the rear of this vehicle, and vehicles V7 and V8 are located at the front of this vehicle. In other words, vehicles V5 and V6 follow this vehicle, and vehicles V7 and V8 precede this vehicle. Thus, the following and preceding vehicles are moving in the same lane as this vehicle. Finally, vehicles V9, V10, V11 and V12 are driving in the right lane L3. Vehicles V1 to V12 are vehicles that can be detected by vehicle sensors 4. Although in FIG. 2 these vehicles are shown as rectangles of the same size, in reality they can be any and can be any size. They may move at different speeds and may have time-varying relative positions. Other vehicles further back or further ahead on this road may not be counted.

Lateral position or offset of a road vehicle can be defined as the position of a vehicle in a lane in a direction perpendicular to the direction in which the vehicle is traveling. As shown in FIG. 2, the vehicles are traveling parallel to the X vector. Therefore, the vehicle lateral position denotes the position of the vehicle along the Y vector perpendicular to the X vector. For each lane L1, L2, L3, the theoretical center line M1, M2, M3 can be defined as the line located at an equal distance from the dividing lines D1, D2, D3, D4, limiting the traffic lane. Thus, the center line M1 is located at the same distance from the dividing lines D1 and D2. The center line M2 is located at the same distance from the dividing lines D2 and D3. The center line M3 is located at the same distance from the dividing lines D3 and D4. The center lines M1, M2 and M3 are theoretical lines, since they are not physically drawn on the traffic lanes, but are calculated depending on the dividing lines D1, D2, D3, D4. The lateral position of a vehicle in a given lane may be determined or computed relative to the center line of that lane and along the orientation of the Y vector. For example, the lateral position may be positive if the center of the vehicle in question is located or otherwise offset to the left of the center line, and negative if the center of the considered vehicle is shifted to the right of the center line.

Fig. 3 schematically illustrates a method for calculating the lateral position of a given vehicle in a lane according to an embodiment of the invention. The method comprises successive steps E0, E1, E2, E3, E4, E5, E6 to calculate the lateral position Tego for a given vehicle, then to control the steering device 3 so that the vehicle assumes the calculated lateral position Tego. Step E0 is a calculation method initialization step. The first step E1 is the step of calculating the first theoretical lateral position T1 of the vehicle. The first lateral position T1 is calculated depending on the lateral position of the vehicle preceding the given vehicle and/or following the given vehicle in the same lane as the given vehicle. Thus, according to the situation shown in FIG. 2, the first lateral position T1 is calculated depending on the lateral position of the following vehicles V5 and V6 and depending on the lateral position of the preceding vehicles V7 and V8. The second step E2 is the step of calculating the second theoretical lateral position T2 of the vehicle. The second lateral position T2 is calculated depending on the position of the vehicles on the lanes adjacent to the lane of the given vehicle. According to the situation shown in FIG. 2, the second lateral position T2 is calculated depending on the position of the vehicles present in the lanes L1 and L3, that is, the vehicles V1, V2, V3, V4, V9, V10, V11, V12. The third step E3 is the step of calculating the third theoretical lateral position T3 of the vehicle. The third lateral position T3 is calculated depending on the static obstacles (eg obstacles or barriers) detected on the sides of the specified traffic lane. The fourth step E4 is a calculation step in which the vehicle's lateral position Tego is calculated depending on the first lateral position T1, on the second lateral position T2, and on the third lateral position T3. The fifth step E5 is a step of autonomously controlling the steering device 3 of this vehicle to make the vehicle assume the theoretical lateral position Tego calculated during the fourth step E4. The sixth step E6 is the step of displaying on the screen 6 of the present vehicle a visual indication showing the relative position of the present vehicle with respect to the theoretical lane center line of the present vehicle, that is, with respect to the center line M2 in the situation shown in FIG. 2.

It should be noted that the lateral position is referred to as "theoretical" as opposed to the actual lateral position. Therefore, the theoretical lateral position calculated at a given moment does not necessarily correspond to the actual lateral position of the vehicle at that moment. The following is a more detailed explanation of each of these steps E0-E6.

During the initialization step E0, some checks and detections are made before the calculation steps to calculate the lateral position Tego of the vehicle. Subsequent steps of the calculation method may be modified, interrupted or stopped if these conditions are not met and/or if no vehicle or obstacle is detected.

In the first sub-step E01 of the initialization step E0, it is verified that the sensors 4 detect the dividing lines D2, D3 of the lane L2 on which the vehicle is traveling. If so, the position of the center lane M2 of the lane L2 on which the vehicle is traveling can be deduced. As mentioned above, the center line M2 can be calculated as a line that is at the same distance from the dividing lines D2 and D3. The center line M2 can also be calculated using a known algorithm or a controller such as LCA or “Lane Centering Assist”. If the dividing lines are missing or poorly visible, the method can be interrupted until the dividing lines are visible again.

In the second sub-step E02 of initialization E0, the curvature of the lane L2 is calculated. If the lane curvature radius of a given vehicle is less than or equal to a predetermined threshold, the method can be interrupted until the lane curvature radius again exceeds the predetermined threshold. For example, you can calculate the radius of curvature of the center line M2. If the radius of curvature is less than a predetermined value, the method is interrupted until the radius of curvature is again greater than the predetermined value. This avoids changing the vehicle's trajectory at too sharp a turn, which could destabilize the vehicle and/or lead to erroneous calculations of the lateral position of the vehicle.

It is also possible to carry out other checks that cause the calculation method to continue. For example, a vehicle user may be able to manually activate or deactivate the lateral position calculation method. The calculation method can also be activated or deactivated automatically depending on other operating parameters of the vehicle, such as detection of an abnormality in the operation of the vehicle, in particular, an anomaly in the operation of the autonomous driving system, detection of the activation of a vehicle trajectory control system such as ESP or ABS. or detection of some critical driving situation.

In the third sub-step E03, the surroundings of the vehicle are scanned using the sensors 4 in order to detect vehicles and/or obstacles surrounding the vehicle. If no vehicle and/or obstacles are detected, the method may be put on hold or interrupted until no vehicles and/or obstacles are detected. If vehicles are detected in the environment of a given vehicle, their position, their respective speed, and even their trajectory can be determined. The position of vehicles can be determined relative to the position of a given vehicle. For example, the position of the surrounding vehicles can be determined in the coordinate system formed by the X and Y vectors, while the center of the coordinate system is the given vehicle. In particular, the distance separating a given vehicle from each detected vehicle can be calculated. It also determines which lane the vehicles are in. If vehicles are detected in the lane of a given vehicle (in front or behind a given vehicle), the lateral position of these vehicles can be calculated. In particular, the position of each of these vehicles with respect to the center line M2 can be calculated. In addition, the longitudinal distance separating a given vehicle from vehicles in the same lane as the given vehicle can be calculated. The longitudinal distance between two vehicles in the same lane can be defined as the distance separating two vehicles along the path of the center line, that is, along the curved abscissa described by the road. Thus, the longitudinal distance separating the two vehicles is greater than the absolute (bird's eye view) distance separating the two vehicles when the center line traces a curve.

During the initialization step E0, it is also possible to detect static objects or obstacles, that is, objects or obstacles that are stationary relative to the road. Ultimately, upon completion of the initialization step E0, a picture of the environment of this vehicle is obtained. According to an embodiment, the picture of a given vehicle can be obtained not by means of the sensors 4 installed on the given vehicle, but via a means of wireless communication with the given vehicle. For example, the position and speed of each vehicle in a given vehicle's environment can be obtained using a vehicle-to-vehicle communication protocol.

In the fourth sub-step E04 of the initialization step E0, in particular, the presence of preceding and/or following vehicles in the lane L2 of the given vehicle can be checked. In particular, firstly, it can be checked that at least one first vehicle has been detected in front of the given vehicle in the lane of the given vehicle. Secondly, it can be checked that at least one second vehicle is detected in front of or behind this vehicle in the lane of this vehicle. In addition, it can be checked that none of the vehicle's flashing lights are activated, indicating that there is no overtaking intention on the part of the vehicle. If these three conditions are met, then the first step of calculating E1 can be executed. Otherwise, the calculation method can be interrupted until these three conditions are met again. Alternatively, the method can be continued without performing the first step of calculating E1 and basing the calculation of the lateral position Tego only on the second lateral position T2 and on the third lateral position T3. According to another variant, the method can be continued only if a vehicle is detected in front of this vehicle and if the speed of this vehicle is low enough.

Sub-steps E01, E02, E03 and E04 can be performed independently of each other, sequentially or in parallel. They can be repeated indefinitely even during the implementation of subsequent steps E1-E6. It should be noted that if the lateral position calculation method is interrupted, stopped, or changed, a given vehicle may gradually position itself conventionally in the center of its lane, such as such that the center of the given vehicle is on the center line M2.

The first calculation step E1 may comprise a sub-step of calculating the weighted average lateral positions of vehicles in front and/or behind in the specified lane, with the weights of each lateral position being a function of the distance separating the given vehicle from the preceding and/or following vehicle in question. In other words, the first lateral position T1 can be calculated using the following formula:

[1]

,

Where

- N denotes the number of vehicles detected in the lane of a given vehicle,

- i denotes the index of vehicles present in the lane of the given vehicle,

- Tvi denotes the lateral position of the vehicle i in the lane of this vehicle,

- avi denotes the weighting factor corresponding to the lateral position of the vehicle i.

Each avi weight can be calculated using the following formula:

[2]

,

Where

- Dvi denotes the longitudinal distance separating the given vehicle from vehicle i,

- Vvi denotes the speed of the vehicle i,

- f and g stand for cartographies, i.e. functions.

For example, mappings f and g can be defined in such a way that the weight coefficients respect the following inequality: av7 > av6 > av8 > av5. The mappings f and g can also be defined so that the weights avi increase as vehicles i approach a given vehicle and if their speeds decrease. The functions f and g can also be adjusted on the vehicle in such a way as to improve the behavior of the vehicle. The avi weights may also change depending on possible system defects of the vehicle's sensors. When vehicle i moves sideways in a given vehicle's lane to change lanes, its weight avi can be reset to 0. In other words, vehicle i's lateral position Tvi does not align while it is making its lane change maneuver.

As was indicated in the description of the initialization sub-step E04, in order to carry out the first calculation step E1, it is preferably necessary that there be at least two vehicles in front of the given vehicle, or one vehicle in front of the given vehicle and one vehicle behind the given vehicle, or only one vehicle in front at low speed. In this case, the first lateral position T1 reproduces the average lateral positions of vehicles located in the same row or on the same lane as the given vehicle. If all vehicles in the same lane as a given vehicle are moving to the left, then that vehicle will also move to the left. Similarly, if all vehicles in the same lane as a given vehicle are shifting to the right, then that vehicle will also shift to the right. Occupying this position, this vehicle merges into the traffic flow. This allows you to get a corridor for the passage of motorcycles and even for special vehicles (for example, ambulances, fire trucks, police cars, ...). This vehicle will not interfere with the passage of motorcycles or special vehicles between vehicles. In addition, this vehicle is located more in the continuation of the vehicle moving in front of it. The driver of the vehicle preceding this vehicle can better observe the road environment with his side mirrors, since this vehicle does not obstruct his view.

In the example shown in FIG. 4, the preceding vehicle V7 and the following vehicle V6 are both further inward of the bend, that is to say, to the right of the center line M2. This vehicle aligns its lateral position with the position of vehicles V6 and V7 and also positions itself on the inside of the turn. In the example in FIG. 5, vehicles V5, V6 and V7 are positioned on the left side of the center line M2, while vehicle V8 is positioned on the right side. As a result of calculating the weighted average lateral positions of vehicles V5-V8, this vehicle in the first lateral position T1 must also be located on the left side of the center line M2.

The second calculation step E2 is schematically illustrated in FIG. 6 and 7. The second step E2 makes it possible to adapt the lateral position of the given vehicle depending on the presence of interfering vehicles in lanes adjacent to the lane of the given vehicle. In particular, vehicles can interfere if they are very wide, such as trucks or buses, or if they are simply not well placed in their own lane. The second step E2 comprises the first sub-step E21 of calculating the theoretical safe lane or the theoretical safe corridor on both sides of the dividing line located between the lane of the given vehicle and the lane adjacent to the lane of the given vehicle. In particular, during this step, it is also possible to calculate two safe corridors on both sides of the two dividing lines D2, D3, which delimit the lane of the given vehicle on the right and left. A safe lane is a virtual surface that can be located at the junction between a given vehicle's lane and an adjacent lane. The center of the safe lane can be located on the median line, so the safe lane is in both the vehicle's lane and the adjacent lane. Preferably the width of the safe corridor can be calculated. The greater this width, the greater the likelihood of detecting the presence of a vehicle in a safe corridor. After determining safe corridors, sensors 4 monitor the potential presence of a vehicle in a safe corridor.

In the second sub-step E22, the presence of the vehicle in the safe corridor is detected. For example, in the situation shown in FIG. 6 detect the presence of vehicle V12 in the safe corridor CS. In this case, it is possible to calculate the distance separating the given vehicle from the vehicle detected in the safe corridor and the speed of the vehicle detected in the safe corridor.

In the third sub-step E23, the second lateral position is calculated depending on the distance separating the given vehicle from the vehicle detected in the safe lane. In particular, the second lateral position T2 may be inversely proportional to the time until the TTS collides with the detected vehicle and proportional to the zone distance that the detected vehicle penetrates into the safe corridor CS. The TTC collision time, which can also be called “time to reach”, can be defined as the time after which a given vehicle could reach a vehicle present in the safe corridor if their trajectories converged and if no correction was made to these trajectories .

For example, the second lateral position T2 can be calculated using the following formula:

[3]

,

Where

- M denotes the number of vehicles detected in the adjacent lane to the left of the lane of the given vehicle,

- j is the index of vehicles present in the adjacent lane on the left,

- P denotes the number of vehicles detected in the adjacent lane to the right of the vehicle's lane,

- k is the index of vehicles present in the adjacent lane on the right,

- Lvj and Lvk denote the penetration distance of vehicles j and k, respectively,

- Gvj and Gvk are the gains associated with vehicles j and k respectively, whereby the gain is a mapping versus time to collision TTC and/or versus speed of vehicles j and k respectively.

Since the gains are dependent on the time to collision of the TTC, the lateral position T2 may increase as a given vehicle approaches the vehicle in question. The shorter the time to collision TTC, the more the gain associated with the vehicle in question can approach 1, and the closer the second lateral position T2 will approach the penetration distance of the vehicle in question into the safe corridor.

The calculation of the second lateral position T2 can be performed if and only if there are vehicles for which the time to collision TTC is less than a predetermined threshold. Thus, vehicles for which the time to collision TTC exceeds this threshold can be ignored. The calculation of the second lateral position T2 may also take into account only vehicles that are not currently performing a lane change maneuver for that vehicle. Such a maneuver can be detected, for example, if the vehicle in question has turned on a light indicator, such as a flashing signal. Algorithms can also be used to detect a vehicle's lane change maneuver without activating its flashing signal.

In the situation shown as an example in FIG. 7, the presence of vehicle V12 is detected in the safe corridor CS to the right of the lane of this vehicle. In this case, no vehicle is detected in the lane to the left of the lane of this vehicle, or even the road does not contain a lane to the left of the lane of this vehicle. According to the above calculation, this vehicle in the second lateral position T2 must move to the left of the center lane M2 in order to maintain a sufficient safety distance from the vehicle V12. On the other hand, in a situation where two interfering vehicles are detected in the safe corridors to the right and left of the vehicle's lane, the vehicle may align its position to the center to balance the distances with the interfering vehicles to the right and left.

The situations shown in Fig. 6 and 7 could occur when the vehicle in question overtakes vehicles V11 and V12 on the left. A similar calculation can cause a given vehicle to shift to the right if a given vehicle on the left is to be overtaken by a vehicle detected in the left safe lane. The calculation method can also be transposed for use when driving on the left and overtaking on the right.

In the third calculation step E3, the third lateral position T3 of the given vehicle is calculated depending on the static objects surrounding the given vehicle. In the same way as for the second calculation step E2, a safe lane is determined around the lines adjacent to the given vehicle. The third lateral position T3 is proportional to the penetration distance of the static object into the safe zone around the dividing line adjacent to the given vehicle. This calculation step makes it possible, for example, to reproduce the behavior of a person who will tend to move his vehicle in the lane if the protective barrier is close to the dividing line adjacent to this vehicle.

In the fourth calculation step E4, the vehicle's lateral position Tego is calculated depending on the first lateral position T1, on the second lateral position T2, and on the third lateral position T3. In particular, the lateral position Tego of a given vehicle can be calculated using a weighted average as follows:

[4]

,

Where

- a1 denotes the weighting factor corresponding to the first lateral position T1,

- a2 denotes the weighting factor corresponding to the second lateral position T2, and

- a3 denotes the weighting factor corresponding to the third lateral position T3.

Preferably, the weighting factors a1, a2 and a3 can be adapted depending on the driving conditions of a given vehicle. In the first sub-step E41 of calculation step E4, the running conditions of the vehicle can be determined. In particular, it is possible to determine the density of traffic on the road that the vehicle is entering. This detection may be based, for example, on a score obtained by counting the number of vehicles present in a given perimeter around a given vehicle. Traffic density can also be estimated by analyzing the longitudinal as well as the lateral position of vehicles around a given vehicle.

In the second sub-step E42 of calculation step E4, the weight coefficients a1, a2 and a3 can be calculated depending on the detected driving conditions of a given vehicle, in particular depending on the traffic density. For example, it can be determined that a1=a2=a3=1/3 if it is necessary to give as much weight to each of the three previously calculated lateral positions T1, T2, T3. These settings can, for example, be used when the traffic is at normal or normal density. If a traffic jam situation is detected, for example, when the number of vehicles in a given perimeter around a given vehicle exceeds a certain threshold, the weighting factors can be determined such that a1=0.2, a2=0.8 and a3=0. Thus, more weight is given to the previously calculated second lateral position T2 and the calculated third lateral position T3 is neglected. Thus, the location of this vehicle in its lane is closer to the position obtained when the vehicle is controlled by the driver. Using a weighting factor of 0 allows the calculation of the corresponding lateral distance to be neglected. For example, if the conditions determined during the initialization sub-step E04 are not met, the weighting factor a1 can be set to zero. The value of these coefficients A1, a2, a3 can be regularly recalculated depending on changes in traffic conditions.

In order to calculate a lateral position that ensures the safety of motorists in all circumstances, it is possible to filter the lateral position calculated using the weighted average, as described above. In particular, in the third sub-step E043, it is possible to determine the ceiling or, in other words, to limit the maximum deviation between the theoretical lateral position of the given vehicle and the theoretical center line of the lane of the given vehicle to the upper limit. This ceiling may depend on the measured bandwidth. This avoids moving the vehicle too much to one side or the other of the lane. In particular, it can be avoided that the vehicle itself enters the previously defined safe corridors. In the fourth sub-step E44, it is also possible to limit the change in time of the theoretical lateral position of the given vehicle. This avoids too sudden changes in lateral position, which could lead to destabilization of the vehicle. Finally, at the end of step E4, an ideal Tego lateral position is obtained, which can be used to control the steering device 3.

In the fifth step, E5 controls the steering device of this vehicle to make it take the lateral position Tego calculated in the fourth step. This control step occurs autonomously, that is, without the participation of the vehicle user. The deviation between the measured real lateral position of a given vehicle and the calculated lateral position of Tego results in the calculation of the desired steering wheel angle and hence the steering command for the steered wheels. Therefore, the steering device 3 turns the steerable wheels of the vehicle so that the vehicle is in the lateral Tego position. Steps E1-E5 may then be repeated at a frequency determined so as to correct in real time the lateral position of the vehicle.

In the sixth step E6, a visual indication showing the relative position of the vehicle with respect to the lane center line of the vehicle can be displayed on the vehicle screen 6 . The visual indication may be, for example, an arrow oriented to the left or oriented to the right, depending on the displacement of a given vehicle to the left or right of the center line. Thus, the off-center position of the vehicle does not take the users of the vehicle by surprise. They understand that the off-center position of this vehicle is the result of a deliberate action.

Thanks to the invention, the lateral position of the vehicle is calculated based on the preliminary calculation of three different lateral positions. Each of the three lateral positions T1, T2, T3 is calculated depending on the part of the environment of the given vehicle. The end result is a more natural lateral position of the vehicle in the lane. The vehicle fits better into the flow of traffic. It maintains safe lateral distances while allowing motorcycles or special vehicles to overtake lanes of vehicles.

Claims (30)

1. A method for calculating the lateral position of a given vehicle (1) on a lane (L2), the method comprising: the first step (E1), which calculates the first theoretical lateral position of the given vehicle (1) in the specified lane (L2) depending on the lateral position in the specified lane (L2) of the vehicles (V7, V8) in front of the given vehicle vehicle, and/or vehicles (V5, V6) following behind this vehicle, and/or the second step (E2), which calculates the second theoretical lateral position of the given vehicle (1) in the specified lane (L2) depending on the position of the vehicles (V1, V2, V3, V4, V9, V10, V11, V12) on traffic lanes (L1, L3) adjacent to the specified traffic lane, the third step (E3), which calculates the third theoretical lateral position of the given vehicle (1) on the specified lane (L2) depending on the static obstacles detected on the sides of the specified lane (L2), a fourth step (E4) in which the lateral position of the given vehicle (1) is calculated using the weighted average of the first lateral position, the second lateral position and the third lateral position. 2. The calculation method according to claim 1, wherein the first calculation step (E1) comprises a sub-step of calculating the weighted average of the lateral positions of the vehicles (V7, V8) in front and/or the vehicles (V5, V6) following behind, in the specified lane, with the weights of each lateral position being a function of the longitudinal distance separating the given vehicle (1) from the considered vehicle (V7, V8) in front and/or from the considered vehicle (V5, V6 ) following behind and the speed of the considered vehicle ahead and/or the considered vehicle following behind. 3. The calculation method according to claim 1 or 2, wherein the second calculation step (E2) comprises: sub-step (E21) in which the theoretical safe corridor (CS) is calculated on both sides of the dividing line (D2), while the dividing line (D2) is located between the lane (L2) of this vehicle and the lane (L1) adjacent to lane of the vehicle, sub-step (E22) in which the presence of a vehicle in a safe corridor is detected, sub-step (E23) in which the second theoretical lateral position (T2) is calculated depending on the distance separating the given vehicle (1) from the vehicle (V12) detected in the specified safe corridor (CS) and depending on the vehicle speed (V12) detected in the specified safe corridor (CS). 4. The calculation method according to any one of paragraphs. 1-3, containing the first execution condition of the calculation method, while the first execution condition is observed: if the dividing lines (D2, D3) of the traffic lane (L2) of this vehicle (1) are detected by this vehicle, and if the lane curvature (L2) of the vehicle is less than or equal to a predetermined threshold. 5. The calculation method according to any one of paragraphs. 1-4, containing the second execution condition of the first stage of the calculation, while the second execution condition is observed: if at least one first vehicle (V7, V8) is detected in front of this vehicle, if at least one second vehicle (V5, V6, V7, V8) is detected in front of or behind this vehicle, and no blinking signal of this vehicle is activated. 6. The calculation method according to any one of paragraphs. 1-5, wherein the fourth step (E4) of the calculation comprises: a sub-step (E41) in which the driving conditions of the vehicle are detected, and a sub-step (E42) calculating a first theoretical lateral position weight, a second theoretical lateral position weight, and a third theoretical lateral position weight depending on the detected driving conditions of the vehicle. 7. The calculation method according to any one of paragraphs. 1-6, wherein the fourth step (E4) of the calculation comprises: sub-step (E43) limiting the deviation between the theoretical lateral position of the given vehicle and the theoretical center line (M2) of the lane (L2) of the given vehicle, and/or sub-step (E44) in which the change in time of the theoretical lateral position of this vehicle is limited. 8. The calculation method according to any one of paragraphs. 1-7 containing: a fifth step (E5) in which autonomous control of the steering device (3) of the vehicle is performed to cause the vehicle to assume the theoretical lateral position calculated in the fourth step (E4), a sixth step (E6), which displays on the screen (6) of this vehicle a visual indication of the position of this vehicle relative to the theoretical center line (M2) of the lane (L2) of this vehicle. 9. A computer program product containing program command codes recorded on a computer-readable medium for performing the steps of the method according to any one of paragraphs. 1-8 when the specified program is executed on the computer. 10. A computer-readable data recording medium on which a computer program is recorded, containing the command codes of the program for executing the method according to any one of paragraphs. 1-8. 11. Steering system, characterized in that it contains a computing device (5), a steering device (3) controlled by a computing device, and means (4) for tracking the environment, while the tracking means (4) are connected to a computing device, while the computing the device is configured to perform the calculation method according to any one of paragraphs. 1-8. 12. Motor vehicle (1), in particular an autonomous vehicle, characterized in that it contains a computing device (5), a steering device (3) controlled by a computing device, and means (4) for tracking the environment of the vehicle, while the means ( 4) tracking connected to the computing device, while the computing device is configured to perform the calculation method according to any one of paragraphs. 1-8.

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