System for contamination removal from optical systems of under vehicle carriage monitoring systems

Abstract

An optical system decontamination system is proposed that prevents contamination of the optical system by contaminants by injecting high-pressure compressed air into the optical system of a vehicle underbody monitoring system from the point of vehicle entry to the point of vehicle exit. The proposed optical system decontamination system prevents contamination of the optical system of the vehicle underbody monitoring system by synchronizing the vehicle's entry and exit with rainfall conditions within the vehicle underbody detection area and injecting high-pressure air into optical systems such as reflectors and transparent plates.

Description

Technology Field

[0001] The present invention relates to a vehicle undercarriage monitoring system, and more specifically, to a vehicle undercarriage monitoring system installed at an entrance or exit of a specific area or a place where vehicle access control is required to search the undercarriage of a vehicle. Background Technology

[0002] A security zone refers to a building or specific area where access by outsiders other than authorized personnel is restricted, or where the leakage of information is limited. Examples of security zones include airports, power plants, research facilities, and national intelligence facilities.

[0003] High protective walls are installed around the security area to prevent unauthorized entry and the unauthorized leakage of confidential information or items. In this case, the security area is equipped with limited entrances, and access is controlled so that it can only be entered through these designated points.

[0004] An administrator is stationed at the entrance to control and manage access for persons and vehicles entering the secure area through prescribed procedures. Access for persons entering the secure area is controlled and managed through identity checks, X-rays, metal detectors, etc.

[0005] In particular, to control the concealment and transport of unauthorized items, hazardous materials, etc. via vehicles, managers inspect the occupants, trunk, and interior of vehicles entering and exiting the security area. However, since the underside of the vehicle is not easily inspected directly, items or explosives are frequently concealed. Therefore, managers directly search the underside of the vehicle using auxiliary tools such as a reflector (or underbody mirror) or a cart equipped with a camera.

[0006] However, search methods utilizing auxiliary tools such as reflectors require a significant amount of time to inspect the entire underside of the vehicle body, and there is a problem in that an effective search cannot be conducted if the manager performing the inspection has low proficiency.

[0007] In addition, the search method using a cart equipped with a camera films the underside of the vehicle as it passes by moving the cart along the rail at a constant speed while the vehicle is stopped on the rail.

[0008] However, the search method using a cart has several drawbacks: first, it takes a significant amount of time for the vehicle to stop and slide the cart equipped with a camera under the vehicle; and second, the short distance between the camera and the underside of the vehicle causes severe image distortion at the edges of the vehicle.

[0009] As a result, the reliability of vehicle inspections in controlling and managing access to security areas is reduced, which may become a problem for security management.

[0010] Recently, to improve the efficiency of vehicle inspection and search, vehicle undercarriage monitoring systems have been installed at the entrances of security areas to inspect vehicles, and reliability is improving dramatically compared to security management by administrators.

[0011] The vehicle undercarriage monitoring system installs cameras embedded underground and acquires images of the vehicle's undercarriage by photographing the undersides of vehicles moving on the ground. In other words, since vehicles of various sizes enter and exit the security area, the system acquires images of the undercarriages of vehicles of various sizes using line scan cameras.

[0012] However, conventional vehicle undercarriage monitoring systems have a problem in that they cannot acquire clear images of the vehicle's undercarriage due to the ingress of dust, rainwater, etc., through the image slit, as an image slit is formed to expose the line scan camera in order to secure the line scan camera's field of view.

[0013] In particular, considering that according to the Korea Meteorological Administration's 30-year average record, the annual average number of rainy days with rainfall of 1 mm or more is 90 days (i.e., 1 / 4 of the year), there is a need for a vehicle undercarriage monitoring system that is not affected by rain.

[0014] Recently, systems that acquire images of the vehicle's underside using multiple aerial cameras (a general term for 2D cameras) have also been released. Since line scanners and aerial cameras ultimately have a structure that illuminates the underside of the vehicle and obtains images using the reflected light, conventional vehicle underside monitoring systems have an optical system between the camera (i.e., image sensor) and the vehicle's underside. At this time, conventional vehicle underside monitoring systems use transparent glass to protect the camera so that foreign substances do not come into direct contact with the camera lens in the path of light rays passing through the optical system, and also use an externally exposed mirror to facilitate the installation of this optical system or to reduce the size of the product.

[0015] However, because conventional vehicle undercarriage monitoring systems require the installation location and the light path for scanning to be exposed upward, they cannot avoid contamination by road dust or oil stains, and especially by rainwater during rainy weather.

[0016] A structure in which a light path connecting a mirror or camera to an image slit is formed obliquely can avoid rainwater falling vertically, but it has the problem that it is difficult to fundamentally prevent the transparent plate of the camera housing (i.e., lens protective glass) from being contaminated by splashing mud when a vehicle's wheel passes through the image slit, which is a narrow, long hole exposed for the light path.

[0017] To solve this problem, a system was also studied that mechanically wipes the transparent plate using a cleaning cloth immediately before scanning the vehicle's underside. However, since contamination by rainwater continues until the scan is finished (i.e., until the vehicle completely passes over the scanner), there is a problem in that one-time contamination removal by a cleaning cloth that acts like a vehicle's wiper cannot prevent contamination of the transparent window. Prior art literature

[0018] Korean Published Patent No. 10-2017-0019596 (Title: Vehicle Underbody Inspection Device and Method) The problem to be solved

[0019] The present invention is proposed to solve the aforementioned conventional problems and aims to provide an optical system contamination removal system that prevents contamination of the optical system by contaminants by spraying high-pressure compressed air into the optical system of a vehicle underbody scanner from the point of entry to the point of exit. In other words, the present invention aims to remove contamination by spraying high-pressure compressed air when transparent plates, reflectors, etc., located in the light path of a vehicle underbody surveillance system for photographing the vehicle underbody are contaminated by dust or rainwater. means of solving the problem

[0020] To achieve the above-mentioned objective, an optical system contamination removal system according to an embodiment of the present invention comprises: a vehicle underbody monitoring system that photographs the underbody of a vehicle located within a detection area; an entry detection sensor positioned in front of the vehicle underbody monitoring system that generates an entry detection signal and outputs an entry detection signal when it detects a vehicle entering the detection area; an exit detection sensor positioned behind the vehicle underbody monitoring system that generates an exit detection signal and outputs an exit detection signal when it detects a vehicle exiting the detection area; a controller connected to the entry detection sensor and the exit detection sensor that outputs an injection start signal in response to the entry detection signal output of the entry detection sensor and generates and outputs an injection stop signal in response to the exit detection signal output of the exit detection sensor; and a high-pressure injector connected to the controller that initiates high-pressure air injection into the optical system of the vehicle underbody monitoring system in response to the injection start signal output of the controller and stops the high-pressure air injection in response to the injection stop signal output of the controller.

[0021] To achieve the above objective, an optical system contamination removal system according to an embodiment of the present invention comprises a camera housing in which a reflector and a camera are built-in and a transparent plate is disposed to form a light path for photographing the reflector and the camera and the underside of a vehicle, an air pipe disposed outside the camera housing, and an air nozzle connected to the air pipe and spraying high-pressure air supplied through the air pipe onto the transparent plate. Effects of the invention

[0022] According to the present invention, the optical system decontamination system of a vehicle undercarriage monitoring system using high-pressure compressed air has the effect of preventing contamination of the optical system of the vehicle undercarriage monitoring system until the vehicle undercarriage scanning (photography) is completed by spraying high-pressure compressed air into the optical system of the vehicle undercarriage scanner from the time of entry to the time of exit.

[0023] In addition, the optical system decontamination system of the vehicle undercarriage monitoring system using high-pressure compressed air prevents optical system contamination until the vehicle undercarriage scan (photography) is completed, thereby having the effect of preventing a decrease in search accuracy caused by vehicle undercarriage images that capture contaminants.

[0024] In addition, the optical system decontamination system of the vehicle undercarriage monitoring system using high-pressure compressed air prevents optical system contamination until the vehicle undercarriage scan (photography) is completed, thereby improving search accuracy and enhancing the reliability of the vehicle undercarriage monitoring system.

[0025] In addition, the optical decontamination system of the vehicle undercarriage monitoring system using high-pressure compressed air operates the high-pressure injector by synchronizing the vehicle's entry and exit with rainfall conditions, thereby minimizing the load on the compressor supplying compressed air. This allows for the minimization of system construction costs and the reduction of maintenance costs by extending the maintenance cycle. Brief explanation of the drawing

[0026] FIGS. 1 to 3 are drawings for explaining a vehicle undercarriage monitoring system to which an optical system contamination removal system according to an embodiment of the present invention is applied. FIGS. 4 to 11 are drawings illustrating modified examples of a vehicle undercarriage monitoring system to which an optical system contamination removal system according to an embodiment of the present invention is applied. FIGS. 12 and 13 are drawings for illustrating an optical system contamination removal system according to an embodiment of the present invention. FIGS. 14 to 21 are drawings for explaining the high-pressure injector of FIG. 12. FIG. 22 is a drawing illustrating a modified example of an optical system contamination removal system according to an embodiment of the present invention. Specific details for implementing the invention

[0027] Hereinafter, in order to provide a detailed explanation sufficient for a person skilled in the art to easily implement the technical concept of the present invention, the most preferred embodiment of the present invention will be described with reference to the accompanying drawings. First, it should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the present invention, if it is determined that a detailed description of related known components or functions may obscure the essence of the present invention, such detailed description is omitted.

[0028] Referring to FIGS. 1 to 3, a vehicle undercarriage monitoring system (100) to which an optical system contamination removal system according to an embodiment of the present invention is applied comprises an outer housing (110), a camera housing (120), a transparent plate (130), a reflector (140), and a line scan camera (150).

[0029] The outer housing (110) is a housing that accommodates equipment for photographing the underside of the vehicle. The outer housing (110) is placed in a space formed by excavating the road through which the vehicle passes. That is, the outer housing (110) is installed by being buried in the road through which the vehicle passes.

[0030] The outer housing (110) has a first receiving space (Z1) formed therein for accommodating the camera housing (120). The first receiving space (Z1) is formed inside the outer housing (110). For example, the outer housing (110) is formed as a cuboid having a rectangular top surface, a bottom surface, and four sides. Accordingly, the first receiving space (Z1) can be formed in a cuboid shape enclosed by the top surface, bottom surface, and multiple sides of the outer housing (110).

[0031] The image slit (S) connects the first receiving space (Z1) of the outer housing (110) to the outer space. That is, the image slit (S) connects the first receiving space (Z1) to the outer space, allowing a line scan camera (150) placed inside the outer housing (110) to photograph the lower area of ​​the vehicle placed in the outer space.

[0032] An image slit (S) is formed in the outer housing (110). The image slit (S) is formed on the upper surface of the outer housing (110). The image slit (S) is formed by removing a portion of the upper surface of the outer housing (110). At this time, the image slit (S) is positioned offset toward the first end of the outer housing (110). Here, the first end of the outer housing (110) is one of the four sides of the outer housing (110), and is exemplified as the side positioned in the direction in which the vehicle exits the outer housing (110).

[0033] The image slit (S) may have a first side (S1) positioned near the first end of the outer housing (110), a second side (S2) facing the first side (S1), a third side (S3) connecting one end of the first side (S1) and one end of the second side (S2), and a fourth side (S4) connecting the other end of the first side (S1) and the other end of the second side (S2). At this time, the second side (S2) is positioned facing the first end of the outer housing (110) with the first side (S1) as the center. In other words, they are arranged in the order of the first end of the outer housing (110), the first side (S1) of the image slit (S), and the second side (S2) of the image slit (S). Here, as an example, the first side (S1) and the second side (S2) of the image slit (S) are parallel to the first side (S1) of the upper surface of the outer housing (110) that is in contact with the first end of the outer housing (110).

[0034] The camera housing (120) is a housing that accommodates equipment for photographing the underside of a vehicle. The camera housing (120) is positioned inside the outer housing (110). That is, the camera housing (120) is positioned within a first receiving space (Z1) formed inside the outer housing (110). The camera housing (120) is positioned so as to be offset in the direction of a second end opposite to a first end of the outer housing (110). The first end of the camera housing (120) is positioned adjacent to the first end of the outer housing (110), and the second end of the camera housing (120) is positioned adjacent to the second end of the outer housing (110). Here, as an example, the second end of the camera housing (120) is a side positioned opposite to the side of the first end of the camera housing (120), and the second end of the outer housing (110) is a side positioned opposite to the side of the first end of the outer housing (110).

[0035] The camera housing (120) is positioned inside the outer housing (110) parallel to the outer housing (110). That is, the camera housing (120) is positioned so that its upper surface is parallel to the upper surface of the outer housing (110).

[0036] A camera housing (120) has a second receiving space (Z2) formed inside, in which a reflector (140) and a line scan camera (150) are received. The second receiving space (Z2) is formed inside the camera housing (120). For example, the camera housing (120) is formed as a cuboid having a rectangular top surface, a bottom surface, and four sides. Accordingly, the second receiving space (Z2) can be formed in a cuboid shape enclosed by the top surface, bottom surface, and multiple sides of the camera housing (120).

[0037] The camera housing (120) is positioned so as not to overlap with the image slit (S). That is, the first end of the camera housing (120) may be positioned on a vertical line perpendicular to the upper surface of the outer housing (110) while passing through the second side (S2) of the image slit (S). In other words, the first end of the camera housing (120) may be positioned on a vertical plane perpendicular to the second side (S2) of the image slit (S) formed in the outer housing (110). Here, the first end of the camera housing (120) is exemplified as being the side closest to the first end of the outer housing (110) among the sides of the camera housing (120).

[0038] In this way, the camera housing (120) is positioned so as not to overlap with the image slit (S). That is, the camera housing (120) is positioned so as not to overlap with the space between the first side (S1) and the second side (S2) of the image slit (S).

[0039] The transparent plate (130) acts as a filter to block the ingress of foreign substances such as dust and rainwater, while enabling the reflection (140) and line scan camera (150) placed inside the camera housing (120) to photograph the underside of the vehicle located outside the outer housing (110). To this end, the transparent plate (130) is composed of a transparent plate-like material such as glass or transparent resin.

[0040] A transparent plate (130) is placed on the upper surface of a camera housing (120). The transparent plate (130) is placed in a slit formed by removing a portion of the upper surface of the camera housing (120). That is, a portion of the entire upper surface area of ​​the camera housing (120) in the direction of the first end is removed to form a slit. The transparent plate (130) is placed in the slit formed on the upper surface of the camera housing (120). At this time, the transparent plate (130) may be placed on the upper part of the reflector (140) and overlap with the reflector (140).

[0041] The reflector (140) is placed inside the camera housing (120). The reflector (140) is placed within the second receiving space (Z2) of the camera housing (120). The reflector (140) is placed within the second receiving space (Z2) of the camera housing (120) so as to be offset toward the first end of the camera housing (120). At this time, the reflector (140) is placed to form an angle (θ) of approximately 45° or less with respect to the lens centerline of the line scan camera (150).

[0042] The reflector (140) reflects the vehicle underside other than the vehicle underside perpendicular to the image slit (S) to the line scan camera (150). That is, the reflector (140) reflects the vehicle underside that is not located directly above the image slit (S) to the line scan camera (150). In other words, the reflector (140) reflects the vehicle underside located in front of or behind the vehicle underside perpendicular to the image slit (S) to the line scan camera (150).

[0043] The line scan camera (150) is placed inside the camera housing (120). The line scan camera (150) is placed within the second receiving space (Z2) of the camera housing (120). The line scan camera (150) is placed within the second receiving space (Z2) of the camera housing (120) so as to be spaced apart from the reflector (140).

[0044] The line scan camera (150) captures the vehicle underside reflected by the mirror (140) to generate an image of the vehicle underside. The line scan camera (150) can capture the vehicle underside that is not perpendicular to the image slit (S). That is, the line scan camera (150) captures the vehicle underside that is not located directly above the image slit (S). In other words, the line scan camera (150) captures the vehicle underside reflected by the mirror (140), but captures the vehicle underside located in front of or behind the vehicle underside that is perpendicular to the image slit (S) to generate an image of the vehicle underside.

[0045] Meanwhile, referring to FIG. 4, the vehicle undercarriage monitoring system (100) according to an embodiment of the present invention installs the reflector (140) at 45° and the camera housing (120) at an oblique angle in order to compensate for the disadvantages of both the exposed reflector camera method and the non-reflector embedded camera method while reducing the size of the product. By installing the camera housing (120) at an oblique angle, even if rainwater falls on the camera housing (120), the rainwater flows down, thereby preventing deterioration of image quality caused by rainwater.

[0046] To this end, the angle (θ) between the reflector (140) and the lens centerline of the line scan camera (150) is 45°, and the camera housing (120) can be positioned to have a predetermined inclination. That is, the camera housing (120) is positioned so as not to be parallel to the outer housing (110). The first end of the camera housing (120) is positioned closer to the lower surface (bottom surface) of the outer housing (110) than the second end of the camera housing (120). The first end of the camera housing (120) is positioned further from the upper surface of the outer housing (110) than the second end of the camera housing (120).

[0047] Meanwhile, as illustrated in FIGS. 1 and FIGS. 4 above, when a camera housing (120) is manufactured and a specific viewing angle is desired, the distance along the light path from the center of the camera lens to the camera housing (120) becomes a factor in determining the minimum width of the reflector (140). That is, the distance along this light path determines the size of the camera housing (120).

[0048] For example, referring to FIG. 5, it is assumed that a system is designed to scan a width of 2500 mm and a distance of 300 mm from the center of the lens to the bottom of the vehicle. The line scan camera (150) is designed so that the reflection angle of the reflector (140) is 45° of the centerline to scan the right-angle upward direction of the outer housing (110), and the height of the reflector (140) is narrowed so that the distance from the center of the lens to the edge of the lens to the reflector (140) is 10 mm.

[0049] Additionally, in the case of a fisheye lens or an ultra-wide-angle lens, the distance from the center of the camera lens to the edge of the camera lens is at least 10mm to 15mm, and assuming this is 15mm, the distance from the lens center axis to the transparent plate (130) of the camera housing (120) is assumed to be 40mm. In this case, when calculating the distance along the light path from the center of the camera lens to the transparent plate (130) of the camera housing (120), it is approximately 65mm.

[0050] Assuming these dimensions, as shown in FIG. 6, the field of view can be illustrated when the vehicle undercarriage monitoring system (100) scans 2500mm away from the center of the lens at a distance of 300mm. In this case, the minimum width of the reflector (140) required is approximately 54.166mm. That is, if designed simply in this way, it can be seen that the internal width of the camera housing (120) must be significantly longer.

[0051] In order to minimize the size of the camera housing (120), the vehicle undercarriage monitoring system (100) according to an embodiment of the present invention sets the distance from the center of the camera lens to the transparent plate (130) through which the light path exits the camera housing (120) to the shortest distance.

[0052] A vehicle undercarriage monitoring system (100) according to an embodiment of the present invention minimizes the width of the reflector (140) in the direction of light propagation and simultaneously minimizes the light path inside the camera housing (120) by bringing the transparent plate (130) of the camera housing (120) into close contact with the reflector (140).

[0053] Referring to FIGS. 7 to 9, the camera housing (120) has a stepped surface (122) on which a transparent plate (130) is placed.

[0054] A step is formed in the camera housing (120). A portion of the first end of the camera housing (120) is removed so that a stepped surface (122) having a height difference with respect to the upper surface of the camera housing (120) is formed.

[0055] The stepped surface (122) is positioned closer to the center of the camera lens than to the upper surface of the camera housing (120). That is, the stepped surface (122) is positioned at a height between the center of the camera lens of the line scan camera (150) and the upper surface of the camera housing (120). The distance between the stepped surface (122) and the lower surface of the camera housing (120) is formed to be shorter than the distance between the upper surface and the lower surface of the camera housing (120). Here, the camera centerline is an imaginary line extended from the center of the camera lens of the line scan camera (150).

[0056] Accordingly, the distance between the upper surface of the camera housing (120) and the stepped surface (122) is formed to be shorter than the distance between the upper surface of the camera housing (120) and the camera centerline, and the stepped surface (122) is positioned closer to the camera centerline than the upper surface of the camera housing (120). At this time, the stepped surface (122) may be positioned parallel to the upper surface of the outer housing (110) or the upper surface of the camera housing (120).

[0057] The transparent plate (130) is placed in a slit formed by removing a portion of the stepped surface (122). As the transparent plate (130) is inserted into the slit formed in the stepped surface (122), it is positioned closer to the camera centerline than the upper surface of the camera housing (120), just like the stepped surface (122). That is, the transparent plate (130) is positioned at a height between the camera centerline of the line scan camera (150) and the upper surface of the camera housing (120). The distance between the transparent plate (130) and the lower surface of the camera housing (120) is formed to be shorter than the distance between the upper surface and the lower surface of the camera housing (120).

[0058] The distance between the upper surface of the camera housing (120) and the transparent plate (130) is formed to be shorter than the distance between the upper surface of the camera housing (120) and the camera centerline, and the transparent plate (130) is positioned closer to the camera centerline than to the upper surface of the camera housing (120). At this time, the transparent plate (130) may be positioned parallel to the upper surface of the outer housing (110) or the upper surface of the camera housing (120).

[0059] In this way, as the transparent plate (130) is formed on the stepped surface (122) of the camera housing (120), the shortest distance from the transparent plate (130) to the center of the reflector (140) can be formed to be shorter than the shortest distance from the line scan camera (150) to the center of the reflector (140).

[0060] At this time, as the reflector (140) is positioned at an angle of approximately 45°, the angle between the reflector (140) and the transparent plate (130) is approximately 45°. The reflector (140) is positioned as close as possible to the camera lens.

[0061] Accordingly, the light path distance inside the camera housing (120) is approximately 30 mm, and the minimum width of the camera housing (120) is 3 / 30 × 250 = 250 mm, so the width of the camera housing (120) can be significantly reduced compared to a camera housing (120) in which no step is formed.

[0062] Meanwhile, referring to FIG. 10, the stepped surface (122) may be formed to have a predetermined slope. That is, the angle between the stepped surface (122) and the upper surface of the camera housing (120) is formed as an acute angle. Accordingly, the stepped surface (122) is not parallel to the upper surface of the camera housing (120) and is formed to have a slope that approaches the lower surface of the camera housing (120) as it goes toward the first end.

[0063] At this time, as the transparent plate (130) is positioned on the stepped surface (122) of the camera housing (120), it is positioned to have a predetermined slope. That is, the angle between the transparent plate (130) and the upper surface of the camera housing (120) is formed as an acute angle. Accordingly, the transparent plate (130) is positioned to have a slope that approaches the lower surface of the camera housing (120) as it moves toward the first end of the camera housing (120).

[0064] Referring to FIG. 11, an inclined surface (124) may be formed in the first end direction of the camera housing (120). The inclined surface (124) has a slope that becomes closer to the lower surface of the camera housing (120) as it moves toward the first end direction of the camera housing (120).

[0065] The inclined surface (124) may be composed of a transparent plate (130). That is, a transparent plate (130) is placed diagonally at the first end of the camera housing (120) to minimize the light path inside the camera housing (120). At this time, the transparent plate (130) may be formed integrally with the camera housing (120) but may be formed of a transparent material different from that of the camera housing (120). The transparent plate (130) may be formed separately from the camera housing (120) and then placed on the inclined surface (124) of the camera housing (120).

[0066] Referring to FIGS. 12 and 13, an optical system contamination removal system (200) according to an embodiment of the present invention comprises an entry detection sensor (210), an exit detection sensor (220), a controller (230), and a high-pressure sprayer (240).

[0067] The entry detection sensor (210) detects vehicle entry into the security area. The entry detection sensor (210) is positioned along the vehicle's path to detect vehicle entry into the security area. The entry detection sensor (210) is positioned in front of the vehicle under-vehicle detection area (i.e., the area where the vehicle under-vehicle monitoring system (100) is positioned) along the vehicle's path to detect vehicles entering the vehicle under-vehicle detection area. When the entry detection sensor (210) detects vehicle entry, it generates an entry detection signal and transmits it to the controller (230).

[0068] An entry detection sensor (210) is configured as a loop sensor buried in the ground or placed on the surface of the ground to detect a vehicle located above it and detect the entry of the vehicle, as an example.

[0069] The exit detection sensor (220) detects the exit of a vehicle from a security area. The exit detection sensor (220) is positioned on the path of a vehicle entering the security area. The exit detection sensor (220) is located behind the vehicle under-vehicle monitoring area along the vehicle's path and detects a vehicle exiting from the vehicle under-vehicle detection area. When the exit detection sensor (220) detects the vehicle exit, it generates an exit detection signal and transmits it to the controller (230).

[0070] An exit detection sensor (220) is positioned between the vehicle lower detection area and the security area and is configured as a loop sensor that is buried in the ground or placed on the surface of the ground to detect a vehicle located above it, thereby detecting the vehicle's exit.

[0071] Meanwhile, the entry detection sensor (210) and the exit detection sensor (220) are positioned to face each other with the vehicle undercarriage monitoring system (100) in between, and in addition to the loop sensor, they are composed of an infrared sensor, a geomagnetic sensor, an image recognition sensor, etc., to detect the entry and exit of the vehicle.

[0072] The controller (230) controls the high-pressure injector (240) based on the detection results of the entry detection sensor (210) and the exit detection sensor (220). That is, when the controller (230) receives an entry detection signal from the entry detection sensor (210), it generates an injection start signal and transmits it to the high-pressure injector (240). When the controller (230) receives an exit detection signal from the exit detection sensor (220), it generates an injection stop signal and transmits it to the high-pressure injector (240). Through this, the controller (230) controls the high-pressure injector (240) to inject compressed air from the time when vehicle entry is detected until the time when vehicle exit is detected.

[0073] The high-pressure sprayer (240) sprays compressed air according to the control of the controller (230). The high-pressure sprayer (240) sprays compressed air onto the target for decontamination to remove contaminants attached to the target for decontamination.

[0074] For example, the high-pressure sprayer (240) is configured to include an air pipe (242) through which compressed air output from the compressor (300) flows, and an air nozzle (244) connected to the air pipe (242) to output compressed air. When a spray start signal is received from the controller (230), the compressor (300) outputs compressed air to the air pipe (242), and the air nozzle (244) sprays the compressed air supplied through the air pipe (242) onto a target for decontamination to remove contaminants attached to the target for decontamination.

[0075] The high-pressure sprayer (240) receives (high-pressure) air from an external compressor (300). At this time, the target for decontamination may be a transparent plate (130) placed in the camera housing (120) according to the structure of the vehicle undercarriage monitoring system (100), or a reflector (140) placed adjacent to the camera. Accordingly, the high-pressure sprayer (240) removes contaminants by spraying compressed air onto the transparent plate (130) or the reflector (140) as an example.

[0076] The high-pressure injector (240) injects compressed air from the time the vehicle enters the vehicle under-vehicle detection area until the time the vehicle exits, under the control of the controller (230). That is, when it receives an injection start signal from the controller (230), it injects compressed air into the contaminant removal target. The high-pressure injector (240) continuously injects compressed air until it receives an injection stop signal from the controller (230). When the high-pressure injector (240) receives an injection stop signal from the controller (230), it stops injecting air.

[0077] Generally, the vehicle undercarriage monitoring system (100) has a structure in which the reflector (140) is exposed, or the reflector (140) is placed inside the camera housing (120) and the transparent plate (130) of the camera housing (120) is placed.

[0078] The camera of the vehicle undercarriage monitoring system (100) uses an ultra-wide angle lens and a fisheye lens to scan (photograph) the entire width of the vehicle from a short distance. The reflector (140) has a length of approximately 80 to 100 cm because it is spaced a certain distance from the lens of the camera. Accordingly, the high-pressure sprayer (240) is configured to include several air nozzles (244) to remove (clean) contaminants from the surface of the reflector (140).

[0079] For example, referring to FIG. 14, since the reflector (140) has an elongated shape in the horizontal direction in the drawing, the high-pressure sprayer (240) may be composed of an air pipe equipped (connected) with a plurality of air nozzles (244). The compressor (300) supplies air to the air pipe, and the air transported through the air pipe is sprayed as compressed air from the plurality of air nozzles (244).

[0080] At this time, since the high-pressure sprayer (240) continuously sprays compressed air while photographing (scanning) the underside of the vehicle, the compressor (300) must be configured as a compressor (300) having a compressed air tank capable of supplying compressed air while photographing multiple vehicles. The high-pressure sprayer (240) requires approximately four or more air nozzles (244) that spray compressed air of about 50 psi to clean the reflector (140) with compressed air, and a compressor (300) of very large capacity is required to keep the four air nozzles (244) open and maintain an air pressure of 50 psi.

[0081] Meanwhile, in FIG. 14, the high-pressure sprayer (240) is shown positioned on the upper part of the reflector (140), but this is a drawing to explain an example of the high-pressure sprayer (240) according to an embodiment of the present invention, and the high-pressure sprayer (240) is not limited to the structure shown in the drawing.

[0082] Additionally, referring to FIG. 15, the high-pressure sprayer (240) is positioned to avoid the light path of the vehicle undercarriage monitoring system (100). That is, since the search accuracy of the vehicle undercarriage monitoring system (100) is reduced if the high-pressure sprayer (240) is positioned to overlap with the light path for photographing the vehicle undercarriage, the high-pressure sprayer (240) is positioned at a location that does not overlap with the light path.

[0083] Referring to FIG. 16, the vehicle undercarriage monitoring system (100) may be configured such that a camera is placed inside a camera housing (120) for camera protection, and the camera can photograph the undercarriage of the vehicle through a transparent plate (130) of the camera housing (120).

[0084] At this time, the camera housing (120) can be configured so that the distance between the camera lens and the transparent plate (130) is relatively short, so that even if the camera in the camera housing (120) is configured with an ultra-wide angle lens, a fisheye lens, etc., a transparent plate (130) having a relatively short length (approximately 35 to 45 cm) can be placed.

[0085] Since the transparent plate (130) is relatively shorter in length than the reflector (140), the area to be cleaned is reduced, and the high-pressure sprayer (240) can achieve a sufficient cleaning effect with approximately two air nozzles (244) that spray compressed air of about 50 psi.

[0086] Referring to FIG. 17, the vehicle undercarriage monitoring system (100) may be configured such that the reflector (140) and the camera are placed inside the camera housing (120) for protection of the reflector (140) and the camera, and the camera can photograph the vehicle undercarriage reflected by the reflector (140) through the transparent plate (130) of the camera housing (120).

[0087] That is, when the light path between the camera lens and the transparent plate (130) becomes very short, the length of the reflector (140) placed inside the camera housing (120) is shortened, and the length of the transparent plate (130) is also shortened, thereby reducing the cross-sectional area of ​​the object to be decontaminated. Accordingly, the optical system decontamination system (200) can achieve a decontamination effect equivalent to or greater than that of the previously described structure while minimizing the amount of compressed air used for decontamination.

[0088] In addition, as previously explained, in order to reduce the light path, a step is formed in the camera housing (120), and a transparent plate (130) is placed on the step surface. In order to photograph the lower part of a vehicle with a width of 2m above 15cm of the ground, a transparent plate (130) with a width of approximately 45cm is required.

[0089] Accordingly, even if the high-pressure sprayer (240) is composed of a single air nozzle (244), it can have a contamination removal effect equivalent to or greater than that of a high-pressure sprayer (240) composed of multiple air nozzles (244). That is, the two surfaces of the camera housing (120) forming a step minimize the dispersion of compressed air, thereby increasing the distance over which the velocity of the sprayed compressed air is maintained, and as the distance over which the compressed air maintains its velocity increases, a sufficient contamination removal effect can be achieved with only one air nozzle (244).

[0090] Referring to FIG. 18, in the case of a camera housing (120) with a step formed therein, if compressed air is sprayed toward the long axis of the step in the drawing, the air is diffused in only two directions (A, B), so even when using a standard nozzle that sprays air at a pressure of about 30 psi, it is possible to effectively clean even the muddy water falling on a transparent plate (130) about 45 cm long. That is, contaminants such as dust and rainwater can be efficiently removed from the transparent plate (130) with only a single air nozzle (244).

[0091] On the other hand, referring to FIG. 19, when compressed air is sprayed toward the long axis of a camera housing (120) where no step is formed, the air spreads in three directions (A, B, C), so the distance over which the velocity of the compressed air is maintained relatively decreases, and thus the decontamination effect is reduced.

[0092] Accordingly, it is preferable that a high-pressure sprayer (240) composed of a single air nozzle (244) be applied to a vehicle undercarriage monitoring system (100) having a camera housing (120) with a stepped structure.

[0093] The air nozzle (244) of the high-pressure sprayer (240) is positioned so that the spray axis is offset in the direction of the step surface rather than the center axis.

[0094] Referring to FIG. 20, the camera housing (120) has a horizontal step surface (HS) and a vertical step surface (VS) in a stepped area. When viewing the camera housing (120) from above, the air nozzle (244) is positioned with its center axis parallel to the vertical step surface (VS). Since the air nozzle (244) must remove contaminants from the step surface, it must be positioned closer to the vertical step surface (VS) as it moves to the left in the drawing (i.e., further away from the air nozzle (244)). Therefore, the air nozzle (244) is positioned so that its spray axis is offset toward the vertical step surface (VS) rather than its center axis.

[0095] Referring to FIG. 21, when viewing the camera housing (120) from the front (vehicle entry direction), the air nozzle (244) is positioned with its center axis parallel to the horizontal step surface (HS). Since the air nozzle (244) must remove contaminants from the step surface, it must be positioned closer to the horizontal step surface (HS) as it moves to the left in the drawing (i.e., further away from the air nozzle (244)). Therefore, the air nozzle (244) is positioned so that its spray axis is offset toward the horizontal step surface (HS) rather than its center axis.

[0096] In this case, the central axis is an axis passing through the center of the air nozzle (244), and the injection axis is an axis passing through the center of the direction in which the air nozzle (244) sprays high-pressure air.

[0097] Meanwhile, when actually using the vehicle undercarriage monitoring system (100), most of the time when contamination removal is needed is when it rains. When it does not rain, there is no problem in acquiring images of the vehicle undercarriage if the contamination is removed about 2-3 times a day. However, when it rains, the contamination must be removed every time the vehicle is scanned.

[0098] If the optical system decontamination system is simply synchronized with the entry detection sensor (210) and the exit detection sensor (220), the maintenance cycle of the system becomes very short due to continuous operation.

[0099] Accordingly, as illustrated in FIG. 22, the optical system contamination removal system (200) according to an embodiment of the present invention further includes a precipitation detection sensor (250) that detects whether precipitation is present, and operates a high-pressure sprayer (240) in accordance with the precipitation condition in conjunction with the entry and exit of a vehicle.

[0100] The precipitation detection sensor (250) generates a precipitation detection signal when it rains and transmits it to the controller (230). In this case, the precipitation detection sensor (250) is configured as a rain sensor to detect precipitation, as an example.

[0101] When the controller (230) receives the precipitation detection signal from the precipitation detection sensor (250) and the entry detection signal from the entry detection sensor (210), it generates an injection start signal and transmits it to the high-pressure injection device (240). At this time, if the controller (230) receives only the entry detection signal, it does not output an injection start signal.

[0102] When the controller (230) receives an exit detection signal from the exit detection sensor (220), it transmits an injection stop signal to the high-pressure injector (240), and after receiving the injection stop signal, the high-pressure injector (240) closes the air nozzle (244) to stop the injection of compressed air.

[0103] Through this, the optical system decontamination system (200) can operate the high-pressure sprayer (240) only while the vehicle undercarriage is being photographed at the same time as it rains, thereby preventing continuous operation of the compressor (300) and the high-pressure sprayer (240) and preventing the maintenance cycle from being shortened.

[0104] Since the high-pressure sprayer (240) does not operate when it is not raining when linked with the rain detection sensor, the optical system decontamination system (200) operates the high-pressure sprayer (240) at set time intervals when rain is not detected by the rain detection sensor. As an example, the controller (230) outputs a spray start signal at approximately 3 to 4 hour intervals when a rain detection signal is not received from the rain detection sensor.

[0105] Although preferred embodiments according to the present invention have been described above, various modifications are possible, and it is understood that those skilled in the art can implement various variations and modifications without departing from the scope of the claims of the present invention. Explanation of the symbols

[0106] 100: Vehicle Underbody Monitoring System 110: External housing 120: Camera housing 130: Transparent plate 140: Reflector 150: Line scan camera 200: Optical system decontamination system 210: Entry detection sensor 220: Exit detection sensor 230: Controller 240: High-pressure injector 242: Air piping 244: Air nozzle 250: Precipitation detection sensor 300: Compressor

Claims

Claim 1 A vehicle underbody monitoring system for photographing the underside of a vehicle located within a detection area; an entry detection sensor positioned in front of the vehicle underbody monitoring system, which generates an entry detection signal and outputs the entry detection signal when it detects a vehicle entering the detection area; an exit detection sensor positioned behind the vehicle underbody monitoring system, which generates an exit detection signal and outputs the exit detection signal when it detects a vehicle exiting the detection area; a controller connected to the entry detection sensor and the exit detection sensor, which outputs an injection start signal in response to the entry detection signal output of the entry detection sensor and generates and outputs an injection stop signal in response to the exit detection signal output of the exit detection sensor; and a high-pressure injector connected to the controller, which initiates high-pressure air injection into the optical system of the vehicle underbody monitoring system in response to the injection start signal output of the controller and stops the high-pressure air injection in response to the injection stop signal output of the controller, wherein the vehicle underbody monitoring system comprises: a camera housing; a transparent plate positioned in a slit formed by removing a part of the camera housing; and a reflector positioned inside the camera housing and positioned below the transparent plate. An optical system contamination removal system comprising a camera disposed inside the camera housing and spaced apart from the reflector. Claim 2 In claim 1, the high-pressure sprayer sprays high-pressure air into the optical system, and the optical system contamination removal system includes an air nozzle in which the spray axis and the center axis are not parallel. Claim 3 In claim 1, the high-pressure sprayer is an optical system decontamination system positioned so as not to overlap with the light path of the vehicle underbody monitoring system that photographs the vehicle underbody. Claim 4 An optical system for removing contaminants according to claim 1, wherein the high-pressure sprayers are spaced apart from each other and include a plurality of air nozzles that spray high-pressure air onto the reflector in response to the spray start signal output of the controller. Claim 5 delete Claim 6 An optical system decontamination system according to claim 1, wherein the transparent plate is disposed in a slit formed on one of the plurality of outer surfaces constituting the camera housing, and the high-pressure sprayer comprises a plurality of air nozzles disposed so as not to overlap with the light path connecting the transparent plate, the reflector, and the camera. Claim 7 An optical system for removing contaminants according to claim 1, wherein the camera housing has a step formed having a horizontal step surface and a vertical step surface, the transparent plate is placed in a slit formed by removing a part of the horizontal step surface, and the high-pressure sprayer includes an air nozzle that sprays high-pressure air onto the horizontal step surface of the camera housing. Claim 8 In claim 7, the optical system contamination removal system wherein the spray axis of the air nozzle is offset in the direction of the horizontal step plane of the camera housing from the center axis of the air nozzle. Claim 9 An optical system contamination removal system according to claim 1, wherein the camera housing has an inclined surface formed thereon, the transparent plate is placed in a slit formed by removing a part of the inclined surface, and the high-pressure sprayer includes an air nozzle that sprays high-pressure air onto the inclined surface of the camera housing. Claim 10 An optical system contamination removal system comprising: a vehicle underbody monitoring system for photographing the underbody of a vehicle located within a detection area; an entry detection sensor positioned in front of the vehicle underbody monitoring system, which generates an entry detection signal and outputs the entry detection signal when it detects a vehicle entering the detection area; an exit detection sensor positioned behind the vehicle underbody monitoring system, which generates an exit detection signal and outputs the exit detection signal when it detects a vehicle exiting from the detection area; a controller connected to the entry detection sensor and the exit detection sensor, which outputs an injection start signal in response to the entry detection signal output of the entry detection sensor, and generates and outputs an injection stop signal in response to the exit detection signal output of the exit detection sensor; a high-pressure injector connected to the controller, which initiates high-pressure air injection into the optical system of the vehicle underbody monitoring system in response to the injection start signal output of the controller, and stops the high-pressure air injection in response to the injection stop signal output of the controller; and a rain detection sensor connected to the controller, which generates a rain detection signal and outputs the rain detection signal to the controller when it detects rain. Claim 11 In claim 10, the above controller is an optical system for decontamination that outputs a spray start signal when a rain detection signal is output from the rain detection sensor and an entry detection signal is output from the entry detection sensor. Claim 12 In claim 10, the above controller is an optical system for removing contaminants that outputs a spray stop signal when a rain detection signal is output from the rain detection sensor and an exit detection signal is output from the exit detection sensor. Claim 13 In claim 10, the above controller is an optical system for removing contaminants that repeatedly outputs a spray start signal and a spray stop signal at set time intervals while a rain detection signal is not output from the rain detection sensor. Claim 14 delete Claim 15 delete Claim 16 delete Claim 17 delete Claim 18 delete

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