Tunnel portal illumination control method and control system

Abstract

The invention relates to the technical field of tunnel lighting, in particular to a tunnel portal lighting control method and system, and the method comprises the steps: S1, obtaining a first image in a short exposure time mode; obtaining a second image in a long exposure mode; s2, synthesizing the second image and the first image into a high-dynamic-range image, and dividing the high-dynamic-range image into a low-brightness area, a transition area and a high-brightness area; s3, generating a brightness transition curve of the transition area; s4, determining a brightness adjusting curve of the transition area according to the maximum brightness of the tunnel portal and the light and shade adaptive pupil area change rate; s5, determining the target brightness of each part of the transition area according to the brightness transition curve and the brightness adjustment curve; and S6, adjusting the brightness of the illumination lamp in the transition area to enable the brightness of each part of the transition area to reach the target brightness. The target brightness is determined according to the brightness transition curve in combination with the brightness adjustment curve, the influence of the brightness adaptive pupil area change rate on the sight line is fully considered, and the change of the brightness of the tunnel portal is more adaptive to the function of human eyes.

Description

Technical Field

[0001] The present invention belongs to the technical field of tunnel lighting, and in particular to a tunnel entrance lighting control method and control system. Background Art

[0002] The change in lighting at the entrance and exit of a tunnel often causes visual adaptation problems for drivers, which are manifested as the "black hole effect" and the "white hole effect". The black hole effect refers to the limited field of vision caused by insufficient light inside when entering a tunnel from strong light, while the white hole effect refers to the momentary glare caused by excessive light outside when exiting a tunnel from darkness. These problems significantly increase the risk of traffic accidents.

[0003] The invention patent with application number CN201010286671.0 discloses an automatic control method for tunnel LED lighting based on an intelligent expert illumination curve. The patent detects the brightness outside the tunnel and reduces the brightness value outside the tunnel to obtain the brightness of the transition section inside the tunnel, but cannot accurately obtain the brightness of the transition section.

[0004] The invention patent with application number CN202210114427.9 discloses a tunnel lighting system with adjustable brightness, which detects the brightness values ​​inside and outside the tunnel. When the brightness value L1 outside the tunnel minus the brightness value L2 in the middle of the tunnel is greater than the first threshold value, the brightness value of each lighting fixture in the entrance transition section is increased in sequence from the exit to the entrance, so that the brightness value of each lighting fixture in the entrance transition section increases one by one along the direction from the exit to the entrance; the brightness value of each lighting fixture in the exit transition section is increased in sequence from the entrance to the exit, so that the brightness value of each lighting fixture in the exit transition section increases one by one along the direction from the entrance to the exit.

[0005] When the brightness value L1 outside the tunnel entrance minus the brightness value L2 in the middle of the tunnel is less than the second threshold, the brightness value of each lighting fixture in the entrance transition section is reduced in sequence from the exit to the entrance, so that the brightness value of each lighting fixture in the entrance transition section decreases one by one along the direction from the exit to the entrance; the brightness value of each lighting fixture in the exit transition section is reduced in sequence from the entrance to the exit, so that the brightness value of each lighting fixture in the exit transition section decreases one by one along the direction from the entrance to the exit. This technology does not provide a method for determining the target brightness of the transition area, and it is difficult to optimize the brightness value of the transition area.

[0006] The invention patent with application number CN202010196481.3 discloses a method for eliminating the black hole phenomenon at the entrance of a tunnel. Brightness sensors are installed inside and outside the tunnel. The brightness inside and outside the tunnel is collected in real time through the brightness sensors to obtain the dark adaptation characteristic curve of the human eye. The illumination brightness of the visual transition section is dynamically and smoothly adjusted according to the dark adaptation characteristic curve of the human eye to eliminate the black hole phenomenon that occurs in the human eye when the vehicle enters the tunnel. Its dark adaptation characteristic curve is determined only by the brightness of the tunnel entrance and the time when the vehicle enters the tunnel. The rate of change of pupil area for light and dark adaptation is not taken into account. The rate of change of pupil area for light and dark adaptation refers to the rate at which the pupil area changes over time when the eyes adapt from a bright environment to a dark environment, or from a dark environment to a bright environment. The generated human eye adaptation characteristic curve is not reasonable enough. In addition, it is necessary to detect the time when the vehicle enters the tunnel, which results in errors. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a tunnel entrance lighting control method and control system, which can more reasonably adjust the tunnel entrance lighting brightness, so that the driver's eyes can better adapt to the brightness changes of the tunnel entrance and exit, thereby improving driving safety.

[0008] In order to solve the above problems, the technical solution adopted by the present invention is: a tunnel entrance lighting control method, comprising: S1. In the short exposure time mode, an image of the interior of the tunnel entrance is collected to obtain a first image; in the long exposure time mode, an image of the interior of the tunnel entrance is collected to obtain a second image, and the second image has the same area as the first image, including a low brightness area, a transition area, and a high brightness area; S2, synthesizing the second image and the first image into a high dynamic range image, analyzing the brightness distribution in the high dynamic range image, and dividing the image into a low brightness area, a transition area, and a high brightness area; S3, generating a brightness transition curve of the transition zone; S4, determining a brightness adjustment curve for the transition zone according to the maximum brightness at the tunnel entrance and the rate of change of the pupil area adapted to light and dark; S5. Determine the target brightness of each part of the transition zone according to the brightness transition curve and the brightness adjustment curve; S6. Adjust the brightness of the lighting fixtures in the transition zone so that the brightness of each part of the transition zone reaches the target brightness.

[0009] Furthermore, in step S2, the process of synthesizing the second image and the first image into a high dynamic range image includes: Image alignment: feature matching is performed on the second image and the first image, and pixel data at the same position of the second image and the first image are aligned; Image fusion: Assign different weights to each pixel according to the exposure value of the image area, giving higher weights to the bright area of ​​the short-exposure image and higher weights to the dark area of ​​the long-exposure image; Tone mapping: compresses the brightness of highlight and shadow areas in an image to the range that the display device can present, while enhancing the contrast of the image to maintain the visual effect of the image.

[0010] Further, in step S2, The central difference method is used to calculate the brightness difference between the two adjacent sampling points before and after, and the illumination change rate m is obtained. The calculation formula is: In the formula, x i is the sampling point at position i, x i-1 and x i+1 are the two sampling points adjacent to position i, I(x i-1 ) is the sampling point x i-1 The brightness at I(x i+1 ) is the sampling point x i+1 The brightness at x i+1 -x i-1 is the distance between two sampling points; At the end facing the interior of the tunnel, the sampling point whose m value is equal to the first threshold or whose difference with the first threshold is the smallest is taken as the inner endpoint; at the end facing the tunnel entrance, the sampling point whose m value is equal to the second threshold or whose difference with the second threshold is the smallest is taken as the outer endpoint, and the area between the inner endpoint and the outer endpoint is taken as the transition zone.

[0011] Furthermore, in step S3, the brightness transition curve is y(x)= b+a(x i -x 0 ), where y(x) is the target brightness at position i, b is the inner endpoint brightness, a is the coefficient, and x 0 is the inner endpoint position, x i -x 0 is the distance from position i to the inner endpoint; The process of determining the a value is as follows: Based on the brightness data (x 1 ,I 1 ),(x 2 ,I 2 ),......,(x n ,I n ), solve the error function by the least squares method and optimize the parameter a of the linear function.

[0012] Furthermore, in step S4, the brightness adjustment curve is Where L(x) is the target brightness at position x, A is the maximum brightness at the tunnel entrance, σ(v e ) is the pupil area change rate v according to light and dark adaptatione Dynamically adjusted transition width, μ is the center position of the transition zone, and x-μ is the distance from position x to position μ.

[0013] Furthermore, in step S5, the first target brightness is calculated according to the brightness transition curve, the second target brightness is calculated according to the brightness adjustment curve, and the average value of the first target brightness and the second target brightness is taken as the final target brightness.

[0014] The control system used in the above tunnel entrance lighting control method includes: A plurality of lamps arranged in the tunnel for lighting the interior of the tunnel; The image acquisition component is used to acquire the image inside the tunnel entrance in a short exposure time mode to obtain a first image; and acquire the image inside the tunnel entrance in a long exposure time mode to obtain a second image, wherein the second image has the same area as the first image, and both include a low brightness area, a transition area, and a high brightness area; Brightness monitoring element, used to obtain the maximum brightness of the tunnel entrance; Processing systems for performing the following processes: The second image and the first image are combined into a high dynamic range image, and the brightness distribution in the high dynamic range image is analyzed to divide the image into a low brightness area, a transition area, and a high brightness area; Generate a brightness transition curve for the transition zone; The brightness adjustment curve of the transition zone is determined according to the maximum brightness of the tunnel entrance and the rate of change of the pupil area adapted to light and dark; Determine the target brightness of each part of the transition zone according to the brightness transition curve and the brightness adjustment curve; Adjust the brightness of the lighting fixtures in the transition zone so that the brightness of each part of the transition zone reaches the target brightness.

[0015] Furthermore, the image acquisition element includes a high dynamic range imaging module, which includes a pixel array and an imaging circuit. The pixel array includes a plurality of first sub-pixels and a plurality of second sub-pixels. The first sub-pixels generate electrical signals based on received light in a bright area, and the second sub-pixels generate electrical signals based on received light in a dark area. The imaging circuit generates a first image and a second image based on the electrical signals generated by the first sub-pixels and the second sub-pixels.

[0016] The beneficial effects of the present invention are: 1. By acquiring the brightness data inside the tunnel entrance through high dynamic range imaging technology, the light distribution at the tunnel entrance and exit can be captured accurately in real time, with better image quality and higher contrast, and it can adapt to complex lighting environments, reduce the later data processing process, and ensure accurate and timely brightness adjustment.

[0017] 2. The present invention determines the target brightness based on the brightness transition curve combined with the brightness adjustment curve, and fully considers the influence of the pupil area change rate of light and dark adaptation on the line of sight, so that the change of the brightness at the tunnel entrance is more adapted to the function of the human eye. When the driver enters and exits the tunnel, the eyes are more comfortable, and the "black hole effect" and "white hole effect" can be better eliminated, and the road conditions ahead can be seen clearly, which is conducive to ensuring driving safety at the tunnel entrance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a flow chart of the tunnel entrance lighting control method of the present invention; Figure 2 It is a schematic diagram of the control system of the present invention. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0020] The tunnel entrance lighting control method of the present invention comprises: S1. In the short exposure time mode, an image of the interior of the tunnel entrance is collected to obtain a first image; in the long exposure time mode, an image of the interior of the tunnel entrance is collected to obtain a second image. The second image has the same area as the first image, including a low brightness area, a transition area and a high brightness area.

[0021] The existing technology mostly uses light sensors for brightness monitoring, but the light sensor can only detect the brightness of the location where the sensor is located, and cannot realize the brightness monitoring of all points in a certain area. Therefore, a large number of light sensors need to be installed, which is costly and has a small monitoring range. In addition, there is a certain response delay in the light sensor, which causes the system to be unable to adjust the light brightness in time. In the present invention, the brightness distribution of the internal area of ​​the tunnel entrance is obtained by collecting and analyzing images, and the image acquisition element can have a wider shooting range. Therefore, only one or two image acquisition elements need to be installed at the tunnel entrance to meet the brightness monitoring requirements, saving implementation costs.

[0022] Specifically, when acquiring images, in areas with stronger light (i.e., bright areas), short exposure can clearly capture more details and improve the usability of the image; in areas with weaker light (i.e., dark areas), increasing the exposure time can capture more details and avoid loss of details in dark areas or images being too dark.

[0023] The short exposure shooting and the long exposure shooting are performed successively by the same image acquisition element to obtain the first image and the second image successively. The same image acquisition element can ensure that the shooting area is completely the same.

[0024] S2. Combining the second image and the first image into a high dynamic range image, analyzing the brightness distribution in the high dynamic range image, and dividing the image into a low brightness area, a transition area, and a high brightness area.

[0025] The second image and the first image acquired by the image acquisition element are low dynamic range images. After the second image and the first image are synthesized into a high dynamic range image, the details of the dark and bright areas on the image are more prominent, and the brightness distribution can be displayed more intuitively.

[0026] The specific process of synthesizing the second image and the first image into a high dynamic range image includes: Image alignment: During the synthesis process, it is necessary to ensure that the two images with different exposures are aligned. The image registration method is used to match the features of the second image with the first image to ensure that the pixel data at the same position in the second image and the first image are accurately aligned. The shooting area of ​​the second image and the first image is exactly the same, so the two images can be completely aligned.

[0027] Image fusion: Assign different weights to each pixel according to the exposure value of the image area, giving higher weights to the bright areas of the short-exposure image and higher weights to the dark areas of the long-exposure image.

[0028] Tone mapping: compresses the brightness of highlight and shadow areas in an image to the range that the display device can present, while enhancing the contrast of the image to maintain the visual effect of the image.

[0029] Finally, output the image.

[0030] In a high dynamic range image, the brightness value of each pixel can be extracted to obtain the brightness value of each point in the shooting area.

[0031] The low brightness area is the area inside the tunnel with low brightness and relatively stable brightness; the high brightness area is the area close to the tunnel entrance with high brightness and relatively stable brightness; the transition zone is the area between the low brightness area and the high brightness area, where the brightness transitions from low brightness in the tunnel to high brightness, and it is also the area where the brightness needs to be adjusted to prevent the occurrence of "black hole effect" and "white hole effect".

[0032] Specifically, the division process of low brightness area, transition area and high brightness area is as follows: according to the brightness distribution of each area on the high dynamic range image, the brightness difference between the two adjacent sampling points is calculated by the central difference method to obtain the illumination change rate m, and the calculation formula is: In the formula, x i is the sampling point at position i, x i-1 and x i+1 are the two sampling points adjacent to position i, I(x i-1 ) is the sampling point x i-1 The brightness at I(x i+1 ) is the sampling point x i+1 The brightness at x i+1 -x i-1 is the distance between two sampling points.

[0033] Along the length of the tunnel, select multiple uniformly distributed sampling points on the high dynamic range image, and calculate the illumination change rate m between the sampling points. The illumination change rate m is the brightness change rate. When the m value is close to or equal to the first threshold or the second threshold, it indicates that the brightness is relatively stable, the change rate is small, the brightness change does not affect the human line of sight, and there is no need to adjust the brightness. When the m value is greater than the first threshold or the second threshold, it indicates that the brightness change rate is large, and it is necessary to control the brightness change curve so that the human eye can better adapt to the brightness change. Therefore, at the end facing the inside of the tunnel, the sampling point with an m value equal to the first threshold or the smallest difference between the m value and the first threshold is taken as the inner endpoint; at the end facing the tunnel entrance, the sampling point with an m value equal to the second threshold or the smallest difference between the m value and the second threshold is taken as the outer endpoint, and the area between the inner endpoint and the outer endpoint is taken as the transition zone. The first threshold and the second threshold can be flexibly set according to actual needs.

[0034] S3. Generate a brightness transition curve in the transition zone.

[0035] The straight line is used as the brightness transition curve, and the brightness transition curve is expressed as y(x) = b+a(x i -x 0 ), where y(x) is the target brightness at position i, b is the inner endpoint brightness, a is the coefficient, and x 0 is the inner endpoint position, x i -x 0 is the distance from position i to the inner endpoint. Among them, coefficient a is an important parameter.

[0036] The process of determining the a value is as follows: Based on the brightness data (x 1 ,I 1 ),(x 2 ,I 2 ),......,(x n ,I n ), solve the error function by the least squares method and optimize the parameter a of the linear function, (x n ,I n ) represents the position x n Brightness I n .

[0037] By generating a brightness transition curve based on actual lighting data and the lighting change rate m, it is possible to ensure that the lighting transition from external strong light into the tunnel is smooth and natural, optimize the driver's visual adaptation process, and avoid the discomfort caused by abrupt brightness changes.

[0038] S4. Determine the brightness adjustment curve of the transition zone according to the maximum brightness at the tunnel entrance and the rate of change of the pupil area adapted to light and dark.

[0039] Specifically, the brightness adjustment curve is Where L(x) is the target brightness at position x, A is the maximum brightness at the tunnel entrance, σ(v e ) is the pupil area change rate v according to light and dark adaptation e Dynamically adjusted transition width, μ is the center position of the transition zone, and x-μ is the distance from position x to position μ.

[0040] σ(v e ) is calculated by the following formula: Among them, v e It represents the rate of change of pupil area in light-dark adaptation. k and β are coefficients obtained through experimental fitting. Through literature analysis and research, k is proposed to be 10 and β is 0.5, and then the width of light-dark adaptation transition is calculated.

[0041] The maximum brightness value A at the tunnel entrance is related to the brightness outside the tunnel. A light sensor can be set at the end face of the tunnel, and the brightness value detected by the light sensor is the maximum brightness value A at the tunnel entrance.

[0042] The pupil area change rate of light-dark adaptation includes the pupil area change rate of light-adaptation and the pupil area change rate of dark-adaptation. When entering the tunnel, the pupil area change rate of dark-adaptation is used. At this time, v e 1mm 2 / s; when leaving the tunnel, the pupil area change rate of light adaptation is adopted, at this time v e -3mm 2 / s.

[0043] S5. Determine the target brightness of each part of the transition area according to the brightness transition curve and the brightness adjustment curve.

[0044] The first target brightness of each sampling point is calculated according to the brightness transition curve, the second target brightness of each sampling point is calculated according to the brightness adjustment curve, and the average value of the first target brightness and the second target brightness is taken as the final target brightness.

[0045] The brightness transition curve can ensure a smooth transition of brightness in the transition zone and avoid abrupt brightness changes. The brightness adjustment curve takes into account the changes in pupil area of ​​the human body to adapt to light and dark, and determines the optimal brightness change law that the human eye can adapt to when entering and exiting the tunnel. Combining the brightness transition curve with the brightness adjustment curve ensures that the final target brightness is close to both the brightness transition curve and the brightness adjustment curve, so that the brightness change in the transition zone is both smooth and can adapt to the changes in the human eye, ensuring that the driver has a good line of sight and improving safety.

[0046] S6. Adjust the brightness of the lighting fixtures in the transition zone so that the brightness of each part of the transition zone reaches the final target brightness.

[0047] The tunnel entrance lighting control system of the present invention is as follows: Figure 2 Shown, including A plurality of lamps arranged in the tunnel may adopt LED lamps to illuminate the interior of the tunnel; The image acquisition component is used to acquire the image inside the tunnel entrance in a short exposure time mode to obtain a first image; and acquire the image inside the tunnel entrance in a long exposure time mode to obtain a second image, wherein the second image has the same area as the first image, and both include a low brightness area, a transition area, and a high brightness area; Brightness monitoring element, used to obtain the maximum brightness of the tunnel entrance; Processing systems for performing the following processes: The second image and the first image are combined into a high dynamic range image, and the brightness distribution in the high dynamic range image is analyzed to divide the image into a low brightness area, a transition area, and a high brightness area; Generate a brightness transition curve for the transition zone; The brightness adjustment curve of the transition zone is determined according to the maximum brightness of the tunnel entrance and the rate of change of the pupil area adapted to light and dark; Determine the target brightness of each part of the transition zone according to the brightness transition curve and the brightness adjustment curve; Adjust the brightness of the lighting fixtures in the transition zone so that the brightness of each part of the transition zone reaches the target brightness.

[0048] Among them, the image acquisition element includes a high dynamic range (HDRI) imaging module, the high dynamic range imaging module includes a pixel array and an imaging circuit, the pixel array includes a plurality of first sub-pixels and a plurality of second sub-pixels, the first sub-pixels generate electrical signals based on received bright area light, and the second sub-pixels generate electrical signals based on received dark area light; the imaging circuit generates a first image and a second image based on the electrical signals generated by the first sub-pixels and the second sub-pixels.

[0049] Using the HDRI imaging module provides the following advantages: 1. Enhanced brightness capture capability: Through pixel-level exposure control, the details of highlight and dark areas are retained to avoid overexposure or underexposure problems that occur in ordinary cameras in high-contrast scenes.

[0050] 2. Improve shooting efficiency: HDRI can obtain complete brightness information with a single shot, rather than multiple exposures of traditional HDR solutions, reducing shooting delays and improving image alignment accuracy.

[0051] 3. Adapt to the complex lighting environment of the tunnel: The contrast range is wider, which can accurately reflect the brightness distribution of the tunnel entrance and exit, and improve the intelligent adjustment ability of the lighting system.

[0052] 4. Reduce the computational burden: The HDRI module directly generates the required short-exposure images and long-exposure images without the need for complex post-image synthesis processing, thus improving the real-time performance of the system.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A tunnel entrance lighting control method, characterized in that: include: S1. In a short exposure time mode, an image of the interior of a tunnel entrance is collected to obtain a first image; In the long exposure mode, an image of the interior of the tunnel entrance is collected to obtain a second image, and the second image has the same area as the first image, including a low brightness area, a transition area, and a high brightness area; S2, synthesizing the second image and the first image into a high dynamic range image, analyzing the brightness distribution in the high dynamic range image, and dividing the image into a low brightness area, a transition area, and a high brightness area; S3, generating a brightness transition curve of the transition zone; S4, determining a brightness adjustment curve for the transition zone according to the maximum brightness at the tunnel entrance and the rate of change of the pupil area adapted to light and dark; S5. Determine the target brightness of each part of the transition zone according to the brightness transition curve and the brightness adjustment curve; S6. Adjust the brightness of the lighting fixtures in the transition zone so that the brightness of each part of the transition zone reaches the target brightness.

2. The tunnel entrance lighting control method according to claim 1, characterized in that: In step S2, the process of synthesizing the second image and the first image into a high dynamic range image includes: Image alignment: feature matching is performed on the second image and the first image, and pixel data at the same position of the second image and the first image are aligned; Image fusion: Assign different weights to each pixel according to the exposure value of the image area, giving higher weights to the bright area of ​​the short-exposure image and higher weights to the dark area of ​​the long-exposure image; Tone mapping: compresses the brightness of highlight and shadow areas in an image to the range that the display device can present, while enhancing the contrast of the image to maintain the visual effect of the image.

3. The tunnel entrance lighting control method according to claim 1, characterized in that: In step S2, The central difference method is used to calculate the brightness difference between the two adjacent sampling points before and after, and the illumination change rate m is obtained. The calculation formula is: In the formula, x i is the sampling point at position i, x i-1 and x i+1 are the two sampling points adjacent to position i, I(x i-1 ) is the sampling point x i-1 The brightness at I(x i+1 ) is the sampling point x i+1 The brightness at x i+1 -x i-1 is the distance between two sampling points; At the end facing the inside of the tunnel, a sampling point whose m value is equal to the first threshold or whose difference between the m value and the first threshold is the smallest is taken as an inner endpoint; At the end facing the tunnel entrance, the sampling point where the m value is equal to the second threshold or the difference between the m value and the second threshold is the smallest is taken as the outer endpoint, and the area between the inner endpoint and the outer endpoint is taken as the transition area.

4. The tunnel entrance lighting control method according to claim 3, characterized in that: In step S3, the brightness transition curve is y(x)= b+a(x i -x0), where y(x) is the target brightness at position i, b is the inner endpoint brightness, a is the coefficient, x0 is the inner endpoint position, and x i -x0 is the distance from position i to the inner endpoint; The process of determining the a value is as follows: according to the brightness data of the transition area (x1, I1), (x2, I2), ..., (x n ,I n ), solve the error function by the least squares method and optimize the parameter a of the linear function.

5. The tunnel entrance lighting control method according to claim 1, characterized in that: In step S4, the brightness adjustment curve is Where L(x) is the target brightness at position x, A is the maximum brightness at the tunnel entrance, σ(v e ) is the pupil area change rate v according to light and dark adaptation e Dynamically adjusted transition width, μ is the center position of the transition zone, and x-μ is the distance from position x to position μ.

6. The tunnel entrance lighting control method according to claim 4, characterized in that: In step S5, the first target brightness is calculated according to the brightness transition curve, the second target brightness is calculated according to the brightness adjustment curve, and the average value of the first target brightness and the second target brightness is taken as the final target brightness.

7. A control system for the tunnel entrance lighting control method according to any one of claims 1 to 6, characterized in that: include A plurality of lamps arranged in the tunnel for lighting the interior of the tunnel; An image acquisition component is used to acquire an image of the interior of the tunnel entrance in a short exposure time mode to obtain a first image; In the long exposure mode, an image of the interior of the tunnel entrance is collected to obtain a second image, and the second image has the same area as the first image, including a low brightness area, a transition area, and a high brightness area; Brightness monitoring element, used to obtain the maximum brightness of the tunnel entrance; Processing systems for performing the following processes: The second image and the first image are combined into a high dynamic range image, and the brightness distribution in the high dynamic range image is analyzed to divide the image into a low brightness area, a transition area, and a high brightness area; Generate a brightness transition curve for the transition zone; The brightness adjustment curve of the transition zone is determined according to the maximum brightness of the tunnel entrance and the rate of change of the pupil area adapted to light and dark; Determine the target brightness of each part of the transition zone according to the brightness transition curve and the brightness adjustment curve; Adjust the brightness of the lighting fixtures in the transition zone so that the brightness of each part of the transition zone reaches the target brightness.

8. The control system according to claim 7, characterized in that: The image acquisition element includes a high dynamic range imaging module, which includes a pixel array and an imaging circuit. The pixel array includes a plurality of first sub-pixels and a plurality of second sub-pixels. The first sub-pixels generate electrical signals based on received light in a bright area, and the second sub-pixels generate electrical signals based on received light in a dark area. The imaging circuit generates a first image and a second image based on the electrical signals generated by the first sub-pixels and the second sub-pixels.

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