Method and related device for selecting information items to be transmitted to the vehicle's onboard system.

Abstract

The present invention relates to a method for selecting an information item from among a plurality of information items emitted by a transmitter located remotely from a vehicle, with the purpose of transmitting the selected information item to at least one system installed in the vehicle, the method providing the following steps: a) a step (E1) of estimating the position of each information item on a map of the movement path according to the absolute position of the received information, b) a step (E2) of determining at least one place of interest in which at least one on-board system should locate the information item it wishes to transmit, c) a step (E3) of selecting from the received information items an information item to be transmitted to the on-board system according to the estimated position of the received information item on the map established in step a) and the place of interest identified in step b).The present invention also relates to a device for selecting an information item from among a plurality of information items emitted by a transmitter located remotely from a vehicle, with the purpose of transmitting the selected information item to a system installed in the vehicle.

Description

[Technical Field]

[0001] The present invention generally relates to a system that enables an automated vehicle to communicate with the outside world. More specifically, the present invention relates to selecting information items from a plurality of information items received at time t from a transmitting side located away from the vehicle, for the purpose of transmitting selected information items to at least one driver assistance system installed in the vehicle.

[0002] More specifically, the present invention relates to a method for selecting information items and a device for selecting information items.

[0003] The present invention is more particularly advantageously applicable to the selection of information items received by a vehicle in relation to technologies generally referred to as "V2X," which include technologies where the transmitting side communicating with the vehicle is another vehicle (V2V), technologies where the transmitting side communicating with the vehicle is road infrastructure (V2I), technologies where the transmitting side communicating with the vehicle is a network transmitter (V2N), and technologies where the transmitting side communicating with the vehicle is a pedestrian (V2P). [Background technology]

[0004] Currently, many vehicles are equipped with onboard driver assistance systems that enable the driver to be assisted while driving, either in dangerous driving situations or simply to enhance driving comfort. Examples of such systems include navigation systems that help the driver follow a route from point A to point B, advanced driver assistance systems (ADAS), or dashboards that display warnings while the vehicle is being driven. To operate effectively, onboard systems must explore and analyze the vehicle's environment, both near and far. For this purpose, vehicles are equipped with physical sensors that collect information about their surroundings. To further enhance their knowledge of their environment, vehicles may also be equipped with V2X technology, which enables them to receive messages from transmitters located far from the vehicle, for example, from other vehicles (V2V), from road infrastructure (V2I), from networks (V2N), or from other road users such as pedestrians (V2P). The messages received from these transmitters include a variety of information items, such as: the transmitter's absolute position (in GPS coordinates), the confidence level of this position, the transmitter's speed, the transmitter's acceleration and / or direction of motion, or any hazards the transmitter encountered or created during its motion (slippery roads, dangerous curves, accidents, traffic congestion, etc.). Therefore, with the increasing number of vehicles to which V2X technology is deployed, the number of information items received per second in a vehicle will eventually become so large that it will be necessary to select the received information items so that each onboard system transmits only the information items that are useful to it; otherwise, there is a risk that the operation of the onboard system will saturate and slow down. [Overview of the project]

[0005] In this regard, the present invention provides a method for selecting information items that can be removed or have their priority lowered, in order to make it easier for the onboard system to process the information items and to prevent the operation of the onboard system from slowing down. More specifically, according to the present invention, a method is provided as defined in the introduction, in which the following is done: a) Estimate the position of each received information item on the driving lane map according to the absolute position of the information item received at time t. b) At least one mounted system to Prioritized sending should Determining the location of at least one object of interest where the information item must be located, and c) Select from the received information items which information items should be transmitted to the onboard system, depending on the estimated location of the received information items in the map established in step a) and the location of interest determined in step b).

[0006] The term "travel lane" refers to any type of road or path that can be taken by vehicles, whether motorized or not, or by pedestrians.

[0007] Therefore, according to the present invention, information items located outside the area of ​​interest are not transmitted to the onboard system or are considered not to be of priority by the system. This makes it possible to reduce the number of information items that need to be processed by the onboard system and to store only the most important information items.

[0008] The following are other advantageous and non-limiting features of the method according to the present invention, which can be performed individually or in any technically possible combination: - In step a), the location of each information item received at time t is estimated within the map using a location procedure selected from either a simplified procedure with rapid execution or a more complex procedure with slower execution, the location procedure being selected according to the density value of the network of driving lanes along the vehicle's reference route. - The selection of the location determination procedure is further carried out according to the statistical error related to the absolute position of the information item received at time t. - The simplified localization procedure includes orthogonal projection of the absolute position of the received information item onto each lane, and selection of the shortest orthogonal projection to estimate the position of the received information item within the map. - The complex localization procedure determines the appropriate lane by projecting the absolute position of the information item received at time t onto a relatively large area of ​​the map, and on the other hand, based on a relatively large number of past positions adopted by the information item received in the time preceding time t. - The complex localization procedure includes a parameterization step in which the size of the map area and the number of past locations to be considered are parameterized according to the statistical error associated with the absolute location of the information item received at time t. - The complex localization procedure further includes an initialization step in which, for each of the past locations adopted in one of the time periods preceding time t, it is selected whether the location to be considered is the absolute location of the information item received in the time period preceding time t or an estimated location on the map, and this selection is made according to the confidence level of the estimated location. - In step b), the location of interest is defined by a spatial filter that indicates the portion of the travel lane to be considered, on the one hand, depending on the vehicle's position at time t, and on the other hand, depending on the vehicle's reference route at time t. - The spatial filter includes a list of driving lane segments. - Spatial filters include: Reference locations within the map, The maximum distance along the vehicle's reference route, measured from the reference location. adjacent driving lanes to be considered range and in some cases, the maximum distance within the adjacent driving lane measured from the reference position. The present invention also provides a device for selecting an information item from a plurality of information items received at time t from a transmitting side located away from the vehicle for the purpose of transmitting the selected information item to a driver assistance system mounted on the vehicle, the device comprising: - a memory unit configured to store a map of the driving lanes, at least one location of interest where the information item to be preferentially transmitted to the mounted system should be located, and the absolute position of the information item received at time t; - a control unit configured to estimate the position of each received information item within the map and to select the received information item to be preferentially transmitted to the mounted system according to the estimated position of the received information item within the map and the location of interest stored in the memory unit.

[0009] The following description, given by way of non-limiting example and with reference to the accompanying drawings, will facilitate an understanding of what the present invention consists of and how it may be carried out.

Brief Description of the Drawings

[0010] [Figure 1] It is a block diagram of a device according to the present invention. [Figure 2] It is a diagram of the main steps of a method according to the present invention. [Figure 3] It is a diagram of the sub-steps included in step a) of the method according to the present invention. [Figure 4] A schematic diagram of an example of a map showing all the information items received at time t, i.e., the selected information items to be transmitted to the mounted system and the unselected information items not to be transmitted to the mounted system.

Modes for Carrying Out the Invention

[0011] Figure 1 shows a device 10 for selecting an information item from a plurality of information items received at time t from a transmission side 100 located away from vehicle 1 for the purpose of transmitting the selected information item to at least one driver assistance system mounted on vehicle 1. For simplicity, the driver assistance systems mounted on the vehicle are referred to as "mounted systems 20, 21, 22" in the remaining description.

[0012] Vehicle 1 is considered to be about to proceed along a road network formed by driving lanes, and the transmission side 100 is considered to be a user of this road network, such as another vehicle, road infrastructure, or pedestrian, etc., who is a stakeholder in this road network. Both vehicle 1 and the transmission side 100 are equipped with the so-called "V2X" technology, whereby they can transmit and receive messages including information items. The driving lanes are, for example, main streets, small public roads, large public roads and highways, as well as pedestrian paths and bicycle paths.

[0013] The received information items are, for example, the following information items: the absolute position of the transmission side (in GPS coordinates), the reliability of this position, the speed of the movement of the transmission side, the acceleration of the transmission side and / or the direction of its movement, or the danger (slippery road, dangerous curve, accident, traffic jam, etc.) encountered or created by the transmission side during its movement.

[0014] Here, vehicle 1 includes, as mounted systems, a navigation system 20 that helps the driver follow a route from point A to point B, an advanced driver assistance system (ADAS) 21, and a dashboard 22 that displays warnings while the vehicle is being driven.

[0015] Device 10 is configured to communicate with each of the mounted systems 20, 21, 22 using wired or wireless communication, preferably using wired communication.

[0016] Each of the mounted systems 20, 21, and 22 requires specific information items to function correctly. However, it does not necessarily require all information items received from all transmitters 100 at time t. Therefore, the mounted systems 20, 21, and 22 transmit information items that are potentially relevant to the nature of the information items, the nature of the transmitter, or, in this case, the location of information items related to the vehicle 1. should The information items are instructed to Vehicle 1.

[0017] The device 10 according to the present invention is an intermediate filter between the transmitting side 100 and the mounted systems 20, 21, and 22, and is transmitted to each of the mounted systems 20, 21, and 22. should The system is configured to spatially sort the information items received from the sender 100 so that only spatial information items are transmitted.

[0018] For example, the navigation system 20 is generally interested in information items that are relatively far from the vehicle 1, while it is of little interest in information items that are very close to the vehicle. For example, the presence of traffic congestion approximately 30 km ahead of the vehicle 1 is of interest to the navigation system 20. The dashboard 22 prefers to use information items that are very close to the vehicle 1, while information items that are very far away are of little use to it. For example, information items located within tens or hundreds of meters of the vehicle 1 are of interest to the dashboard 22, but information items located further away are of no interest to it. The ADAS 21 uses both information items that are very close to the vehicle and information items located at an intermediate distance from the vehicle, but does not use information items that are relatively far from the vehicle 1. For example, the ADAS 21 uses information items located within a few kilometers of the vehicle, but does not use anything further away. To provide an index, in an urban or urban environment, an information item is considered close to the vehicle, i.e., within the visible range of the conventional vehicle sensor 30, when it is located between 0 meters and 150 to 200 meters from the vehicle; at an intermediate distance when it is located between 200 meters and 1 to 2 kilometers from the vehicle; and far away when it is located more than 2 kilometers away. It should be understood that these distance indices depend on the road topology and the vehicle's speed. When the vehicle is traveling on a highway at 130 km / h, these indices should increase. In any case, these indices should not be considered limiting in the context of the present invention.

[0019] The information items transmitted by the transmitter 100 are received by the vehicle 1, and in particular by the device 10, via relatively long-range wireless communication, for example, via radio waves.

[0020] As shown in Figure 1, the device 10 according to the present invention comprises the following: - A memory unit 11 is configured to store a map of the driving lanes, at least one location of interest where an information item to be transmitted to the onboard systems 20, 21, and 22 must be located, and the absolute position Zi of the i-th information item received at time t, - A control unit 12 is configured to estimate the location of each received information item received from the transmitter 100 on the map, and to select the information items to be transmitted to the onboard systems 20, 21, and 22 according to the estimated location Xi of the information item on the map and the location of the object of interest stored in the memory unit 11.

[0021] As shown in Figure 1, the memory unit 11 is configured to communicate with the control unit 12. This communication can be wired or wireless. Preferably, the memory unit 11 and the control unit 12 are mounted on the vehicle 1 and communicate via wired communication.

[0022] The control unit 12 includes at least one computer configured to perform calculations.

[0023] As shown in Figure 1, the device 10 according to the present invention is further configured to communicate with at least one sensor 30 of the vehicle for the purpose of acquiring certain information items directly relating to the vehicle 1, in particular, which are hereinafter referred to as the vehicle's "driving scenario".

[0024] For example, device 10 is configured to communicate with a vehicle's GPS sensor that delivers the absolute position of vehicle 1, or a speed sensor that gives the speed of vehicle 1. Here again, for example, device 10 is also configured to communicate with an onboard navigation system 20 (in which case the navigation system 20 is considered to be a sensor) that provides the vehicle's reference route, i.e., the actual route taken by vehicle 1 at time t or the most likely route that vehicle 1 is likely to take at time t. The way in which the navigation system 20 determines the most likely route does not form part of the present invention and is not described in detail. When the navigation system 20 is not turned on, device 10 is configured to communicate with a computer (as a sensor) configured to calculate the vehicle's reference route, for example, in the form of the most likely route that vehicle 1 is likely to take at time t. The most likely route that vehicle 1 is likely to take is, in this case, defined in a statistical formula and recalculated each time the vehicle is used. The way in which the computer calculates this route is known in itself and does not form part of the present invention.

[0025] Furthermore, device 10 is configured to perform a method according to the present invention, the main steps of which are shown schematicly in Figure 2.

[0026] More precisely, device 10 is configured to perform a method for selecting an information item from a plurality of received information items at time t, for the purpose of transmitting the selected information item to at least one of the onboard systems 20, in which case the following is done: a) Estimate the position Xi of each received information item in the driving lane map stored in the memory unit 11 according to the absolute position Zi of the information item received at time t (block E1 in Figure 2), b) At least one mounted system 20, 21, 22 to To be sent should Determine the location of at least one object of interest where the information item must be located (block E2 in Figure 2). c) Select from the received information items which information items to be transmitted to the onboard systems 20, 21, and 22, according to the estimated position Xi of the received information item in the map established in step a) and the location of interest determined in step b) (block E3 in Figure 2).

[0027] Steps a), b), and c) are performed more specifically by the control unit 12 of device 10.

[0028] In practice, steps a) and b) can be performed independently and in parallel with each other, but step c) must always be performed after steps a) and b).

[0029] In step b), the control unit 12 receives, on the one hand, a wish list defining the location of interest from each of the onboard systems 20, 21, and 22, and on the other hand, data relating to the vehicle's driving scenario from the vehicle's sensor 30.

[0030] A driving scenario may include, for example, one or more of the following parameters: vehicle speed, external weather conditions, whether the vehicle is traveling in an urban environment or on a highway, the vehicle's reference route, traffic density, speed limits, the number and nature of physical sensors in the vehicle, and the complexity of the lane network at time t.

[0031] The locations of interest reflect the preferences of the onboard systems 20, 21, and 22 regarding whether or not to prioritize the reception of certain information items, depending on their spatial origin.

[0032] For example, ADAS21 can instruct the control unit 12 to always receive all information items located within a 200-meter radius around vehicle 1 when the vehicle is traveling at less than 70 km / h, and all information items located within a 700-meter radius around the vehicle when the vehicle is traveling at more than 70 km / h, with information items located within a 400-meter radius taking precedence over others. ADAS21 can add other conditions, for example, that it wants to acquire all information items originating from lanes adjacent to the driving lanes of the reference route taken by vehicle 1, only when the vehicle is in an urban environment. ADAS21 can further configure the size of the radius of locations of interest from which ADAS21 wants to receive information items, depending on weather conditions. For example, ADAS21 can be instructed to increase the radius of locations of interest from which information items must originate in the event of adverse weather conditions.

[0033] Each of the other mounted systems 20 and 22 thereby instructs the control unit 12 of device 10 with its own conditions, and thus the control unit 12 knows all the criteria that the control unit 12 must consider in order to determine the location of the object of interest from which the information items must originate so that they can be transmitted to the mounted systems 20, 21, and 22.

[0034] The control unit 12 then determines a spatial filter for each of the mounted systems 20, 21, and 22, based on the location of interest and the driving scenario of the vehicle 1, which specifically defines the desires of the mounted systems 20, 21, and 22 within the space surrounding the vehicle 1. In practice, the spatial filter indicates the portion of the map's driving lane where the mounted systems 20, 21, and 22 wish to receive information items.

[0035] The spatial filter depends, on the one hand, on the position of the vehicle at time t, and on the other hand, on the other hand, on the vehicle's reference route at time t, i.e., the actual route or the most likely route taken by vehicle 1 at time t (this route is given, for example, by the navigation system 20).

[0036] The position of vehicle 1 is either the absolute position of vehicle 1, given by latitude, longitude, and altitude, or the estimated position of the vehicle on the map, the estimated position being obtained from the absolute position of vehicle 1. Here, the absolute position of vehicle 1 and the reference route of vehicle 1 at time t are provided by the GPS sensor 30 and the navigation system 20, respectively. In one variant, the vehicle's reference route may be provided by a computer.

[0037] According to a first variant of the embodiment, called the “explicit” variant, the map is defined as a set of lane segments and nodes. Each segment, identified by index idx, represents a lane portion or section without intersections and may be of any size. Each node represents an intersection between one or more lane segments. Thus, two segments with different index idx are separated by a node.

[0038] According to this first variant, the spatial filter that defines the location of the object of interest at each time t includes a subset of travel lane segments and nodes.

[0039] According to a second variant of the embodiment, called the “implicit” variant, the spatial filter includes: - Generally, the reference location on the map is the location of vehicle 1. - The maximum distance on the reference route of vehicle 1, measured from the reference position. - Adjacent driving lanes that should be considered range , and - In some cases, the maximum distance within adjacent lanes measured from the reference position.

[0040] A lane adjacent to a reference route is considered to obstruct that reference route, either directly or indirectly. A first-class adjacent lane corresponds to a lane that directly crosses the reference route, while a second-class adjacent lane is a lane that crosses a first-class adjacent lane. In other words, any lane leaving a reference route is a first-class adjacent lane, and any lane leaving a first-class adjacent lane is a second-class adjacent lane.

[0041] From these implicit information items, the control unit 12 can determine which travel lane sections are of interest to the onboard systems 20, 21, and 22.

[0042] Regardless of the transformation mode, the spatial filter changes over time because, on the one hand, the driving scenario changes, and on the other hand, because vehicle 1 moves.

[0043] Therefore, the control unit 12 checks very regularly whether the spatial filter is appropriate, given the vehicle's driving scenario and the position of vehicle 1.

[0044] Preferably, in step b), the control unit 12 determines a set of spatial filters F corresponding to the driving scenario of vehicle 1 over the entire journey of the vehicle, rather than a single spatial filter, with each spatial filter relating to a portion of the reference route of vehicle 1.

[0045] Furthermore, the memory unit 11 is configured to have multiple sets Fx of spatial filters in its memory, each set Fx corresponding, for example, to a certain frequently occurring route of a vehicle or to a specific time period.

[0046] The control unit 12 can then select a spatial filter from the set of spatial filters Fx in memory that corresponds to one part of the vehicle's journey, which facilitates the control unit 12 in determining the spatial filter at time t, and the set is related to the entire journey taken by the vehicle 1.

[0047] The control unit 12 also checks whether the set of spatial filters F related to the entire journey is appropriate or whether it needs to be changed. This verification is performed, for example, only if it occurs very regularly or if modifications to the vehicle's journey with respect to the reference route occur.

[0048] The spatial filters for each set are stored and updated in the memory unit 11 based on a learning method that takes into account the vehicle's journey history and / or the possibilities of each spatial filter in particular.

[0049] Therefore, at the end of step b), the control unit 12 knows, in the form of a spatial filter or a set of spatial filters, the geographical location from which the information items to be processed by each onboard system must originate.

[0050] In this regard, step a) is to locate the information item received by vehicle 1 at time t, and this locateging operation generally has two stages: - First, it is necessary to select the best candidate, i.e., the lane section most likely to originate from which the received information item is likely to originate, from among several possible lane sections, and then, - After the best candidate is found among the possible travel lanes, it is necessary to project the absolute position Zi of the received information item onto this travel lane section in order to determine the estimated position Xi of the information item on the map.

[0051] Step a) of the method according to the present invention will be described in more detail here with reference to Figure 3, which gives an overview of the main substeps included therein.

[0052] During the first substep of selection, represented by block A1 in Figure 3, the following is performed: - Select a positioning procedure that will be performed by the control unit 12 to select the best candidate from among the possible travel lane sections, and then, - Identify the location of the information items received at time t for this lane section.

[0053] More precisely, for each information item received at time t, the control unit 12 selects a location identification procedure to be executed from among a simplified location identification procedure that requires rapid execution (path i in Figure 3) or a complex location identification procedure that requires slower execution (path j in Figure 3). This selection is made according to the density value of the network of travel lanes along the reference route taken by vehicle 1.

[0054] Here, the density value of the network of driving lanes (or road network) corresponds to the total length of the driving lanes in a given area. This density value is TR / m 2 The density value is given by a metric. The density value is evaluated for relatively large areas, and the size of the area depends on the driving scenario. The density value is evaluated, for example, based on a map and / or based on the number of intersections (nodes) between various driving lane sections within a given area of ​​the map. This density value indicates the complexity of the road network. Low values ​​correspond to less complex road networks, for example, rural areas, while high values ​​correspond to complex road networks, for example, urban areas. Prioritically, the more complex the road network, the more difficult it is to locate information items, insofar as information items tend to originate from a large number of separate driving lane sections that are close to each other.

[0055] Therefore, when the density value is higher than a predetermined maximum threshold, the control unit 12 is programmed to select a location procedure called the complex location procedure (path j in Figure 3). Computationally more resource-intensive and therefore slower, this procedure is given priority to maximize the accuracy and reliability of location determination when there are many candidate lane sections. In contrast, when the density value is lower than a predetermined minimum threshold, the control unit 12 is programmed to select a location procedure called the simplified location procedure (path i in Figure 3). The simplified procedure is computationally less resource-intensive and therefore faster to execute.

[0056] The selection of the location determination procedure is further determined according to the statistical error associated with the absolute location Zi of the information item received at time t.

[0057] Specifically, when the density value falls between the minimum threshold and the maximum threshold, the control unit 12 uses a confidence ring for the absolute position Zi to select whether a simplified or complex localization procedure should be performed.

[0058] In practice, each received information item is related to an absolute position Zi delivered by the GPS of the transmitting side 100 that sent the information item. This absolute position Zi is given in terms of latitude, longitude, and altitude. The transmitting side 100 of the received information item gives an absolute position Zi with relatively high or low confidence. Thus, the absolute position Zi is related to a confidence ring, which is generally formed in an ellipse and represents the variance of the error. The larger the confidence ring, the lower the confidence of the absolute position Zi, and therefore the higher the statistical error associated with the absolute position Zi. Conversely, the smaller the confidence ring, the higher the confidence of the absolute position Zi, and therefore the lower the statistical error associated with the absolute position Zi.

[0059] When the density value falls between the minimum and maximum thresholds, the control unit 12 compares the statistical error associated with the absolute position Zi with a predetermined minimum error value. If the statistical error associated with the absolute position Zi is lower than the minimum error value, the control unit 12 selects a simplified positioning procedure (path i in Figure 3). In contrast, if the statistical error associated with the absolute position Zi is higher than the minimum error value, the control unit 12 selects a complex positioning procedure (path j in Figure 3). Here, the statistical error associated with the absolute position Zi of the i-th information item is thought to depend on the aforementioned confidence ring. For example, the statistical error is the variance of the set of positions included in the confidence ring, or in practice, the standard deviation of the set of positions included in the confidence ring.

[0060] In practice, complex localization procedures may be suitable specifically for dynamically localizing information items, that is, for localizing information items that move over time, while simplified localization procedures may prove sufficient in relation to static information items.

[0061] When the simplified positioning procedure is selected by the control unit 12, the path i shown in Figure 3 is executed.

[0062] The simplified location procedure includes a first step of acquiring data (block I1 in Figure 3), during which the control unit 12 retrieves from the memory unit 11 all possible travel lane sections from which information items tend to have been sent.

[0063] In practice, in the first step (block I1), the control unit 12 determines the search area in which the control unit 12 intends to locate the information item. According to the first variant, in step b) of the method, the control unit 12 then retrieves from the memory unit 11 all the lane sections included in the set of spatial filters F used at time t, and selects from among these lane sections of the map k sections, referred to as Rk,i, which are associated with the absolute position Zi of the received information item, in particular those located near the absolute position Zi.

[0064] According to the second variation of the first step (block I1), the control unit 12 retrieves all travel lane sections Rk,i included in the spatial filters of the set of spatial filters F used in step b). According to this second variation, the search area then includes all travel lane sections Rk,i of the vehicle journey.

[0065] In either of the variants intended to be used to perform the first step (block I1), each running lane section Rk,i is mathematically defined as a segment, described by a linear equation with coefficients -a / b and -c / b.

[0066] The starting point Sk,i and ending point Ek,i of segment Rk,i are described by (Sk,i;Ek,i)∈Rk,i.

[0067] The simplified positioning procedure then includes an orthogonal projection step (block I2 in Figure 3), during which the control unit 12 performs the calculation of the orthogonal projection of the absolute position Zi of the received information item to each travel lane section Rk,i acquired in the preceding step (I1).

[0068] The control unit 12 then calculates the distance d(Zi, Rk,i) between the absolute position Zi and its orthogonal projection onto the travel lane Rk,i by performing the following calculations. [Calculation 1] TIFF0007874629000001.tif17170

[0069] The intersection between the segment Rk,i and the orthogonal projection of the absolute position Zi can be directly found using a closed form. The intersection is called I k,i and is so-called.

[0070] T is the maximum allowable distance between the absolute position Zi and its orthogonal projection with respect to whether the driving lane section should be regarded as a candidate to be retained. In other words, the driving lane section Rk,i is regarded as a possible candidate if and only if it obeys the following equation. [Calculation 2] f(Z i ,R k,i ) = d(Z i ,R k,i ) < T AND I k,i ∈(S k,i ;E k,i ) ∀k,i

[0071] The simplified position identification procedure finally includes a decision step (block I3 in Figure 3), during which the control unit 12 selects the best candidate from the retained driving lane sections. In practice, the best candidate corresponds to the shortest orthogonal projection required to locate the received information item with respect to one of the driving lane sections of the map.

[0072] To select the best candidate driving lane section Ri as the one from which the information item with the absolute position Zi originated, the control unit 12 performs the following calculation. [Calculation 3] R i = argmin{R k,i ∈F} with f(Z i ,R k,i ) < T

[0073] The estimated position Xi of an information item in the map is then considered to be the intersection Ik,i obtained between the driving lane section Ri and the orthogonal projection of the absolute position Zi onto this section Ri. In other words, the estimated position Xi of an information item in the map is the result of the shortest orthogonal projection of the absolute position Zi onto the surrounding driving lane sections.

[0074] The control unit 12 then determines, with a confidence level L(Ri), which travel lane section Ri the received information item originated from, and which estimated position Xi within the travel lane section Ri the information item originated from.

[0075] The confidence level L(Ri) for determining the driving lane Ri from the information item is calculated in a known manner. For example, this confidence level L(Ri) can be given by two separate calculations. According to the first calculation, for each candidate driving lane section Ri,k,j, the confidence level L(Ri,k,j) is the ratio between the posterior probability that the estimated position Xi is in section Ri,k,j, given the absolute position Zi, and the maximum value of all other probabilities calculated for all other candidate driving lane sections Ri,k,m, having m different from j. According to the second calculation, for each candidate driving lane Ri,k,j, the confidence level L(Ri,k,j) is the ratio between the posterior probability that the estimated position Xi is in section Ri,k,j, given the absolute position Zi, and the mean value of all other probabilities calculated for all other candidate driving lane sections Ri,k,m, having m different from j.

[0076] In the final step of the simplified location method, represented by block A2 in Figure 3, the confidence level L(Ri) regarding the determination of the lane from which the information item originated is compared to a predetermined confidence threshold Th2. The predetermined confidence threshold Th2 is greater than or equal to 0, which ensures that one of the best candidate lane sections is selected. The predetermined confidence threshold Th2 actually depends on the size of the confidence ring with respect to the absolute position Zi and the size of the search area in which it attempted to locate the information item.

[0077] If the confidence level L(Ri) is higher than a predetermined confidence threshold Th2, the memory unit 11 records that, with confidence level L(Ri), the information item received at time t originated from the driving lane Ri, and more specifically, that the information item was located at the estimated position Xi on the map at that time t. Therefore, in the memory unit 11, the absolute position Zi, the estimated position Xi, the driving lane section Ri where the transmitter 100 of the information item was located, and the confidence level L(Ri) are related to time t and the received information item.

[0078] By convention, unless otherwise specified, the notations Xi, Zi, Ri, and L(Ri) used in the text correspond to parameters at time t and are equivalent to the notations Xi(t), Zi(t), Ri(t), and L(Ri(t)).

[0079] When a complex positioning procedure is selected by the control unit 12, the path j shown in Figure 3 is executed. The complex positioning procedure uses a well-known algorithm called a hidden Markov model (HMM), but includes preliminary steps before the execution of this algorithm that allow the computation time to be optimized without reducing the confidence of the results, or at least with minimal loss of confidence.

[0080] This algorithm has the ability to determine the best lane section in which a received information item is likely to be found, and the probability that the information item is actually found in this section. To find the best section, the control unit 12 uses the past positions of the information item (and the confidence level of these positions) to estimate the most likely path taken by the information item. To arrive at a result, the algorithm attributes the probability to each candidate lane section and the transition probability associated with the information item's movement from one candidate section at time t-1 to another candidate section at time t.

[0081] To find the travel lane section Ri on which the absolute position Zi of an information item received at time t should be projected, a complex localization procedure determines, on the one hand, a relatively large area of ​​the map within which the section should be searched, and on the other hand, a relatively large number of past positions adopted by the information item in the time preceding time t, which should be considered to be the path the information item should follow.

[0082] In other words, the complex positioning procedure (route j in Figure 3) includes a first substep (block J1 in Figure 3) in which the control unit 12 parameterizes, on the one hand, the area of ​​the map that will contain all candidate lane sections, and on the other hand, the number of past positions adopted by the received information item in the time preceding time t which should be used to determine the best of the candidates.

[0083] Therefore, during the parameterization step, the control unit 12 parameterizes the size of the map region and the number of past locations to be considered in order to evaluate the best candidate.

[0084] The larger the area of ​​the map from which the best candidate is sought among all lane sections in the region, the higher the probability of finding the best candidate, but the larger the number of lane sections to be evaluated, and therefore the longer the computation time. In practice, to parameterize the size of the search area, the control unit 12 sets a parameter C, which is a multiplicative factor multiplied by the confidence ring with respect to the absolute position Zi of the information item. Thus, the search area is equal to C times the confidence ring. Parameter C is equal to at least 2.

[0085] Using past positions adopted by the information item, the control unit 12 has the ability to trace the course of the information item. Due to the effect of the HMM, the control unit 12 considers it almost impossible for the information item to originate from one of these travel lane sections, and therefore the control unit 12 has the ability to eliminate some of the travel lane sections that were initially candidates. The more positions that have been traversed, the more accurate the course traced by the control unit 12 becomes, and thus the higher the probability of finding the best candidate from all possible sections. In practice, to parameterize the number of past positions that the control unit 12 must consider, the control unit 12 sets a parameter M corresponding to the number of past positions. Parameter M is equal to at least 2.

[0086] Parameters M and C are parameterized according to a confidence ring regarding the absolute position Zi of the information item received at time t. More precisely, the statistical error resulting from the confidence ring regarding the absolute position Zi is compared to a predetermined maximum error value. When the statistical error associated with the absolute position Zi is higher than the maximum error value, the control unit 12 preferably parameterizes a larger search area in the map, and a larger number of past positions are used. For example, the control unit 12 sets parameter C to be equal to 3 or 5, and parameter M to be equal to 4, 6, or 10. When the statistical error associated with the absolute position Zi is lower than the maximum error value, the control unit 12 preferably parameterizes a smaller search area, and a smaller number of past positions are used. For example, the control unit 12 sets parameter C to be equal to 2 or 3, and parameter M to be equal to 2 or 4. According to one possible variant, parameters C and M may not be correlated with each other, such that the control unit 12 can parameterize a large number of past positions and a small search area, and vice versa. Nevertheless, the parameterization of parameters M and C still depends on a comparison of a confidence ring with respect to the absolute position Zi delivered by the GPS of the information item transmitter 100, and the resulting statistical error having a predetermined maximum error value.

[0087] The complex localization procedure (path j in Figure 3) further includes an initialization step (block J2 in Figure 3) during which, for each past location adopted in one of the preceding time periods, it is determined whether the location to be considered is an absolute location Zi or an estimated location Xi in the map of information items received in time prior to time t, and this determination is made according to the confidence level of the absolute or estimated location Zi or Xi, respectively.

[0088] More precisely, it is the absolute position Zi or estimated position Xi that has the highest confidence in being retained as the position of the information item received in a time preceding time t. Therefore, when the confidence L(Ri) for estimated position Xi is close to zero (or below a predetermined threshold), the absolute position Zi is the position retained for the i-th information item received in a time preceding time t, while when the confidence L(Ri) for estimated position Xi is high (above a predetermined threshold), the estimated position Xi is the position retained for the i-th information item received in a time preceding time t.

[0089] In practice, the confidence level for the estimated position Xi is calculated at the end of the method, as will be explained in detail below (block J4 in Figure 3).

[0090] Results obtained in the preceding time will potentially be reused when relevant, so the initialization step (block J2) allows the execution speed of the method to be increased by reducing the complexity and number of computations.

[0091] The initialization step J2 is performed after the parameterization step J1.

[0092] A complex localization method includes a step (block J3 in Figure 3) of evaluating whether the information item remained stationary between time t-1 and time t when it was sent.

[0093] To do this, in step J3 of block, the absolute positions Zi(t) and Zi(t-1) of the information items are compared.

[0094] More precisely, the control unit 12 compares the distance between absolute positions Zi(t) and Zi(t-1) with a threshold Th1. If the distance between absolute positions is less than the threshold Th1, the control unit 12 considers that the information item has not moved.

[0095] In practice, the distance between absolute positions is calculated as follows: [Calculation 4] ||Z i (t) New Z i (t-1)|| 2

[0096] By doing so, the control unit 12 avoids unnecessary calculations and directly obtains the calculation results performed at time t-1.

[0097] If the control unit 12 determines that the information item has not moved or has moved very little, then, in the step represented by block J5 in Figure 3, the control unit 12 determines that the lane section Ri(t) where the transmitter was located at time t is the same as the lane section Ri(t-1) where the transmitter was located at time t-1, the confidence L(Ri(t)) of the lane section selected as the best candidate at time t is equal to the confidence L(Ri(t-1)) of the lane section selected as the best candidate at time t-1, and the estimated position Xi(t) of the information item received at time t is equal to the estimated position Xi(t-1) of the information item received at time t-1. This is represented as follows: [Calculation 5] R i (t)=R i (t-1);L(R i (t) = L(R i (t-1));X i (t) = X i (t-1)

[0098] In contrast, if the distance between absolute positions is greater than the threshold Th1, the control unit then executes an HMM (it will be recalled that HMM stands for Hidden Markov Model).

[0099] In step J4 of block, the HMM algorithm derives the best lane section in which the received information item is likely to be found, and the probability Prob(Rk,i|Z) that the information item is actually found in this section. As previously mentioned, to find the best section, the control unit 12 uses the past positions of the information item (and the confidence level of these positions) to estimate the most likely path taken by the information item. The HMM reduces the probability to each candidate lane section and the transition probability associated with the transition of the information item between the candidate section at time t-1 and the candidate section at time t. In practice, the HMM calculates the probability that the received information item is actually found in that section, depending on the following: - Distance (Euclidean distance or distance based on great circles), and - Transition probability.

[0100] Expressions for describing transition probabilities can be found in the literature and are known in themselves.

[0101] Therefore, the algorithm establishes a sequence of candidate sections that best represent the movement of the information items.

[0102] The two potential effects of errors and false alarms must be minimized in order to achieve the highest possible reliability of the results obtained.

[0103] Possible error p(error) i This is defined as the probability that the absolute position Zi of an information item cannot be positioned in the correct lane section Rk,i by the algorithm, given that it actually originates from section Rk,i. Mathematically, the possible errors can be expressed as follows: [Calculation 6] TIFF0007874629000002.tif10170

[0104] False Alarm P falseIt is defined as the probability that the absolute position Zi of a received information item is associated with a driving lane section Ri by the algorithm, when it actually originates from a different driving lane section Rk,i. Mathematically, a false alarm can be expressed as follows: [Calculation 7] TIFF0007874629000003.tif11170

[0105] In step J4 of block, the control unit 12 performs a series of calculations to estimate the reliability of the results output by the algorithm.

[0106] The confidence estimate indicates the confidence level of the algorithm in associating information items with the correct lane sections.

[0107] The confidence level L(Ri) is measured using the following equation. [Calculation 8] TIFF0007874629000004.tif18170

[0108] The higher the confidence level L(Rk,i), the more likely it is that the best candidate among the possible lane sections Rk,i will be found at the end of the algorithm. Therefore, the best candidate section Rk,i is the candidate section associated with the highest confidence level L(Rk,i).

[0109] In the following steps, represented by block J6 in Figure 3, the control unit determines the estimated position Xi of the i-th information item received at time t on the map. To do this, knowing the travel lane section Ri from which the information item originated (this section is selected from all sections Rk,i), the control unit 12 projects the absolute position Zi perpendicular to section Ri.

[0110] In the final step, which is identical to the steps described in detail in relation to the simplified localization procedure, the control unit 12 estimates whether it is necessary to implement the new "data" obtained in the memory unit 11 for the information item received at time t, namely, the lane section Ri(t) where the sender 100 of the information item was located, the confidence level L(Ri(t)) of the determination of this section, and the estimated position Xi(t) of the information item for that section (Block A2 in Figure 3).

[0111] Step a) of the method allows the information items to be located with greater accuracy and at a lower cost.

[0112] In step c), the method according to the present invention combines the results of steps a) and b). Thus, all received information items are located on the map in step a), the spatial filters associated with each onboard system 20, 21, and 22 are known from step b), and the control unit 12 checks which received information items are located in the travel lane sections located within the spatial filters in order to send only these information items to the onboard systems 20, 21, and 22.

[0113] If a received information item is located in a travel lane section outside the spatial filter, that information item is not transmitted to the onboard systems 20, 21, and 22. In contrast, if a received information item is located in a travel lane section within the spatial filter, that information item is transmitted to the onboard systems 20, 21, and 22, which are able to process it.

[0114] Figure 4 shows an example of a map in which all information items received by device 10 are indicated. The location of vehicle 1 is marked with a cross. Information items are represented by empty circles, filled circles, or circles with stars. In practice, only information items represented by empty circles are transmitted here to one of the onboard systems 20, 21, and 22; information items represented by filled circles are located in driving lanes that never intersect with the driving lane of the most likely route taken by the vehicle; and information items represented by circles with stars are located too far from the vehicle of interest to the onboard systems 20, 21, and 22.

[0115] The present invention is by no means limited to the embodiments described and illustrated, and implementation of any variant of the present invention is within the capabilities of those skilled in the art.

[0116] In particular, it is conceivable that vehicle 1 includes a processing unit configured to sort information items received from the transmitter 100 according to their nature and / or the type of transmitter 100 that sent them. For example, the processing unit is positioned upstream of the device according to the present invention so that the device according to the present invention receives only information items of a nature that tends to be of interest to at least one of the onboard systems of vehicle 1. If the device according to the present invention is positioned upstream of the processing unit, this is entirely conceivable, and the device spatially identifies all received information items before they are filtered according to their nature or the nature of their transmitters. Communication between the filter and the device according to the present invention is preferably wired communication.

[0117] According to another conceivable variant, in step c), information items located in a driving lane section outside the spatial filter may be transmitted to the onboard system not at all, but with instructions that they must be processed, though less urgently than other information items. Thus, the present invention makes it possible to classify the received information items in order of priority and importance according to their location on the map.

Claims

1. A method for selecting an information item from a plurality of information items received at time t from a transmitting side (100) located away from the vehicle (1), for the purpose of transmitting the selected information item to at least one driver assistance system (20, 21, 22) installed in the vehicle (1), a) Estimating the position of each received information item in the driving lane map according to the absolute position (Zi) of the information item received at time t, b) Determining the location of at least one object of interest where the information item to be preferentially transmitted to the at least one driver assistance system (20, 21, 22) must be located, c) Select from the received information items an information item to be transmitted to the driver assistance system, based on the estimated location (Xi) of the received information item on the map established in step a) and the location of the object of interest determined in step b). A method characterized in that, in step a), the location of each information item received at time t is estimated in the map using a location procedure selected from among a simplified procedure with rapid execution or a complex procedure with slower execution, wherein the location procedure is selected according to the density value of the network of driving lanes along the route taken.

2. The method according to claim 1, wherein the selection of the positioning procedure is further performed in accordance with a statistical error related to the absolute position (Zi) of the information item received at time t.

3. The method according to claim 1 or 2, wherein the simplified positioning procedure includes orthogonal projection of the absolute position of the received information item onto each travel lane, and selection of the shortest orthogonal projection for positioning the received information item within the map.

4. The method according to any one of claims 1 to 3, wherein the complex localization procedure determines the travel lane (Ri) suitable for projecting the absolute position (Zi) of the information item received at time t onto a relatively wide area of ​​the map, on the one hand, and on the other hand, based on a relatively large number of past positions adopted by the information item received at a time preceding time t.

5. The method of claim 4, referencing claim 2, wherein the complex localization procedure includes a parameterization step in which the size of the region of the map and the number of past locations to be considered are parameterized in accordance with the statistical error relating to the absolute location (Zi) of the information item received at time t.

6. The method according to claim 4 or 5, wherein the complex location procedure further includes an initialization step of selecting, for each of the past locations taken in one of the times preceding time t, whether the location to be considered is the absolute location (Zi(t-1)) of the information item received in the time preceding time t or the estimated location (Xi(t-1)) in the map, and the selection is made in accordance with a confidence level (L(Ri(t-1))) associated with the estimated location (Xi(t-1)).

7. The method according to any one of claims 1 to 6, wherein in step b), the location of interest is defined by a spatial filter that indicates the travel lane (Ri) to be considered, on the one hand, the position of the vehicle at time t, and on the other hand, the reference route of the vehicle at time t.

8. The method according to claim 7, wherein the spatial filter includes a subset of travel lane segments (idx) and nodes.

9. The aforementioned spatial filter, Reference location in the aforementioned map, The maximum distance of the vehicle along the reference route, measured from the reference position, The range of adjacent driving lanes to be considered, and Depending on the circumstances, the maximum distance within the adjacent travel lane measured from the reference position. The method according to claim 7, including the method described in claim 7.

10. A device (10) for selecting an information item from a plurality of information items received at time t from a transmitting side (100) located away from the vehicle (1), for the purpose of transmitting the selected information item to a driver assistance system (20, 21, 22) installed in the vehicle, A memory unit (11) is configured to store a map of the driving lanes, at least one location of interest where the information item to be preferentially transmitted to the driver assistance systems (20, 21, 22) must be located, and the absolute position (Zi) of the information item received at time t. A control unit (12) is configured to estimate the location of each received information item within the map, and to select the received information item to be preferentially transmitted to the driver assistance systems (20, 21, 22) according to the estimated location of the received information item within the map and the location of the object of interest stored in the memory unit (11). A device (10) comprising, wherein the control unit (12) is configured to estimate the location of each received information item in the map using a location procedure selected from among simplified procedures that perform quickly or complex procedures that perform more slowly, the location procedure being selected according to the density value of the network of driving lanes along the route taken.

Images