Dynamic retroreflection brightness coefficient detection and evaluation system

Abstract

The invention discloses a marked line detection device which comprises a camera configured to acquire an image of a detected position at a downwards inclined observation angle; the laser source is configured to project single-wavelength laser to the detected position at a downward inclined projection angle; wherein the marking detection device comprises a first mode and a second mode, in the first mode, the camera collects images under the condition that the laser source projects laser, and in the second mode, the camera collects images under the condition that the laser source does not project laser; wherein the marking detection device is configured to detect marking detection data corresponding to the detected position, and the marking detection data corresponding to the detected position comprises a first image collected in the first mode and a second image collected in the second mode. The invention further discloses a marking retroreflection brightness coefficient detection and evaluation system with the marking detection device and a vehicle.

Description

Technical Field

[0001] The present application relates to the field of highway transportation, and in particular to a dynamic inspection and evaluation system for retroreflective brightness coefficient. Background Art

[0002] Road traffic markings are key traffic control facilities painted on the road surface, which are designed to channel traffic flow, guide vehicle alignment, and ensure traffic safety. These markings have multiple functions of defining lane boundaries, regulating and managing driver driving behavior, guiding driver vision, indicating and warning road conditions ahead, and clarifying the right of way.

[0003] After being rolled over for a long time, the road traffic markings have poor reflectivity at night, reduced visibility, and potential safety hazards. In order to ensure the safety and visibility of road markings, they need to be regularly inspected and evaluated for timely maintenance. An important criterion for judging whether road markings need maintenance is the retro-reflective brightness coefficient of road traffic markings.

[0004] At present, the detection method of retro-reflective brightness coefficient of road traffic markings mainly relies on handheld devices. Although handheld devices are mature in technology and easy to carry, they are mainly used for laboratory testing and contact measurement of constructed markings, and are not suitable for large-area rapid measurement. At present, the use of non-contact measurement vehicle-mounted equipment is also proposed, but non-contact measurement vehicle-mounted equipment is easily affected by various factors when measuring marking parameters, resulting in the inability to quickly and accurately measure the retro-reflective brightness coefficient of the marking.

[0005] In view of this, the industry hopes to provide a solution that can reduce the impact of various external factors and can quickly and accurately determine whether the retro-reflective brightness coefficient of the marking to be inspected is qualified.

[0006] The content of this background technology description is only for facilitating understanding of the relevant technology in this field and is not regarded as an admission of the prior art. Summary of the invention

[0007] Therefore, the embodiments of the present application hope to provide a solution that can reduce the influence of various external factors and can quickly and accurately determine the retroreflective brightness coefficient of the marking to be inspected and evaluate whether it is qualified.

[0008] In a first aspect, a marking line detection device is provided, comprising:

[0009] a camera configured to capture an image of the inspected location at a downwardly tilted observation angle; and a laser source configured to project a single wavelength laser light at a downwardly tilted projection angle toward the inspected location;

[0010] The marking line detection device includes a first mode and a second mode, in which the camera captures images when the laser source projects laser light, and in which the camera captures images when the laser source does not project laser light;

[0011] The marking line detection device is configured to detect and obtain marking line detection data corresponding to the detected position, and the marking line detection data corresponding to the detected position includes a first image collected in the first mode and a second image collected in the second mode.

[0012] Optionally, the camera is located above the laser source, and the camera and the laser source have approximately the same lateral position transverse to the projection direction of the laser source.

[0013] Optionally, the ratio of the camera height of the camera to the light source height of the laser source is (24±0.5) / (13±0.5), the observation angle of the camera is 2.29°±0.05°, and the projection angle of the laser source is 1.24°±0.05°.

[0014] Optionally, the marking line detection device further comprises a filter mounted on the camera, the wavelength of the filter corresponding to the wavelength of the single-wavelength laser projected by the laser source.

[0015] Optionally, the marking detection device includes multiple cameras and multiple laser sources, each camera is matched with a laser source, the multiple cameras are spaced apart from each other in a laser projection direction transverse to the laser source, and each camera and its matched laser source have approximately the same lateral position in the projection direction transverse to the laser source.

[0016] Optionally, the marking line detection device further includes a distance sensing unit, and the distance sensing unit is configured to obtain an actual projection distance of the laser projected by the laser source to the detected position.

[0017] Optionally, the marking line detection device further includes an ambient light sensing unit, and the ambient light sensing unit is configured to obtain ambient light parameters when acquiring the first and / or second image, wherein the marking line detection data also includes the ambient light parameters.

[0018] In a second aspect, a marking retroreflective brightness coefficient inspection and evaluation system is provided, characterized in that it includes:

[0019] The marking detection device according to the first aspect of the present application;

[0020] The retroreflective brightness coefficient determining device is configured to determine the retroreflective brightness coefficient of the marking line at the detected position based on the marking line detection data corresponding to the detected position.

[0021] Optionally, the retroreflective brightness coefficient determining device comprises:

[0022] An acquisition unit configured to acquire the marking line detection data corresponding to the detected position;

[0023] A first marking line recognition unit configured to identify a first marking line region in the first image using a given image segmentation algorithm;

[0024] a second marking line recognition unit configured to identify a second marking line region in the second image using a given image segmentation algorithm;

[0025] A first image processing unit configured to extract a first grayscale value of a first reticle area in the first image;

[0026] a second image processing unit configured to extract a second grayscale value of a second reticle area in the second image;

[0027] The retroreflection brightness coefficient calculation unit is configured to calculate the retroreflection brightness coefficient of the marking line at the detected position according to the first gray value, the second gray value and a given retroreflection brightness coefficient standard value.

[0028] Optionally, the retroreflective brightness coefficient determining device comprises:

[0029] The retroreflective brightness coefficient evaluation unit is configured to receive the retroreflective brightness coefficient calculated by the calculation unit, and judge the retroreflective performance of the marking line according to a preset performance indicator threshold to evaluate whether it meets the prescribed safety standards.

[0030] In a second aspect, a vehicle is provided, characterized in that it comprises a road marking detection device according to an embodiment of the present application.

[0031] In one embodiment, a marking detection device is provided, which obtains a first image captured by the camera when a laser source projects laser light and a second image captured by the camera when the laser source does not project laser light, and uses the first and second images together as marking detection data. This can avoid the influence of external factors when calculating parameters related to marking visibility, and also facilitates the rapid and accurate determination of parameters related to marking visibility, such as retroreflection brightness coefficient.

[0032] The optional features and other effects of the embodiments of the present application are partially described below, and partially can be understood by reading this document. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Hereinafter, embodiments of the present application will be described in detail in conjunction with the accompanying drawings. The elements shown are not limited to the proportions shown in the drawings and the same or similar reference numerals in the drawings represent the same or similar elements, wherein:

[0034] Figure 1 A schematic diagram of a marking detection device according to an embodiment of the present application is shown;

[0035] Figure 2 An example diagram showing a first image of marking line detection data detected by a marking line detection device according to an embodiment of the present application;

[0036] Figure 3 An example diagram showing a second image of marking line detection data detected by the marking line detection device according to an embodiment of the present application;

[0037] Figure 4 A schematic diagram of a marking detection device according to an embodiment of the present application is shown;

[0038] Figure 5 A schematic diagram of a marking detection device according to another embodiment of the present application is shown;

[0039] Figure 6 A schematic diagram showing a marking line detection device according to another embodiment of the present application; and

[0040] Figure 7 A schematic diagram of a marking line retroreflective brightness coefficient inspection and evaluation system according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with specific implementation methods and drawings. Here, the illustrative implementation methods and descriptions of the present application are used to explain the present application, but are not intended to limit the present application.

[0042] The term "including" and its variations used in this document represent open inclusion, that is, "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "based at least in part on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one other embodiment". In order to facilitate the understanding of this specification, the sequential terms "first", "second", etc. are used in this document to distinguish different elements / items / objects, and do not indicate the order or importance of different elements / items / objects. In particular, the method steps represented by the terms "first", "second", etc. are not used to indicate the order of method execution; when an embodiment contains elements / items / objects represented in a later order, the elements / items / objects represented by the terms "first", "second", etc. in the previous order are not necessarily essential technical features of the embodiment.

[0043] As mentioned above, the embodiments of the present application aim to provide a marking detection solution that can reduce the influence of various external factors and can quickly and accurately determine the parameters of the marking to be detected.

[0044] In this regard, refer to Figure 1In an embodiment of the present application, a marking line detection device 100 is provided. The marking line detection device 100 includes a camera 110 and a laser source 120 .

[0045] Continue to refer Figure 1 The camera 110 may be configured to capture an image of the detected position at a downwardly inclined observation angle. The laser source 120 may be configured to project a single wavelength laser (e.g., Figure 1 (shown schematically in medium grey).

[0046] In a preferred embodiment of the present application, the single-wavelength laser may be an infrared laser or a green laser. In a preferred example, the wavelength of the single-wavelength laser may be about 808 nm. The detection data obtained by the marking detection device 100 of the embodiment of the present application, which includes both the single-wavelength laser projected image and the non-projected image, is particularly useful for detecting or identifying markings, especially markings in an image under outdoor natural light environment.

[0047] In some embodiments of the present application, the marking detection device may further include a filter mounted on the camera, and the wavelength of the filter may correspond to the wavelength of the single-wavelength laser projected by the laser source. In a specific embodiment, the wavelength of the filter is 808nm. The setting of the filter further helps to detect or identify markings in images under outdoor natural light environments.

[0048] Combined with reference Figures 1 to 3 In some embodiments of the present application, the marking line detection device 100 may include a first mode and a second mode. In the first mode, the camera 110 projects a laser beam from the laser source 120 (see Figure 1 In the second mode, the camera 110 captures images when the laser source 120 does not project laser light (not shown). Thus, the marking line detection device 100 can detect and obtain marking line detection data corresponding to the detected position, and the marking line detection data preferably includes the first image captured in the first mode (such as Figure 2 ) and a second image acquired in the second mode (as shown Figure 3 According to the detection data obtained by the marking detection device 100 in the embodiment of the present application, for example, the first image and / or the second image can be independently used to quickly determine various parameters of the marking to be detected, and can also be used to assist in optimization based on other existing data, such as correcting various parameters of the existing marking to be detected, especially the retroreflective brightness parameters of the marking to be detected.

[0049] Continue to refer Figure 1In some embodiments of the present application, the camera 110 may be located above the laser source 120. Although not shown in the figure, the camera 110 and the laser source 120 have approximately the same lateral position in a direction transverse to the projection direction of the laser source, that is, the camera 110 is approximately located directly above the corresponding laser source 120.

[0050] Continue to refer Figure 1 In a specific embodiment of the present application, the camera height H of the camera 110 of the marking detection device 100 is c The light source height H of the laser source 120 l The ratio is (24±0.5) / (13±0.5), the observation angle of the camera 110 is 2.29°±0.05°, and the projection angle of the laser source 120 is 1.24°±0.05°.

[0051] Continue to refer Figure 1 In the embodiment of the present application, the detection position of the road marking detection device 100 may include various road surfaces, including but not limited to road surfaces with road markings, and may also include road surfaces with road marking standard plates placed. In an exemplary embodiment, the road marking standard plate may have any suitable length, such as a length of 50 cm. Figure 1 In the embodiment shown, when the light is projected onto the reticle standard plate, the light projection position may be the width W of the reticle standard plate. s The midpoint of , but the application is not limited to this.

[0052] like Figure 1 As shown, in some embodiments of the present application, the marking detection device 100 may further include a distance sensing unit 130, and the distance sensing unit 130 is configured to obtain the actual projection distance of the laser light projected by the laser source 120 to the detected position. In some embodiments, the distance sensing unit 130 can be configured synchronously with the light projection of the laser source 120, for example, the time t0 of the light projection of the laser source 120 can be obtained, and the time t1 when the distance sensing unit 130 receives the reflected light of the projected light can be obtained, and the light projection distance can be determined accordingly. In one example, the distance sensing unit 130 is, for example, a TOF sensor, but the present application is not limited thereto. The detection data including the light projection distance acquired in real time by the marking detection device 100 with the distance sensing unit 130 according to the present application is particularly conducive to quickly and accurately acquiring the parameters of the marking to be detected, and is conducive to the optional subsequent processing of the parameters of the marking to be detected, such as correction processing.

[0053] like Figure 1 As shown, in some embodiments of the present application, the marking line detection device 100 may further include an ambient light sensing unit 140, and the ambient light sensing unit 140 is configured to obtain ambient light parameters when collecting the first and / or second images. Accordingly, the marking line detection data will also include the ambient light parameters.

[0054] like Figure 4 As shown, in some embodiments of the present application, the marking line detection device 100 includes a plurality of cameras 110 and a plurality of laser sources 120 (not marked), and each of the cameras 110 is matched with one of the laser sources 120. The plurality of cameras 110 are arranged spaced apart from each other in a direction transverse to the laser projection direction of the laser source 120, and each of the cameras 110 and the laser source 120 matched with each other have substantially the same transverse position in a direction transverse to the projection direction of the laser source.

[0055] In some embodiments of the present application, in combination with reference Figures 4 to 6 The road marking detection device 100 may be a vehicle-mounted road marking detection device. In the vehicle-mounted road marking detection device, for example, cameras and matching laser sources may be installed at the left front side and the right front side of the vehicle and at an optional middle position, respectively.

[0056] In some embodiments of the present application, reference Figure 4 and Figure 5 At least one of the road marking detection devices 100 can be installed to the front side of the vehicle via a bracket 400 .

[0057] Continue to refer Figure 4 and Figure 5 , the three marking line detection devices 100 ( Figure 4 Only the camera 110 is shown), and the marking detection device 100 is installed to the front side of the vehicle by the bracket 400 connected to the front side of the vehicle, wherein one marking detection device 100 is installed at the middle position of the front side of the vehicle shown in the figure, and the other two marking detection devices 100 are installed at the left front side position and the right front side position of the front side of the vehicle shown in the figure. It should be understood that in other embodiments, other numbers of the marking detection devices 100 can be connected to the front side of the vehicle through the bracket / connection device, which falls within the scope of the present application.

[0058] In some embodiments of the present application, reference Figure 6 At least one of the road marking detection devices 100 can be integrated into the front of the vehicle in a built-in manner. However, it can be understood that the positions shown in the figure are only examples, and the road marking detection device 100 can also be reasonably built into other positions in the vehicle, which falls within the scope of the present application.

[0059] In some embodiments of the present application, although not shown, the road marking detection device 100 of the above-mentioned embodiment can be connected to a cloud or remote electronic device for communication, such as a direct communication connection or a communication connection relayed through a vehicle's communication unit, thereby transmitting the detection data obtained by the road marking detection device 100 in real time.

[0060] The above text describes a line marking detection device 100 according to an embodiment of the present application in combination with the accompanying drawings. The line marking detection device 100 acquires a first image captured by the camera when a laser source projects laser light and a second image captured by the camera when the laser source does not project laser light. The first and second images are used together as line marking detection data. This can avoid the influence of external factors when calculating parameters related to line marking visibility, thereby facilitating rapid and accurate determination of parameters related to line marking visibility.

[0061] In some embodiments of the present application, the parameters related to the visibility of the marking line may include a retroreflection brightness coefficient. At this time, the marking line detection data obtained by the marking line detection device 100 according to the embodiment of the present application can be used in the retroreflection brightness coefficient determination method to quickly and accurately determine the retroreflection brightness coefficient.

[0062] As an example, the method for determining the retroreflective brightness coefficient may include the following steps:

[0063] Acquire a first image and a second image corresponding to a detected position in the marking line detection, wherein the first image is an image captured when a single-wavelength laser is projected, and the second image is an image captured when a single-wavelength laser is not projected; identify a first marking line area in the first image using a given image segmentation algorithm; identify a second marking line area in the second image using a given image segmentation algorithm; extract a first grayscale value of the first marking line area in the first image; extract a second grayscale value of the second marking line area in the second image; and calculate the retroreflective brightness coefficient of the marking line at the detected position based on the first grayscale value, the second grayscale value and a given retroreflective brightness coefficient standard value.

[0064] However, it can be understood that the above-mentioned method for determining the retroreflective brightness coefficient is only used as an example. The line marking detection data obtained by the line marking detection device 100 according to the embodiment of the present application can be used for any existing suitable method for determining line marking visibility-related parameters, so as to quickly and accurately determine line marking visibility-related parameters, such as the retroreflective brightness coefficient of the line marking.

[0065] In a further embodiment, the marking detection data obtained by the marking detection device 100 according to the embodiment of the present application can also be used to further optimize the already determined marking visibility related parameters and enter the retroreflection brightness coefficient for further processing, such as correction processing.

[0066] As an example, the correction method for the user to correct the retroreflective brightness coefficient may include the following steps:

[0067] Acquire an original retroreflection brightness coefficient to be corrected determined based on marking line detection data, wherein at least a portion of the marking line detection data is obtained in the case of projection light, and the projection light has a calibrated projection distance; acquire an actual projection distance of the projection light to a detected position when the marking line detection data is obtained; determine a distance correction coefficient based on the calibrated projection distance and the actual projection distance; and correct the original retroreflection brightness coefficient to be corrected based on the distance correction coefficient to obtain a distance-corrected retroreflection brightness coefficient.

[0068] However, it can be understood that the above-mentioned correction method of the retroreflective brightness coefficient is only used as an example, and the marking detection data obtained by the marking detection device 100 according to the embodiment of the present application can be used for any existing appropriate correction method of marking visibility-related parameters.

[0069] In some embodiments of the present application, reference Figure 7 , a marking retroreflective brightness coefficient inspection and evaluation system 700 is also provided, comprising a marking detection device 710 and a retroreflective brightness coefficient evaluation device 720 according to any one of the above embodiments of the present application. The retroreflective brightness coefficient evaluation device is configured to determine the marking retroreflective brightness coefficient at the detected position according to the marking detection data corresponding to the detected position, and perform evaluation, including but not limited to evaluating whether the marking retroreflective brightness coefficient meets the prescribed safety standards.

[0070] In some embodiments of the present application, the retroreflective brightness coefficient determination device 720 may include an acquisition unit 721, a first marking line recognition unit 722, a second marking line recognition unit 723, a first image processing unit 724, a second image processing unit 725, and a retroreflective brightness coefficient calculation unit 726, wherein:

[0071] The acquisition unit 721 is configured to acquire the marking line detection data corresponding to the detected position.

[0072] The first reticle recognition unit 722 is configured to identify a first reticle region in the first image using a given image segmentation algorithm.

[0073] The second marking line identification unit 723 is configured to identify the second marking line region in the second image using a given image segmentation algorithm.

[0074] The first image processing unit 724 is configured to extract a first grayscale value of a first reticle area in the first image.

[0075] The second image processing unit 725 is configured to extract a second grayscale value of a second reticle area in the second image.

[0076] The retroreflection brightness coefficient calculation unit 726 is configured to calculate the retroreflection brightness coefficient of the marking line at the detected position according to the first grayscale value, the second grayscale value and a given retroreflection brightness coefficient standard value.

[0077] In some embodiments of the present disclosure, reference Figure 7 The retroreflective brightness coefficient determination device 720 may also include a retroreflective brightness coefficient evaluation unit 727, which is configured to receive the retroreflective brightness coefficient calculated by the calculation unit, and judge the retroreflective performance of the marking according to a preset performance indicator threshold to evaluate whether it meets the prescribed safety standards.

[0078] In some embodiments of the present application, a vehicle is further provided, the vehicle comprising the road marking detection device according to any one of the above embodiments of the present application. The vehicle may be combined with the road marking detection device 100 in a manner including but not limited to any one of the above embodiments of the present application.

[0079] In this article, multiple embodiments of the present application are described, but for the sake of simplicity, the description of each embodiment is not exhaustive, and the same or similar features or parts between the various embodiments may be omitted. In this article, "one embodiment", "some embodiments", "example", "specific example", or "some examples" are intended to be applicable to at least one embodiment or example according to the present application, rather than all embodiments. The above terms do not necessarily mean to refer to the same embodiment or example. In the absence of mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples.

[0080] The exemplary system of the present application has been specifically shown and described with reference to the above embodiments, which is only an example of the best mode for implementing the present system and method. It will be appreciated by those skilled in the art that various changes can be made to the embodiments of the system described herein when implementing the present system without departing from the spirit and scope of the present application defined in the appended claims.

Claims

1. A marking detection device, characterized in that: include: a camera configured to capture an image of the inspected location at a downwardly inclined viewing angle; and a laser source configured to project a single wavelength laser light at a downwardly inclined projection angle toward the detected location; The marking line detection device includes a first mode and a second mode. In the first mode, the camera collects images when the laser source projects laser light, and in the second mode, the camera collects images when the laser source does not project laser light. The marking line detection device is configured to detect and obtain marking line detection data corresponding to the detected position, and the marking line detection data corresponding to the detected position includes a first image acquired in the first mode and a second image acquired in the second mode.

2. The marking detection device according to claim 1, characterized in that: The camera is located above the laser source, and the camera and the laser source have approximately the same lateral position in a direction transverse to the projection direction of the laser source.

3. The marking detection device according to claim 1, characterized in that: The ratio of the camera height of the camera to the light source height of the laser source is (24±0.5) / (13±0.5), the observation angle of the camera is 2.29°±0.05°, and the projection angle of the laser source is 1.24°±0.05°.

4. The marking detection device according to claim 1, characterized in that: The marking line detection device further comprises a filter mounted on the camera, wherein the wavelength of the filter corresponds to the wavelength of the single-wavelength laser projected by the laser source.

5. The marking line detection device according to claim 1, characterized in that: The marking line detection device includes a plurality of the cameras and a plurality of the laser sources, each of the cameras is matched with one of the laser sources, the plurality of cameras are spaced apart from each other in a laser projection direction transverse to the laser source, and each of the cameras and the laser source matched with each of the cameras have approximately the same transverse position in the projection direction transverse to the laser source.

6. The marking line detection device according to any one of claims 1 to 5, characterized in that: The marking line detection device further includes a distance sensing unit, which is configured to obtain an actual projection distance of the laser light projected by the laser source to the detected position.

7. The marking line detection device according to any one of claims 1 to 5, characterized in that: The marking line detection device further includes an ambient light sensing unit, and the ambient light sensing unit is configured to obtain ambient light parameters when acquiring the first and / or second image, wherein the marking line detection data further includes the ambient light parameters.

8. A marking line retroreflection brightness coefficient inspection and evaluation system, characterized in that: include: The marking detection device according to any one of claims 1 to 7; The retroreflective brightness coefficient determining device is configured to determine the retroreflective brightness coefficient of the marking line at the detected position according to the marking line detection data corresponding to the detected position.

9. The marking line retroreflection brightness coefficient inspection and evaluation system according to claim 8, characterized in that: The retroreflective brightness coefficient determining device comprises: An acquisition unit configured to acquire the marking line detection data corresponding to the detected position; A first marking line recognition unit configured to identify a first marking line region in the first image using a given image segmentation algorithm; a second marking line recognition unit configured to identify a second marking line region in the second image using a given image segmentation algorithm; a first image processing unit configured to extract a first grayscale value of a first reticle area in the first image; a second image processing unit configured to extract a second grayscale value of a second reticle area in the second image; The retroreflection brightness coefficient calculation unit is configured to calculate the retroreflection brightness coefficient of the marking line at the detected position according to the first grayscale value, the second grayscale value and a given retroreflection brightness coefficient standard value.

10. The marking line retroreflection brightness coefficient inspection and evaluation system according to claim 9, characterized in that: The retroreflective brightness coefficient determining device also includes: The retroreflective brightness coefficient evaluation unit is configured to receive the retroreflective brightness coefficient calculated by the calculation unit, and judge the retroreflective performance of the marking line according to a preset performance indicator threshold to evaluate whether it meets the prescribed safety standards.

11. A vehicle, characterized in that: It comprises a marking line detection device according to any one of claims 1 to 7.

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