Method for determining the nature of a traffic lane on which a motor vehicle is traveling.

Abstract

Method for determining the nature of a traffic lane on which a motor vehicle is traveling. Method for determining, by a motor vehicle management system, the nature of a traffic lane on which the motor vehicle is traveling, the method comprising the following steps: a step of acquiring data, in particular images, by the management system, on the basis of the acquired data, a step of detecting events, in particular events in the environment of the motor vehicle, for each detected event and for each type of traffic lane, a step of assigning a score characterizing the probability that the vehicle is on a lane of a given nature knowing that the event has occurred, for each type of traffic lane, a step of calculating an average of the scores assigned, a step of comparing the averages calculated for each type of traffic lane and assigning,to the traffic lane on which the motor vehicle is traveling, a nature, in particular the nature with the highest average. No figure for the abstract.,

Description

Title of the invention: Method for determining the nature of a traffic lane on which a motor vehicle is traveling.

[0001] The invention relates to a method for determining the nature of a traffic lane on which the motor vehicle is traveling. The invention also relates to a method for determining a maximum authorized speed where the motor vehicle is traveling. The invention also relates to a management system implementing the method for determining the nature of the traffic lane on which the motor vehicle is traveling and / or the method for determining a maximum authorized speed where the motor vehicle is traveling. The invention also relates to a motor vehicle comprising such a system. The invention also relates to a computer program implementing one of the methods mentioned. The invention finally relates to a recording medium on which such a program is recorded.

[0002] On some current motor vehicles, a vehicle system makes it possible to determine the maximum authorized speed at the location where the vehicle is located. Regulatory developments will soon make such a system mandatory on all new vehicles marketed. Furthermore, these systems must be capable of determining and displaying the maximum authorized speed almost permanently.

[0003] Such systems are known, but they require, in addition to the presence of a camera necessary to detect speed limit signs, the use of: - a GPS system to locate the vehicle on the road network, and - a map memory to determine the limitations relating to the different sections of roadways.

[0004] Furthermore, the map memory must be regularly updated to take into account changes in the road traffic network or changes in traffic rules on the road traffic network.

[0005] Known systems are therefore expensive.

[0006] The aim of the invention is to provide a system and a method for determining the nature of a traffic lane on which the motor vehicle is traveling, remedying the above drawbacks and improving the devices and methods known from the prior art. In particular, the invention makes it possible to produce a system and a method which are simple and reliable while using a minimum of resources.

[0007] According to the invention, a method allows the determination, by a management system of a motor vehicle, of a nature of a traffic lane on which the motor vehicle is traveling. The method comprises the following steps: - a data acquisition step, in particular images, by the system of management, - on the basis of the acquired data, a step of detecting events, in particular events in the environment of the motor vehicle, for each detected event and for each type of traffic lane, a step of assigning a score characterizing the probability that the vehicle is on a lane of a given type knowing that the event has occurred, - for each type of traffic lane, a step of calculating an average of the marks awarded, and - a step of comparing the averages calculated for each type of traffic lane and allocation, to the traffic lane on which the motor vehicle is traveling, a type, in particular the type presenting the highest average.

[0008] The method can be executed in real time and / or the steps can be iterated at a fixed time interval and / or at a fixed movement interval of the motor vehicle.

[0009] A decreasing weighting may be applied to the scores assigned as the motor vehicle moves away from the location of detection of the event, for example a decreasing weighting of 10% per kilometer.

[0010] Events may include events from the following categories: - detection of an explicit speed sign, and / or - detection of an implicit speed sign, and / or - detection of a contextual traffic sign, and / or - detection of a traffic lane structure, and / or - detection of a ground marking, and / or - detection of dynamic information from a motor vehicle, and / or - detection of other objects in the environment of the motor vehicle and their possible dynamics, in particular detection of other road users, such as pedestrians, cyclists, motorcycles, trucks, other vehicles.

[0011] According to the invention, a method allows the determination, by a management system of a motor vehicle, of a maximum authorized speed on the traffic lane where the motor vehicle is traveling. The method comprises the following phases: - a phase of implementation of the method for determining the nature of a traffic lane on which the motor vehicle defined above is traveling, and - a phase of using the nature of the traffic lane to determine the maximum authorized speed.

[0012] The method may comprise a phase of displaying the maximum authorized speed.

[0013] The use phase may include a step of not taking into account a detection of an explicit speed limit sign.

[0014] The use phase may include a step of interpreting the meaning of an implicit traffic sign.

[0015] According to the invention, a motor vehicle management system comprises hardware and / or software elements implementing one and / or other of the preceding methods, in particular hardware and / or software elements designed to implement one and / or other of the preceding methods.

[0016] According to the invention, a management system comprises means for implementing one and / or the other of the preceding methods.

[0017] According to the invention, a motor vehicle comprises a management system defined previously.

[0018] According to the invention, a computer program product comprises program code instructions recorded on a computer-readable medium for implementing the steps of one and / or the other of the methods defined above when said program operates on a computer.

[0019] According to the invention, a computer program product downloadable from a communications network and / or recorded on a data medium readable by a computer and / or executable by a computer, is characterized in that it comprises instructions which, when the program is executed by the computer, lead the latter to implement one and / or the other of the methods defined previously.

[0020] According to the invention, a data recording medium, readable by a computer, on which a computer program is recorded, comprises program code instructions for implementing one and / or the other of the methods defined above.

[0021] According to the invention, a computer-readable recording medium comprises instructions which, when executed by a computer, cause the latter to implement one and / or the other of the methods defined above.

[0022] The invention also relates to a signal from a data medium, carrying the computer program product defined above.

[0023] The attached drawing represents, by way of example, an embodiment of a motor vehicle according to the invention and an embodiment of a determination method according to the invention.

[0024] [Fig.l] is a schematic representation of an embodiment of a motor vehicle according to the invention.

[0025] [Fig.2] is a flowchart of an embodiment of a determination method according to the invention.

[0026] [Fig.3] is a table giving examples of scores, weights and weight decays for different events.

[0027] [Fig.4] is a table giving examples of scores, weights and weight decays for different events.

[0028] [Fig.5] is a table giving examples of grades, weightings and de- growth of weights for different events.

[0029] [Fig.6] is a table giving examples of scores, weights and weight decays for different events.

[0030] [Fig.7] is a table giving examples of scores, weights and weight decays for different events.

[0031] [Fig.8] is a table giving examples of scores and weightings for different events.

[0032] An embodiment of a motor vehicle 1 according to the invention is described below with reference to [Fig.l].

[0033] The motor vehicle 1 is for example a passenger motor vehicle or a utility motor vehicle. However, the vehicle may be of any type. The motor vehicle is intended to use the road traffic network.

[0034] The motor vehicle 1 comprises a management system 2 or a system 2 for determining the nature of the traffic lane on which the motor vehicle is traveling and / or for determining a maximum authorized speed where the motor vehicle is traveling, i.e. the maximum authorized speed on the section of traffic lane where the vehicle is traveling.

[0035] The system comprises a set of sensors 3, 5 for acquiring data and a computer 4 for processing the data.

[0036] The system also comprises an information display element 6, such as a screen 6, in particular an element for displaying the nature of the traffic lane on which the motor vehicle is traveling and / or the authorized speed limit where the motor vehicle is located. Preferably, this display element is provided on a dashboard in the passenger compartment of the motor vehicle.

[0037] Advantageously, the set of sensors comprises at least one camera 3 making it possible to acquire images capable of being processed by the computer 4. The camera 3 is preferably positioned behind the windshield or at the level of a grille at the front of the motor vehicle. The camera is further arranged and configured to take at least shots of the environment in front of the motor vehicle.

[0038] The set of sensors may further comprise sensors 5 capable of providing dynamic information of the motor vehicle, in particular a longitudinal speed sensor of the motor vehicle and / or a yaw rate sensor of the motor vehicle and / or an acceleration sensor making it possible to provide different accelerations of the motor vehicle.

[0039] The determination system 2 comprises all the hardware and / or software elements 2, 3, 4, 41, 42, 43, 44, 5, 6 implementing or governing a method for determining the nature of the traffic lane on which the motor vehicle is traveling and / or for determining a maximum authorized speed at which the motor vehicle is traveling. In particular, the determination device 2 comprises the hardware and / or software elements 41, 42, 43, 44 making it possible to implement the steps of the determination method. These different elements may comprise software modules.

[0040] The computer 4 advantageously comprises all or part of the following elements: - a module 41 for processing the acquired data, - a module 42 for detecting events, in particular events in the environment of the motor vehicle, - a module 43 for assigning a score characterizing the probability of encountering an event on the traffic lane, for each event detected and for each type of traffic lane, - a module 44 for calculating an average of the marks awarded for each type of traffic lane, - a module 45 for comparing the averages calculated for each type of traffic lane.

[0041] A mode of execution of the method for determining a maximum authorized speed at which the motor vehicle is traveling is described below with reference to [Fig.2],

[0042] In a first phase E1, a mode of execution of the method for determining the nature of a traffic lane on which the motor vehicle is traveling is implemented. This mode of execution of the method for determining the nature of a traffic lane on which the motor vehicle is traveling is described in more detail below.

[0043] In a second step E2, the nature of the traffic lane determined previously is used to determine the maximum authorized speed. Preferably, the nature of the traffic lane can be: - urban road (where the speed limit in France is 50 km / h by default), - extra-urban or rural roads, for example departmental roads, national roads (with the French designation, where the speed limit in France is 80 km / h by default), - expressway (where the speed limit in France is 110 km / h by default), - motorway (where the speed limit in France is 130 km / h by default).

[0044] In particular, this information on the nature of the traffic lane makes it possible to determine, as seen previously, a default speed limit value. Thus, in the absence of recognition of a speed limit sign, it is possible, knowing the nature of the lane on which the vehicle is traveling, to determine by assumption the authorized speed limit value.

[0045] Advantageously, in this phase E2, in a step S70, the authorized speed limit value determined by the display element 6 is displayed by default on the display element 6. system 2. However, if an explicit speed limit sign is detected and recognized by system 2 (for example a 30 km / h limit on an urban road), it is the speed indicated by this sign which is considered and displayed on display element 6.

[0046] Furthermore, in this phase of use, it is possible to disregard an explicit speed limit sign which has been detected and recognized (or partially recognized) by the management system 2. This is for example the case in the three situations mentioned below: - system 2 detected and recognized an 80 km / h speed limit sign located at the rear of a truck in front of the vehicle equipped with system 2 while vehicle 1 was traveling on an urban road limited to 50 km / h, - system 2 detected and recognized a 50 km / h speed limit sign located on an adjacent lane while vehicle 1 was traveling on a motorway lane limited to 130 km / h, - system 2 detected and recognized a 50 km / h speed limit sign without detecting the display of a sign restricting the speed limit to a particular category of vehicle or to particular weather conditions while vehicle 1 was traveling on a motorway lane limited to 130 km / h.

[0047] In all these cases, the detected and inconsistent speed limits are not considered and are therefore not displayed on the display element 6. On the contrary, in this case, it is: - the default speed limit on the track, or - the latest recognized and consistent limitation information, which is considered and displayed on the display element 6. Thus, the use phase may include a step of not taking into account a detection of an explicit speed limit sign.

[0048] Furthermore, the use phase may include a step of interpreting the meaning of an implicit traffic sign. This is particularly the case for an end of speed limit sign. Such a sign does not indicate the authorized speed limit after passing the sign. However, this authorized speed limit can be determined if the nature of the traffic lane on which the vehicle 1 is traveling is known. This knowledge is obtained by implementing the first phase E1 of the determination method. The authorized speed limit is then the default authorized speed limit on this traffic lane.

[0049] It should also be noted that, in certain use cases, no sign (whether explicit or implicit) is simply present. This is for example the case when the vehicle enters a town from a rural road. In such a case, the analysis of images of the environment, in particular of buildings, can make it possible to de- terminate the nature of the traffic lane when no sign is encountered.

[0050] Advantageously, the determination method is executed in real time. By “executed in real time”, it is meant that the different phases of the method are iterated at reduced time intervals, for example every 20 ms or 10 ms. Alternatively, the different phases of the method can be iterated at a fixed movement interval of the vehicle 1, for example every 50 m or every 100 m. As a further alternative, the different steps of the method can be iterated each time a new event is detected, in particular each time new data acquired by the camera lead to an event detection by the module 42.

[0051] Preferably, the following rules are also implemented: - When a change in the nature of the traffic lane is determined, the speed limit authorized by default is displayed on the lanes of the new nature determined. - When determining an authorized speed limit different from the default authorized speed limit on roads of the determined nature, this different speed is displayed if it satisfies one of the following two conditions (i) the speed difference is reasonable (for example, a direct change from a speed limit of 130 km / h to 50 km / h directly is not reasonable), or (ii) a particular circumstance justifies a large difference in speed limit (for example, a roadworks zone, a motorway exit or variable speed signage on a light panel. - The authorized speed limit differs from the default authorized speed limit on the roads of the determined nature, we return to the default authorized speed limit if (i) an end of speed limit sign is detected or (ii) a change of road is detected, in particular after an intersection or a roundabout (detectable via a sign, an analysis of the steering wheel angle, a yaw angle or vehicle dynamics) or (iii) another sign is detected and indicates the return to the default speed limit or indicates a new exceptional limit.

[0052] As seen previously, the determined nature of the road advantageously makes it possible to define upper speed limits which should not be displayed on an explicit sign. For example, if the nature of the road is "urban road", one should not encounter a sign indicating an authorized speed limit of 130 km / h. This makes it possible, for example, to filter out aberrant speed limits. For example, a 120 km / h limit sign positioned at the rear of a heavy vehicle (over 12t) can thus be discriminated against, so that the management system will not take this sign into account if the motor vehicle is on an urban road. In another example, on a motorway, the management system can detect non-existent or erroneous signs and consider certain traffic signs as town entrance signs.Again, knowing the nature of the traffic lane, certain detections can be discriminated and excluded from the logic of . decision making.

[0053] A mode of execution of the first phase El is described below in detail with reference to [Fig.2]. This mode of execution of the first phase can be seen as a mode of execution of a method for determining the nature of the traffic lane on which the motor vehicle is traveling. The first phase comprises the following steps.

[0054] In a first step S10, the system 2 acquires data, in particular images. This data is provided by the camera 3 and by all of the other sensors 5.

[0055] In a second step S20, the data are processed by the system 2, in particular by the computer 4 of the system 2. This processing includes all the processes for processing the electrical signals provided by the cameras 3 and other sensors 5. This processing may include image processing, in particular signal processing making it possible to put the signals into optimized forms to carry out the third detection step S30 which follows.

[0056] In the third step S30, using the acquired data, the system 2 detects events, in particular events occurring in the environment of the motor vehicle or state events of the motor vehicle.

[0057] For example, events may fall into the following categories: - detection of an explicit speed sign (e.g. 130 km / h speed limit sign), and / or - detection of an implicit speed sign (e.g. end of speed limit sign, sign indicating the motorway nature of the road or the express nature of the road), and / or - detection of a contextual traffic sign (any other sign or any other characteristic of a sign such as a background color of a sign), and / or - detection of a traffic lane structure (such as a roundabout, a bend, a structure such as a bridge), and / or - detection of a road marking (such as a continuous white line, a broken white line, a pedestrian crossing), and / or - detection of dynamic information from the motor vehicle 1 (such as speed, steering angle of the steered wheels, acceleration), and / or - detection of other objects in the environment of the motor vehicle 1 and their possible dynamics (such as a pedestrian, a cyclist, a motorcyclist, another motor vehicle, a building).

[0058] In a fourth step S40, for each detected event and for each type of traffic lane, the system 2 attributes a note or a score characterizing the probability that the vehicle is on a lane of a given type knowing that the event occurred. These scores are preferably stored in a memory and assigned to a detected event as soon as the event has been detected. The tables in Figures 3 to 8 give examples of scores assigned to the different events encountered.

[0059] In a fifth step S50, for each type of traffic lane, the system 2 calculates an average of the scores awarded. An average score or score is then obtained for each category of traffic lane.

[0060] Advantageously, in calculating the average, the different scores assigned can be weighted differently. In particular, the weighting is preferably decreasing as the motor vehicle moves away from the location of detection of the event, for example decreasing weightings of -10% per kilometer or -20% per kilometer can be envisaged. This makes it possible to take into account the fact that as the vehicle moves away from the location of detection of the event, this event becomes less and less relevant for determining the nature of the traffic lane on which the vehicle is located. The tables in Figures 3 to 8 give examples of weightings and decreases in the weightings.

[0061] Furthermore, the weightings may also be different for the different categories of events mentioned above, as illustrated in the tables of Figures 3 to 8.

[0062] Preferably, to relieve the calculation resources, only a certain number of the last detected events can be retained to calculate the averages each associated with a type of traffic lane.

[0063] The average score can be defined as follows: Quotient of: - the sum, over all events, of the weighted scores of these events (weightings depending on the distance of the vehicle from the location of detection of the event where applicable), over

[0064] - the sum, over all events, of the weightings (weightings of depending on the distance from the vehicle to the location of detection of the event).

[0065] We therefore have:

[0066] :____7 \ (mtee( typeVotera note tvpeVoie = \ ' / L,^apdecre\d,;)]

[0067] With:

[0068] - note (typeVoie), the note associated with the type of track “typeVoie”; E, the set of detected events; - note(typeVoie)y the note characterizing the probability of being on a track of nature typeWay when event e is encountered; - ae, the weighting associated with event e; - decr / d^), the decrease in the weighting of event e as a function of the distance from event e.

[0069] Preferably, a score is no longer taken into account when its weighting becomes zero (due to the decrease in weighting). Therefore, negative weighting is not used in this formula.

[0070] For example, system 2 detected - an end of expressway sign (see [Fig.4]) 4 km ago (weighting 45-20%=36), - a roundabout at the moment (weighting 10) (see [Fig.6]), - an average speed of the motor vehicle over the last kilometer of 90 km / h (weighting 15) (see [Fig.8]).

[0071] The average score corresponding to the hypothesis that vehicle 1 is on an urban road is: (36x50%+10xl00%+15x0%) / (36+10+15)=0.459

[0072] The average score corresponding to the hypothesis that vehicle 1 is on an extra-urban road is: (36x50%+10x0%+15x20%) / (36+10+15)=0.344

[0073] The average score corresponding to the hypothesis that vehicle 1 is on an expressway is: (36x0%+10x0%+15x80%) / (36+10+15)=0.197

[0074] The average score corresponding to the hypothesis that vehicle 1 is on a motorway is: (36x0%+10x0%+15x0%) / (36+10+15)=0

[0075] In a sixth step S60, the system 2 compares the average scores calculated for each type of traffic lane and assigns a type of lane to the traffic lane on which the motor vehicle is traveling.

[0076] For example, system 2 assigns to the traffic lane on which the motor vehicle is traveling the nature of the lane with the highest average score. In the case described above, with a score of 0.459, system 2 can consider that the vehicle is traveling on an urban road.

[0077] As an alternative to the example of attribution of the nature as soon as a note of a nature of track exceeds the note of the nature retained as the nature of the track on which the vehicle is traveling until now, a hysteresis logic can be implemented to manage this attribution. In fact, to avoid instabilities, a change of attribution from a first nature to a second nature can be made when: - the average rating of the second nature is higher than the average rating of the first nature permanently for a predetermined duration, for example a duration of several seconds, and / or - the average grade of the second nature is higher than the average grade of the first nature by at least a predetermined percentage, for example the average grade of the second nature is worth at least 1.1 times the average grade of the first nature.

[0078] The solutions described above have the advantage of not using GPS resources to locate the motor vehicle and of not using mapping storing in memory a model of traffic lane networks and the authorized speed limits on each section of these lanes.

[0079] The solutions described make it possible to maximize the number of indices collected, thus making it possible to secure and make more reliable the determination of the nature of the traffic lane on which the motor vehicle is traveling and, consequently, to secure and make more reliable the determination of the authorized speed limit where the motor vehicle is located.

Claims

Claims

1. Method for determining, by a management system (2) of a motor vehicle (1), a nature of a traffic lane on which the motor vehicle is traveling, the method comprising the following steps: • a step of acquiring data, in particular images, by the management system, • on the basis of the acquired data, a step of detecting events, in particular events in the environment of the motor vehicle, • for each detected event and for each type of traffic lane, a step of assigning a score characterizing the probability that the vehicle is on a lane of a given nature knowing that the event has occurred, • for each type of traffic lane, a step of calculating an average of the scores assigned, • a step of comparing the averages calculated for each type of traffic lane and assignment,to the traffic lane on which the motor vehicle is traveling, a nature, in particular the nature with the highest average.,

2. Determination method according to the preceding claim, characterized in that the determination method is executed in real time and / or in that the steps are iterated at a fixed time interval and / or at a fixed movement interval of the motor vehicle.

3. Determination method according to one of the preceding claims, characterized in that a decreasing weighting is applied to the scores assigned as the motor vehicle moves away from the location of detection of the event, for example a decreasing weighting of 10% per kilometer.

4. Determination method according to one of the preceding claims, characterized in that the events include events of the following categories: • detection of an explicit speed sign, and / or • detection of an implicit speed sign, and / or • detection of a contextual traffic sign, and / or • detection of a traffic lane structure, and / or • detection of a road marking, and / or • detection of dynamic information from a vehicle to the car, and / or • detection of other objects in the environment of the vehicle to the car and their possible dynamics, in particular detection of other users of the traffic lane, such as pedestrians, cyclists, motorcycles, trucks, other vehicles.

5. Method for determining, by a management system (2) of a motor vehicle (1), a maximum authorized speed on the traffic lane on which the motor vehicle is traveling, the method comprising the following phases: • a phase of implementing the method for determining the nature of a traffic lane on which the motor vehicle is traveling according to one of the preceding claims, and • a phase of using the nature of the traffic lane to determine the maximum authorized speed.

6. Determination method according to the preceding claim, characterized in that it comprises a phase of displaying the maximum authorized speed.

7. Determination method according to one of claims 5 and 6, characterized in that the use phase comprises a step of not taking into account a detection of an explicit speed limit sign.

8. Determination method according to one of claims 5 to 7, characterized in that the use phase comprises a step of interpreting the meaning of an implicit traffic sign.

9. Management system (2) of a motor vehicle (1), the management system comprising hardware and / or software elements (3, 4, 5, 6) implementing the method according to one of claims 1 to 8, in particular hardware elements (3, 4, 5, 6) and / or software designed to implement the method according to one of the preceding claims.

10. Motor vehicle (1) comprising a management system (2) according to the preceding claim.

11. A computer program product comprising program code instructions recorded on a computer-readable medium for implementing the steps of the method according to any one of claims 1 to 8 when said program is running on a computer.

12. Data recording medium (4), readable by a computer, on which is recorded a computer program comprising program code instructions for implementing the method according to one of claims 1 to 8.

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