Vehicle chassis imaging device based on light path folding

Abstract

The utility model relates to the technical field of vehicle chassis imaging devices, and provides a vehicle chassis imaging device based on light path folding, which comprises a lighting device, a camera device and a light path folding unit, the light path folding unit comprises a plurality of reflectors, every two reflectors are oppositely arranged according to a set included angle, and the length and direction of a light path are changed through sequential reflection of the reflectors, so that an incident light path passing through an incident port of the light path folding unit and an emergent light path passing through an emergent port of the light path folding unit meet the set included angle; and the shooting direction of the camera device faces the reflected light exit port of the light path folding unit. According to the utility model, the optical path folding unit adopting a plurality of reflectors is arranged, so that the imaging device realizes the extension of an optical path under a certain device volume, thereby solving the problem of distortion of a shot image, reducing the distortion rate and improving the imaging quality.

Description

Technical Field

[0001] This utility model relates to the technical field of vehicle chassis imaging devices, specifically to a vehicle chassis imaging device based on optical path folding. Background Technology

[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.

[0003] With increasingly stringent security requirements, vehicles entering and exiting security-controlled areas must undergo comprehensive inspections. The vehicle chassis area, being a concealed location where items can easily be hidden, has become a key focus of security checks. Current chassis inspection methods generally suffer from poor image quality, primarily manifested in varying degrees of distortion in the chassis images. This results in significant differences between the imaged chassis and the actual chassis, severely impacting the staff's assessment of the vehicle's chassis condition and easily leading to missed inspections or misjudgments. The causes of image distortion mainly include the following:

[0004] First, the imaging angle design is unreasonable. Existing vehicle chassis inspection devices use cameras that point directly upwards at the vehicle chassis to capture images, and wide-angle lenses are commonly used to cover a large chassis area. With this arrangement, the central area of ​​the image is relatively clear, but the edges of the chassis are prone to image distortion due to the larger angle of light incidence, resulting in barrel or pincushion distortion, thus causing a mismatch between the center and edge proportions of the chassis image. In this scheme, the optical path length L is linearly related to the volume V: V = 1.8L. Directly increasing the optical path length would lead to an excessively large volume, increasing the setup cost of the inspection device.

[0005] Secondly, unstable vehicle trajectories during actual testing can also lead to imaging problems. Existing equipment requires the vehicle to travel precisely along the center of the chassis inspection device to produce a complete and symmetrical chassis image. When the driver fails to maintain strict centering, the chassis image will shift to one side, compromising image integrity and further affecting the inspection results. Due to width limitations, existing vehicle chassis inspection equipment struggles to accommodate complete imaging requirements even after vehicle deviation. When the vehicle deviates from the centerline by ≥150mm (the industry standard allows for such deviation), the image loss rate reaches as high as 40%. Utility Model Content

[0006] To address the aforementioned problems, this invention proposes a vehicle chassis imaging device based on optical path folding. It employs an optical path folding unit with multiple reflectors, enabling the imaging device to extend the optical path within a given device volume. This solves the problem of image distortion, reduces the distortion rate, and improves image quality.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] One or more embodiments provide a vehicle chassis imaging device based on optical path folding, including an illumination device, a camera device, and an optical path folding unit;

[0009] The optical path folding unit includes multiple mirrors, with each pair of mirrors arranged opposite each other at a set angle. The length and direction of the optical path are changed by reflecting the light in sequence through the mirrors, so that the incident light path through the inlet of the optical path folding unit and the outgoing light path through the outlet meet the set angle.

[0010] The camera is positioned so that it is pointing towards the reflected light outlet of the optical path folding unit.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0012] In this embodiment, while maintaining the overall size of the device, the optical path for imaging is lengthened through an optical path folding unit, solving the distortion problem inherent in directly shooting upwards with a camera. This device effectively extends the optical path by incorporating an optical path folding unit. The unit contains multiple mirrors arranged at predetermined angles. Incident light is reflected by the first mirror, changing direction, and then reflected sequentially by multiple mirrors, thus folding and expanding the optical path in a compact manner, achieving the goal of lengthening the optical path within a limited space. The camera then captures the final image signal by pointing it towards the exit of the emitted light. This folded path optimizes the viewing angle during chassis imaging and avoids image distortion caused by wide-angle shooting, especially effectively suppressing proportional distortion in edge areas.

[0013] The imaging device in this embodiment optimizes the imaging angle by extending the optical path without significantly increasing the size. Especially when using a conventional focal length lens, the optical path folding structure achieves balanced image quality at the center and edges, thereby improving the accuracy and completeness of the chassis image. Furthermore, due to the extended optical path, the same camera can capture a larger area, which is less affected by vehicle deviation, resulting in stronger adaptability to vehicle trajectory deviations, reducing the probability of image loss, and improving the system's stability and fault tolerance.

[0014] The advantages and additional advantages of this utility model will be described in detail in the following specific embodiments. Attached Figure Description

[0015] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute a limitation thereof.

[0016] Figure 1 This is a schematic diagram of the imaging device according to Embodiment 1 of this utility model;

[0017] Figure 2 This is a schematic diagram of the first structure of the imaging device of Embodiment 1 of this utility model, which cascades two optical path folding units;

[0018] Figure 3 This is a schematic diagram of the second structure of the imaging device of Embodiment 1 of this utility model, which cascades two optical path folding units;

[0019] Figure 4 This is a schematic diagram of the imaging device according to Embodiment 2 of this utility model;

[0020] Figure 5 This is a first structural schematic diagram of the imaging device according to Embodiment 3 of this utility model;

[0021] Figure 6 This is a second structural schematic diagram of the imaging device according to Embodiment 3 of this utility model;

[0022] Figure 7 This is a schematic diagram of the imaging device of Embodiment 3 of this utility model, which cascades two rectangular reflective components;

[0023] Figure 8 This is a schematic diagram of the imaging device of Embodiment 3 of this utility model, which cascades two optical path folding units;

[0024] Figure 9 This is a schematic diagram of the imaging device according to Embodiment 3 of this utility model;

[0025] The components include: 1. Camera device; 2. Lighting device; 3. Optical path folding unit; 31. Housing; 41. Fixing base; 42. First reflector; 51. Fourth reflector; 52. Fifth reflector; 53. Sixth reflector; 61. Seventh reflector; 62. Eighth reflector assembly; 63. Ninth reflector assembly; 64. Tenth reflector; 71. Eleventh reflector; 72. Base; 73. Twelfth reflector; 74. Thirteenth reflector. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] It should be noted that the following detailed description is exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0028] It should be noted that the terminology used herein is for descriptive purposes only and is not intended to limit the exemplary embodiments according to this invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. It should be noted that, without conflict, the various embodiments and features within those embodiments can be combined with each other. The embodiments will now be described in detail with reference to the accompanying drawings.

[0029] Example 1

[0030] In one or more of the technical solutions disclosed in the implementation methods, such as Figures 1 to 3 As shown, a vehicle chassis imaging device based on optical path folding includes: an illumination device 2, a camera device 1, and an optical path folding unit 3.

[0031] Lighting device 2 is used to provide a light source to the vehicle chassis;

[0032] The optical path folding unit 3 includes multiple reflectors, with each pair of reflectors arranged opposite each other at a set angle. The length and direction of the optical path are changed by reflecting the light in sequence through the reflectors, so that the incident light path through the inlet of the optical path folding unit 3 and the outgoing light path through the outlet meet the set angle.

[0033] The camera device 1 is pointing towards the exit port of the last-stage optical path folding unit 3.

[0034] In this embodiment, while maintaining the overall size of the device, the optical path for imaging is lengthened through the optical path folding unit 3, solving the distortion problem inherent in directly shooting upwards with the camera. This device effectively extends the imaging optical path by incorporating the optical path folding unit 3. The optical path folding unit 3 contains multiple mirrors arranged at predetermined angles. Incident light changes direction after being reflected by the first mirror and is reflected sequentially by multiple mirrors, thus folding and expanding the optical path in a compact manner, achieving the goal of lengthening the optical path within a limited space. The camera then captures the final image signal by pointing it towards the exit of the emitted light. Through this folded path, the viewing angle during chassis imaging is optimized, while avoiding image distortion caused by wide-angle shooting, especially effectively suppressing proportional distortion in edge areas.

[0035] The imaging device in this embodiment optimizes the imaging angle by extending the optical path without significantly increasing the size. Especially when using a conventional focal length lens, the optical path folding structure achieves balanced image quality at the center and edges, thereby improving the accuracy and completeness of the chassis image. Furthermore, due to the extended optical path, the same camera can capture a larger area, which is less affected by vehicle deviation, resulting in stronger adaptability to vehicle trajectory deviations, reducing the probability of image loss, and improving the system's stability and fault tolerance.

[0036] Optionally, the camera device 1 is a standard lens camera.

[0037] When the existing imaging device has a short optical path and uses a wide-angle camera, if the driver is not driving in the center, the image under the vehicle will be distorted in the direction the vehicle chassis passes, and the displayed image will be completely different from the image when the driver is driving in the center. In this embodiment, by extending the optical path and using a non-wide-angle camera, the image captured by the under-vehicle camera will not be distorted regardless of whether the vehicle's driving trajectory is centered or not, and the image will be complete.

[0038] Furthermore, multiple optical path folding units 3 can be cascaded, with the reflected light inlets and outlets of adjacent optical path folding units 3 connected, and the reflected light outlet of the last optical path folding unit 3 facing the camera lens of the imaging device.

[0039] In this embodiment, the optical path folding unit 3 is a modular structure, which enables the optical path to be extended multiple times.

[0040] In this embodiment, the optical path can be lengthened to a smaller size by folding the optical path of the camera using a single optical path folding unit 3. In this case, the housing 31 can be omitted, and the reflector can be set at the corresponding angle directly, which is also within the protection scope of the solution in this embodiment. Alternatively, the optical path can be lengthened by cascading multiple optical path folding units 3.

[0041] Furthermore, in order to realize the step-by-step stacking of optical path folding units 3, the optical path folding unit 3 can also be provided with a housing 31. The reflector of the optical path folding unit 3 is set inside the housing 31, and an opening is set at a predetermined position on the housing 31 as the outlet N2 and the inlet N1.

[0042] In some embodiments, the adjacent optical path folding units 3 connected in multiple stages are connected to the inlet port N1 through the outlet port N2. This can be that the outlet port N2 of the upper-level optical path folding unit 3 is connected to the inlet port N1 of the lower-level optical path folding unit 3; or, the outlet port N2 of the upper-level optical path folding unit 3 is connected to the outlet port N2 of the lower-level optical path folding unit 3.

[0043] It should be noted that, since the reflected light path is reversible, the light path folding unit 3 reflects light through the set reflector. When the outlet is the light path inlet, the inlet becomes the light path outlet.

[0044] In some embodiments, the internal structure of each optical path folding unit 3 in each cascade may be different. Specifically, the number and angle of the reflectors inside the optical path folding unit 3 may be the same or different.

[0045] An achievable structure, such as Figures 1 to 3 As shown, the optical path folding unit 3 has an incident optical path through the inlet N1 and an outgoing optical path through the outlet N2 with a set angle of 90 degrees. The optical path folding unit 3 includes a first reflector 42, a second reflector, and a third reflector arranged in sequence opposite to each other. The angle between the three reflectors and the horizontal plane is 45 degrees. The first reflector 42 and the second reflector are arranged with their mirror surfaces facing upwards and at the same height. The third reflector is arranged with its mirror surface facing downwards and directly above the second reflector.

[0046] The fixture 41 is also available. The fixture 41 is U-shaped and has two opposite and perpendicular inclined surfaces on its concave side. The two inclined surfaces are used to set the second reflector and the third reflector, respectively.

[0047] It should be noted that the relative arrangement of reflectors refers to the mirrors being arranged opposite each other. In this embodiment, light reflected by one reflector is reflected again by the other. The angles between the reflectors and the horizontal plane in this embodiment refer to acute angles, and this applies to subsequent embodiments as well. For example, if all three reflectors are at 45 degrees to the horizontal plane, with two reflectors facing upwards and the third facing downwards, and the third reflector is opposite to the second reflector, the third reflector should be positioned with its top facing downwards, and the second reflector should be positioned with its bottom facing upwards, to satisfy the requirement of relative arrangement between the second and third reflectors. However, the angles are all acute angles between the reflectors and the horizontal plane.

[0048] In this embodiment, multiple Figure 1 When the optical path folding unit 3 is cascaded, it can be as follows: Figure 2 As shown, the outlet N2 of the upper-level optical path folding unit 3 is connected to the inlet N1 of the lower-level optical path folding unit 3, or as shown in the diagram. Figure 3 As shown, the outlet N2 of the upper-level optical path folding unit 3 is connected to the outlet N2 of the lower-level optical path folding unit 3. Figure 2 and Figure 3In order to clearly illustrate, the cascaded optical path folding units 3 are spaced a certain distance apart in the figure. Two optical path folding units 3 can be directly aligned and fitted at the opening. The housings 31 of the optical path folding units 3 can be directly fixedly connected, such as by plugging in.

[0049] When in use, the vehicle chassis is illuminated by the lighting device 2, and the reflected light enters the optical path folding unit 3 through the chassis. After being reflected by the optical path folding unit 3, it enters the camera device 1 to achieve imaging.

[0050] Optionally, the camera device 1 can be a camera, and the lighting device 2 can be an LED light;

[0051] Specifically, the position of the lighting device 2 can be adjusted by setting a support frame so that the lighting device is closer to the vehicle chassis to achieve better lighting effect.

[0052] The optical path folding unit 3 provided in this embodiment constructs a U-shaped folded optical path structure by using three sets of mirrors with an incident angle of 45°. The arrows in each figure indicate the direction of light propagation, and the straight lines with arrows represent the propagation optical path. While increasing the total length of the optical path, it successfully achieves high integration and spatial compression of the optical path. Compared to the larger optical cavity volume required by traditional symmetrical layouts, this structure effectively compresses the optical path transmission space through the asymmetrical arrangement of the mirrors, reducing the overall cavity volume. For example, with a designed camera optical path length of 3.2 meters, the volume is reduced to 0.24 m. 3 The volume is reduced by about 50%, which greatly reduces the equipment's footprint and installation space.

[0053] Example 2

[0054] This embodiment provides an implementation structure of the optical path folding unit 3. Compared with embodiment 1, the structure of the optical path folding unit 3 provided in this embodiment is different from that in embodiment 1, but the rest of the structure is exactly the same.

[0055] like Figure 4 As shown, the optical path folding unit 3 has an incident light path through the inlet N1 and an outgoing light path through the outlet N2 with a set angle of 90 degrees. The optical path folding unit 3 includes a fifth reflector 52, a fourth reflector 51, and a sixth reflector 53 arranged in sequence opposite to each other. The fifth reflector 52 has its mirror surface facing upward and has an angle of 45 degrees with the horizontal plane. The fifth reflector 52 is used to reflect vertically downward incident light. The fourth reflector 51 is arranged opposite to the fifth reflector 52 and at the same height. The fourth reflector 51 and the sixth reflector 53 are arranged opposite to each other and have the same angle, so that the light path reflected by the fourth reflector 51 is emitted in the horizontal direction after being emitted by the sixth reflector 53.

[0056] Optionally, the angle α between the fourth reflecting mirror 51 and the horizontal plane is greater than 80 degrees and less than 90 degrees;

[0057] In this embodiment, the optical path folding unit 3 can also be provided with a housing 31. When performing multi-level stacking, the stacking method is the same as that in embodiment 2, and will not be described again in this embodiment.

[0058] The optical path folding unit 3 in this embodiment has a longer optical path than the optical path folding unit 3 in embodiment 1. It approximately adjusts one optical path in the optical path folding unit 3 in embodiment 1 from the side of the quadrilateral to the diagonal, which can further improve the folding efficiency of the optical path and obtain a longer optical path under the same housing volume.

[0059] In use, the light reflected from the chassis travels vertically downward to the fifth reflector 52, which then reflects the light horizontally to the fourth reflector 51. The fourth reflector 51 reflects the light to the sixth reflector 53, which is parallel to it. Thus, the reflected light is emitted in parallel and enters the camera lens to form an image. The light emitted from the outlet N2 is horizontal, which also improves the stability of the camera device 1.

[0060] Example 3

[0061] This embodiment provides an implementation structure of the optical path folding unit 3. Compared with embodiment 1, the structure of the optical path folding unit 3 provided in this embodiment is different from that in embodiment 1, but the rest of the structure is exactly the same.

[0062] like Figures 5 to 8 As shown, the optical path folding unit 3 includes a seventh reflector 61, a rectangular reflection path assembly, and a tenth reflector 64 arranged sequentially; the rectangular reflection assembly includes an eighth reflector assembly 62 and a ninth reflector assembly 63 arranged opposite to each other;

[0063] The mirrors of the seventh mirror 61 and the tenth mirror 64 face upwards and are at an angle of 45 degrees to the ground, with the mirrors of the two mirrors facing each other.

[0064] Both the eighth reflector assembly 62 and the ninth reflector assembly 63 include a bracket and two reflectors. The bracket includes two inclined surfaces, which are fixedly connected and have an included angle of 90 degrees. The two reflectors of the eighth reflector assembly 62 are respectively disposed on the inner side of the two inclined surfaces. The two reflectors of the ninth reflector assembly 63 are respectively disposed on the outer side of the two inclined surfaces. The eighth reflector assembly 62 and the ninth reflector assembly 63 are arranged vertically relative to each other at a set interval, so that the mirror surfaces of the reflectors are opposite each other and parallel.

[0065] like Figure 5 As shown in the schematic diagram without housing 31, this optical path structure can be formed using a corresponding reflector fixing device. Figure 5In this context, where space permits, the distance between the eighth reflector assembly 62 and the ninth reflector assembly 63 can be longer, resulting in a longer optical path. For example, the ninth reflector assembly 63 can be positioned higher.

[0066] In the above embodiments, a rectangular wave-shaped optical path is constructed using six sets of fixed-angle reflectors (45°±0.2°), which can increase the optical path length within a limited space. For example, a device with a length of L and a height of L can be installed on the ground. Figure 5 The structure can achieve an optical path length of at least 4L; for Figure 5 The actual imaging device was fabricated based on the structure, and the vertical projection overlap rate of adjacent mirror groups was tested to be ≥70%, and the edge distortion rate was ≤0.35%, which effectively reduced the distortion rate and improved the imaging effect.

[0067] In a further technical solution, in the optical path folding unit 3, the rectangular reflective components between the seventh reflector 61 and the tenth reflector 64 can be configured as multiple components connected sequentially to form an optical path with a shape resembling a rectangular wave, such as... Figure 7 As shown, taking the setting of two rectangular reflective components as an example, setting the structure of two rectangular reflective components increases the optical path by nearly the side length of a rectangle, making the optical path longer.

[0068] Optionally, in this embodiment, the optical path folding unit 3 can be provided with a housing 31, and multiple optical path folding units 3 can be stacked and cascaded, with the structure as follows: Figure 8 As shown, since the optical path folding unit 3 in this embodiment is symmetrical, the cascaded structures are identical. Each optical path folding unit 3 can be placed obliquely in the horizontal plane, and the optical path folding units 3 are not arranged side by side in a straight line to improve space utilization.

[0069] Example 4

[0070] This embodiment provides an implementation structure of the optical path folding unit 3. Compared with embodiment 1, the structure of the optical path folding unit 3 provided in this embodiment is different from that in embodiment 1, but the rest of the structure is exactly the same.

[0071] The optical path folding unit 3 in this embodiment is a variation of the structure in embodiment 1. When a single optical path folding unit 3 is used, the imaging device 1 and the illumination device 2 can be arranged on the same vertical plane. This structure makes the structure of the imaging device more compact, thereby further reducing the volume of the entire imaging device.

[0072] like Figure 9As shown, the optical path folding unit 3 includes an eleventh reflector 71, a twelfth reflector 73, and a thirteenth reflector 74 arranged sequentially. The twelfth reflector 73 and the thirteenth reflector 74 face upward and are arranged symmetrically opposite each other in the vertical direction. The included angle γ between the twelfth reflector 73 and the thirteenth reflector 74 is greater than 150 degrees and less than 180 degrees. The twelfth reflector 73 is used to receive incident light. The mirror surfaces of the eleventh reflector 71 and the twelfth reflector 73 are parallel and opposite each other. The light reflected by the twelfth reflector 73 is reflected vertically downward by the eleventh reflector 71 to the thirteenth reflector 74, and the thirteenth reflector 74 reflects the light to the camera lens area.

[0073] Optionally, the twelfth reflector 73 and the thirteenth reflector 74 can be set on the same base 72.

[0074] Preferably, the angle β between the eleventh reflector 71 and the horizontal plane is greater than 0 degrees and less than 30 degrees; since the three reflecting mirrors in this embodiment are arranged in parallel or axially symmetrically, they have the same angle with the horizontal plane.

[0075] The final outlet of the optical path folding unit 3 in this embodiment is tilted, and multiple optical path folding units 3 in this embodiment can also be cascaded.

[0076] The optical path folding units 3 in the above embodiments can all be cascaded as a module unit. The hybrid cascading of the optical path folding units 3 in the various embodiments, that is, the cascaded optical path folding units 3, can have different structures, or they can be cascaded using optical path folding units 3 with the same internal structure.

[0077] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

[0078] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the scope of protection of the present utility model.

Claims

1. A vehicle chassis imaging device based on optical path folding, characterized in that: Includes lighting devices, camera devices, and optical path folding units; The optical path folding unit includes multiple mirrors, with each pair of mirrors arranged opposite each other at a set angle. The length and direction of the optical path are changed by reflecting the light in sequence through the mirrors, so that the incident light path through the inlet of the optical path folding unit and the outgoing light path through the outlet meet the set angle. The camera is positioned so that it is pointing towards the reflected light outlet of the optical path folding unit.

2. The vehicle chassis imaging device based on optical path folding as described in claim 1, characterized in that: Multi-stage optical path folding units are cascaded, with the reflected light inlets and outlets of adjacent optical path folding units connected, and the reflected light outlet of the last stage optical path folding unit facing the camera lens of the imaging device.

3. The vehicle chassis imaging device based on optical path folding as described in claim 1, characterized in that: The optical path folding unit is also equipped with a housing, and the reflector of the optical path folding unit is set inside the housing. An opening is set at a predetermined position on the housing, which serves as the outlet N2 and the inlet N1 of the optical path folding unit.

4. The vehicle chassis imaging device based on optical path folding as described in claim 3, characterized in that: The adjacent optical path folding units in the multi-level connection are connected to the inlet port N1 through the outlet port N2. The outlet port N2 of the upper-level optical path folding unit is connected to the inlet port N1 of the lower-level optical path folding unit; or, the outlet port N2 of the upper-level optical path folding unit is connected to the outlet port N2 of the lower-level optical path folding unit.

5. The vehicle chassis imaging device based on optical path folding as described in claim 1, characterized in that: The optical path folding unit includes a first reflector, a second reflector, and a third reflector arranged in sequence and opposite to each other. The angle between each of the three reflectors and the horizontal plane is 45 degrees. The first and second reflectors face upward and are arranged at the same height. The third reflector faces downward and is located directly above the second reflector.

6. The vehicle chassis imaging device based on optical path folding as described in claim 5, characterized in that: The optical path folding unit also includes a mounting base, which is U-shaped. The recessed side of the mounting base is set with two opposing and perpendicular inclined surfaces, which are used to set the second reflector and the third reflector, respectively.

7. The vehicle chassis imaging device based on optical path folding as described in claim 1, characterized in that: The optical path folding unit includes a fifth mirror, a fourth mirror, and a sixth mirror arranged in sequence and opposite to each other. The fifth mirror faces upward and is at a 45-degree angle to the horizontal plane. The fifth mirror is used to reflect vertically downward incident light. The fourth mirror faces the fifth mirror and is set at the same height. The fourth mirror and the sixth mirror are arranged opposite each other and at the same angle so that the light reflected by the fourth mirror is emitted in a horizontal direction after being emitted by the sixth mirror.

8. The vehicle chassis imaging device based on optical path folding as described in claim 1, characterized in that: The optical path folding unit includes a seventh reflector, a rectangular reflection path assembly, and a tenth reflector arranged sequentially; the rectangular reflection assembly includes an eighth reflector assembly and a ninth reflector assembly arranged opposite to each other; The mirrors of the seventh and tenth reflectors face upwards at an angle of 45 degrees to the ground, and the mirrors of the two reflectors are positioned opposite each other. Both the eighth and ninth reflector assemblies include a bracket and two reflectors. The bracket includes two inclined surfaces, which are fixedly connected and have an included angle of 90 degrees. The two reflectors of the eighth reflector assembly are respectively located inside the two inclined surfaces. The two reflectors of the ninth reflector assembly are respectively located outside the two inclined surfaces. The eighth and ninth reflector assemblies are arranged vertically relative to each other at a set interval, so that the mirror surfaces of the reflectors are opposite each other and parallel.

9. The vehicle chassis imaging device based on optical path folding as described in claim 8, characterized in that: The rectangular reflective components between the seventh and tenth reflectors are arranged in a series of interconnected components to form a light path with a shape similar to a rectangular wave.

10. The vehicle chassis imaging device based on optical path folding as described in claim 1, characterized in that: The optical path folding unit includes an eleventh mirror, a twelfth mirror, and a thirteenth mirror arranged sequentially. The twelfth and thirteenth mirrors face upwards and are arranged symmetrically opposite each other in the vertical direction. The angle between the twelfth and thirteenth mirrors is greater than 150 degrees and less than 180 degrees. The twelfth mirror is used to receive incident light. The mirror surfaces of the eleventh and twelfth mirrors are parallel and opposite each other. The light reflected by the twelfth mirror is reflected vertically downwards by the eleventh mirror and then reflected by the thirteenth mirror to the camera lens area.

Images