Method for distinguishing secondary road signs from primary road signs

Abstract

This invention relates to a method for distinguishing between auxiliary road signs and main road signs, comprising: - acquiring a main image of the environment in front of or behind a vehicle using a main camera, the main image including images of main road signs and auxiliary road signs located in front of or behind the vehicle; - acquiring an auxiliary image of the environment on one side of the vehicle using an auxiliary camera, the auxiliary image including images of main road signs and auxiliary road signs located on the side; - determining, using the main camera, a primary color of the main road sign and an auxiliary color of the auxiliary road sign from the main image; - transmitting, using the main camera, a primary position vector of the main sign having its primary color and an auxiliary position vector of the auxiliary sign having its auxiliary color, as inferred from the main image, to a control unit; - transmitting, using the auxiliary camera, the primary position vector of the main road sign and the auxiliary position vector of the auxiliary road sign, as inferred from the auxiliary image, to the control unit; - determining, using the primary position vector and the auxiliary position vector, a relative position vector of the auxiliary road sign relative to the main road sign in the auxiliary field of view of the auxiliary camera; - associating the auxiliary color with the relative position vector.

Description

[0001] This invention relates to a method for distinguishing between auxiliary signs and main signs of a road on which a vehicle is located. It is particularly applicable, but not limited to, motor vehicles. The invention also relates to a distinguishing device for implementing the distinguishing method.

[0002] In the field of motor vehicles, there are methods for detecting road signs, the methods including:

[0003] -Illuminate the road in front of the motor vehicle using the main camera;

[0004] - The main camera acquires an image of the road sign in front of the motor vehicle;

[0005] - Detect road signs ahead of the motor vehicle using the main camera;

[0006] - Detect road signs to the side of the motor vehicle using an auxiliary camera;

[0007] - Perform the determined functions based on the detected road signs.

[0008] Depending on the application using the detection method, the defined functions performed are, for example:

[0009] - Functions that assist in parking the motor vehicle; or

[0010] - Functions that assist the motor vehicle in changing lanes or in keeping it within the lane.

[0011] The auxiliary camera is an infrared or near-infrared camera because infrared light is invisible to the naked eye. This allows compliance with current regulations prohibiting the use of cameras that illuminate the sides of a vehicle using visible light. Therefore, pedestrians or vehicles located to the side of the vehicle will not be dazzled or disturbed by the visible light.

[0012] One drawback of this existing technology is that infrared or near-infrared auxiliary cameras cannot distinguish colors. Therefore, if there is a section of road under work or construction with both standard white main road signs (as standard road signs) and standard yellow auxiliary road signs (as temporary road signs), the auxiliary camera cannot differentiate between these two types of road signs, and the road sign detection system cannot function correctly. Consequently, in order to perform a defined function, it is unclear which road sign to follow.

[0013] In this context, the present invention relates to a method for distinguishing between auxiliary signs and main signs of the road on which a vehicle is located, in order to address the aforementioned drawbacks.

[0014] Therefore, the present invention proposes a method for distinguishing between auxiliary signs and main signs of a road where a vehicle is located, characterized in that the distinguishing method includes:

[0015] - A main image of the external environment of the vehicle in front of or behind the vehicle is acquired by the main camera, the main image including images of the main road signs and the auxiliary road signs located in front of or behind the vehicle;

[0016] - Acquire auxiliary images of the external environment located on at least one side of the vehicle using at least one auxiliary camera, the auxiliary images including images of the main road sign and the auxiliary road sign located on at least one side of the vehicle;

[0017] - Determine the primary color of the main road sign from the main image using the main camera;

[0018] - The auxiliary color of the auxiliary road sign is determined from the main image using the main camera;

[0019] - The main position vector of the main marker with its associated main color and the auxiliary position vector of the auxiliary marker with its associated auxiliary color are transmitted to the electronic control unit via the main camera, and the main position vector and the auxiliary position vector are inferred from the main image;

[0020] - The main position vector of the main road sign and the auxiliary position vector of the auxiliary road sign are transmitted to the electronic control unit through the auxiliary camera, and the main position vector and the auxiliary position vector are inferred from the auxiliary image;

[0021] - The electronic control unit determines the relative position vector of the auxiliary road sign with respect to the main road sign in the auxiliary field of view of the auxiliary camera from the main position vector and the auxiliary position vector;

[0022] - The electronic control unit associates the auxiliary color of the auxiliary road sign in the auxiliary field of view with the relative position vector.

[0023] Therefore, as will be seen in detail below, by distinguishing between main road signs and auxiliary road signs, we can know which road signs should be followed in order to perform the defined functions.

[0024] According to a non-limiting embodiment, the differentiation method may also include one or more additional features obtained individually or in any technically possible combination of those features.

[0025] According to a non-limiting embodiment, the relative position vector is determined by a constant angle defined between the following:

[0026] -The principal point of the main image at the main road sign and on the longitudinal axis of the vehicle; with

[0027] - An auxiliary point of the main image located at the auxiliary road sign and on the longitudinal axis of the vehicle.

[0028] According to a non-limiting embodiment, the relative position vector is determined by a variable angle defined between the following:

[0029] -The principal point of the main image at the main road sign and on the longitudinal axis of the motor vehicle, and

[0030] - An auxiliary point of the main image located at the auxiliary road sign and on the longitudinal axis of the vehicle.

[0031] According to a non-limiting embodiment, the differentiation method further includes:

[0032] - Illuminate the main road signs and auxiliary road signs in front of or behind the vehicle, and / or

[0033] - Illuminating at least one side of the vehicle the main road sign and the auxiliary road sign.

[0034] According to a non-limiting embodiment, the electronic control unit is either part of the main camera or separate from the main camera.

[0035] Furthermore, a method for locating a vehicle relative to auxiliary signs on a road on which the vehicle travels is proposed, the road including main road signs and the auxiliary road signs, characterized in that the locating method includes:

[0036] - A main image of the external environment of the vehicle in front of or behind the vehicle is acquired by the main camera, the main image including images of the main road signs and the auxiliary road signs located in front of or behind the vehicle;

[0037] - Acquire auxiliary images of the external environment located on at least one side of the vehicle using at least one auxiliary camera, the auxiliary images including images of the main road sign and the auxiliary road sign located on at least one side of the vehicle;

[0038] - Determine the primary color of the main road sign from the main image using the main camera;

[0039] - The auxiliary color of the auxiliary road sign is determined from the main image using the main camera;

[0040] - The main position vector of the main marker with its associated main color and the auxiliary position vector of the auxiliary marker with its associated auxiliary color are transmitted to the electronic control unit via the main camera, and the main position vector and the auxiliary position vector are inferred from the main image;

[0041] - The main position vector of the main road sign and the auxiliary position vector of the auxiliary road sign are transmitted to the electronic control unit through the auxiliary camera, and the main position vector and the auxiliary position vector are inferred from the auxiliary image;

[0042] - The electronic control unit determines the relative position vector of the auxiliary road sign with respect to the main road sign in the auxiliary field of view of the auxiliary camera from the main position vector and the auxiliary position vector;

[0043] - The electronic control unit associates the auxiliary color of the auxiliary road sign in the auxiliary field of view with the relative position vector;

[0044] - Calculate the position of the vehicle relative to the auxiliary road sign as a function of the relative position vector.

[0045] A device for distinguishing between auxiliary signs and main signs of a road where a vehicle is located is also proposed, characterized in that the distinguishing device comprises:

[0046] - A main camera, configured to acquire a main image of the external environment of the vehicle located in front of or behind the vehicle, the main image including images of the main road signs and the auxiliary road signs located in front of or behind the vehicle;

[0047] - At least one auxiliary camera, the at least one auxiliary camera being configured to acquire auxiliary images of the external environment located on at least one side of the vehicle, the auxiliary images including images of the main road sign and the auxiliary road sign located on the at least one side of the vehicle;

[0048] The main camera is also configured to determine the primary color of the main road sign and the secondary color of the secondary road sign from the main image, and to transmit to the electronic control unit the primary position vector of the main sign with its associated primary color and the secondary position vector of the secondary sign with its associated secondary color, and to infer the primary position vector and the secondary position vector from the main image.

[0049] The auxiliary camera is also configured to transmit the main position vector of the main road sign and the auxiliary position vector of the auxiliary road sign to the electronic control unit, and to infer the main position vector and the auxiliary position vector from the auxiliary image;

[0050] Furthermore, the distinguishing device further includes:

[0051] - The electronic control unit is configured to determine, from the primary position vector and the secondary position vector, the relative position vector of the auxiliary road sign relative to the primary road sign in the secondary field of view of the auxiliary camera, and to associate the secondary color of the auxiliary road sign in the secondary field of view with the relative position vector.

[0052] A better understanding of the invention and its various applications will be gained by reading the following description and studying the accompanying drawings:

[0053] Figure 1a This is a flowchart of a method for distinguishing between auxiliary signs and main signs of a road where a vehicle is located, according to a first non-limiting embodiment of the present invention.

[0054] Figure 1b This is a flowchart of a method for distinguishing between auxiliary signs and main signs of a road where a vehicle is located, according to a second non-limiting embodiment of the present invention.

[0055] Figure 2 This is a schematic diagram, from above, of a vehicle situated on a road including main road signs and auxiliary road signs, according to a non-limiting embodiment.

[0056] Figure 3 This is a schematic diagram of a device for distinguishing between auxiliary signs and main signs of a road, according to a non-limiting embodiment, which allows for implementation of... Figure 1a and Figure 1b The method of differentiation

[0057] Figure 4a According to the first non-limiting embodiment, from Figure 2 A schematic diagram viewed from above a vehicle, the diagram including points on main road signs and auxiliary road signs used to determine the position of one road sign relative to another.

[0058] Figure 4b According to the first non-limiting embodiment, Figure 3 A schematic diagram of the main image captured by the main camera of the distinguishing device, viewed from above, the main image containing... Figure 4a The dots on the main road signs and auxiliary road signs,

[0059] Figure 5a According to the second non-limiting embodiment, from Figure 2 A schematic diagram viewed from above a vehicle, the diagram including points on main road signs and auxiliary road signs used to determine the position of one road sign relative to another.

[0060] Figure 5b According to the second non-limiting embodiment, Figure 3 A schematic diagram of the main image captured by the main camera of the distinguishing device, viewed from above, the main image containing... Figure 5a The dots on the main road signs and auxiliary road signs,

[0061] Figure 6 This is a flow chart of a method for locating a vehicle relative to auxiliary signs and main signs of the road on which the vehicle is located, according to a non-limiting embodiment.

[0062] Unless otherwise specified, elements that are identical in structure or function in the various figures shall retain the same reference numerals.

[0063] Refer to Figure 1 to Figure 5b A method 1 according to the present invention for distinguishing between an auxiliary sign M2 and a main sign M1 of road R1 where vehicle 5 is located is described. In a non-limiting embodiment, vehicle 5 is a motor vehicle. A motor vehicle refers to any type of motor vehicle. Throughout the remainder of the specification, this embodiment is considered a non-limiting example. Therefore, throughout the remainder of the specification, vehicle 5 is also referred to as motor vehicle 5. Motor vehicle 5 has a width L1*2 (e.g., ... Figure 2 , Figure 4a and Figure 5a (as shown in the diagram) and the length extending along the longitudinal axis Ax, which is perpendicular to the horizontal axis Ay and passes through its center.

[0064] Method 1 for distinguishing Figure 3 The distinguishing device 3 shown in the figure above is implemented, and the distinguishing device includes:

[0065] -Main camera 31, and

[0066] -At least one auxiliary camera 32, and

[0067] - Electronic control unit 33.

[0068] The main camera 31 is positioned in front of or behind the vehicle 5, while the at least one auxiliary camera 32 is positioned on one side of the vehicle 5. Figure 2As illustrated in the non-limiting example, the main camera 31 is located in front of the motor vehicle 5. In one non-limiting embodiment, it is positioned behind the windshield, at the level or height of the rearview mirror. The main camera 31 is a camera that operates within the visible range. The main camera 31 is configured to acquire RGB color images from the exterior of the motor vehicle 5.

[0069] like Figure 2 As illustrated in the non-limiting example, the auxiliary camera 32 is located on the left side of the motor vehicle 5. In one non-limiting embodiment, it is arranged in a side mirror. In a non-limiting embodiment, the auxiliary camera 32 is an infrared (wavelength between 700 nm and 1 mm) or near-infrared (wavelength about 850 nm) camera, or a long-wave infrared (LWIR) camera (wavelength about 10 μm) camera, or a short-wave infrared (SWIR) camera (wavelength about 1 μm). The auxiliary camera 32 is configured to acquire infrared images from the exterior of the motor vehicle 5.

[0070] According to a non-limiting embodiment, the electronic control unit 33 is either part of or separate from the main camera 31. In a non-limiting embodiment (not shown), the distinguishing device 3 includes auxiliary cameras 32 located on each side of the motor vehicle 5, one on the left-hand side and one on the right-hand side.

[0071] Method 1 allows for the differentiation between the auxiliary sign M2 and the main sign M1 on road R1 where motor vehicle 5 is located. For example... Figure 2 As illustrated, the main road sign M1 represents the standard sign for road R1, while the auxiliary road sign M2 represents a sign related to construction on road R1. Therefore, the main road sign M1 is a permanent sign, while the auxiliary road sign M2 is a temporary sign. The main road sign M1 has a primary color C1, while the auxiliary road sign M2 has a secondary color C2. The two colors C1 and C2 are different. Therefore, in a non-limiting example, the primary color C1 is white (in...). Figure 2 (The central color is shown in a darker shade), while the secondary color C2 is yellow (in...). Figure 2 (Illustrated in light color).

[0072] To distinguish between auxiliary road sign M2 and main road sign M1, according to a first non-limiting embodiment, such as Figure 1a As illustrated in the diagram, Method 1 includes the following steps. Note that some steps are performed in parallel.

[0073] In the first step E1, as Figure 1a As illustrated in F1(31, I1), the main camera 31 acquires a main image I1 of the external environment in front of or behind the motor vehicle 5. Therefore, the main image I1 includes images of the main road sign M1 and the auxiliary road sign M2 located in front of or behind the motor vehicle 5. Figure 2As illustrated in the non-limiting example illustration, the acquired main image I1 is an image of the external environment located in front of the motor vehicle 5. Figure 2 The diagram shows the main field of view (FOV1) of the main camera 31 (dashed line), in which the main road sign M1 and the auxiliary road sign M2 are seen. Note that in this non-limiting embodiment, this step is performed consecutively. Assuming the main camera 31 is a camera operating within the visible range, the main image I1 shows the colors C1 and C2 of the two main road signs M1 and the auxiliary road sign M2. Therefore, as... Figure 2 As shown, the main road sign M1 and the auxiliary road sign M2 are represented by two different colors in the main field of view (FOV1), one dark and one light. The camera's field of view is called the horizon.

[0074] In the second step E2, as Figure 1a As illustrated in F2(32, I2), at least one auxiliary camera 32 acquires an auxiliary image I2 of the external environment of at least one side of the motor vehicle 5. Therefore, the auxiliary image I2 includes images of the main road sign M1 and the auxiliary road sign M2 on one side of the motor vehicle 5. (As shown in...) Figure 2 In the non-restrictive example illustrated, the side of interest is the left-hand side of motor vehicle 5. Figure 2 The auxiliary field of view (FOV2) of the auxiliary camera 32 is shown (dashed line), in which the main road sign M1 and the auxiliary road sign M2 are seen. Note that in this non-limiting embodiment, this step is performed consecutively. Therefore, it is performed in parallel with the first step E1. Assuming that the auxiliary camera 32 is a camera operating in the infrared or near-infrared light range, the auxiliary image I2 does not show the colors C1, C2 of the two main road signs M1 and the auxiliary road sign M2.

[0075] In the third step E3, as follows Figure 1a As illustrated above with F3(31, I1, C1(M1)), the main camera 31 determines the primary color C1 of the main road sign M1 from the main image I1. Figure 2 (Represented in dark gray). Since the main camera 31 operates within the visible range, it can distinguish the colors of each other. In the non-limiting example illustrated, it determines that the primary color C1 of the main road sign M1 is white.

[0076] In step E4, as follows Figure 1a As illustrated in the diagram above (F4(31, I1, C2(M2))), the auxiliary camera 31 determines the auxiliary color C2 (in the main image I1) of the auxiliary road sign M2. Figure 2 (Represented in light gray). In the non-limiting example shown, it determines that the secondary color C2 of the auxiliary road sign M2 is yellow (e.g., ...). Figure 2 (The light gray illustration in the image).

[0077] In step E5, as in Figure 1a As shown in F5(31, 33, M1(P1, C1), M2(P2, C2)), the main camera 31 transmits a main position vector P1 with its associated main color C1 and an auxiliary position vector P2 with its associated auxiliary color C2 to the electronic control unit 33, obtaining the main position vector P1 and the auxiliary position vector P2 from the main image I1. The main position vector P1 and the auxiliary position vector P2 are relative to the position of the motor vehicle 5, and in particular relative to the line 51 tangent to the side 50 of the motor vehicle 5.

[0078] exist Figure 4a and Figure 4b In the first non-limiting embodiment illustrated above, the principal position vector P1 (p01->P1) is inferred from the angle β1 between the longitudinal axis Ax and the principal point p1 of the principal image I1 located at the horizontal (i.e., vertical) position of the principal road sign M1. Therefore, we have:

[0079] [Mathematical Equation 1]

[0080] LP1=d1sinβ1-L1

[0081] Where LP1 is its length, p01 is its origin on line 51 tangent to side 50, and d1 is the distance between main point p1 and center point p0 at the bottom of main image I1.

[0082] Similarly, in Figure 4a and Figure 4b In the first non-limiting embodiment illustrated above, the auxiliary position vector P2 (p02->p2) is inferred from the same angle β1 between the longitudinal axis Ax and the auxiliary point p2 of the auxiliary image I1 located at the horizontal (i.e., vertical) position of the auxiliary road sign M2. Therefore, we have:

[0083] [Mathematical Equation 2]

[0084] LP2=d2sinβ1-L1

[0085] Where LP2 is its length, p02 is its origin on line 51 tangent to side 50, and d2 is the distance between auxiliary point p2 and center point p0 at the bottom of main image I1.

[0086] exist Figure 5a and Figure 5b In the second non-limiting embodiment illustrated above, the principal position vector P1 (p03->p1) is inferred from the angle θ1 between the vertical axis Ax and the principal point p1 of the principal image I1 located at the horizontal (i.e., vertical) position of the principal road sign M1. Therefore, we have:

[0087] [Mathematical Equation 3]

[0088] LP1=d1sinθ1-L1

[0089] Where LP1 is its length, p03 is its origin on line 51 tangent to side 50, and d1 is the distance between principal point p1 and center point p0 at the bottom of main image I1. Center point p0 represents the position of main camera 31.

[0090] Similarly, in Figure 5a and Figure 5b In the second non-limiting embodiment illustrated above, the auxiliary position vector P2 (p03->p2) is inferred from an angle θ2, different from angle θ1, between the longitudinal axis Ax and the auxiliary point p2 of the main image I1 located at the horizontal (i.e., vertical) position of the auxiliary road sign M2. Therefore, we have:

[0091] [Mathematical Equation 4]

[0092] LP2=d2sinθ2-L1

[0093] Where LP2 is its length, p03 is its origin on the line 51 tangent to the side 50, and d2 is the distance between the auxiliary point p2 and the center point p0 at the bottom of the main image I1. The center point p0 represents the position of the main camera 31. In this case, the main point p1 and the auxiliary point p2 are aligned on a line perpendicular to the vertical axis Ax.

[0094] Note that in order to perform the above calculations in the first and second embodiments, it is assumed that the motor vehicle 5 is traveling parallel to the lines of road signs M1 and M2, and that road signs M1 and M2 are themselves parallel.

[0095] In step E6, as in Figure 1aAs shown in F6(32, 33, M1(P1, C1), M2(P2, C2)), the auxiliary camera 32 transmits the main position vector P1 of the main road sign M1 and the auxiliary position vector P2 of the auxiliary sign M2 to the electronic control unit 33, obtaining the main position vector P1 and the auxiliary position vector P2 from the auxiliary image I2. The main position vector P1 and the auxiliary position vector P2 are relative to the position of the motor vehicle 5, specifically relative to the position of the line 51 tangent to the side 50 of the motor vehicle 5. Therefore, the auxiliary camera 32 also transmits the main position vector P1 and the auxiliary position vector P2, but from its perspective. Thus, the electronic control unit 33 will receive two main position vectors P1 (one from the main camera 31 and the other from the auxiliary camera 32) and two auxiliary position vectors P2 (one from the main camera 31 and the other from the auxiliary camera 32). The main position vector P1 from the main camera 31 is also referred to as the first main position vector P1, and the main position vector P1 from the auxiliary camera 32 is also referred to as the second main position vector P1. Similarly, the auxiliary position vector P2 from the main camera 31 is also referred to as the first auxiliary position vector P2, and the auxiliary position vector P2 from the auxiliary camera 32 is also referred to as the second auxiliary position vector P2.

[0096] Use the same method as in step E5 of the fifth procedure. Figure 5a and Figure 5b The two non-limiting embodiments illustrated in the figure determine the main position vector P1 and the auxiliary position vector P2, the main image I1 is replaced by the auxiliary image I2, and the center point p0 of the main camera 31 is replaced by the center point (not shown) of the auxiliary camera 32.

[0097] Note that, via an appropriate communication link, such as a CAN or Ethernet link in the non-limiting example, the main camera 31 has transmitted the main image I1 to the electronic control unit 33, and the auxiliary camera 32 has transmitted the auxiliary image I2 to the electronic control unit 33. Note that as the vehicle 5 moves along the road R1, the main image I1 and the auxiliary image I2 are refreshed.

[0098] In step E7, as follows Figure 1aAs illustrated in F7(33, P3, M1, M2), the electronic control unit 33 determines the relative position vector P3 (pA->pB) of the auxiliary road sign M2 relative to the main road sign M1 in the auxiliary field of view FOV2 from the main position vector P1 and the auxiliary position vector P2, i.e., from the first main position vector P1 and the second main position vector P1, and from the first auxiliary position vector P2 and the second auxiliary position vector P2. Since it has received the main position vector P1 and the auxiliary position vector P2 from the main camera 31 and the auxiliary camera 32, the electronic control unit 33 can infer the relative position vector P3' in the main field of view FOV1 from these, and thus infer the direction in which the relative position vector P3 in the auxiliary field of view FOV2 is toward or away from the vehicle 5.

[0099] To determine the relative position vector P3 in the auxiliary field of view FOV2, the electronic control unit 33 can perform the following calculations.

[0100] like Figure 4a As illustrated in the diagram, in the first non-limiting embodiment, the relative position vector P3' is determined by a constant angle β1 defined between the following:

[0101] -The principal point p1 of the main image I1 at the horizontal (height) level of the main road sign M1 and at the longitudinal axis Ax of the motor vehicle 5; and

[0102] - Auxiliary point p2 of the main image I1 at the horizontal (height) level of the auxiliary road sign M2 and at the longitudinal axis Ax of the vehicle 5.

[0103] The main point p1 is located at a distance d1 from the main camera 31, and the auxiliary point p2 is located at a distance d2 from the main camera 31. The main point p1 and the auxiliary point p2 are aligned on a line L0 passing through the main camera 31, which intersects the main road sign M1 and the auxiliary road sign M2 and defines an angle β1 with the longitudinal axis Ax.

[0104] As a function of the velocity V of the vehicle 5, it is known at what time the principal point p1 and the auxiliary point p2 in the main field of view (FOV1) of the main camera 31 will enter the auxiliary field of view (FOV2) of the auxiliary camera 32. Therefore, it is known that the principal point p1 and the auxiliary point p2 seen by the main camera 31 correspond to the third point pA and the fourth point pB, respectively. These two points pA and pB are aligned on the horizontal axis Ay, which is perpendicular to the longitudinal axis Ax of the vehicle 5. The third point pA is located at a distance dA from the vehicle 5, and the fourth point pB is located at a distance dB from the vehicle 5 along the horizontal axis Ay. Therefore, the following relationship exists.

[0105] [Mathematical Equation 5]

[0106] d A =d1sinβ1-L1=LP1

[0107] Where LP1 is the length of the position vector P1, and

[0108] [Mathematical Equation 6]

[0109] d B =d2sinβ1-L1=LP2

[0110] Where LP2 is the length of the position vector P2.

[0111] Where L1 is half the width of vehicle 5. Using this relationship, it can be verified that the third point pA and the fourth point pB seen by the auxiliary camera 32 are approximately located at calculated distances dA and dB. Distances dA and dB can be used to infer the relative position vector P3 (pA->pB), where its length is dB-dA and its origin is pA. The direction of position vector P3 is the same as the direction of position vector P3' towards or away from vehicle 5. Through distance dA, it is known that point pA belongs to marker M1. Through distance dB, it is known that point pB belongs to marker M2.

[0112] like Figure 5a As illustrated in the diagram, in the second non-limiting embodiment, the relative position vector P3' is determined by a constant angle θ defined between the following:

[0113] -The principal point p1 of the main image I1 at the horizontal (height) level of the main road sign M1 and at the longitudinal axis Ax of the motor vehicle 5, and

[0114] - Auxiliary point p2 of the main image I1 at the horizontal (height) level of the auxiliary road sign M2 and at the longitudinal axis Ax of the motor vehicle 5.

[0115] The principal point p1 is located at a distance d1 from the main camera 31, and the auxiliary point p2 is located at a distance d2 from the main camera 31. The principal point p1 and the auxiliary point p2 are aligned on the line L0, which is perpendicular to the longitudinal axis Ax and intersects the main road sign M1 and the auxiliary road sign M2.

[0116] As a function of the velocity V of the vehicle 5, it is known at what time the principal point p1 and the auxiliary point p2 in the main field of view (FOV1) of the main camera 31 will enter the auxiliary field of view (FOV2) of the auxiliary camera 32. Therefore, it is known that the principal point p1 and the auxiliary point p2 seen by the main camera 31 correspond to the third point pA and the fourth point pB, respectively. These two points pA and pB are aligned on the horizontal axis Ay, which is perpendicular to the longitudinal axis Ax of the vehicle 5. The third point pA is located at a distance dA from the vehicle 5, and the fourth point pB is located at a distance dB from the vehicle 5 along the horizontal axis Ay. Therefore, the following relationship exists.

[0117] [Mathematical Equation 7]

[0118] d A =d1sinθ1-L1=LP1

[0119] Where LP1 is the length of the position vector P1, and

[0120] [Mathematical Equation 8]

[0121] d B =d2sinθ2-L1=LP2

[0122] Where LP2 is the length of the position vector P2.

[0123] Where L1 is half the width of vehicle 5. Using this next relationship, it can be verified that the third point pA and the fourth point pB seen by the auxiliary camera 32 are approximately located at the calculated distances dA and dB. Distances dA and dB can be used to infer the relative position vector P3, where its length is dB-dA and its origin is pA. Based on distance dA, it is known that point pA belongs to marker M1. Based on distance dB, it is known that point pB belongs to marker M2.

[0124] In step E8, as follows Figure 1a As illustrated in F8(33, P3, C2), the electronic control unit 33 (using calculated distances dA and dB) associates the auxiliary color C2 in the auxiliary field of view FOV2 with the relative position vector P3 of the auxiliary road sign M2 (relative to the main road sign M1). The electronic control unit 33 can associate the auxiliary color C2 with the relative position vector P3 using data transmitted from the main camera 31 (i.e., the main position vector P1 with its associated main color C1 and the auxiliary position vector P2 with its associated auxiliary color C2 as seen by the main camera 31) and data transmitted from the auxiliary camera 32 (i.e., the main position vector P1 and the auxiliary position vector P2 as seen by the auxiliary camera 32).

[0125] Therefore, by determining the auxiliary color C2 of the auxiliary road sign M2 and its relative position vector P3 with respect to the main road sign M1, the auxiliary road sign M2 and the main road sign M1 can be distinguished.

[0126] exist Figure 1b In the second non-limiting embodiment illustrated in the figure, in addition to steps E1 to E8, the differentiation method 1 may also include the following supplementary steps:

[0127] - Illuminate the main road sign M1 and auxiliary road sign M2 in front of or behind vehicle 5. Figure 1b The previous step E2' is illustrated as F2'(M1, M2)); and / or

[0128] - Illuminating at least one side of the main road sign M1 and auxiliary road sign M2 of vehicle 5 ( Figure 1b The previous step E2” is illustrated as F2” (M1, M2)).

[0129] Illumination is provided by an optical module (not shown). Illumination is particularly useful at night. Note that these steps are performed simultaneously with all steps E1 through E8.

[0130] Therefore, method 1 is distinguished by Figure 3 The distinguishing device 3 shown in the diagram above is implemented.

[0131] like Figure 3 As shown in the diagram, the distinguishing device 3 includes a main camera 31, the at least one auxiliary camera 32, and components of an electronic control unit 33.

[0132] The main camera 31 is therefore configured as follows:

[0133] - Obtain a main image I1 of the external environment of the vehicle 5 located in front of or behind the vehicle 5, the main image I1 including images of the main road sign M1 and the auxiliary road sign M2 located in front of or behind the vehicle 5 (the function is illustrated as f1(31, I1)).

[0134] - Determine the primary color C1 of the main road sign M1 from the main image I1 (the function is illustrated as f3(31, I1, C1(M1)));

[0135] - Determine the auxiliary color C2 of the auxiliary road sign M2 (the function is illustrated as f4(31, I1, C2(M2)));

[0136] - Transmit the main position vector P1 of the main road sign M1 with its associated main color C1 and the auxiliary position vector P2 of the auxiliary sign M2 with its associated secondary color C to the electronic control unit 33, and infer the main position vector P1 and the auxiliary position vector P2 from the main image I1 (the function is illustrated as f5(31, 33, M1(P1, C1), M2(P2, C2)).

[0137] The at least one auxiliary camera 32 is configured to:

[0138] - Obtain an auxiliary image I2 of the external environment located on at least one side of the vehicle 5, the auxiliary image I2 including images of the main road sign M1 and the auxiliary road sign M2 located on at least one side of the vehicle 5 (the function is illustrated as f2(32, I2));

[0139] - Transmit the main position vector P1 of the main road sign M1 and the auxiliary position vector P2 of the auxiliary sign M2 to the electronic control unit 33, and infer the main position vector P1 and the auxiliary position vector P2 from the auxiliary image I2 (the function is illustrated as f6(32, 33, M1(C1), M2(C2)).

[0140] The electronic control unit 33 is configured to:

[0141] - Determine the relative position vector P3 of the auxiliary road sign M2 with respect to the main road sign M1 in the auxiliary field of view FOV2 of the auxiliary camera 32 from the main position vector P1 and the auxiliary position vector P2 (the function is illustrated as f7(33, P3, M1, M2)).

[0142] - The auxiliary color C2 in the auxiliary field of view FOV2 is associated with the relative position vector P3 of the auxiliary road sign M2 (the function is illustrated as f8(33, P3, C2)).

[0143] Therefore, method 1 can be used by any other process that needs to distinguish between the main road sign M1 and the auxiliary road sign M2, especially when using an auxiliary camera 32 that cannot distinguish between the two road signs. Therefore, it can be used in method 2 to locate vehicle 5 relative to the auxiliary sign M2 of the road R1 on which vehicle 5 is traveling. The location method 2 in... Figure 6 The diagram shows the steps E1 through E8 of method 1, as well as subsequent additional steps.

[0144] In step E9, as illustrated in F9(33, Pos(P3), 5), the electronic control unit 33 calculates the position Pos of the motor vehicle 5 relative to the auxiliary road sign M2 as a function of the relative position vector P3 of the auxiliary road sign M2. Therefore, this position Pos is inferred from the previously calculated distance dB. Thus, the position of the motor vehicle 5 relative to the road sign M2 is determined.

[0145] After calculating the position Pos, the determined function is executed as the expected application function.

[0146] In a non-limiting embodiment, the defined function performed is:

[0147] - An automatic parking function for the motor vehicle 5 in the case of an autonomous vehicle, i.e., an automated driving vehicle;

[0148] -A function to assist the parking of the motor vehicle 5 in the case of non-autonomous vehicles, i.e., non-automatic vehicles, in road construction zones;

[0149] - Functions for automatically changing lanes in the case of autonomous vehicles, i.e., self-driving vehicles;

[0150] - A function to display the colors of road signs on the side of the vehicle on the human-machine interface instead of in black and white;

[0151] - Functions used to assist in changing lanes, assist in staying in the lane in road construction zones, etc.

[0152] It should be understood that the specification of this invention is not limited to the embodiments and fields described above. Therefore, in a non-limiting embodiment, the positioning method 2 may further include illuminating the main road sign M1 and auxiliary road sign M2 located in front of or behind the vehicle 5, and illuminating the main road sign M1 and auxiliary road sign M2 located on at least one side of the vehicle 5. Note that in the figures, the standard road sign is located to the right of the temporary road sign. Naturally, the reverse is also applicable. In this case, the auxiliary road sign M2 would be located to the right of the main road sign M2. Therefore, in a non-limiting embodiment, the distinguishing device 3 may include two auxiliary cameras 32, each arranged on one side of the vehicle 5, for acquiring auxiliary images I2 of each side of the vehicle 5. Therefore, in another non-limiting embodiment, the main camera 31 may be arranged outside the rear of the central observation mirror. Similarly, in another non-limiting embodiment, the auxiliary camera 32 may be arranged outside the side mirrors.

[0153] Therefore, the present invention described herein has the following advantages in particular:

[0154] - It allows for the differentiation of auxiliary road sign M2 from main road sign M1 (especially due to their color), and establishes the position of auxiliary road sign M2 relative to main road sign M1;

[0155] - It allows inferring the position Pos of vehicle 5 relative to the main road sign M1 and the auxiliary road sign M2, and thus determining which road sign to follow.

Claims

1. A method (1) for distinguishing between an auxiliary road sign (M2) and a main road sign (M1) of the road (R1) where a vehicle (5) is located, characterized in that, The distinguishing method (1) includes: - The main camera (31) acquires a main image (I1) of the external environment of the vehicle (5) in front of or behind the vehicle (5), the main image (I1) including images of the main road sign (M1) and the auxiliary road sign (M2) located in front of or behind the vehicle (5). - An auxiliary image (I2) of the external environment located on at least one side of the vehicle (5) is acquired by at least one auxiliary camera (32), the auxiliary image (I2) including images of the main road sign (M1) and the auxiliary road sign (M2) located on at least one side of the vehicle (5); -The main color (C1) of the main road sign (M1) is determined (E3) from the main image (I1) by the main camera (31); -The auxiliary color (C2) of the auxiliary road sign (M2) is determined (E4) from the main image (I1) by the main camera (31); - The main position vector (P1) of the main road sign (M1) with its associated main color (C1) and the auxiliary position vector (P2) of the auxiliary road sign (M2) with its associated secondary color (C2) are transmitted (E5) to the electronic control unit (33) via the main camera (31), and the main position vector (P1) and the auxiliary position vector (P2) are inferred from the main image (I1). - The main position vector (P1) of the main road sign (M1) and the auxiliary position vector (P2) of the auxiliary road sign (M2) are transmitted to the electronic control unit (33) via the auxiliary camera (32), and the main position vector (P1) and the auxiliary position vector (P2) are inferred from the auxiliary image (I2). - The electronic control unit (33) determines (E7) the relative position vector (P3) of the auxiliary road sign (M2) in the auxiliary field of view (FOV2) of the auxiliary camera (32) relative to the main road sign (M1) from the main position vector (P1) and the auxiliary position vector (P2). -The relative position vector (P3) of the auxiliary road sign (M2) in the auxiliary field of view (FOV2) is associated with the auxiliary color (C2) by the electronic control unit (33) (E8). The relative position vector (P3) is determined by a constant angle (β1) between the following two terms: -The longitudinal axis (Ax) of the vehicle (5) is, with - A half-line, the half-line taking the center point (p0) at the bottom of the main image (I1) as its origin, and passing through the main point (p1) of the main image (I1) at the level of the main road sign (M1) and passing through the auxiliary point (p2) of the main image (I1) at the level of the auxiliary road sign (M2). Furthermore, the relative position vector (P3) is determined by a variable angle (θ) defined by two values ​​(θ1, θ2), wherein: - A value (θ1) is defined as a line between the longitudinal axis (Ax) of the vehicle (5) and a half-line that takes the center point (p0) at the bottom of the main image (I1) as its origin and passes through the main point (p1) of the main image (I1) at the level of the main road sign (M1), and - Another value (θ2) is defined as the main point (p1) and the auxiliary point (p2) of the main image (I1) being aligned along a line (L0) perpendicular to the longitudinal axis (Ax) of the vehicle (5) between the longitudinal axis (Ax) of the vehicle (5) and the half line between the center point (p0) as its origin and the auxiliary point (p2) at the level of the auxiliary road sign (M2).

2. The distinguishing method (1) according to claim 1, wherein, The distinguishing method (1) also includes: - Illuminate (E2') the main road sign (M1) and the auxiliary road sign (M2) in front of or behind the vehicle (5), and / or - Illuminate (E2”) the main road sign (M1) and the auxiliary road sign (M2) on at least one side of the vehicle (5).

3. The distinguishing method (1) according to claim 1 or 2, wherein, The electronic control unit (33) is either part of the main camera (31) or separate from the main camera (31).

4. A method (2) for positioning a vehicle (5) relative to an auxiliary road sign (M2) on a road (R1) on which the vehicle (5) travels, the road (R1) comprising a main road sign (M1) and the auxiliary road sign (M2), characterized in that, The positioning method (2) includes: - The main camera (31) acquires a main image (I1) of the external environment of the vehicle (5) in front of or behind the vehicle (5), the main image (I1) including images of the main road sign (M1) and the auxiliary road sign (M2) located in front of or behind the vehicle (5). - An auxiliary image (I2) of the external environment located on at least one side of the vehicle (5) is acquired by at least one auxiliary camera (32), the auxiliary image (I2) including images of the main road sign (M1) and the auxiliary road sign (M2) located on at least one side of the vehicle (5); -The main color (C1) of the main road sign (M1) is determined (E3) from the main image (I1) by the main camera (31); -The auxiliary color (C2) of the auxiliary road sign (M2) is determined (E4) from the main image (I1) by the main camera (31); - The main position vector (P1) of the main road sign (M1) with its associated main color (C1) and the auxiliary position vector (P2) of the auxiliary road sign (M2) with its associated secondary color (C2) are transmitted (E5) to the electronic control unit (33) via the main camera (31), and the main position vector (P1) and the auxiliary position vector (P2) are inferred from the main image (I1). - The main position vector (P1) of the main road sign (M1) and the auxiliary position vector (P2) of the auxiliary road sign (M2) are transmitted to the electronic control unit (33) via the auxiliary camera (32), and the main position vector (P1) and the auxiliary position vector (P2) are inferred from the auxiliary image (I2). - The electronic control unit (33) determines (E7) the relative position vector (P3) of the auxiliary road sign (M2) in the auxiliary field of view (FOV2) of the auxiliary camera (32) relative to the main road sign (M1) from the main position vector (P1) and the auxiliary position vector (P2). -The relative position vector (P3) of the auxiliary road sign (M2) in the auxiliary field of view (FOV2) is associated with the auxiliary color (C2) by the electronic control unit (33) (E8). - Calculate (E9) the position (Pos) of the vehicle (5) relative to the auxiliary road sign (M2) as a function of the relative position vector (P3). The relative position vector (P3) is determined by a constant angle (β1) between the following two terms: -The longitudinal axis (Ax) of the vehicle (5) is, with - A half-line, the half-line taking the center point (p0) at the bottom of the main image (I1) as its origin, and passing through the main point (p1) of the main image (I1) at the level of the main road sign (M1) and passing through the auxiliary point (p2) of the main image (I1) at the level of the auxiliary road sign (M2). Furthermore, the relative position vector (P3) is determined by a variable angle (θ) defined by two values ​​(θ1, θ2), wherein: - A value (θ1) is defined as a line between the longitudinal axis (Ax) of the vehicle (5) and a half-line that takes the center point (p0) at the bottom of the main image (I1) as its origin and passes through the main point (p1) of the main image (I1) at the level of the main road sign (M1), and - Another value (θ2) is defined as the main point (p1) and the auxiliary point (p2) of the main image (I1) being aligned along a line (L0) perpendicular to the longitudinal axis (Ax) of the vehicle (5) between the longitudinal axis (Ax) of the vehicle (5) and the half line between the center point (p0) as its origin and the auxiliary point (p2) at the level of the auxiliary road sign (M2).

5. A device (3) for distinguishing between an auxiliary road sign (M2) of a road (R1) where a vehicle (5) is located and a main road sign (M1) of said road (R1), characterized in that, The distinguishing device (3) includes: - Main camera (31), the main camera is configured to acquire a main image (I1) of the external environment of the vehicle (5) located in front of or behind the vehicle (5), the main image (I1) including images of the main road sign (M1) and the auxiliary road sign (M2) located in front of or behind the vehicle (5). - At least one auxiliary camera (32), the at least one auxiliary camera being configured to acquire an auxiliary image (I2) of the external environment located on at least one side of the vehicle (5), the auxiliary image (I2) including images of the main road sign (M1) and the auxiliary road sign (M2) located on at least one side of the vehicle (5). The main camera (31) is also configured to determine the primary color (C1) of the main road sign (M1) and the secondary color (C2) of the auxiliary road sign (M2) from the main image (I1), and to transmit to the electronic control unit (33) the primary position vector (P1) of the main road sign (M1) with its associated primary color (C1) and the secondary position vector (P2) of the auxiliary road sign (M2) with its associated secondary color (C2), and to infer the primary position vector (P1) and the secondary position vector (P2) from the main image (I1). - The auxiliary camera (32) is also configured to transmit the main position vector (P1) of the main road sign (M1) and the auxiliary position vector (P2) of the auxiliary road sign (M2) to the electronic control unit (33), and to infer the main position vector (P1) and the auxiliary position vector from the auxiliary image (I2); Furthermore, the distinguishing device (3) is characterized in that it further includes: - The electronic control unit (33) is configured to determine, from the primary position vector (P1) and the secondary position vector (P2), the relative position vector (P3) of the auxiliary road sign (M2) relative to the primary road sign (M1) in the secondary field of view (FOV2) of the auxiliary camera (32), and to associate the relative position vector (P3) of the auxiliary road sign (M2) in the secondary field of view (FOV2) with the secondary color (C2). The relative position vector (P3) is determined by a constant angle (β1) between the following two terms: -The longitudinal axis (Ax) of the vehicle (5) is, with - A half-line, the half-line taking the center point (p0) at the bottom of the main image (I1) as its origin, and passing through the main point (p1) of the main image (I1) at the level of the main road sign (M1) and passing through the auxiliary point (p2) of the main image (I1) at the level of the auxiliary road sign (M2). Furthermore, the relative position vector (P3) is determined by a variable angle (θ) defined by two values ​​(θ1, θ2), wherein: - A value (θ1) is defined as a line between the longitudinal axis (Ax) of the vehicle (5) and a half-line that takes the center point (p0) at the bottom of the main image (I1) as its origin and passes through the main point (p1) of the main image (I1) at the level of the main road sign (M1), and - Another value (θ2) is defined as the main point (p1) and the auxiliary point (p2) of the main image (I1) being aligned along a line (L0) perpendicular to the longitudinal axis (Ax) of the vehicle (5) between the longitudinal axis (Ax) of the vehicle (5) and the half line between the center point (p0) as its origin and the auxiliary point (p2) at the level of the auxiliary road sign (M2).

Images