Vehicle type detection equipment and system thereof

Abstract

The utility model discloses vehicle type detection equipment and a system thereof, and the equipment comprises a first light detection device which is used for generating a section scanning light curtain so as to scan the section of a target vehicle; and the second light detection device is used for generating a contour line scanning light curtain to scan the contour line of the target vehicle. Wherein the interval between the first light detection device and the second light detection device is arranged in a manner that the section scanning light curtain and the contour line scanning light curtain intersect in the scanning period. According to the vehicle type detection equipment provided by the invention, the tangent plane data can be aligned according to the contour line data of the target vehicle, so that the three-dimensional image of the target vehicle is restored, the arrangement cost of an intelligent traffic detection system is greatly reduced, and the application range of the intelligent traffic detection system is widened.

Description

Technical Field

[0001] The present disclosure generally relates to the field of traffic detection. More specifically, the present disclosure relates to a vehicle type detection device. Background Art

[0002] Traffic detection refers to the method of identifying and classifying target vehicles on the move, which can usually be completed manually or with traffic detection equipment; among them, traffic detection equipment refers to various devices that can be used in the field of traffic detection to detect target vehicles.

[0003] In the traditional field of traffic detection, there is a method of identifying and classifying vehicles through ETC electronic tags and manual confirmation of vehicle models. However, the above method has many problems and can no longer meet the current development status of the field of traffic detection. These problems include: the mismatch between the electronic tags and the actual vehicle models caused by lax review during the issuance of ETC electronic tags; the inaccuracy and low efficiency of manual confirmation of vehicle models during actual operation.

[0004] In addition, there is an intelligent traffic detection system on the market. The system obtains the original data of the target vehicle through traffic detection equipment; then extracts and analyzes the original data to obtain the characteristic information of each target; finally, the vehicle is classified by extracting the characteristics to complete the automatic identification and type classification of the vehicles traveling within the designated position and set time point in the road traffic.

[0005] In the above-mentioned intelligent traffic detection system, LiDAR detectors have been widely used as a new type of traffic detection equipment in recent years. However, traditional LiDAR detectors have certain requirements for installation methods and are currently mostly used in a few environments that are easy to install. Their application in more complex spaces such as highway entrances and exits is greatly limited.

[0006] In view of this, there is an urgent need to provide an innovative vehicle type detection device in order to expand the application scope of the intelligent traffic detection system and improve traffic management efficiency. Utility Model Content

[0007] In order to at least solve one or more of the technical problems mentioned above, the present disclosure proposes a vehicle type detection device in multiple aspects. The vehicle type detection device has low requirements for the use environment, can greatly reduce the cost and installation difficulty of the intelligent traffic detection system, and expand the application scope of the intelligent traffic detection system.

[0008] In a first aspect, the present disclosure provides a vehicle type detection device, comprising: a first light detection device, which is used to generate a section scanning light curtain, wherein the section scanning light curtain is used to scan the section of a target vehicle; and a second light detection device, which is used to generate a contour line scanning light curtain, wherein the contour line scanning light curtain is used to scan the contour line of the target vehicle, wherein the contour line is any horizontal contour line consistent with the direction of movement of the vehicle; wherein the interval between the first light detection device and the second light detection device is set so that the section scanning light curtain intersects with the contour line scanning light curtain during scanning.

[0009] In a second aspect, the present disclosure provides a vehicle type detection system, comprising the vehicle type detection device described in the first aspect.

[0010] According to a vehicle type detection device as provided above, the embodiment of the present disclosure uses the contour line data of the target vehicle obtained by the second light detection device to align the section data of the target vehicle obtained by the first light detection device to restore the three-dimensional image of the target vehicle and thus determine the vehicle type of the target vehicle. Furthermore, the vehicle type detection device described in the present disclosure can also obtain the appearance of the target vehicle to further process the aforementioned three-dimensional image of the target vehicle, thereby obtaining a more realistic three-dimensional image of the target vehicle; and identify the target vehicle to complete the automatic identification of the target vehicle type and vehicle type classification. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] By reading the detailed description below with reference to the accompanying drawings, the above and other objects, features and advantages of the exemplary embodiments of the present disclosure will become readily understood. In the accompanying drawings, several embodiments of the present disclosure are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0012] Figure 1 A schematic diagram of the working mode of a gantry-type optical equipment traffic detection system is shown;

[0013] Figure 2 A schematic diagram showing the working mode of an intelligent traffic detection system using a vehicle type detection device according to an embodiment of the present disclosure is shown;

[0014] Figure 3a A first view of a vehicle type detection device according to an embodiment of the present disclosure is shown;

[0015] Figure 3b A second view of a vehicle type detection device according to an embodiment of the present disclosure is shown;

[0016] Figure 4a A schematic plan view of a contour line scanning light curtain at different angles of an embodiment of the present disclosure is shown;

[0017] Figure 4bA schematic plan view of another contour line scanning light curtain at a different angle according to an embodiment of the present disclosure is shown;

[0018] Figure 5 A schematic flow chart showing a method for determining a vehicle model according to an embodiment of the present disclosure;

[0019] Figure 6 A schematic flow chart of a method for determining a real-time position of a target vehicle based on contour line data according to an embodiment of the present disclosure is shown;

[0020] Figure 7a A curve diagram showing contour line data of an embodiment of the present disclosure is shown;

[0021] Figure 7b A schematic diagram of a curve showing contour line data of two cycles of an embodiment of the present disclosure;

[0022] Figure 7c A schematic diagram of a step difference curve of contour line data of two cycles of the disclosed embodiment is shown;

[0023] Figure 8 A schematic plan view of a contour line scanning light curtain according to an embodiment of the present disclosure is shown;

[0024] Fig. 9 A flow chart of a method for aligning slice data according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0026] It should be understood that the terms "include" and "comprising" used in the specification and claims of the present disclosure indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections thereof.

[0027] It should also be understood that the terms used in this disclosure are only for the purpose of describing specific embodiments and are not intended to limit the disclosure. As used in this disclosure and claims, the singular forms of "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It should also be further understood that the term "and / or" used in this disclosure and claims refers to any combination of one or more of the associated listed items and all possible combinations, including these combinations.

[0028] As used in this specification and claims, the term "if" may be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" may be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0029] The specific implementation of the present disclosure is described in detail below with reference to the accompanying drawings.

[0030] In the current traffic detection scenario, an intelligent traffic detection system is known. The intelligent traffic detection system may include at least two laser radars, which are arranged on the side and above the road through a gantry. Specifically, the laser radar arranged on the side of the road performs a cross-sectional scan of the target vehicle, and the laser radar arranged above the road determines the forward distance of the target vehicle within a certain time through laser ranging; then, the three-dimensional image of the target vehicle is determined based on the aforementioned cross-sectional data and laser ranging data, and the target vehicle is identified and classified.

[0031] Figure 1 A schematic diagram of the working mode of a gantry-type optical equipment traffic detection system is shown.

[0032] like Figure 1 As shown, the gantry-type optical equipment traffic detection system 100 includes a first optical detection device 110, a first gantry 130, a second optical detection device 120, and a second gantry 140; the working section 150 is the working section of the gantry-type optical equipment traffic detection system 100. For ease of understanding, in this figure, the direction from the first gantry 130 to the second gantry 140 is the moving direction of the target vehicle.

[0033] The first light detection device 110 is used to perform cross-sectional scanning on the target vehicle passing through the working section 150 to obtain cross-sectional data of the target vehicle. The target vehicle can be any vehicle that can move along the length of the road, such as a car, a truck, a train, etc., which will not be described in detail below. The first light detection device 110 can be a point light source laser radar, which is arranged on one side or both sides of the road, and its arrangement height can be adjusted according to the height of the target vehicle. The first light detection device 110 can also be an array laser radar ( Figure 1 (not shown), similarly, it can be arranged on one side or both sides of the road, and its array length can be adjusted according to the height of the target vehicle (the array length is used to indicate the number of laser beams included in the laser array). Specifically, when the target vehicle passes through the working section 150, the first light detection device 110 performs continuous cross-sectional scanning on the target vehicle at a given frequency; and based on the principle of light reflection, the position of the scanning point is determined according to the reflection distance of the light emitted by the first light detection device 110, that is, the position of a point on the outer contour of the target vehicle. The point cloud data obtained by a single scanning cycle of the first light detection device 110 is the cross-sectional data of a certain outer contour of the target vehicle.

[0034] The second light detection device 120 is used to determine the distance the target vehicle has advanced within a certain time, so as to align the multiple cross-sectional data acquired by the first light detection device 110. The second light detection device 120 can be a laser radar, which is arranged above the road. Its arrangement height can be adjusted according to the height of the target vehicle; its arrangement position can be adjusted according to the length of the target vehicle and the position of the first light detection device. Specifically, when the target vehicle passes through the working section 150, the second light detection device 120 emits a detection light at another given frequency to a point on the target vehicle; and based on the principle of light reflection, the distance the target vehicle has advanced between two scanning cycles of the second light detection device 120 is determined according to the reflection distance and time of the detection light emitted by the second light detection device 120. The aforementioned advancement distance can be used to align the cross-sectional data of multiple cross sections acquired by the first light detection device 110.

[0035] The first gantry 130 is used to fix the first light detection device 110, and its position can be determined according to the position of the first light detection device 110, and its height can be adjusted according to actual conditions. The second gantry 140 is used to fix the second light detection device 120, and its position and height can be determined according to the position of the second light detection device. The working section 150 can be a section of any road, and its length and position can be adjusted according to actual conditions.

[0036] In existing intelligent traffic detection systems, the following are usually used: Figure 1As shown in the figure, the second optical detection device 120 needs to be arranged above the working section 150 and is separated from the first optical detection device 110 by a certain distance along the moving direction of the target vehicle, so as to leave enough space and time for the second optical detection device 120 to determine the forward distance of the target vehicle within a certain time.

[0037] The inventors noticed that the construction of the above-mentioned intelligent traffic detection system occupies a large area and requires the construction of a gantry to meet the installation requirements of the second light detection device 120, resulting in a narrow application range and cannot be widely used in more complex spaces such as highway entrances and exits.

[0038] The inventors also noticed that in the above-mentioned intelligent traffic detection system, the second light detection device 120 determines the distance traveled by the target vehicle within a certain time by a point on one side of the target vehicle close to the second light detection device 120. This method is prone to errors, resulting in the inability to align the cross-sectional data of the outer contour of the target vehicle, thereby increasing the difficulty of identifying and classifying the target vehicle.

[0039] In order to at least solve one or more of the technical problems mentioned above, the present disclosure provides a vehicle type detection device. Specifically, the vehicle type detection device includes: a first light detection device, which is used to generate a section scanning light curtain, and the section scanning light curtain is used to scan the section of the target vehicle; and a second light detection device, which is used to generate a contour scanning light curtain, and the contour scanning light curtain is used to scan the contour line of the target vehicle, and the contour line is any horizontal contour line consistent with the movement direction of the target vehicle. Wherein, the interval between the first light detection device and the second light detection device is set so that the section scanning light curtain and the contour scanning light curtain intersect during scanning.

[0040] In the above vehicle type detection device, the target vehicle is scanned by the contour scanning light curtain of the second light detection device to obtain the contour data of the target vehicle, and one or more feature points of the target vehicle are determined according to the number of contour lines to calibrate the fixed points on the horizontal contour line of the target vehicle close to the side of the contour scanning light curtain, and then the section data of the target vehicle obtained by the section scanning light curtain is aligned according to the displacement distance of the fixed point on the horizontal contour line within a certain time, thereby improving the restoration degree of the three-dimensional image restoration of the target vehicle. Furthermore, in this method, the section scanning light curtain and the contour scanning light curtain can be arranged together to reduce the difficulty and cost of arranging the intelligent traffic detection system and broaden its application scope.

[0041] Figure 2 The working mode schematic diagram of the intelligent traffic detection system using a vehicle type detection device according to the embodiment of the present disclosure is shown. Figure 2As shown, the intelligent traffic detection system 200 includes a section scanning light curtain 210, a contour scanning light curtain 220 and a vehicle type detection device 240; the working section 230 is the working section of the intelligent traffic detection system 200. For ease of understanding, Figure 3a , Figure 3b The front shown in FIG. 1 is the moving direction of the target vehicle.

[0042] It can be observed from the figure that the vehicle type detection device 240 can be arranged on one side of the working section 230 to detect the vehicle type of the target vehicle. Among them, the side of the working section 230 can be any side. The working section 230 can be a section of any road, and its length and position can be adjusted according to actual conditions.

[0043] Further, the vehicle type detection device 240 may include a first light detection device ( Figure 2 ) and a second light detection device (not shown) that generates a contour line scanning light curtain 220 Figure 2 (not shown in the figure), wherein the first light detection device may be a laser radar or other light device that can scan the cross section of the target vehicle. The light source of the first light detection device may be a point light source or an array light source. When the light source of the first light detection device is a point light source, preferably, the scanning light emitted by it is a scanning light of equal angles; when the light source of the first light detection device is an array light source, the scanning light emitted by it is a scanning light of equal spacing, so as to facilitate subsequent data processing. Similarly, the second light detection device may be a laser radar or other light device that can scan the contour of the target vehicle. The light source of the second light detection device may be a point light source or an array light source. When the light source of the second light detection device is a point light source, preferably, the scanning light emitted by it is a scanning light of equal angles; when the light source of the second light detection device is an array light source, the scanning light emitted by it is a scanning light of equal spacing, so as to facilitate subsequent data processing.

[0044] In one implementation scenario, the section scanning light curtain 210 disclosed in the present invention can be generated by the vehicle type detection device 240 to obtain the section data of the target vehicle. It can be observed from the figure that the section scanning light curtain 210 can be a discontinuous surface composed of multiple scanning light rays, and is perpendicular to the contour scanning light curtain 220; wherein the scanning light rays are emitted by the vehicle type detection device 240. As an example, the aforementioned section data can be point cloud data of the outer contour of the target vehicle close to the side of the section scanning light curtain 210 and tangent to the section scanning light curtain 210, which is used to indicate the shape and size of the section of the target vehicle close to the side of the section scanning light curtain 210. Specifically, when the target vehicle passes through the section scanning light curtain 210, the section scanning light curtain 210 continuously scans the target vehicle at a given second frequency. Based on the reflection principle of light, the position of the scanning point can be determined according to the reflection distance of the light emitted by the section scanning light curtain 210, that is, the position of any point on the outer contour of the target vehicle close to the side of the section scanning light curtain 210 and tangent to the section scanning light curtain 210. The shape and size of a certain section of the target vehicle can be determined based on the point cloud data obtained in a single scanning cycle of the section scanning light curtain 210.

[0045] In one implementation scenario, the above-mentioned contour scanning light curtain 220 can be generated by the vehicle type detection device 240 to obtain the contour data of the target vehicle. Figure 2 It can be observed that the contour scanning light curtain 220 is a discontinuous surface composed of multiple scanning light rays, and is parallel to the working section 230; wherein the scanning light rays are emitted by the vehicle type detection device 240. The contour data is the point cloud data of any contour line parallel to the working section 230 on the outer contour of the target vehicle close to the contour scanning light curtain 220, which is used to indicate the position change of the target vehicle when traveling on the working section 230. Specifically, when the target vehicle passes through the contour scanning light curtain 220, the contour scanning light curtain 220 continuously scans the target vehicle at a given first frequency. Similarly, based on the reflection principle of light, the position of any contour line parallel to the working section 230 on the outer contour of the target vehicle close to the contour scanning light curtain 220 can be determined according to the reflection distance of the scanning light emitted by the contour scanning light curtain 220. The position change of the target vehicle on the working section 230 can be determined according to the position change of the contour line between the scanning cycles of any two contour scanning light curtains.

[0046] As mentioned above, the contour scanning light curtain is used to scan the contour of the target vehicle; wherein the contour is any horizontal contour line consistent with the moving direction of the target vehicle, that is, Figure 2Any contour line parallel to the working section 230 on the outer contour of the side close to the contour line scanning light curtain 220. As mentioned above, the position change of the target vehicle on the working section 230 can be determined according to the position change of the contour line between the scanning cycles of any two contour line scanning light curtains; therefore, the contour line should be consistent with the moving direction of the target vehicle. It can be understood that when the aforementioned contour line is any horizontal contour line consistent with the moving direction of the target vehicle, the plane where the contour line scanning light curtain is located can be any plane rotated around the horizontal axis consistent with the moving direction of the vehicle within a certain angle. Among them, the aforementioned certain angle can be adjusted according to the height of the second detection device and the actual situation of the target vehicle. It can also be understood that after the section scanning light curtain scans the section of the target vehicle, it needs to be aligned according to the displacement distance of the target vehicle within a certain time to restore the three-dimensional image of the target vehicle. Therefore, the section scanned by the section scanning light curtain on the target vehicle is inconsistent with the moving direction of the target vehicle, so that the section data obtained in different scanning cycles can be aligned according to the position change of the target vehicle in its moving direction. Furthermore, the displacement distance of the target vehicle within a certain time can be determined based on the contour data acquired by the contour scanning light curtain; therefore, the plane where the section scanning light curtain is located intersects with the plane where the contour scanning light curtain is located, so that the section data can be aligned according to the contour data.

[0047] In one embodiment, in order to allow the section scanning light curtain and / or the contour line scanning light curtain to adjust the angle according to the actual application situation, the vehicle type detection equipment also includes a plurality of rotating devices, and the plurality of rotating devices are connected to the first light detection device and / or the second light detection device to drive the first light detection device and / or the second light detection device to rotate. Specifically, the plurality of rotating devices include a first rotating device and a second rotating device, wherein the first rotating device is connected to the first light detection device so that the first light detection device adjusts the angle of the section scanning light curtain by the drive of the first rotating device, and the second rotating device is connected to the second light detection device so that the second light detection device adjusts the angle of the contour line scanning light curtain by the drive of the second rotating device. In another embodiment, preferably, the section scanning light curtain is perpendicular to the ground, and the contour line scanning light curtain is parallel to the ground, so as to facilitate the subsequent data processing when the section data is aligned according to the contour line data.

[0048] Considering that the vehicle type detection equipment is arranged on any side of any working section, in order to facilitate use, the first light detection device and the second light detection device need to be fixed; therefore, the vehicle type detection equipment described in the present disclosure also includes a fixing device for fixing the first light detection device and the second light detection device so that the section scanning light curtain and the contour line scanning light curtain intersect during scanning.

[0049] In one implementation scenario, after the first light detection device and the second light detection device are fixed, it is expected that certain protection can also be provided to the first light detection device and the second light detection device. Specifically, the fixing device includes a housing, a cavity is formed inside the housing and a plurality of through holes are opened on the surface facing the outside, wherein the first light detection device and the second light detection device are arranged in the cavity, and the section scanning light curtain and the contour line scanning light curtain respectively scan the outside through the first through hole and the second through hole in the plurality of through holes. It can be understood that the above-mentioned fixing device is schematic and not restrictive, and the fixing device may also include other devices that can be used to fix the first light detection device and the second light detection device so that the section scanning light curtain and the contour line scanning light curtain intersect during scanning.

[0050] In another implementation scenario, it is expected that when restoring the three-dimensional image of the target vehicle based on the section data obtained by the aforementioned section scanning light curtain and the contour data obtained by the contour scanning light curtain, and then determining the model of the target vehicle, the details of the appearance of the target vehicle can be further improved and the target vehicle can be automatically identified; therefore, the vehicle model detection equipment can also include multiple cameras, which are respectively fixed on the fixing device to shoot the target vehicle. Specifically, the multiple cameras include a first camera and / or a second camera arranged in the cavity, wherein the first camera is used to identify the target vehicle and the second camera is used to obtain the appearance of the target vehicle. The first camera can identify the target vehicle, for example, by identifying the target vehicle according to the license plate of the target vehicle. The specific identification process is known to those skilled in the art and will not be repeated here. The second camera can obtain the appearance of the target vehicle, for example, by shooting the target vehicle, and then improve the three-dimensional image of the target vehicle according to the appearance of the target vehicle in the shot video.

[0051] It is understandable that when the fixing device is a housing, and the first camera and / or the second camera are disposed in a cavity inside the housing, it is necessary to provide a through hole on the housing so that the first camera and / or the second camera can photograph the target vehicle. Specifically, the plurality of through holes further include a third through hole and / or a fourth through hole, wherein the third through hole is used to provide the first camera with a field of view outside the housing, and the fourth through hole is used to provide the second camera with a field of view outside the housing.

[0052] It can also be understood that the first camera and / or the second camera disclosed in the present invention can be a photosensitive lens based on optics and electronics, which can obtain an image of the target vehicle through a transparent medium. Therefore, the vehicle type detection equipment also includes a plurality of lenses, each of which is arranged at a corresponding plurality of through holes to provide protection for the plurality of cameras. Specifically, the plurality of lenses may include a first lens arranged at a third through hole, for providing certain protection for the first camera; the plurality of lenses may also include a second lens arranged at a fourth through hole, for providing certain protection for the second camera.

[0053] Figure 3a A first view of a vehicle type detection device according to an embodiment of the present disclosure is shown. Figure 3a For further explanation.

[0054] like Figure 3a As shown, the vehicle type detection device includes a fixing device 301, a first light detection device 303, a second light detection device 302, a first lens 304 and a second lens 305. As mentioned above, the fixing device 301 may include a housing, which may be a cubic housing with a cavity formed inside. It can be observed from the figure that a first through hole 307 and a second through hole 306 are provided on the surface of the fixing device 301. The first light detection device 303 and the second light detection device 302 are sequentially arranged below the internal cavity of the fixing device 301, so that the section scanning light curtain generated by the first light detection device 303 and the contour line scanning light curtain generated by the second light detection device 302 intersect during scanning. Specifically, the first light detection device 303 is arranged at a position corresponding to the first through hole 307, so that the section scanning light curtain generated by the first light detection device 303 can be scanned externally through the first through hole 307. The second light detection device 302 is arranged at a position corresponding to the second through hole 306, so that the contour line scanning light curtain generated by the second light detection device 302 can be scanned externally through the second through hole 306. It can also be observed from the figure that a third through hole 308 and a fourth through hole 309 are also provided on the surface of the fixing device 301. A first lens 304 is arranged at the third through hole 308, which is used to prevent objects outside the fixing device 301 from entering the internal cavity to protect the device inside the cavity. A second lens 305 is arranged at the fourth through hole 309, which is used to prevent objects outside the fixing device 301 from entering the internal cavity to protect the device inside the cavity.

[0055] Figure 3b A second view of a vehicle type detection device according to an embodiment of the present disclosure is shown. Figure 3b For further explanation. It is understandable that Figure 3a and Figure 3b The vehicle type detection device in is the same vehicle type detection device. Figure 3a The first view of Figure 3b The second view in FIG. 1 is two relative views of the vehicle model detection equipment.

[0056] like Figure 3bAs shown, the vehicle type detection device may further include a first camera 310 and a second camera 311. Specifically, the first camera 310 is disposed at a position corresponding to the third through hole 308 in the internal cavity of the fixture 301, so that the third through hole 308 can provide the first camera 310 with a field of view outside the fixture 301; the second camera 311 is disposed at a position corresponding to the fourth through hole 309 in the internal cavity of the fixture 301, so that the fourth through hole 309 can provide the second camera 311 with a field of view outside the fixture 301.

[0057] Understandably, Figure 3a and Figure 3b The vehicle type detection equipment shown in is illustrative and not restrictive, and those skilled in the art may make certain adjustments without violating the intent of this disclosure.

[0058] Considering the limited width of the working section in the actual application scenario, when the length of the target vehicle is large, it is difficult to completely scan the target vehicle to obtain complete contour data; or, the number of scanning lights needs to be increased, which increases the requirements for the vehicle type detection equipment and increases the cost of the intelligent traffic detection system. Therefore, in some embodiments, the angle of the contour scanning light curtain can be adjusted to reduce the difficulty of detecting target vehicles with a large length. The adjustment of the angle of the contour scanning light curtain refers to the rotation of the contour scanning light curtain with the vehicle type detection equipment as the axis; the size of the angle adjustment is related to factors such as the length of the target vehicle and the distance between the vehicle type detection equipment and the target vehicle.

[0059] Figure 4a FIG. 2 shows a schematic plan view of a contour line scanning light curtain at different angles of an embodiment of the present disclosure. Figure 4a As shown, the X-axis direction is the width direction of the target vehicle; the Y-axis direction is the moving direction of the target vehicle; L1 and L2 are the lengths of the target vehicle, and L1 and L2 are equal; A is the boundary light of the first contour line scanning light curtain, that is, the two outermost light rays of the first contour line scanning light curtain; B is the boundary light of the second contour line scanning light curtain, that is, the two outermost light rays of the second contour line scanning light curtain; a is the angle of the first contour line scanning light curtain, that is, the angle between the two boundary light rays of the first contour line scanning light curtain; b is the angle of the second contour line scanning light curtain, that is, the angle between the two boundary light rays of the second contour line scanning light curtain.

[0060] from Figure 4aIt can be observed that the first contour line scanning light curtain scans the target vehicle with a length of L1, and the second contour line scanning light curtain scans the target vehicle with a length of L2; when L1=L2, the angle b between the two boundary rays of the second contour line scanning light curtain is smaller than the angle a between the two boundary rays of the first contour line scanning light curtain. Specifically, when the angles between the adjacent scanning rays of the first contour line scanning light curtain and the second contour line scanning light curtain are the same, since b is smaller than a, the number of scanning rays emitted by the second contour line scanning light curtain is smaller than the number of scanning rays emitted by the first contour line scanning light curtain. Through the above method, the requirements for traffic detection equipment can be reduced.

[0061] Figure 4b FIG. 2 shows a plan view of another contour line scanning light curtain at a different angle according to an embodiment of the present disclosure. Figure 4b As shown, the X-axis direction is the width direction of the target vehicle; the Y-axis direction is the moving direction of the target vehicle; L3 and L4 are the lengths of the target vehicle; C is the boundary light of the third contour line scanning light curtain, that is, the two outermost light rays of the third contour line scanning light curtain; D is the boundary light of the fourth contour line scanning light curtain, that is, the two outermost light rays of the fourth contour line scanning light curtain; c is the angle of the third contour line scanning light curtain, that is, the angle between the two boundary light rays of the third contour line scanning light curtain; d is the angle of the fourth contour line scanning light curtain, that is, the angle between the two boundary light rays of the fourth contour line scanning light curtain; wherein, c=d.

[0062] from Figure 4b It can be observed that the third contour line scanning light curtain scans the target vehicle with a length of L3, and the fourth contour line scanning light curtain scans the target vehicle with a length of L4; when c=d, the length L4 of the target vehicle that can be scanned by the fourth contour line scanning light curtain is greater than the length L3 of the target vehicle that can be scanned by the third contour line scanning light curtain. Specifically, since c=d, when the angles between adjacent scanning light rays are the same, the number of scanning light rays emitted by the third contour line scanning light curtain and the fourth contour line scanning light curtain is equal, and the fourth contour line scanning light curtain can scan target vehicles with a larger length. Through the above method, when the length of the target vehicle changes significantly, the scanning range of the contour line scanning light curtain can be increased by adjusting the angle, which significantly enhances the flexibility and convenience of using the equipment.

[0063] The process of determining the vehicle type by using the contour data acquired by the contour scanning light curtain and the section data acquired by the section scanning light curtain will be described in detail below in conjunction with the method flow chart.

[0064] Figure 5 FIG. 1 is a schematic flow chart of a method for determining a vehicle type according to an embodiment of the present disclosure. It is understood that the section scanning light curtain, the contour scanning light curtain, the section data and the contour data in the method here can be Figure 2 The section scanning light curtain, contour scanning light curtain, section data and contour data in the figure will not be repeated here.

[0065] like Figure 5 As shown, in step S510, the section data is acquired, and the section data is generated when the section scanning light curtain scans the target vehicle in the second time interval. The second time interval is the time period from the start of scanning to the end of scanning by the section scanning light curtain.

[0066] In step S520, contour line data is obtained, and the contour line data is horizontal contour line data of the side of the target vehicle close to the contour line scanning light curtain, which is generated by the contour line scanning light curtain when scanning the target vehicle in the first time interval; wherein the second time interval is a sub-interval of the first time interval. The first time interval is the time period experienced by the contour line scanning light curtain when starting and ending scanning. The second time interval is a sub-interval of the first time interval, that is, the second time interval is a certain time period in the first time interval. Schematically, in one embodiment, the second time interval can be [9:00, 10:00], and the first time interval can be [8:55, 10:05].

[0067] Next, in step S530, the real-time position of the target vehicle is determined. The real-time position of the target vehicle in the first time interval is determined based on the contour line data and the first time interval. Specifically, the contour line data is the horizontal contour line data of the target vehicle close to the side of the contour line scanning light curtain, which can be used to indicate the position change of the target vehicle when driving. Further, since the contour line data is generated when the contour line scanning light curtain scans the target vehicle in the first time interval, the position change of the target vehicle indicated by the contour line data is also the real-time position of the target vehicle in the first time interval.

[0068] Finally, in step S540, the section data is aligned. The section data is aligned based on the real-time position and the second time interval to restore the three-dimensional image of the target vehicle and thereby determine the model of the target vehicle. Specifically, since the second time interval is a sub-interval of the first time interval, the aforementioned real-time position can also be used to indicate the real-time position of the target vehicle in the second time interval. Furthermore, since the section data is generated when the section scanning light curtain scans the target vehicle in the second time interval, the position of the target vehicle each time the section scanning light curtain scans can be determined based on the aforementioned real-time position, thereby aligning the section data. Finally, a three-dimensional image of the target vehicle is obtained based on the aligned section data to thereby determine the model of the target vehicle.

[0069] In some embodiments, before determining the real-time position of the target vehicle as described above, the contour line data needs to be processed to determine the real-time position of the target vehicle through feature points. The contour line data is generated when the contour line scanning light curtain continuously scans the target vehicle at a first frequency. Among them, the time period for continuous scanning of the contour line scanning light curtain is the first time interval. The first frequency is the frequency when the contour line scanning light curtain continuously scans the target vehicle, which is used to indicate the number of scans of the contour line scanning light curtain per unit time. Its value can be adjusted according to the actual application situation, and the present disclosure does not impose any restrictions in this regard. The reciprocal of the first frequency is the period of the contour line scan, which is used to indicate the time required for a single contour line scan; the time length of the first time interval divided by the first frequency is the number of periods of the contour line scan, which is used to indicate the number of scans of the contour line scanning light curtain in the first time interval. The following will be combined with Figure 6 A method for determining the real-time position of a target vehicle based on contour line data is described in detail, and the same contents regarding the contour line data are not repeated in the description.

[0070] Figure 6 A schematic flow chart of a method for determining a real-time position of a target vehicle based on contour line data according to an embodiment of the present disclosure is shown.

[0071] like Figure 6 As shown, in step S610, a feature point is determined. In one embodiment, the feature point can be determined based on the contour line data, and the feature point is used to calibrate a fixed point on the target vehicle. Since the contour line data is the horizontal contour line data of the target vehicle on one side close to the contour line scanning light curtain, the feature point calibration is also a fixed point on the horizontal contour line of the target vehicle on one side close to the contour line scanning light curtain. The feature point can be one or more, and preferably multiple. By calibrating multiple fixed points on the target vehicle through multiple feature points, the error in determining the real-time position of the target vehicle can be effectively reduced.

[0072] In one embodiment, determining feature points based on contour line data in the above step S610 may include: establishing a coordinate axis with the forward direction of the target vehicle as the X-axis and the width direction of the target vehicle as the Y-axis; and processing the contour line data with the coordinate axis as the reference system to obtain a curve of the contour line data in the coordinate axis within a single scanning cycle of the contour line scanning light curtain; and determining feature points based on the peak value of the above curve. Specifically, the contour line data may be laser radar point cloud data, and the presentation form of the point cloud data may be the distance of a certain point from the laser radar and the angle of the laser light, as shown in Table 1.

[0073] Table 1: Contour data

[0074] sequence angle distance 1 0.42 d1 2 0.84 d2 3 1.26 d3 4 1.68 d4 5 2.1 d5 6 2.52 d6 7 2.94 d7

[0075] Table 1 shows a table of contour line data of the embodiment of the present disclosure. The contour line data shown in Table 1 is the data obtained in any scanning cycle of the contour line scanning light curtain, and the sequence in the table is used to represent any laser light in the contour line scanning cycle; the angle is used to represent the angle between any laser light and the outermost laser light, and the outermost laser light can be any one of the two outermost laser lights; the distance is used to represent the distance from the reflection point of any laser light to the laser radar, and the laser light reflection point refers to the point where the laser light is reflected after being irradiated to a certain point on the target vehicle.

[0076] Furthermore, a coordinate system is established with the forward direction of the target vehicle as the X-axis and the width direction of the target vehicle as the Y-axis; the above-mentioned contour line data is processed with the coordinate axis as the reference system to obtain the curve of the above-mentioned contour line data in the coordinate axis, such as Figure 7a shown.

[0077] Figure 7a A curve diagram of contour line data of an embodiment of the present disclosure is shown. The scale units of the horizontal and vertical axes in the figure are both millimeters; 1, 2, 3 and 4 are the four peaks of the curve. Curve S1 in the figure is used to represent the horizontal contour line of the target vehicle close to the contour line scanning light curtain obtained in a single contour line scanning cycle; Peak 1, Peak 2, Peak 3 and Peak 4 are used to represent the reflection points whose distance to the laser radar is significantly different from other reflection points in a single scanning cycle, which can be used as feature points to calibrate fixed points on the horizontal contour line of the target vehicle close to the contour line scanning light curtain.

[0078] Then, in step S620, the displacement distance of the feature point is determined. The displacement distance of the feature point between the first contour line scanning cycle and the second contour line scanning cycle is determined based on the first contour line data and the second contour line data; wherein the displacement distance is used to indicate the distance that the target vehicle advances between two cycles of the contour line scanning light curtain. The contour line data may include the first contour line data of the first contour line scanning cycle and the second contour line scanning cycle. The first contour line scanning cycle and the second contour line scanning cycle are any two scanning cycles of the contour line scanning light curtain in the first time interval. Specifically, the first position of the feature point of the target vehicle in the first contour line scanning cycle can be determined according to the first contour line data; and the second position of the feature point of the target vehicle in the second contour line scanning cycle can be determined according to the second contour line data. The distance difference between the first position and the second position, i.e., the displacement distance of the feature point, can be used to indicate the distance that the target vehicle advances between the first contour line scanning cycle and the second contour line scanning cycle.

[0079] In one embodiment, determining the displacement distance of the feature point between the first contour line scanning cycle and the second contour line scanning cycle based on the first contour line data and the second contour line data includes: performing step difference calculation on the first contour line data and the second contour line data to determine the displacement distance of the feature point between the first contour line scanning cycle and the second contour line scanning cycle. Specifically, the first contour line data and the second contour line data are obtained in a coordinate system where the forward direction of the target vehicle is the X axis and the width direction of the target vehicle is the Y axis, such as Figure 7b shown. Figure 7b A graph schematically shows contour line data of two cycles of an embodiment of the present disclosure. Figure 7b The contour line data in are respectively the curve S2 of the first contour line data and the curve S3 of the second contour line data; wherein, Figure 7a The same contents will not be repeated here.

[0080] Furthermore, the curve S2 of the second contour line data is slid within a given range with a certain step length, and the difference between the feature points of the first contour line data and the feature points of the second contour line data is calculated each time the sliding occurs, so as to obtain a step difference curve diagram of the curve S1 of the first contour line data and the curve S2 of the second contour line data, as shown in FIG. Figure 7c shown. Figure 7c A schematic diagram of a step difference curve of contour line data of two cycles of the disclosed embodiment is shown. Figure 7c The length of the horizontal axis is used to indicate the range of the step difference, and the scale of the horizontal axis is used to indicate the step length of the step difference; the vertical axis is used to indicate the range of the difference. Figure 7c When the curve S4 is at the minimum value, it means that the curve of the first contour line data and the curve of the second contour line data overlap; at this time, the step length of the curve of the second contour line data represents the position distance between the feature points of the first contour line data and the feature points of the second contour line data. The aforementioned position distance is the forward distance of the target vehicle between the first contour line scanning cycle and the second contour line scanning cycle.

[0081] It can be understood that the range of the step difference is greater than or equal to the forward distance of the target vehicle between the first contour scanning cycle and the second contour scanning cycle; the step of the step difference is less than the forward distance of the target vehicle between the first contour scanning cycle and the second contour scanning cycle. In one embodiment, the forward speed of the target vehicle is 30 kilometers per hour, the scanning cycle of the contour scanning light curtain is 1 / 60 seconds, and the forward distance of the target vehicle between the two contour scanning cycles is 138 millimeters. Therefore, the range of the step difference can be any length greater than or equal to 138 millimeters, and the step of the step difference can be any length less than 138 millimeters; preferably, the range of the step difference is determined to be 200 millimeters, and the step of the step difference is determined to be 1 millimeter to improve the accuracy and credibility of the results.

[0082] Considering that the contour line scanning light curtain may include a discontinuous surface composed of multiple scanning light rays, the contour line data obtained when scanning the target vehicle includes discontinuous contour line data. If the contour line data is discontinuous contour line data, the contour line data is interpolated to make the contour line data continuous and uniform; and, based on the interpolation multiple of the interpolation, a weighted step difference calculation is performed on the first contour line data and the second contour line data to determine the displacement distance of the feature point. In one embodiment, interpolating the contour line data may include converting the data obtained by the contour line scanning light curtain into a scatter plot in a reference system with the forward direction of the target vehicle as the X-axis and the width direction of the target vehicle as the Y-axis; and then interpolating the aforementioned scatter plot to obtain a curve of continuous contour data. In another embodiment, interpolating the contour line data may also include using the sequence in Table 1 as the horizontal coordinate to obtain a scatter plot with the vertical coordinate being the position of any point of the second scanning contour line on the side of the target vehicle close to the contour line scanning light curtain in the forward direction of the target vehicle. Figure 1 , and the ordinate is the scatter point of the position of any point of the second scanning contour line on the side of the target vehicle close to the contour scanning light curtain in the width direction of the target vehicle Figure 2 ; Then, the two scatter plots are interpolated to obtain continuous curves, and then the continuous curves obtained are fitted to obtain a curve of continuous contour line data.

[0083] Furthermore, the light source of the contour line scanning light curtain may be a point light source. When the light source of the contour line scanning light curtain is a point light source, its resolution will change with the angle of the scanning light (e.g. Figure 8 As shown). Therefore, the aforementioned interpolation of the contour line data includes non-uniform interpolation. Furthermore, after the non-uniform interpolation is performed on the discontinuous contour line data, the feature points located at different positions can be weighted; and then the weighted step difference between the curve of the first contour line data and the curve of the second contour line data is calculated based on the weighted feature points.

[0084] Figure 8 FIG. 2 shows a schematic plan view of a contour line scanning light curtain according to an embodiment of the present disclosure. Figure 8 As shown in the figure, the X axis is the width direction of the target vehicle; the Y axis is the forward direction of the target vehicle; L5 is the length of the target vehicle; D is the center line of the contour scanning light curtain; D1 is the distance between two points on the second scanning contour line on the side of the target vehicle close to the contour scanning light curtain; D2 is another distance between two other points on the second scanning contour line on the side of the target vehicle close to the contour scanning light curtain. It can be observed from the figure that D1 is greater than D 2，That is, the closer the scanning light is to the center line D, the closer the distance between its reflection points on the target vehicle is. Therefore, when the feature point is closer to the point on the target vehicle corresponding to the center line, the smaller the interpolation multiple of the nearby data is when interpolating, the higher the authenticity of the data is, and the greater the weight is when performing step difference calculation.

[0085] Finally, in step S630, the real-time position is determined. The real-time position of the target vehicle in the first time interval is determined based on the displacement distance, the first frequency and the first time interval. In one embodiment, the first time interval includes a starting moment, and determining the real-time position of the target vehicle in the first time interval based on the displacement distance, the first frequency and the first time interval includes: determining the scanning period of the contour line scanning corresponding to the displacement distance; determining the moment corresponding to the displacement distance based on the first frequency, the starting moment and the scanning period; determining the real-time position of the target vehicle in the first time interval according to the displacement distance and the aforementioned moment. Specifically, the displacement distance may correspond to the first contour line scanning period and the second contour line scanning period, and the difference between the first contour line scanning period and the starting moment is M contour line scanning periods, and the difference between the first contour line scanning period and the second contour line scanning period may be N contour line scanning periods (M, N are integers greater than or equal to 0). The moment T corresponding to the displacement distance can be obtained according to the following formula (1):

[0086] T = starting time + M * contour line scanning period + N * contour line scanning period (1)

[0087] The section data is generated when the section scanning light curtain continuously scans the target vehicle at a second frequency. Among them, the time period of continuous scanning of the section scanning light curtain is the second time interval. The second frequency is the frequency when the section scanning light curtain continuously scans the target vehicle, which is used to indicate the number of scans of the section scanning light curtain per unit time. Its value can be adjusted according to the actual application situation, and the present disclosure does not impose any restrictions in this regard. The inverse of the second frequency is the period of the section scanning, which is used to indicate the time required for a single section scan; the time length of the second time interval divided by the second frequency is the number of periods of the contour line scanning, which is used to indicate the number of scans of the section scanning light curtain in the second time interval. The same content will not be repeated below.

[0088] In the aforementioned step S540, the slice data needs to be aligned based on the real-time position, that is, the slice data is arranged at a certain interval; wherein the certain interval refers to the distance the target vehicle advances between two scanning cycles of the slice scanning light curtain. Since the second time interval corresponding to the slice data is a sub-interval of the first time interval corresponding to the real-time position, the relationship between the real-time position and the slice data can be determined by the relationship between the second time interval and the first time interval, and the slice data is aligned based on the real-time position to restore the three-dimensional image of the target vehicle and determine the vehicle type. Fig. 9A schematic diagram of a method for aligning slice data according to an embodiment of the present disclosure is shown below. Fig. 9 Further explanation is given on aligning slice data based on real-time position and second time interval.

[0089] In step S910, determine the effective calculation interval. Determine the effective calculation interval of the first time interval based on the second time interval. The section data of the target vehicle is generated when the target vehicle passes through the section scanning light curtain, so the effective calculation interval for aligning the section data is the second time interval during which the section scanning light curtain is scanned. Furthermore, the second time interval is a sub-interval of the first time interval, and the first time interval is intercepted by the length of the second time interval to be the effective calculation interval of the first time interval. Exemplarily, in one embodiment, the second time interval includes the moment when the target vehicle enters the section scanning light curtain and the moment when the target vehicle exits the section scanning light curtain; the effective calculation interval is the period between the moment of entry and the moment of exit.

[0090] Next, enter step S920 to extract the effective value of the real-time position. The effective value of the real-time position is extracted based on the effective calculation interval. The real-time position is the change of the position of the target vehicle in the first time interval over time. Since the target vehicle has no section data that needs to be aligned outside the effective calculation interval, extracting the real-time position based on the effective calculation interval can reduce the amount of calculated data to improve efficiency and reduce interference.

[0091] Finally, in step S930, the section data is aligned. The section data is aligned based on the effective value and the second frequency. Since the second time interval is a subinterval of the first time interval, the corresponding relationship between the effective value and the section data can be determined based on the second frequency, so that the section data is aligned to restore the three-dimensional image of the target vehicle to determine the vehicle model.

[0092] Specifically, it is considered that the first frequency and the second frequency may be the same or different. If the first frequency and the second frequency are the same, the time interval of the aforementioned effective values ​​is the period of the section scanning light curtain, and the section data can be directly aligned according to the interval of the effective values. If the first frequency and the second frequency are different, the effective values ​​are processed based on the second frequency so that the time interval of the effective values ​​is the same as the period of the section scanning light curtain; and the section data are aligned based on the processed effective values. Schematically, in one embodiment, when the first frequency is different from the second frequency, the effective values ​​are resampled with the second frequency as a reference so that the time interval of the effective values ​​is the same as the period of the section scanning light curtain; the above method can flexibly set the parameters of the contour scanning light curtain and the section scanning light curtain according to actual conditions.

[0093] In some feasible implementations, various aspects of the present disclosure may also be implemented as a vehicle type detection system, including a vehicle type detection device and a program code, wherein the vehicle type detection device may be the aforementioned vehicle type detection device; and the program code is used to enable the processor to execute the method described above when executed by the processor.

[0094] It is apparent that such embodiments are provided by way of example only. Those skilled in the art may think of many changes, modifications and alternatives without departing from the thought and spirit of the present disclosure. It should be understood that in the process of practicing the present disclosure, various alternatives to the disclosed embodiments described herein may be adopted. The attached claims are intended to define the scope of protection of the present disclosure, and therefore cover equivalents or alternatives within the scope of these claims.

Claims

1. A vehicle type detection device, characterized in that: include: A first light detection device, which is used to generate a section scanning light curtain, wherein the section scanning light curtain is used to scan the section of the target vehicle; as well as A second light detection device, which is used to generate a contour line scanning light curtain, wherein the contour line scanning light curtain is used to scan the contour line of the target vehicle, and the contour line is any horizontal contour line consistent with the moving direction of the vehicle; The interval between the first light detecting device and the second light detecting device is set so that the section scanning light curtain intersects with the contour line scanning light curtain during scanning.

2. The vehicle type detection device according to claim 1, characterized in that: It also includes a fixing device for fixing the first light detecting device and the second light detecting device so that the section scanning light curtain and the contour scanning light curtain intersect during scanning.

3. The vehicle type detection device according to claim 2, characterized in that: The fixing device comprises a housing, a cavity is formed inside the housing and a plurality of through holes are opened on the surface of the housing. The first light detection device and the second light detection device are arranged in the cavity, and the section scanning light curtain and the contour line scanning light curtain respectively perform the scanning externally through the first through hole and the second through hole of the plurality of through holes.

4. The vehicle type detection device according to claim 3, characterized in that: It also includes a plurality of cameras which are respectively fixed on the fixing devices to take pictures of the target vehicle.

5. The vehicle type detection device according to claim 4, characterized in that: The multiple cameras include a first camera and / or a second camera disposed in the cavity, wherein the first camera is used to identify a target vehicle and the second camera is used to obtain an appearance of the target vehicle.

6. The vehicle type detection device according to claim 5, characterized in that: The plurality of through holes further include a third through hole and / or a fourth through hole, wherein the third through hole is used to provide the first camera with a field of view outside the housing, and the fourth through hole is used to provide the second camera with a field of view outside the housing.

7. The vehicle type detection device according to claim 4, characterized in that: It also includes a plurality of lenses, wherein each lens is disposed at a corresponding position of the plurality of through holes to provide protection for the plurality of cameras.

8. The vehicle type detection device according to claim 1, characterized in that: It also includes a plurality of rotating devices, which are connected to the first light detection device and / or the second light detection device to drive the first light detection device and / or the second light detection device to rotate.

9. The vehicle type detection device according to claim 8, characterized in that: The multiple rotating devices include a first rotating device and a second rotating device, wherein the first rotating device is connected to the first light detecting device so that the first light detecting device adjusts the angle of the section scanning light curtain by driving the first rotating device, and the second rotating device is connected to the second light detecting device so that the second light detecting device adjusts the angle of the contour line scanning light curtain by driving the second rotating device.

10. A vehicle type detection system, characterized in that: Comprising a vehicle type detection device according to any one of claims 1-9.

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