METHODS AND SYSTEMS FOR SPEED RECOMMENDATION

Description

[0001] The present invention relates to the field of methods and systems for driver assistance, and more particularly to methods and systems for assisting a user in driving a vehicle such as speed recommendations along a vigilance zone.

[0002] Here we mean by " zone de vigilance "Any area of ​​a road network where particular attention to vehicle speed is required. More generally, a vigilance zone is a geographical area extending along a section of road where the speed and / or variation in vehicle speed on that section of road should, for safety reasons, be monitored."

[0003] Various reasons may justify defining a vigilance zone along a given section of road, such as: the particular geometric configuration of this section of road which includes, for example, a sharp bend, a series of bends, a roundabout, a crossroads, a dead end, a narrowed roadway, a level crossing, a dangerous descent, or an opening onto a quay; the qualities of the road surface on this section of road, for example a non-draining surface, a paved roadway; one or more road traffic rules to be observed on this section of road, for example priority to the right, a yield sign, traffic lights, a stop sign, a speed control zone, a speed bump, or toll barriers; human activities near or on this section of road, for example a school zone; obstacles and the state of traffic on this section of road, for example a traffic jam, a vehicle stopped on the roadway, an accident, or an object on the road;the weather conditions in a region covering this section of road, for example fog, freezing fog, snow, or black ice; various events taking place near or on this section of road, for example roadworks, a social movement, or an oversized load.

[0004] Prior art exists for devices installed in a motor vehicle to inform the driver of their approach to or entry into a traffic congestion zone. Document WO2017 / 174623 describes a method and device for identifying traffic jams or areas of regular traffic disruption at certain times of day. The method uses historical vehicle position data, and a congestion value is calculated by dividing the traffic speed on a given road segment by the average speed for the period under consideration. A delay is then deduced from this ratio when the road segment is being used, and this delay is provided as information to drivers of vehicles approaching frequently congested areas.The US2017 / 057411 document describes a system for managing truck fleets, a device that provides a recommended speed to the driver, based on a statistical analysis of the average speeds of vehicles that have traveled in a dangerous area, such as a highway on-ramp.

[0005] In these systems, information concerning this vigilance zone, including in particular the maximum speed set by the authorities or the managers of the road, is generally provided to the driver.

[0006] For this purpose, areas of the road network are identified beforehand as vigilance zones, and data concerning them (the reason for vigilance in this zone, the applicable speed limit, the geographical coordinates and the direction of traffic concerned) are stored.

[0007] As soon as it is determined that the instantaneous speed of the vehicle in a vigilance zone is greater than a fixed threshold value previously associated with this zone, an alert is communicated to the driver by the on-board device, in audible and / or visual form.

[0008] Existing systems have drawbacks.

[0009] In particular, these devices provide no assistance to the driver with regard to the appropriate variation of speed along the vigilance zone.

[0010] It is therefore up to the driver to adapt the speed of the vehicle, taking into account the applicable speed limit, based on what he can see, his experience, what he knows about the performance of the vehicle, and what he knows about his own capabilities.

[0011] As a result, no assistance is offered by existing methods and systems to the driver in adapting the vehicle's speed.

[0012] Existing driver assistance systems installed in the vehicle, as well as any road signs placed in a vigilance zone, only teach discreet speed limits (such as 130km / h, 110km / h, 90km / h, 70km / h, 50km / h or 30km / h) that the driver must observe in these zones.

[0013] Furthermore, what the driver can see from the vigilance zone in which he is driving depends in particular on his abilities, the weather conditions, the performance of the vehicle and the configuration of the road.

[0014] A driver's experience may lead them to overestimate their abilities, and the driver's age and / or condition may influence their perception of risk.

[0015] The driver may overestimate their reaction capabilities, or not know precisely the vehicle's capabilities.

[0016] The invention aims to overcome, at least in part, the drawbacks of prior art driver assistance devices.

[0017] One object of the invention is to offer a speed monitoring system, almost in real time, along a vigilance zone.

[0018] Another object of the invention is to modulate an alert of appropriate or recommended speeds in a vigilance zone, by information including data relating to the driver, data relating to the vehicle, data relating to other drivers, data relating to the vigilance zone, data relating to the external environment, and / or data relating to the vehicle's route.

[0019] Another object of the invention is to offer a personalized driving assistance system for a vehicle, particularly in a zone of recommended speeds.

[0020] Another object of the invention is to provide a device to assist in driving a vehicle, minimizing the risk of accidents for the driver.

[0021] Another object of the invention is to provide a driving assistance device, configured to alert the driver in a relevant manner to the excessive speed of his vehicle in a vigilance zone.

[0022] Another object of the invention is to improve the reliability of alerts communicated to motorists in vigilance zones.

[0023] Another object of the invention is to automatically determine vigilance zones in a road network.

[0024] Another object of the invention is to dynamically update information relating to a vigilance zone.

[0025] Another object of the invention is to recommend different speeds associated with different positions in a vigilance zone.

[0026] Another object of the invention is to propose speed support systems and methods on a speed profile associated with a vigilance zone, this speed profile being chosen according to data relating to the driver, data relating to the vehicle, data relating to other drivers, data relating to the vigilance zone, and / or data relating to the external environment.

[0027] Another object of the invention is to provide a database that can be used almost in real time, in particular by an embedded device, this database including up-to-date metadata relating to areas of vigilance.

[0028] To this end, a remote server configured for this purpose is proposed, according to a first aspect. collect travel speed data associated with positions on a road; calculate a statistical value of the speed data associated with substantially the same position of said positions; calculate a difference between the calculated statistical value and a predefined speed limit associated with said substantially the same position of the road; at least when the calculated positive difference is greater than a predefined threshold value, generate, on the basis of a digital map of the road, location data defining a vigilance zone in which special attention to travel speed is required, the vigilance zone covering a section of the road and incorporating said substantially the same position.

[0029] By " écart "Here, we refer to the positive difference between a predefined speed limit and the statistical value calculated at a given location on the road. The creation of a vigilance zone is linked to the observation that the predefined speed limit is higher than the calculated statistical value, by a value exceeding a threshold."

[0030] Various additional features can be provided, either alone or in combination: the remote server is further configured to determine, among the collected speed data, travel speed data associated with positions within the vigilance zone; determine a speed profile approximating the variation of the determined speed data according to their positions within the vigilance zone, this speed profile associating a recommended travel speed with a given position within the vigilance zone, the determined speed profile being associated with said vigilance zone; collect, with the travel speed data, descriptive data of a driving context;based on predefined criteria distinguishing at least one first driving context and a second driving context, distinguish in the collected travel speed data at least one first group of travel speed data and a second group of travel speed data, a first speed profile corresponding to the first group and a second speed profile corresponding to the second group being associated with said vigilance zone and, respectively, said first driving context and said second driving context; filter the collected travel speed data so as to take into consideration for the calculation of the statistical value only the travel speed data in a predefined direction of travel on the road, the determined speed profile being associated with said predefined direction of travel;generate the location data defining said vigilance zone when the radius of curvature of the road at said substantially the same position is less than a predefined radius value; the statistical value being a mean, the mode, or the median; the vigilance zone comprising a plurality of contiguous rectangular segments following the curvature of the road segment.

[0031] According to a second aspect, a speed recommendation system for movement is proposed according to claim 8.

[0032] A fourth aspect proposes a method for recommending travel speed comprising the following steps: collection of travel speed data associated with positions on a road; calculation of a statistical value of the speed data associated with substantially the same position of said positions; calculation of a difference between the calculated statistical value and a predefined speed limit associated with said substantially the same position of the road; at least when the calculated difference is greater than a predefined threshold value, generation, on the basis of a digital map of the road, of location data defining a vigilance zone covering a section of the road and incorporating said substantially the same position; detection of the presence of a driver assistance device on a section of road covered by the generated vigilance zone; identification of a predetermined speed profile associated with the vigilance zone, this speed profile associating a given position in the vigilance zone with a recommended travel speed;Determination of the position of the driver assistance device within the vigilance zone; determination of a speed of movement of the driver assistance device approximately at the determined position; determination, from the speed profile, of a recommended speed of movement associated with the determined position; calculation of a difference between the determined speed of movement and the determined recommended speed of movement; triggering of an alert at least when the calculated difference is greater than a predefined alert threshold value.

[0033] Other features and advantages of the invention will become clearer and more concrete upon reading the following description of embodiments, which is made with reference to the accompanying drawings in which: there figure 1 schematically illustrates modules of the speed recommendation system in a vigilance zone, according to various embodiments; the figure 2 schematically illustrates a plurality of vigilance zones, according to various modes of implementation; and the figure 3 schematically illustrates speed profiles associated with a vigilance zone, according to various implementation methods.

[0034] By referring to the figure 1 , it is schematically represented as a vehicle 1 equipped with a driving assistance device 2.

[0035] Vehicle 1, in particular a motor vehicle, is any mobile means with controllable speed of movement, such as, for example, a motorcycle, a car, a truck, an all-terrain vehicle, or a bus.

[0036] The driver assistance device 2 is, in one embodiment, a user device or included in a user terminal suitable for installation in the vehicle 1 .

[0037] As an alternative, the device 2 driver assistance is an integral part of the vehicle 1 .

[0038] The device 2 The driver assistance system includes a location module, allowing the device's current geographical location to be determined. 2 driver assistance and, consequently, that of the vehicle 1 in which this device 2 is installed.

[0039] For this purpose, the location module includes, in one embodiment, satellite location means (such as GPS, GLONASS, GALILEO, or BeiDou) and / or terrestrial networks.

[0040] More generally, the device 2 The driver assistance system is configured to generate location data allowing the device to be located relatively or absolutely. 2 driver assistance in a road network.

[0041] The device2 The driver assistance system also includes a processor capable of determining the speed of movement, or more generally, speed of movement data, of this device. 2 driver assistance and, consequently, that of the vehicle 1 in which this device 2 driver assistance is installed.

[0042] The speed of movement of the device 2 Driver assistance can be determined from the variation over time of the vehicle's position. 1 and / or retrieved from a speed sensor fitted to the vehicle 1 .

[0043] The device 2 The driver assistance system also includes a communication module capable of bidirectional communication with a server. 3 remote. This communication is established via any suitable wireless data communication network (e.g., GPRS, 3G, 4G, or 5G).

[0044] The device 2 The driver assistance system is, in one embodiment, a mobile user terminal such as a smartphone. This mobile user terminal includes a software application, a processor, a location module, and a communication module capable of communicating with the server. 3 distant.

[0045] The device 2 driver assistance communicates to the server 3 remote travel speed data associated with positions on the road 5 of the vehicle 1. This data can be transmitted to the server 3 remote, real-time or delayed (i.e., temporarily stored and then transmitted to the server). This data can be transmitted to the server 3 remote at the request of the latter, for example when the vehicle 1 is located on a road 5 or a predefined section of road.

[0046] Travel speed data associated with positions on the road 5 of the device 2 Driver assistance systems include, for example, time-stamped data of successive positions, so that a speed can be estimated at successive positions. This speed data may also include instantaneous speeds measured at different positions on the road. 5 .

[0047] Position data can include geographic coordinates (such as GPS coordinates in the form of latitude and longitude), curvilinear abscissas on the road 5 or, more generally, any data providing information on the vehicle's position 1 in absolute terms (with respect to a fixed point) or relative terms (for example, with respect to the previous position of the vehicle) 1 or any other position).

[0048] The server 3remote collection, in a database 31 , the travel speed data associated with positions on the road 5 which are communicated to him through devices 2 driver assistance systems, respectively, installed in vehicles 1 having already crossed the road 5 or a section of that road 5 .

[0049] The server 3 remote is provided with a digital map of a road network (i.e., a road network map) incorporating the road 5 This digital map includes, in addition to the geographical location data of the road 5 Speed ​​limits (or speed restrictions) for travel, respectively, associated with segments / sections of this road 5 This digital map can also include one or two directions of traffic, associated with the road. 5 .

[0050] In one embodiment, the device 2 driver assistance communicates to the server 3 distant from descriptive data of the current driving context of the vehicle 1 .

[0051] Descriptive data for a driving context includes information relating to current weather conditions (e.g. temperature, wind speed and direction, visibility, rainfall, rain, fog, freezing fog, or snow cover).

[0052] The device 2 driver assistance systems can obtain such information using sensors and / or dedicated means integrated within them and / or retrieve it from other means or user equipment (e.g., dedicated platforms or mobile applications).

[0053] The device 2 driver assistance systems can also obtain this information from the vehicle. 1(for example, based on the operating status of the windshield wipers, defogging systems, window defrosting systems or air conditioning).

[0054] Descriptive data of the current driving context includes information relating to the temporal context such as the time (rush hour, day / night, sunrise / sunset causing glare), the day (working day, weekend, holiday), or the month (season).

[0055] In addition, the descriptive data of the current driving context includes information contained in a driver profile. This information can be entered by the user (age, gender, year of obtaining the driver's license, number of kilometers driven per year, average reaction time, preferences) or determined by the device. 2 driver assistance.

[0056] In one embodiment, a user profile is determined by the device 2 driver assistance based on available user data. This user profile is, for example, of the type "learner driver", "experienced driver", "elderly person", "sporty driving", "aggressive driving", "normal driving".

[0057] In one embodiment, the user profile is chosen from a predefined list. Starting from a predefined user profile, the device 2 The driver assistance system "learns" the user's specific characteristics during its use and, consequently, refines the user profile. The more the device 2 The more driver assistance technology is used, the more representative the user profile.

[0058] In one embodiment, the device 2The driver assistance system is configured to detect drowsiness (sleepiness) or fatigue in the user. The device 2 driver assistance systems are capable of analyzing early signs of drowsiness or fatigue in the user, as such states can impact reaction time, risk assessment, and braking quality.

[0059] For this purpose, the device 2 driver assistance regularly observes symptoms or signs of user drowsiness or fatigue, such as the vehicle's time in operation since its last stop and / or the time of driving relative to critical times and / or a driver inactivity index deduced from successive changes in vehicle heading and / or speed over a given period of time.

[0060] In one embodiment, user information is communicated to the server 3 remotely and anonymously.

[0061] Descriptive information about the driving context also includes information about the vehicle 1 This information includes, for example, the vehicle's laden weight, the vehicle's unladen weight, whether the vehicle is towing a trailer (or a van, a caravan), the engine power, the vehicle's make, the vehicle type (commercial vehicle, off-road vehicle, sports car, motorcycle, for example), the date and content of the last vehicle inspection, the mileage, and, more generally, any information about the vehicle. 1 which can impact its braking performance, such as for example the quality / pressure of the tires.

[0062] As an alternative or in combination, the device 2The driver assistance system sends a message to the driver asking questions about at least one piece of information describing the driving context (start / end of work, change in a speed limit or road traffic rule, presence of an object on the road, a vehicle stopped on the roadway, an accident, a social movement or an exceptional convoy, for example).

[0063] For this purpose, the device 2 driver assistance includes means of querying the vehicle user (a screen and / or a speaker for example) on descriptive information about the driving context.

[0064] The device 2 driver assistance includes means (a keyboard, a touch keyboard or a microphone for example or, more generally, any means of data input), capable of allowing the user to answer this question.

[0065] The server uses the speed data and information relating to the corresponding driving contexts. 3 remote to determine areas of vigilance 4 on the road 5 .

[0066] In one embodiment, the server 3 remote applies processing aimed at filtering or eliminating extreme speed data, which is not representative of traffic on the road 5 or on a section of that road 5 For example, only speeds between a first threshold value and a second threshold value are retained.

[0067] The collected speed data can also be filtered by the direction of movement of the device. 2 driver assistance.

[0068] As an alternative or in combination, the server 3The system classifies the collected speed data into a plurality of groups, based on predefined criteria that distinguish driving contexts. These criteria can be temporal (day / night for example), meteorological (good / bad weather for example), related to the user (learner / experienced driver for example), to the vehicle (passenger car or utility vehicle for example), or a combination of these criteria.

[0069] The classification of speed data is based on information relating to driving contexts such as the temporal context (night driving, rush hour driving for example), the climatic context (driving in bad weather / in good weather), the vehicle context (vehicle performance, vehicle category), and / or the user profile ("learner driver", "experienced driver", "elderly person", "sporty driving", "normal driving").

[0070] The server 3remote is also configured to calculate a statistical value from the collected speed data that are associated with roughly the same position on the road 5 Two positions are considered to be substantially the same when they are separated by a distance less than a predefined threshold distance (1m, 2m, 3m, 5m, or 10m, for example).

[0071] The calculated statistical value is, for example, an average (the arithmetic, geometric, harmonic, or quadratic mean, for example), or even the mode or the median.

[0072] In one embodiment, the server 3 distant travels the road 5 to calculate a statistical value (for example, the average) of the speed data recorded at each position on the road 5 .

[0073] In another embodiment, the server 3The remote method calculates a statistical value (e.g., the average) of the speed data recorded at each position within a segment of the road. 5 (for example, a section including one or more turns).

[0074] Alternatively, the server 3 The distance calculates the statistical value (e.g., the average) of speed data recorded at roughly the same location. This location is, for example, a critical point on the road. 5 such as a point where the radius of curvature of the road 5 is less than a predefined value.

[0075] In another embodiment, the server 3 The distance determines a function approximating the variation of the speed data collected as a function of positions on the road 5where this speed data was collected. In this case, the statistical value of the travel speed data associated with a position is given by the value at that position of the approximation function. For each position on the road 5 the server 3 The distance calculates a difference between the velocity given by the function at this position and the limiting velocity associated with this position.

[0076] More generally, the server 3 distant determines at least one position on the road 5 An approximation of the collected velocity data that are associated with substantially the same position. This approximation is, in one embodiment, a statistical value of the collected velocity data that are associated with substantially the same position.

[0077] This statistical value can be the mean, mode, or median of a plurality of speed data points associated with roughly the same position, or the value at that position of a function approximating the variation of the speed data collected as a function of positions on a segment of the road. 5 including this position.

[0078] The server 3 distant calculates a difference between the statistical value calculated at a position on route 5 and a speed limit associated with that route position 5 .

[0079] The term "gap" here refers to the positive difference between the limit speed and the calculated statistical value.

[0080] The creation of a vigilance zone is linked to the observation that the predefined speed limit is higher than the calculated statistical value, by a value exceeding a threshold. The speed limit is, for example, as will become clearer later in this description, a speed limit on a curve determined from the radius of curvature of the road.

[0081] The calculated deviation can be a deviation (the difference between the calculated statistical value and the speed limit) or a relative deviation (the deviation multiplied by one hundred and divided by the speed limit). In another embodiment, the calculated deviation is a standard deviation.

[0082] When the calculated difference exceeds a predefined threshold value, the server 3 remote generates, based on the digital road map 5 location data defining a vigilance zone 4 covering a section of the road 5 .

[0083] This area of ​​vigilance 4 incorporates the road position 5 where the calculated deviation is greater than the predefined threshold value. When the calculated deviation is small, the server 3 distant identifies that drivers adjust their speeds to take into account a particular feature of the road section, such as a curve.

[0084] When the statistical value is calculated at a position on the road 5 is much lower than a speed limit associated with that position on the road 5 The gap is large and the server 3 distant identifies that drivers adjust their speeds to take into account a context, for example, poor road surface.

[0085] A zone of vigilance 4 thus corresponds to a section of the road 5 This area of ​​vigilance 4 includes, for example, a turn.

[0086] The vigilance zone 4extends longitudinally along the axis of the road 5 The vigilance zone 4 follows the curvature (that is, the sinuosity or geometry) of the road 5 .

[0087] For this reason, the vigilance zone 4 includes, in one embodiment, a polygon (simple or crossed) and / or a plurality of simple polygons 41-44 contiguous, which follow the route 5 Simple polygons 41-44 are, in one embodiment, rectangular segments (or sections) 41-44 .

[0088] A zone of vigilance 4 is a model using one or more rectangular segments 41-44 , or more generally by one or more polygons 41-44 adjoining, of a section of the road 5 .

[0089] The number of rectangular segments 41-44 constituting a zone of vigilance 4 depends on the curvature of the road5 at this location.

[0090] A predefined maximum misalignment angle between the axis of a rectangular segment and the local axis (i.e., at that location) of the road 5 allows us to determine the number of segments composing a vigilance zone 4 .

[0091] This maximum angle is, for example, 15°, 20°, 25° or 30°.

[0092] A small maximum angle (10° or 15° for example) improves the correspondence between location data and the vigilance zone. 4 and the actual location of the section of the road 5 , but increases the number of segments and, consequently, the volume of data relating to this area of ​​vigilance 4 .

[0093] The width of a rectangular segment is chosen to account for any difference between the actual location of the road 5 and the digital map of the road network from which the vigilance zone4 is created.

[0094] This width is also chosen to account for an inaccuracy in the device's localization module. 2 driver assistance.

[0095] Information relating to the section of road covered by the vigilance zone 4 are associated with this area of ​​vigilance 4 This information includes, for example, the direction of traffic. 7 A speed limit, the number of traffic lanes, the width of the traffic lanes, the radius of curvature, the superelevation value, and the gradient. One or more of these pieces of information can be retrieved from the digital road map. 5 .

[0096] Location data for a vigilance zone 4 allowing its geographical location on the road 5This location data includes geographic coordinates (e.g., latitude and longitude) and / or distances (e.g., radius, length, width), allowing the location (or definition), within a predefined coordinate system, of an area of ​​the globe covering a segment of the road 5 .

[0097] Location data for a vigilance zone 4 include location data for rectangular segments 41-44 (or, more generally, polygons) 41-44 ) constituting it.

[0098] The location data of a rectangular segment can be defined in an absolute and / or relative manner.

[0099] A rectangular segment can be defined by geographical coordinates of one or more points (corners, center, midpoint(s) of one or more side(s)), and / or by distances (width, length).

[0100] In one embodiment, the location data of each of the segments constituting a vigilance zone 4 are established by a width and by the geographical coordinates (latitude and longitude) of the midpoints (a first point A and a second point B) of the two opposite sides of the rectangular segment perpendicular to the axis of the road 5 The vector connecting point A to point B corresponds to the direction of traffic on the section of road represented by the rectangular segment in question.

[0101] Advantageously, a zone of vigilance 4 only applies to one direction of traffic. For example, for a section of road with a dangerous bend in both directions, there are two vigilance zones. 4 are created.

[0102] In other implementations, the information associated with the vigilance zone 4 include data defining the direction(s) of traffic7 on the stretch of road 5 who are affected by this vigilance zone 4 .

[0103] The direction of traffic 7 associated with the vigilance zone 4 is that of the road 5 at the level of each of the polygons 41-44 constituting this area of ​​vigilance 4 .

[0104] The direction of traffic 7 in the vigilance zone 4 is, in one embodiment, determined from the direction of travel of the vehicle 1 by examining the evolution of its position data.

[0105] This allows the use of, for the creation of a vigilance zone 4 a road network map that does not teach the direction of travel 7 or a map of the road network including information on traffic directions 7 are not up to date.

[0106] The vigilance zone 4extends along the road 5 on either side of a position at which the calculated gap is greater than the predefined threshold value (called the critical point) 6 ) of, respectively, a first curvilinear distance and a second curvilinear distance. These curvilinear distances can be chosen according to the speed limit associated with the road 5 at this position.

[0107] These curvilinear distances can also be chosen according to the type of road 5 (motorway, national road, or regional road for example), depending on the driving context (weather conditions, user profile, vehicle performance) 1) and / or the value of the calculated deviation at the position in question. One or each of these curvilinear distances can be determined by tracing back, section by section, the route taken by the user that will pass through the position at which the calculated deviation is greater than the predefined threshold value, up to a maximum distance.

[0108] For example, a vigilance zone 4 is built starting from either side of the road's position 5 where a maximum difference between the statistical value of the recorded speeds and the speed applicable to that position is observed, respectively, of a first distance and a second distance. A first distance is chosen by progressively moving away in the opposite direction of the direction of traffic 7 on the road 5 which leads to this position and a second distance is chosen by gradually moving away in the direction of traffic 7 on the road 5from this position.

[0109] For example, the first and second distances are 150 and 20 meters respectively for a vigilance zone. 4 covering an uncontrolled intersection, 100 and 200 meters for a vigilance zone 4 covering a traffic jam, or 300 and 50 meters for a vigilance zone 4 covering an accident on a motorway.

[0110] In the illustrative example of the figure 1 the vigilance zone 4 spreads out on either side of the critical point 6 of a sharp turn.

[0111] In one embodiment, several areas of vigilance 4 of different lengths are constructed.

[0112] For example, three areas of vigilance 4 are built starting from a critical point 6(the point where the difference between the statistical value of the recorded speeds and a speed limit associated with that point is greater than the threshold value) on the road 5 and gradually moving away from it in the opposite direction to the direction of traffic 7 on the road 5 up to, respectively, three distances (for example 100, 200 or 300 meters).

[0113] In the illustrative example of the figure 2 three areas of vigilance 4 are created, based on data relating to the critical point 6 included in a roundabout.

[0114] In one embodiment, the server 3 remote checks, in order to improve the reliability of the vigilance zones 4 determined from speed data readings, the consistency of the data determined with data included in the digital road network map (in particular, when the vigilance zone 4determined covers one or a series of sharp turns, a stop sign, an intersection, a roundabout, a crossroads, or a dead end).

[0115] For example, as soon as the statistical value of the speed data recorded at a point on a road segment is lower than a speed limit applicable at that point on the road 5 of at least one predefined positive value (for example, 10 km / h, 15 km / h, or 20 km / h) or is less than a given percentage of this speed limit (for example, 80%, 75%, or 60%), a vigilance zone 4 covering a section of road on either side of this point is generated by the server 3 distant.

[0116] In another embodiment, to generate a vigilance zone 4 including a position where the difference between the average of the recorded speeds and the speed limit associated with the road 5at this position is greater than the predefined threshold value, the server 3 remote checks if the geometry (or topology) of the road 5 This position includes one or more specific predefined physical configurations. A physical configuration of the road 5 is said to be particular as soon as a reason for vigilance is determined there.

[0117] A list of particular physical configurations advantageously includes a bend of a predefined radius of curvature, a predefined slope and / or cross slope, a predefined intersection (in particular, not controlled by markings, barriers, signs or traffic lights), a hilltop having a predefined slope and / or cross slope, or a combination of these configurations.

[0118] A particular road configuration 5 can be determined from its digital map. For example, when a road 5is defined by a Cartesian equation of the type y = f(x), a geometric turn can be identified by calculating the radius of curvature, according to the following formula: ρ x = 1 + y ′ 2 3 2 y ′ ′ where ρ is the radius of curvature of the road 5 y' and y'' are respectively the first derivative and the second derivative of y with respect to x.

[0119] As an alternative or in combination, a particular physical configuration of the road 5 can be determined from position data received from a plurality of 2 driver assistance devices, respectively, installed in vehicles 1 For example, based on the position data collected and expressed in an orthonormal coordinate system, a geometric turn is determined by the following formula: ρ t = x ′ 2 + y ′ 2 3 2 x ′ y ′ ′ − y ′ x ′ ′ where ρ is the radius of curvature of the road 5and y' and y'' (respectively, x' and x'') are respectively the first derivative and the second derivative of y (respectively, of x) with respect to time t.

[0120] More generally, a geometric turn is a succession of points on the road having a radius of curvature less than a predefined threshold and having a constant direction (right turn, left turn).

[0121] A speed limit associated with the point of the bend where the road curves 5 is maximum (the curvature being the inverse of the radius of curvature) is determined from descriptive parameters of this curve, such as the curvature, the superelevation or the slope of the road 5 at this bend. For example, this speed limit is determined from the radius of curvature of route 5 as follows: V limite = pgμ where ρ is the radius of curvature of the road 5, g is the acceleration due to gravity (g=9.81 m / s²) and µ is a coefficient of road adhesion (a coefficient of friction between the tires and the road surface).

[0122] Alternatively, the speed limit associated with the point of the bend where the curvature of road 5 is maximum is determined from the superelevation d, the radius of curvature ρ and the road friction µ as follows: V limite = ρg d + μ 1 − dμ

[0123] In one embodiment, the speed limit V_limit associated with the point of the bend where the road curvature 5 The maximum speed limit is determined from a statistical analysis of the speed data recorded at that point. For example, this speed limit is the average of the speeds recorded at that critical point of the curve. Alternatively, the speed limit is the mode, the minimum value, the maximum value, or the median value of the speeds recorded approximately at the critical point of the curve.

[0124] Among all the curves identified on a route 5, some can be classified as dangerous - and therefore added to the list of specific physical configurations - based on filters incorporating, alone or in combination: a first filter, based on the volume and diversity of the speed data recorded (the number of GPS data points in a turn and / or the number of devices 2(distinct driver assistance systems having passed through this section of road and / or the diversity of driving contexts); a second filter, based on the validity of the bend (consistency of the statistical value of the speeds recorded at the critical point of a bend with the theoretical speed of the bend calculated according to the radius of curvature of the road); a third filter, based on the consistency between the study upstream of the bend and inside the bend (the average of the speeds recorded and the applicable speed limit must be similar); a fourth filter, based on the danger of the bend (according to the deceleration coefficient specific to this bend).

[0125] For each turn, a regression method applied to the speeds recorded at different distances traveled in the turn makes it possible to determine a profile (deceleration, target speed of passage) specific to that turn.

[0126] Information associated with a vigilance zone 4 include at least one profile 8 speed. When more than one direction of traffic 7 is affected by the vigilance zone 4, a profile 8 Speed ​​is associated with each direction of travel.

[0127] As illustrated by the figure 3 a profile 8 speed includes recommended speeds (on the y-axis of the graph of the figure 3 ), at different positions or, equivalently, at different distances traveled within the vigilance zone 4 (on the x-axis of the graph of the figure 3 ).

[0128] More generally, a profile 8 speed includes speeds to adopt along the vigilance zone 4 in the direction of traffic 7 which allow the vehicle 1 to cross this area safely.

[0129] A profile 8speed is a model of variations, depending on the distance traveled in the vigilance zone 4, speed data collected associated with positions within the vigilance zone 4 .

[0130] In one embodiment, a profile 8 speed is a function approximating the variations, depending on the positions within the vigilance zone 4 speed data collected associated with positions within the vigilance zone 4 .

[0131] To do this, regression methods (multilinear, polynomial, or other) can be used to determine a function approximating the variation as a function of position (or distance traveled) within the vigilance zone. 4velocity data collected. Various modeling techniques, curve fitting or analysis of state-of-the-art experimental data can be used for this purpose.

[0132] Thus, for a vigilance zone 4 generated, the server 3 remote is configured for determine, among the collected speed data, those that are associated with positions within this vigilance zone 4 and determine a profile 8 speed approaching the variation of the determined speed data, depending on their positions in the vigilance zone 4.

[0133] In an advantageous embodiment, illustrated by the figure 3 several profiles 8 speed limits are associated with the same vigilance zone 4 by driving context. For this, the server 3 remote selects all speed data associated with positions within a vigilance zone 4 ; filters the selected data, removing extreme speed data; based on the driving context information provided with the speed data, classifies the filtered speed data into a plurality of groups, corresponding to distinct driving contexts (e.g., driving in bad weather and learner driver, night driving and loaded vehicle); determines a speed profile 8 per driving context (i.e., per speed data group), by modeling the speed data corresponding to that context.

[0134] Different profiles 8 Speed ​​limits can also be considered for contiguous segments constituting the vigilance zone 4.

[0135] In another embodiment, a profile 8The default speed, determined from all collected speed data regardless of driving context, is associated with the vigilance zone. 4.

[0136] In another embodiment, instead of being determined independently of the drivers, the speeds recorded in a vigilance zone 4 are processed by user, so as to be remembered as a profile 8 speeds are the speeds recorded by a driver considered to be a typical user.

[0137] Alternatively or in combination, the recorded travel speed data are assigned coefficients so that the calculated statistical value is weighted (such as a weighted average). In one embodiment, these coefficients are associated with user profiles, such as user reliability indices. A user's reliability index is proportional to their use of the device.2 assistance with driving and / or compliance with applicable speed limits over a given period of time.

[0138] In one embodiment, a profile 8 The initial speed is determined theoretically, based on the geometry of the road segment and the speed limit and / or traffic regulations applicable there. This profile 8 The initial speed is subsequently refined dynamically, using speed readings at different positions or distances traveled within the vigilance zone. 4.

[0139] For example, a first theoretical approximation of a profile 8 speed along a segment (or polygon) of a vigilance zone 4 including a turn is given by the following equation v D = v cible _ sortie 2 − 2 aD Or v(D) is the recommended speed at a remaining distance D to be covered by the vehicle 1in this segment, in the direction of travel associated with it; v_cible_sortie is the target exit speed of this segment; a is the acceleration (or, more precisely, the deceleration), assumed constant, of the vehicle 1 in this segment of the vigilance zone 4 (for example -2m / s 2<, -3m / s 2<, or -5m / s 2<).

[0140] In one embodiment, the acceleration a is a constant specific to each segment of the vigilance zone 4.

[0141] In another embodiment, the recommended speed profile 8 takes into account the user's reaction time in the following way: v D = v cible _ sortie 2 − 2 a D − d where v(D) is the recommended speed for the remaining distance D to be covered by the vehicle 1 in a segment of the vigilance zone 4 in the direction of travel associated with it; v_cible_sortie is the target exit speed of this segment of the vigilance zone 4; a is a predefined negative constant associated with this segment of the vigilance zone 4 and / or to a user profile; d is the distance traveled by the vehicle 1 during the user's reaction time. This distance d is given by the product of the current speed of the vehicle by the user's reaction time (d=current_vehicle_speed * user_reaction_time).

[0142] It is assumed in the above that the quantity ( D-d ) is positive. Otherwise, v(D) is given by v_target_output (i.e., v(D)= v_target_output).

[0143] As soon as a vigilance zone 4 is generated or updated, the server 3 remote stores information about her in the database 31 and thus makes them available to the devices 2 driving assistance and / or communicates them to them.

[0144] In one embodiment, and in order to facilitate the detection of vehicle entry 1 in a zone of vigilance 4 among all the areas of vigilance 4 available in the database 31 data relating to areas of vigilance 4 located at a predefined distance from the vehicle's current position 1 are received (in a buffer) by the device 2 driver assistance, from the server 3 distant.

[0145] In another embodiment, the device 2 retrieved from the server 3 data from a predefined number of vigilance zones 4 and / or those located below a predefined distance from the vehicle's current position 1 .

[0146] Alternatively, the device 2 retrieved from the server 3 data from the vigilance zones 4located within a predefined distance of the vehicle's current position and accessible via the road network from that position. This predefined distance is either a straight line distance or a curved line distance following the road's alignment, between the vehicle's current position and the vehicle. 1 and a predefined point in the vigilance zone 4 .

[0147] This predefined point can be the center of a vigilance zone 4 , an entry point into a vigilance zone 4 depending on the direction of traffic associated with it, an exit point from the vigilance zone 4 depending on the direction of traffic associated with it, a point on the first rectangular segment (in the direction of traffic) of a vigilance zone 4 .

[0148] In another embodiment, the data relating to the vigilance zones 4data located between two lines of longitude and two lines of latitude are loaded into a buffer memory of the device 2 driver assistance systems. These lines of longitude (respectively, latitude) are chosen on either side of the vehicle's current longitude (respectively, latitude). 1 i.e., the areas of vigilance 4 located within a square or rectangle centered on the vehicle's current position 1 .

[0149] In another embodiment, all the vigilance zones 4 are stored (or embedded) in the device 2 driver assistance. Periodic communication between the device 2 driver assistance and the server 3 remote, in this case, relates to updating the information contained in the device 2 driver assistance (a new vigilance zone) 4or an update of data relating to a vigilance zone 4 existing). This advantageously reduces the size of the data to be downloaded.

[0150] In another embodiment, when the device 2 driver assistance offers a navigation service, the device 2 driver assistance retrieves advantageously from the server 3 remote access to data relating to vigilance zones 4 located on the vehicle's route 1 .

[0151] The device's processor 2 The driver assistance system detects, based on its location data, the entry or presence of the vehicle. 1 in a zone of vigilance 4 (i.e., in any one of the rectangular segments constituting it) thanks to geofencing of the vehicle 1 compared to the vigilance zones 4 .

[0152] In one embodiment, the processor regularly compares the geographical coordinates (latitude and longitude) of the vehicle 1 to the location data of the vigilance zone 4 to detect the entry or presence of the vehicle 1 in this area of ​​vigilance 4 .

[0153] In one embodiment, the detection of entry or presence of the device 2 driver assistance in a vigilance zone 4 focuses only on a limited list of all vigilance zones 4 This reduced list of areas of concern 4 Candidates are determined based on the device's location data. 2 driver assistance.

[0154] A comparison between the direction of travel of the vehicle 1 in the vigilance zone 4 and the direction of traffic relative to this vigilance zone 4is not necessary when the road 5 includes one direction of traffic and / or when the device 2 the driver assistance system provides the route to be followed by the vehicle 1 .

[0155] In one embodiment, the direction of movement or the heading of the vehicle 1 (or the direction of movement of the device) 2 driver assistance) in the vigilance zone 4 is determined from the vehicle's geographical coordinates 1 in a plurality of positions within the vigilance zone 4 .

[0156] In one embodiment, the vehicle's heading and direction of travel within the vigilance zone 4 are determined in relation to a common reference point (for example, geographic north), in order to facilitate their comparison. The vehicle 1 is considered to be travelling in the direction of travel associated with the vigilance zone 4when the angular deviation between the vehicle's heading 1 (which is the same as the direction of movement of the device) 2 driver assistance) and the direction of travel associated with each of the rectangular segments of the vigilance zone 4 is less than a predefined value (for example, 20°, 25°, 30°, or 35°).

[0157] When a vehicle 1 including the device 2 driver assistance enters a vigilance zone 4 and travels in the direction of traffic 7 associated with this area of ​​vigilance 4, the device's processor 2 driving assistance: determines the vehicle's position 1 in the vigilance zone 4 or, equivalently, the distance travelled or the distance remaining to be travelled by that vehicle 1 in the vigilance zone 4 ; determines the speed of the vehicle 1(or, the speed of movement of the device) 2 driver assistance) in the vigilance zone 4 at the determined distance; determines, from the profile 8 speed associated with the vigilance zone 4, a recommended speed corresponding to the determined position (or, to the distance travelled) of the vehicle 1 in the vigilance zone 4 ; calculates a difference between a given vehicle speed 1 and the recommended speed; generates an alert, at least when the difference between the determined vehicle speed 1 and the recommended speed is higher than a predefined alert threshold value.

[0158] The driver assistance processor is also configured to determine the direction of travel of the vehicle. 1 in the vigilance zone 4 and to use the profile 8 of speed associated with the determined direction of movement.

[0159] In one embodiment, the device 2 driver assistance determines the current driving context of the vehicle 1 based on the descriptive driving context data, described above, available to it. In this case, to determine a recommended speed, the device 2 driver assistance uses the profile 8 speed that corresponds to the current driving context of the vehicle 1 .

[0160] The distance travelled by the vehicle 1 in a zone of vigilance 4 is the curvilinear distance traveled since entering the vigilance zone 4 This distance is determined by the processor, using successive location data within the vigilance zone. 4 of the vehicle 1 .

[0161] The alert is intended to prompt the driver to adjust the vehicle's speed. 1so that its speed roughly follows / describes the profile 8 speed. This comparison also aims to determine the vehicle's speed at certain critical points within the vigilance zone. 4 be approximately equal to a target speed. The instantaneous or near-instantaneous speed of the vehicle 1 is, in fact, constantly compared along the vigilance zone 4 at recommended speeds from speed profile 8 which vary depending on the vehicle's position 1 in this area of ​​vigilance 4.

[0162] Comparing the instantaneous speed of the vehicle 1 to a distance travelled within the vigilance zone 4 at a recommended speed over the same distance aims to determine if the vehicle's current speed follows (or changes according to) the profile 8 speed, and alert the driver as soon as he deviates from it by a predefined amount.

[0163] The calculated difference between the instantaneous speed of the vehicle 1 to a distance travelled within the vigilance zone 4 and the recommended speed at that same distance is an absolute deviation, a relative deviation, or a standard deviation.

[0164] For the purpose of economical driving and / or driving comfort, the device 2 The driver assistance system is capable of suggesting recommended speeds, based on the calculated deviation value, so as to allow the driver to smoothly approach or reach a profile 8 speed.

[0165] In one embodiment, the alert threshold value is specific to each vigilance zone. 4 and / or to each driving context (i.e., to each user profile, each temporal context, each climatic context, or each vehicle context). In another embodiment, the alert threshold value decreases as the vehicle 1is approaching a critical point in the vigilance zone 4 (for example, the point where the curvature is greatest in a bend, the beginning of a traffic jam, the site of an accident, an uncontrolled intersection, the crest of a hill, the location of a school exit).

[0166] The issuing of an alert takes into account user preferences, previously specified in a user profile. User preferences include, for example, different security levels such as "high", "medium", "low medium", and "low", allowing for the identification of areas requiring vigilance. 4 in which the user is alerted, the frequency of alerts in a vigilance zone 4, the alert threshold value, and / or the display mode of an alert.

[0167] An alert is thus issued to the user when they have traveled a certain distance within the vigilance zone. 4when at least one condition is met. In one embodiment, this condition relates to the difference between the current speed of the vehicle 1 and a recommended speed, both determined at approximately the same distance travelled (or remaining distance), relative to a predefined alert threshold value. In combination, other conditions relating to the driving context and / or direction of travel are considered.

[0168] The driver alert includes (visually and / or audibly) the recommended speed and / or the calculated deviation. In one embodiment, the alert includes an overlay of the vehicle's current speed on the same coordinate system. 1 and, at least partially, the profile 8 speed.

[0169] This alert may also include metadata concerning the area of ​​vigilance 4(the reason for the alert, such as "sharp turn" or "accident", the total length of the alert zone, the date of the last update, the number of users whose speed data was used to establish the speed profile) 8 (for example), the remaining curvilinear distance to be covered in the vigilance zone 4, and / or an invitation from the driver to reduce their speed such as "slow down", "caution, excessive speed", or "adjust your speed".

[0170] The instantaneous speeds of the vehicle 1 in the vigilance zone 4 as well as the positions at which these speeds are determined by the device 2 driver assistance information is communicated to the server 3 distant.

[0171] The server 3 remote uses this new data to update the data relating to the vigilance zone 4 which has just been crossed.

[0172] The server 3 remote thus constantly updates the data relating to the vigilance zones 4 (New areas may be added, others removed, and others modified), including vigilance zones 4 covering a changing event such as a traffic jam, fog, black ice, roadworks, a social movement, or an oversized convoy.

[0173] To improve reliability and to update data relating to a vigilance zone 4, the server 3 remote sends to at least one vehicle 1 having just passed through a vigilance zone 4 a question message relating to at least one piece of information concerning this area (for example its existence, its level of danger, relevance of the recommended speed).

[0174] For this purpose, the device 2Driver assistance systems include means of interrogating the vehicle user (a screen and / or a speaker, for example). 1 on information concerning the vigilance zone 4 immediately after passing over it. The device 2 The driver assistance system includes means (such as a keyboard, a touchscreen keyboard, or a microphone, or more generally, any data input device) that allow the user to answer this question. The user's response is communicated, via the communication module of the driver assistance device 2, to the remote server 3.

[0175] The relevance of recommended speeds along a vigilance zone 4 is improved with the increase in the number of users in the community who have the device 2 driver assistance systems and passing through this vigilance zone 4This relevance is further enhanced when speed readings are taken in different climatic conditions and / or different time contexts (day, night, season, time, glare, working days, weekend, holidays), and / or different user profiles and / or different types and performance of vehicles.

[0176] Advantageously, the speed recommendation system described above is able to refine its accuracy during use at several levels: firstly, at the general level of all drivers using it (communication of speed data in vigilance zones) 4 existing profiles to refine profiles 8 speed and outside existing vigilance zones to detect new ones), and on the other hand at the individual level of each driver and / or vehicle (user profile).

[0177] Advantageously, the above speed recommendation system allows a user with the device in their vehicle to 2 driver assistance to adapt one's driving, based on experimental data from drivers with a profile similar to one's own.

[0178] Advantageously, in the same driving context, drivers with similar profiles are thus assigned the same profile 8 speed to follow in a vigilance zone.

[0179] Advantageously, by recommending an appropriate speed per position, the different embodiments described above improve road safety, particularly in mobile and / or temporary vigilance zones (traffic jam, fog, an object on the road, a vehicle stopped on the roadway, an accident, a social movement, an exceptional convoy).

Claims

1. A remote server (3) configured to - collect travel speed data associated with positions on a road (5); - calculate a statistical value of the speed data associated with substantially a same position of said positions; - the server being characterised in that it is configured to calculate a positive difference between the statistical value calculated and a predefined limit speed associated with said substantially same position of the road (5); - at least when the positive difference calculated is greater than a predefined threshold value, generate, based on a digital map of the road (5), location data defining a vigilance zone (4) in which particular attention to the travel speed is required, the vigilance zone (4) covering a road section of the road (5) and integrating said substantially same position.

2. The remote server (3) according to claim 1, characterised in that it is further configured to - determine, among the speed data collected, travel speed data associated with positions included in the vigilance zone (4); - determine a speed profile (8) that is a function approaching variations, according to the positions in the vigilance zone (4) of the speed data collected associated with positions included in the vigilance zone (4), this speed profile (8) associating with a given position in the vigilance zone (4) a recommended travel speed, the speed profile (8) determined being associated with said vigilance zone (4).

3. The remote server (3) according to the preceding claim, characterised in that it is further configured to - collect, with the travel speed data, descriptive data of a driving context such as climatic conditions, vehicle performance; - based on predefined criteria distinctive of at least one first driving context and a second driving context, distinguish in the travel speed data collected at least one first group of travel speed data and a second group of travel speed data, a first speed profile corresponding to the first group and a second speed profile corresponding to the second group being associated with said vigilance zone (4) and, respectively, with the first driving context and with the second driving context.

4. The remote server (3) according to claim 2 or 3, characterised in that it is further configured to filter the travel speed data collected so as to take into consideration for the calculation of the statistical value only the travel speed data in a predefined direction of travel on the road (5), the determined speed profile being associated with said predefined direction of travel.

5. The remote server (3) according to any of the preceding claims, characterised in that the statistical value is an average, the mode, or the median.

6. The remote server (3) according to any of the preceding claims, characterised in that it is further configured to generate the location data defining said vigilance zone (4) when the radius of curvature of the road (5) at said substantially same position is less than a predefined radius value.

7. The remote server (3) according to any of the preceding claims, characterised in that the vigilance zone (4) comprises a plurality of joint rectangular segments (41-44) following the curvature of the road section.

8. A travel speed recommendation system, this system comprising the remote server (3) of any of claims 1 to 7 and a driving assistance device (2) to be embedded in a vehicle (1) comprising a location module configured to generate location data for locating a position of the driving assistance device (2); a processor configured to - detect, based on the location data, the presence of the driving assistance device (2) in a predefined vigilance zone (4) in which particular attention to the travel speed is required; - identify a predetermined speed profile (8) associated with the vigilance zone (4), this speed profile (8) associating with different given positions in the vigilance zone (4) a recommended travel speed; - determine the position of the driving assistance device (2) in the vigilance zone (4); - determine a travel speed of the driving assistance device (2) substantially at the position determined; - determine from the speed profile (8) a recommended travel speed associated with the position determined; - calculate a deviation between the travel speed determined and the recommended travel speed determined; - trigger an alert at least when the deviation calculated is greater than a predefined alert threshold value.

9. The system according to the preceding claim, characterised in that the driving assistance device (2) is a mobile user terminal.

10. The system according to claim 8 or 9, characterised in that it further comprises a communication module configured to communicate to the remote server (3) travel speed data associated with positions of the driving assistance device (2).

11. The system according to any of claims 8 to 10, characterised in that the processor is further configured to determine a travel direction in the vigilance zone (4) of the driving assistance device (2), the identified speed profile being further associated with the travel direction determined.

12. The system according to any of claims 8 to 11, characterised in that it is configured to determine, based on a plurality of data, a driving context of the vehicle (1), the identified speed profile (8) being further associated with the driving context determined.

13. The system according to claim 12, characterised in that the driving context comprises a plurality of pieces of information integrating the driving time, the driving date, climate information, information relating to the vehicle (1), information relating to the road sections covered by the vigilance zone (4), and / or information relating to the driver of the vehicle (1).

14. A travel speed recommendation method comprising the following steps: - collecting travel speed data associated with positions on a road (5); - calculating a statistical value of the speed data associated with substantially a same position of said positions; - the method being characterised in that it comprises the following steps of calculating a positive difference between the statistical value calculated and a predefined limit speed associated with said substantially same position of the road (5); - at least when the positive difference calculated is greater than a predefined threshold value, generating, based on a digital map of the road (5), location data defining a vigilance zone (4) in which particular attention to the travel speed is required, the vigilance zone (4) covering a road section of the road (5) and integrating said substantially same position; - detecting the presence of a driving assistance device (2) on a road section covered by the vigilance zone (4) generated; - identifying a predetermined speed profile (8) associated with the vigilance zone (4), this speed profile (8) associating with different given positions in the vigilance zone (4) a recommended travel speed; - determining the position of the driving assistance device (2) in the vigilance zone (4); - determining a travel speed of the driving assistance device (2) substantially at the position determined; - determining, from the speed profile (8), a recommended travel speed associated with the position determined; - calculating a deviation between the travel speed determined and the recommended travel speed determined; - triggering an alert at least when the deviation calculated is greater than a predefined alert threshold value.