Method for selecting a preferred lane for a motor vehicle to pass through a toll zone

Abstract

The invention relates to a method for a motor vehicle (100) to select a preferred lane (230) for entering a toll zone (200) comprising a plurality of lanes (210, 220), the method comprising the following steps: a) detecting the lanes of the toll zone, b) determining, for at least some of the lanes, first data (d) relating to the distance between the motor vehicle and the respective lane ij ), and second data related to the number of other vehicles located on the corresponding lane; c) minimizing a cost function that depends on each first data and each second data to identify the preferred lane; and d) determining the possibility or risk of the motor vehicle changing lanes to move towards the preferred lane.

Description

Technical Field

[0001] The present invention generally relates to the field of driver assistance and to the field of autonomous vehicles.

[0002] The invention more particularly relates to a method for selecting a preferred lane for a motor vehicle in which to approach a toll zone comprising a plurality of lanes.

[0003] The invention also relates to a method for controlling an autonomous motor vehicle so as to drive it towards the preferred lane. Background Art

[0004] A decision-making assistance method is known from document DE 10 2012 022 629, which allows a decision to be made as to which lane a vehicle should use when arriving at a toll zone.

[0005] In this document, the vehicle is equipped with wireless communication means adapted to receive data transmitted by the charging zone. These data relate to open and closed lanes, the means of payment accepted in each lane, and the number of third-party vehicles waiting in each lane (if the third-party vehicles themselves are equipped with communication means, information on the number of third-party vehicles can be used).

[0006] The main disadvantage of this method is that it requires wireless communication to be established between the motor vehicle and the charging area, which is not practically guaranteed. In addition, this method also requires that both the motor vehicle and the charging area are equipped with expensive communication devices. Summary of the invention

[0007] In order to remedy the above-mentioned drawbacks of the prior art, the present invention provides a method in which a vehicle very reliably and safely determines which lane it must preferably use to pass through a toll zone, without having to communicate with the toll zone.

[0008] More specifically, according to the present invention, there is provided a method for selecting a preferred lane for a motor vehicle to enter a toll zone, the method comprising the following steps:

[0009] a) Detect the lanes in the toll area,

[0010] b) determining, for at least one part of the lanes, first data relating to the distance of the motor vehicle from the respective lane and second data relating to the number of third-party vehicles located in the respective lane,

[0011] c) calculating a value of a cost function for each lane in the portion based on the corresponding first data and the corresponding second data, and identifying the preferred lane as a lane for which the value of the cost function is the lowest value among the calculated values, and

[0012] d) determining whether the motor vehicle is able to change lane to move to the preferred lane, or determining the risk of doing so.

[0013] Thus, by means of the present invention, the choice of lane for approaching a charging zone depends not only on the number of vehicles in each lane, but also on the distance of the current vehicle from each lane, and on the potential dangers that will be encountered when reaching the preferred lane. Thus, the present invention allows motor vehicles to travel safely.

[0014] Preferably, the method uses only the equipment of the motor vehicle.The method is therefore reliable whether or not the toll area is equipped with communication means.

[0015] The following are other non-limiting and advantageous features of the method according to the invention:

[0016] the motor vehicle is equipped with at least one distance measuring sensor, and in step b), the second data are an estimate of the number of third-party vehicles located in each of said lanes, the estimate being determined from measurements performed by said distance measuring sensor;

[0017] - in step c), the value of the cost function of the lane of each of the parts is calculated based on the sum of the corresponding first data weighted by the first coefficient and the corresponding second data weighted by the second coefficient;

[0018] - given a lane adjacent to the lane being used by the motor vehicle and located on one side of the preferred lane relative to the lane being used by the motor vehicle, in step d), checking whether the manoeuvring time required for the motor vehicle to change lanes to reach a desired position in said adjacent lane is strictly shorter than the arrival time required for a third party vehicle travelling in said adjacent lane to reach the desired position;

[0019] - in step d), checking a dual criterion relating to the relative speed of the motor vehicle with respect to two third-party vehicles travelling in front of and behind the motor vehicle in the adjacent lane;

[0020] - As a variant or in addition, in step d), a criterion relating to the manoeuvre time required for the motor vehicle to change lane is checked;

[0021] the motor vehicle is equipped with an image acquisition device and a computing unit, wherein in step a), the image acquisition device acquires an image of the toll area and the computing unit processes said image in order to detect open lanes of the toll area and in step b), the computing unit determines first data and second data for each open lane;

[0022] the motor vehicle is equipped with an image acquisition device and a computing unit, the image acquisition device acquiring, in step a), an image of the toll area and the computing unit processing, in step b), said image in order to evaluate the first data;

[0023] -The motor vehicle is equipped with a geolocation device, a memory storing a route map and a calculation unit, which, in step b), calculates the first data based on the geolocation position of the motor vehicle and the geometry of the toll area, the geolocation position being obtained by the geolocation device and the geometry being stored in the memory.

[0024] The invention also relates to a method for controlling an autonomous motor vehicle, the method comprising:

[0025] - Steps a) to d) of the selection method defined above, then comprising

[0026] - The step of controlling the motor vehicle in question to go to the desired lane.

[0027] Preferably, if the desired lane is not adjacent to the lane currently being used by the motor vehicle, steps a) to d) are repeated after the vehicle changes lanes for the first time. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The following description, given by way of non-limiting examples with reference to the accompanying drawings, will allow a clear understanding of what the invention consists of and how it can be implemented.

[0029] In the attached picture:

[0030] - Figure 1 is a schematic diagram of a motor vehicle suitable for implementing the selection method according to the invention;

[0031] - Figure 2 An example of a selection method according to the present invention is shown in the form of a flow chart;

[0032] - Figures 3 to 6 is a top view of the charging area, which includes Figure 1 Various vehicles including motor vehicles. DETAILED DESCRIPTION

[0033] Firstly, it should be noted that identical or similar elements appearing in different drawings have been referred to by the same reference numerals as much as possible and will not be described every time.

[0034] Figure 1 The motor vehicle 100 is shown seen from above.

[0035] As can be seen from the figure, the motor vehicle 100 is here a conventional automobile, comprising a chassis supported by wheels and which itself supports various pieces of equipment including a drive train, brakes and a steering unit.

[0036] This may be a problem for manually controlled vehicles, in which case the manually controlled vehicle will be equipped with means for displaying destination information to the driver, or preferably, it may be a problem for autonomous vehicles. Furthermore, discussed in the remainder of this specification is the case of autonomous vehicles which will be considered here.

[0037] The motor vehicle 100 is equipped with sensors which allow it to determine its position in its environment and thus be able to drive itself autonomously, ie without human intervention.

[0038] Any type of sensor may be used.

[0039] exist Figure 1 In the example shown, the motor vehicle 100 is equipped with a camera 130 that is oriented toward the front of the vehicle so as to capture images of the environment located in front of the vehicle.

[0040] In addition, the motor vehicle 100 is equipped with at least one (radar, lidar or sonar) distance measuring sensor. Here, more precisely, five radar sensors 121, 122, 123, 124, 125 are equipped at the four corners of the vehicle and in the central position of the front of the vehicle.

[0041] The motor vehicle 100 is also equipped with a geo-positioning system 141 , for example comprising a GNSS receiver (typically a GPS sensor).

[0042] In order to process the information delivered by these various components and to be able to generate control settings for the drive train, the braking device and the steering unit, the motor vehicle 100 is equipped with a computer 140 .

[0043] The computer 140 includes a processor (CPU), a random access memory (RAM), a read-only memory (ROM), an analog-to-digital converter, and various input and / or output interfaces.

[0044] The computer 140 can receive input signals from various sensors via its input interface.

[0045] Furthermore, the computer 140 is connected to a memory 142 in which a route map is stored. Here the problem will be considered as a detailed map in which the geometry of the toll zone is given.

[0046] The read-only memory of the computer 140 , for its part, stores application software consisting of a computer program containing instructions that are executed by the processor to allow the computer to implement the methods described below.

[0047] Finally, by means of the output interface of this computer, the controller can transmit the settings to the various units of the vehicle.

[0048] On the one hand Figure 3 and Figure 4 and on the other hand Figure 5 and Figure 6 , two charging areas 200 are shown as seen from above.

[0049] Each of these charging areas 200 comprises a toll booth 201, at which the user of each vehicle must pay a toll. Each charging area 200 also comprises a number N of lanes 210, 220, 230, 240 (in Figure 3 and Figure 4 In , N is equal to 4, and in Figure 5 and Figure 6 , N is equal to 8) for entering the toll station 201.

[0050] The toll booth 201 includes an LED panel above each lane with a sign displayed on it. For example, if the lane is closed and no traffic is allowed, the sign may show a red cross, or if the lane is open, the sign may show a green arrow. The sign may also show other things (blue card if payment by bank card is possible, orange "t" if remote payment is possible, etc.).

[0051] In the rest of this description, the following distinction will be made among lanes:

[0052] - the current lane 210 , which is the lane being used by the motor vehicle 100 in question;

[0053] - adjacent lanes 220, which are two lanes located on both sides of the current lane 210; and

[0054] - A preferred lane 230 which, as will become clearer in the remainder of this description, is considered the lane most suitable for allowing rapid passage through the toll booth 201 in complete safety.

[0055] The lane denoted by reference numeral “ 240 ” is a lane that does not satisfy the above three criteria.

[0056] like Figures 3 to 6As shown, motor vehicles other than the above-mentioned motor vehicle 100 (these motor vehicles are hereinafter referred to as third-party vehicles 300, 310, 320) are also considered to be traveling in the lane of the toll zone.

[0057] Among these third-party vehicles, the following distinction is made:

[0058] a preceding vehicle 310 , which is a third-party vehicle that is traveling in one of the two adjacent lanes 220 (ie, the lane that the motor vehicle 100 desires to enter) and is located in front of the motor vehicle 100 , and

[0059] A following vehicle 320 , which is a third-party vehicle that is traveling in the same adjacent lane 220 and is located behind the motor vehicle 100 .

[0060] When the motor vehicle 100 (which is considered autonomous here) approaches the toll booth 200, it must select one of the lanes 210, 220, 230, 240. In other words, the computer 140 must judge when to change lanes when it arrives at the toll booth, so as to pass the toll booth 201 as quickly and in complete safety.

[0061] To this end, its computer 140 implements a method comprising a number of main steps.

[0062] The first step previously consisted in the computer 140 verifying that the data measured by the various pieces of equipment (radar sensor and camera) of the motor vehicle 100 were available.

[0063] In particular, these data may not be available, especially depending on the weather.

[0064] To this end, the computer 140 receives from each piece of equipment of the motor vehicle a confidence index (here expressed as a confidence percentage of the reliability of the measurement results of this equipment), which the computer compares with a preset threshold value.

[0065] If the confidence index is not high enough, the process will be interrupted. In the opposite case, implementation Figure 2 The method shown.

[0066] A first step a) of the method comprises determining the geographical environment of the site.

[0067] To this end, the computer 140 uses the camera 130 alone, or uses the geo-positioning device 141 coupled to the memory 142, or a combination of all these elements.

[0068] More precisely, here the computer acquires the images captured by the camera 130 and the geo-positioned position of the motor vehicle 100 .

[0069] Taking into account this geo-positioned location, motor vehicle 100 is able to find a floor plan of toll zone 200 in memory 142 .

[0070] Therefore, the number N of lanes of the highway section 200 can be determined.

[0071] The computer 140 then assigns each lane an identifier denoted below as “j”. The identifier is here a natural integer, included between 1 and N, the lane identified by the integer j=1 being the leftmost lane.

[0072] Next, through a process for processing the acquired images, the computer 140 identifies the signs located above each lane. The computer then identifies the shape and color of each sign to determine which lanes are open.

[0073] exist Figure 3 In the configuration shown, the lane identified by the integer j=4 is closed, while the other lanes are open.

[0074] exist Figure 4 In the configuration shown, all lanes are open.

[0075] exist Figure 5 and Figure 6 In the configuration shown, the lanes identified by integers j=4, j=6, and j=8 are closed, while the other lanes are open.

[0076] In a second step b1), the computer determines the extent to which the motor vehicle 100 is away from each open lane.

[0077] To this end, the computer calculates, for each open lane, first data relating to the distance of the motor vehicle 100 from this lane.

[0078] Here, the first data is the Euclidean distance d between the motor vehicle 100 and a point located in the center of the lane in question and flush with the toll booth 201. ij The estimated value of .

[0079] The index “i” here corresponds to a natural integer identifying the current lane 210 , and the index “j” corresponds to a natural integer identifying the lane 210 , 220 , 230 , 240 in question.

[0080] The Euclidean distance d ij It is obtained taking into account the geo-positioned position of the motor vehicle 100 and the floor plan of the toll area 200 read from the memory 142 .

[0081] In a third step b2), the computer 140 evaluates the congestion situation of each open lane of the charging area 200 .

[0082] To this end, the computer 140 calculates, for each open lane, second data relating to the number of third-party vehicles 300 , 310 , 320 located in this lane.

[0083] Here, the second data is the number n of third-party vehicles 300, 310, 320 located in the lane. j The assessed value.

[0084] Here, the evaluation value is obtained by means of measurements performed by the radar sensor 122 located at the center position of the front of the motor vehicle 100, the radar sensor 121 located at the left position of the front of the motor vehicle 100, and the radar sensor 123 located at the right position of the front of the motor vehicle 100. The evaluation value is refined through processing of an image acquired by the camera 130 of the motor vehicle 100.

[0085] The fourth step c) consists in selecting, among all lanes that the motor vehicle 100 can easily enter, the lane that requires the shortest waiting time to pass through the toll booth 201 .

[0086] The criterion used for this purpose is the cost function J ij , the cost function depends at least on the Euclidean distance d of the motor vehicle 100 from each lane. ij The estimated value of and the number of vehicles in each lane n j The assessed value.

[0087] The cost function J ij It can be expressed in many different ways. Here, it is expressed as follows:

[0088] J ij =d ij ·ζ ij +n j γ j

[0089] Among them, ij and γ j are two weighting factors.

[0090] The values ​​of these weighting factors are selected to favor the speed of passing through the toll booth (with the risk that the motor vehicle 100 has to change lanes many times) or the comfort of the passengers by selecting a lane that is preferably close to the current lane 210. The values ​​of these weighting factors can be preset (stored in the computer's read-only memory) or can be parameterized according to the preferences of the vehicle's passengers or the category of the vehicle (ambulance, vehicle for transporting goods, etc.). These weighting factors can also be expressed in the form of a function, for example with the data d to which the weighting factors refer ij 、nj It can be expressed in the form of a function (affine function, inverse function, square function, etc.).

[0091] The computer uses the same mathematical formula to calculate the cost function J for each lane of the charging area 200. ij The value of .

[0092] Then, the preferred lane 230 is the cost function J ij Smallest lane. Examples that clearly illustrate which lane is preferred in various configurations will be described in detail later in this specification.

[0093] A fifth step d) comprises determining whether the motor vehicle 100 can change lane 210 , 220 , 230 , 240 without risk in order to move towards the preferred lane 230 .

[0094] This step can be performed in a number of different ways.

[0095] Here, the computer 140 calculates the maneuvering time t required for the motor vehicle 100 to reach the adjacent lane 220 (into which the motor vehicle wishes to drive). EGO and the position 221 at which the vehicle will stop after the lane change.

[0096] Next, if there is a preceding vehicle 310 and / or a following vehicle 320, the computer 140 calculates the arrival time t required for these vehicles 310, 320 to arrive at the position 221. OBJ .

[0097] The criterion for determining whether the motor vehicle 100 can change lanes then consists simply in verifying the following inequality:

[0098] t EGO <min(t OBJ )+δt

[0099] Here, δt is a preset safety margin stored in the read-only memory of the computer 140 .

[0100] If the inequality is not verified (which means that changing lane would entail a risk), motor vehicle 100 remains in its lane 210 and the method starts again with step a).

[0101] In the opposite case, the computer 140 implements step e) which comprises controlling the steering unit of the motor vehicle 100 so that the motor vehicle 100 travels from the current lane 210 to the adjacent lane 220 (a lane located on one side of the desired lane 230 ).

[0102] At this stage, we can first assume that the adjacent lane 220 and the desired lane 230 are the same lane ( Figure 3In this case, the method ends here.

[0103] In the opposite case ( Figure 4 ), the motor vehicle 100 cannot move directly to the desired lane 230 without prior checking by changing lanes again.

[0104] Instead, the method is completely restarted before the motor vehicle 100 changes lanes again. Thus, if the configuration has changed, the motor vehicle 100 can quickly adapt to the change.

[0105] Now we can describe in more detail Figures 3 to 6 Three examples are shown.

[0106] exist Figure 3 In the first example shown, motor vehicle 100 is traveling in a current lane 210 identified by integer i=j=2.

[0107] Lane 240 identified by integer j=4 is closed.

[0108] Then, the computer 140 calculates three cost functions J 21 , J 22 and J 23 .

[0109] The desired lane 230 will then be the lane with the lowest cost function. It will be appreciated that the results will depend greatly on the weighting factors used.

[0110] Therefore, if conservative behavior is preferred, motor vehicle 100 will choose not to change lanes given the small number of vehicles in its lane 210 .

[0111] In contrast, if a more aggressive behavior is preferred, motor vehicle 100 will choose to change lanes given the very small number of vehicles in left adjacent lane 220 .

[0112] In this case, the motor vehicle will verify in advance whether it can change lanes without danger. Here, when the leading vehicle 310 and the rear vehicle (not shown) are away from the position 221 to which the vehicle desires to move, the motor vehicle 100 will be able to enter the lane 230 of expectation without danger.

[0113] exist Figure 4 In the second example shown, motor vehicle 100 is traveling in a current lane 210 identified by integer i=j=2.

[0114] Here, all lanes of the charging area 200 are open. Here, there are three third-party vehicles 300, 310, 320 in each lane, except for the rightmost lane, in which there is only a single third-party vehicle 300.

[0115] Then, the computer 140 calculates four cost functions J 21 , J 22 , J 23 and J 24 .

[0116] The lane selected will be the one with the lowest cost function. Here, therefore, the result will depend greatly on the weighting factors used. Thus, the motor vehicle 100 will choose to move to the lane 220 on the right only if very aggressive behavior is supported.

[0117] In this case, the motor vehicle 100 will here again verify whether it can change lanes without danger. In the present case, with the preceding vehicle 310 and the following vehicle 320 far from the position 221 in the adjacent lane 220 to which the vehicle wishes to move, the motor vehicle 100 will be able to move into the adjacent lane 220 without danger. The computer will then again be able to calculate the cost functions for the four lanes before choosing whether to remain in its lane or actually move to the initially desired lane.

[0118] exist Figure 5 and Figure 6 In the third example shown (which is the case in both figures), the motor vehicle 100 is initially travelling in a current lane 210 identified by the integer i=j=4.

[0119] This lane and the lanes identified by integers j = 6 and j = 8 are closed. Therefore, the vehicle must change lanes.

[0120] Then, the computer 140 calculates five cost function values ​​J 41 , J 42 , J 43 , J 45 and J 47 .

[0121] Here, the selected lane will again be the lane with the lowest value of the cost function. Here, the result of this selection will again depend greatly on the weighting factors used, but in any case, the motor vehicle 100 will choose to change lanes.

[0122] like Figure 5 As shown, the motor vehicle may choose to move toward the leftmost desired lane 230 .

[0123] However, if Figure 6As shown, after the first lane change, the motor vehicle can observe that it cannot change lanes again because the position 221 it wishes to enter is already occupied by a previous third-party vehicle 310. In this case, the computer decides not to change lanes again to pass the toll booth 210.

[0124] Various modifications of the embodiments described here are conceivable.

[0125] In particular, step d) can be performed in different ways.

[0126] Through the first example, the safety of the entry can be verified, and more vehicles can be considered. Therefore, not only the time t of the front vehicle 310 and the rear vehicle 320 can be calculated OBJ , and the time t that any third-party vehicle 300 (particularly those third-party vehicles that have turned on the indicator with the intention of entering the adjacent lane) that can reach the position 221 to which the motor vehicle 100 is expected to move can be calculated OBJ .

[0127] By way of a second example, as an alternative, it is possible to verify the safety of the approach, instead of comparing the time t EGO ,t OBJ , but rather examines criteria related to the relative speeds of these vehicles with respect to each other.

[0128] Thus, the check can be based on a comparison of the relative speed of the motor vehicle 100 with respect to the preceding vehicle 310 with a first threshold and a comparison of the relative speed of the motor vehicle 100 with respect to the following vehicle 320 with a second threshold to verify that these relative speeds are compatible with a lane change in complete safety.

[0129] In the embodiment described with reference to the figures, the vehicle is autonomous. As a variant, this may not be the case. In such a case, the fifth step e) would no longer consist of automatically steering the motor vehicle 100 towards the desired lane 230, but would consist of displaying on the screen of the vehicle information allowing the driver to know to which lane he must move in order to pass the toll booth as quickly as possible and in complete safety.

Claims

1. A selection method for selecting a preferred lane (230) for a motor vehicle (100) to enter a charging area (200) comprising a plurality of lanes (210, 220, 230, 240), the selection method comprising the following steps: a) detecting lanes (210, 220, 230, 240) of the toll area (200), b) determining, for at least a portion of the lanes (210, 220, 230, 240), first data relating to the distance of the motor vehicle (100) from the respective lane (210, 220, 230, 240) and second data relating to the number of third-party vehicles (300, 310, 320) located in the respective lane (210, 220, 230, 240), c) calculating a value of a cost function for each lane (210, 220, 230, 240) in the portion based on the corresponding first data and the corresponding second data, and identifying the preferred lane (230) as the lane with the lowest value of the cost function, and d) determining whether the motor vehicle (100) is able to change lanes (210, 220, 230, 240) to move to the preferred lane (230), or determining a risk of doing so, The toll booth of the toll zone (200) displays a sign above each lane, indicating whether the lane is open and acceptable means of payment, The motor vehicle (100) is equipped with an image acquisition device (130) and a computing unit (140), wherein in step a), the image acquisition device (130) acquires an image of the toll area (200), and the computing unit processes the image to detect open lanes of the toll area, and in step b), the computing unit (140) determines first data and second data for each open lane, and wherein, in step c), the value of the cost function for each lane (210, 220, 230, 240) in the portion is calculated based on the sum of the corresponding first data weighted by the first coefficient and the corresponding second data weighted by the second coefficient, The first coefficient and the second coefficient can be changed according to the preference of the passengers of the motor vehicle (100) or the type of the motor vehicle (100).

2. The selection method according to claim 1, wherein: The motor vehicle (100) is equipped with at least one ranging sensor (121, 122, 123, 124, 125), and in step b), the second data is an estimate of the number of third-party vehicles (300) located in each of the lanes (210, 220, 230, 240), the estimate being determined based on measurements performed by the ranging sensor (121, 122, 123, 124, 125).

3. The selection method according to claim 1 or 2, wherein: Given a lane (220) which is adjacent to the lane (210) being used by the motor vehicle (100) and is located on one side of the preferred lane (230) relative to the lane (210) being used by the motor vehicle (100), in step d), it is checked whether the maneuvering time required for the motor vehicle (100) to change lanes to reach a desired position (221) in the adjacent lane (220) is strictly shorter than the arrival time required for a third-party vehicle (310, 320) being driven in the adjacent lane (220) to reach the desired position.

4. The selection method according to claim 1 or 2, wherein: Given a lane (220) which is adjacent to the lane (210) being used by the motor vehicle (100) and is located on one side of the preferred lane (230) relative to the lane (210) being used by the motor vehicle (100), in step d), a dual criterion is checked relating to the relative speed of the motor vehicle (100) relative to two third-party vehicles (310, 320) travelling in front of and behind the motor vehicle (100) in the adjacent lane (220).

5. The selection method according to claim 1 or 2, wherein: The motor vehicle (100) is equipped with a geolocation device (141), a memory (142) storing a route map, and a computing unit (140), which in step b) calculates the first data based on the geolocation position of the motor vehicle (100) and the geometry of the toll zone (200), the geolocation position being obtained by the geolocation device (141) and the geometry being stored in the memory (142).

6. A control method for controlling an autonomous motor vehicle, the control method comprising: - Steps a) to d) of the selection method as defined in one of the preceding claims, then comprising - A control step of controlling the motor vehicle in question to go to the preferred lane (230).

7. The control method according to claim 6, wherein: If the preferred lane (230) is not adjacent to the lane (210) being used by the motor vehicle (100), then after the vehicle changes lanes for the first time to get closer to the preferred lane (230), steps a) to d) and the control step are repeated.

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