A fill light adjustment system for a box girder inspection robot

Abstract

The present invention discloses a fill light adjustment system for a box girder inspection robot, comprising: an inspection robot body, an image acquisition device for inspecting and photographing the box girder, an annular light frame disposed on the periphery of the image acquisition device, and multiple independent fill lights and light sensors uniformly distributed on the annular light frame, all of which are connected to a control system; the number of light sensors being the same as the number of fill lights, the illumination area formed by N fill lights being divided into N small areas, the N light sensors detecting the light intensity of the corresponding small areas; and the control system adjusting the brightness and illumination angle of the independently corresponding fill light based on the light intensity detected by each light sensor. The present invention can automatically adjust the brightness and illumination angle of the fill light based on the light intensity and position of the imaging area, thereby ensuring light uniformity in image capture and further improving the imaging effect of the image acquisition device.

Description

Technical Field

[0001] The present invention relates to the technical field of box girder inspection, and in particular to a fill light adjustment system of a box girder inspection robot. Background Art

[0002] Currently, inspections of the interior of continuous box girders are performed on concealed areas of bridge structures. These inspections face challenges such as high-altitude work, limited power and network connectivity, crossing mountains and rivers, and limited operating time, all of which pose safety risks to manual labor. Furthermore, due to the widespread distribution and large geographical spans of bridges, numerous inspections within the box girders are required, including for water seepage, cracks, and hollowing. This results in heavy, demanding, and time-consuming manual labor.

[0003] The lighting conditions inside the box girder are poor, the surface materials are diverse, and the space sizes vary greatly. Currently, there are two main methods for detecting internal defects in box girders: manual inspection and inspection robots.

[0004] The manual method involves using a camera to perform a rough scan from a distance to locate fatigue cracks. This is not only labor-intensive but also subject to biased test results. Furthermore, the internal structure of the box girder is difficult to navigate, and some are not equipped with lighting. The top plate, in particular, cannot be observed up close, making it difficult to mark and record. Manual inspection is subject to numerous objective factors and significant subjective influences.

[0005] The inspection robot method uses the image acquisition device carried by the inspection robot to scan the inside of the box girder. However, it often faces poor lighting conditions inside the box girder, diverse surface materials, and large differences in space size, which causes the captured pictures to be blurred and low in contrast, making it difficult to accurately identify cracks and other defects.

[0006] Existing fill lights have fixed brightness and angles, which cannot guarantee stable and clear imaging effects. Summary of the Invention

[0007] In view of the deficiencies in the prior art, the present invention provides a fill light adjustment system for a box girder inspection robot.

[0008] The present invention discloses a fill light adjustment system for a box girder inspection robot, comprising: an inspection robot main body, an image acquisition device for inspecting and photographing the box girder provided on the inspection robot main body, an annular light frame provided on the periphery of the image acquisition device, the annular light frame connected to the inspection robot main body, a plurality of independent fill lights and light sensors uniformly distributed on the annular light frame, the fill lights being capable of independent brightness and angle adjustment, and all the fill lights and light sensors being connected to a control system;

[0009] The number of the light sensors is the same as the number of the fill lights, and the illumination area formed by the N fill lights is divided into N small areas, and the N light sensors detect the light intensity of the corresponding small areas;

[0010] The control system adjusts the brightness and illumination angle of the corresponding fill light based on the light intensity detected by each light sensor.

[0011] As a further improvement of the present invention, the light sensor is installed at the front end of the corresponding fill light.

[0012] As a further improvement of the present invention, the control system adjusts the brightness and illumination angle of the corresponding fill light based on the light intensity detected by each light sensor; including:

[0013] Calculate the light intensity difference between the light intensity detected by each light sensor and its reference light intensity value, and compare the light intensity difference with the light intensity threshold. If the light intensity difference is greater than the light intensity threshold, calculate the driving current value corresponding to the fill light that needs to be adjusted, and issue a dimming instruction to the control system, which controls the corresponding fill light to adjust the brightness. The reference light intensity value is: the average light intensity value of the area corresponding to the clearest image captured by the image acquisition device under laboratory environment testing;

[0014] The image acquisition device acquires an image of the inner wall of the box girder, calibrates the relationship between the image coordinates and the actual coordinates of the inner wall of the box girder, and draws a corresponding fill light area in the image coordinate area; according to a computer image processing algorithm, the color image acquired by the image acquisition device is converted into a grayscale image, and each divided small image area is divided into a plurality of small color blocks; the average pixel value of each small color block, that is, the brightness value, is calculated; the average value of the brightness value of each small color block that divides the small image area is taken as the brightness average value of the small image area; the brightness value of each small color block is compared with the brightness average value of the small image area; if the brightness values ​​of M consecutive small color blocks are all less than the brightness average value, the center point of the central color block among the M color blocks is taken as a reference, and according to the relationship between the image coordinates and the actual coordinates of the inner wall of the box girder, the rotation angle of the fill light is calculated, and the angle of the fill light is adjusted by a control system to perform fill light processing on the small image area.

[0015] As a further improvement of the present invention, the image acquisition device is a camera, and the fill light is an LED light, a xenon lamp or a laser light.

[0016] As a further improvement of the present invention, the annular light stand is a U-shaped bracket with the opening facing downward and both ends are detachably connected to the inspection robot body through a quick-release structure. A reinforcement bracket is installed in the middle of the annular light stand. The top of the reinforcement bracket is screwed to the cross bar of the annular light stand, and the bottom end is detachably connected to the inspection robot body through a quick-release structure. The quick-release structure includes one of a snap-on structure and a plug and slot matching structure.

[0017] As a further improvement of the present invention, the control system of the inspection robot body is connected to the controller of each fill light to achieve brightness adjustment of each fill light.

[0018] As a further improvement of the present invention, the fill light is installed on an electric pan-tilt platform, and the electric pan-tilt platform is installed on the annular light stand. The control system of the inspection robot body is connected to the controller of each electric pan-tilt platform to achieve angle adjustment of each fill light.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention provides an annular light frame around the periphery of the image acquisition device, on which multiple fill lights are arranged. The annular multi-fill light fill light structure provided around the image acquisition device can provide sufficient illumination for the inspection robot in low-light or no-light environments, ensuring that the image acquisition device and other sensors carried by the robot can capture clear, high-quality images and data.

[0021] The annular light stand of the present invention is installed on the inspection robot body with a quick-disassembly structure, which facilitates the disassembly of the annular light stand and the inspection robot body, so that both can conveniently enter the box beam through the manhole at the bottom of the box beam;

[0022] The brightness and illumination angle of each fill light of the present invention can be automatically adjusted based on the light intensity and position of the imaging area, thereby ensuring the uniformity of light for image capture and further improving the imaging effect of the image acquisition device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the fill light adjustment system of the box girder inspection robot disclosed in the present invention;

[0024] Figure 2 for Figure 1 Schematic diagram of the middle ring light stand;

[0025] Figure 3 for Figure 1 Installation diagram of the fill light.

[0026] In the picture:

[0027] 1. Inspection robot body; 2. Image acquisition device; 3. Ring light stand; 4. Fill light; 5. Electric pan / tilt head; 6. Light sensor; 7. Control system. DETAILED DESCRIPTION

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0029] The present invention is described in further detail below with reference to the accompanying drawings:

[0030] like Figure 1-3 As shown, the present invention provides a fill light adjustment system for a box girder inspection robot, which improves the fill light structure of the existing box girder inspection robot; the existing box girder inspection robot includes a walking component (chassis, wheel set, etc.), a control system and a carrying component (image acquisition device, sensor, etc.); the box girder inspection robot body 1 uses a lightweight, miniaturized wheeled or tracked mobile robot motion chassis, which facilitates the inspection robot to migrate from the manhole at the bottom of the box girder to the inside of the box girder; a mechanical device that can be quickly disassembled (such as a bayonet structure, a slot and plug-matching buckle structure, and other existing conventional quick-release structures) is arranged around the motion chassis; the present invention is provided with a ring-shaped light stand 3 on the periphery of the image acquisition device, and the ring-shaped light stand 3 is connected to the inspection robot body 1 through the above-mentioned quick-release structure, and a plurality of independent fill lights 4 and light sensors 6 are evenly distributed on the ring-shaped light stand 3. Specifically: the image acquisition device 2 is a camera, the fill light 4 is an LED light, a xenon lamp or a laser light, and the light sensor 6 is a photodiode, a phototransistor or a photoresistor, etc. The light sensor 6 can measure the light intensity in the current environment and convert the light intensity into an electrical signal. These sensors usually have high sensitivity and a wide dynamic range, and can accurately sense various lighting conditions from dark to bright. The annular light stand 3 is preferably a door-shaped stand (U-shaped stand), a circular stand or a C-shaped stand with the opening facing downward, so as to form an annular lighting area around the image acquisition device 2; the material of the annular light stand 3 is selected according to actual needs to meet the use requirements of the inspection robot; the image acquisition device 2 is located at the center of the annular light stand 3, such as Figure 2The center position shown. Furthermore, when the annular light stand is a U-shaped stand with the opening facing downward, its two ends are detachably connected to the inspection robot body through a quick-release structure, and a reinforcement bracket is installed in the middle of the annular light stand. The top of the reinforcement bracket is screwed to the crossbar of the annular light stand, and the bottom end is detachably connected to the inspection robot body through a quick-release structure. The quick-release device of the present invention can be a socket quick-release device similar to a seat belt. A lock buckle is installed at a preset position of the box girder inspection robot body, and a plug is installed at the tail end of the annular light stand 3. When the plug is inserted into the lock buckle, the annular light stand 3 can be stably installed on the box girder inspection robot body.

[0031] The fill light 4 of the present invention is installed on the annular light stand 3 through the electric pan-tilt head 5. Specifically, the fill light 4 is installed on the movable end of the electric pan-tilt head 5, and the fixed end of the electric pan-tilt head 5 is fixedly installed on the annular light stand 3. The angle adjustment of the fill light in the horizontal and vertical directions can be achieved through the electric pan-tilt head 5. The electric pan-tilt head involved in the present invention is an existing conventional structure, so it will not be elaborated on here. For example, a household camera is a combination of a commonly used camera + an electric pan-tilt head. Furthermore, the control system of the inspection robot body of the present invention is connected to the controller of each electric pan-tilt head to achieve angle adjustment of each fill light. Each fill light of the present invention can achieve independent control of brightness and angle to adapt to the environment and target detection objects at different positions inside the box girder, and avoid overexposure of the image due to excessive brightness or loss of image details due to excessive darkness.

[0032] The fill lights of this invention are evenly distributed across different parts of the robot, providing multi-angle illumination for optimal lighting in various inspection scenarios. The fill light system is powered by the robot's internal battery and centrally managed by the robot's control system. It features a quick-release feature for rapid deployment and retrieval, and can be easily moved from outside the box girder to inside through a manhole at the bottom.

[0033] The number of light sensors 6 of the present invention is consistent with that of the fill lights 4, and the illumination area formed by N fill lights is divided into N small areas. The N light sensors detect the light intensity of the corresponding small areas. The light sensor 6 is installed at the front end of the corresponding fill light 4, and can be installed on the lampshade of the fill light 4 or on the movable end of the electric pan-tilt platform of the fill light. The control system 7 of the inspection robot body 1 is connected to the controller of each fill light 4 (which controls the brightness of the fill light and the movement of the electric pan-tilt platform) and each light sensor 6 to adjust the brightness and illumination angle of the corresponding fill light based on the light intensity detected by each light sensor. Figure 2 For example, the control system of the inspection robot body 1 of the present invention connects the controllers of all the fill lights in parallel through wires. The controller can realize the switching and brightness adjustment of the fill lights, and then the switching and brightness adjustment of each fill light can be realized through the control system of the inspection robot body 1.

[0034] The control system 7 adjusts the brightness and illumination angle of the corresponding fill light based on the light intensity detected by each light sensor, specifically including:

[0035] S1. Divide the area illuminated by the fill light into N small areas equal to the number of fill lights. The center of each small area is the illumination center of the fill light. The fill lights are numbered one by one with the partitioned small areas. Install a light sensor in the small area where the fill light is located to detect the light intensity in the nearby area.

[0036] S2. Test in a laboratory environment. Adjust the fill light on the electric pan / tilt head to the reference position (the central axis of the fill light is parallel to the normal of the measured area). Adjust the brightness of the fill light so that the image captured by the camera of the box girder robot is clearest. Note the brightness value of the light sensor in each small area and take the average brightness value of each light sensor as the reference value for brightness adjustment.

[0037] S3. In an actual detection environment, the light sensor detects the light intensity of the small area where it is located and obtains the light intensity value of the small area; the light intensity difference between the light intensity detected by each light sensor and its reference light intensity value is calculated, and the light intensity difference (absolute value) is compared with the light intensity threshold. If it is greater than the light intensity threshold, the driving current value corresponding to the fill light that needs to be adjusted is calculated, and a dimming instruction is issued to the control system. The control system controls the corresponding fill light to adjust the brightness; further, according to the different light intensities, multiple thresholds can be set to distinguish different lighting conditions. For example, several levels such as "bright", "medium", "dim", and "dark" can be defined. The adjustment strategy of the light source is determined by the IF-THEN rule. For example, if the light intensity difference (absolute value) is greater than the threshold X, the brightness of the light source is increased by Y%. At the same time, a closed-loop control system of the PID controller is used to continuously adjust the light source brightness through the light source compensation device according to the data fed back by the light sensor. The brightness of the fill light is automatically turned on or adjusted according to the data fed back by the light sensor, while keeping the image quality within the ideal range.

[0038] S4. The image acquisition device acquires an image of the inner wall of the box girder, calibrates the relationship between the image coordinates and the actual coordinates of the inner wall of the box girder, and draws the corresponding fill light area in the image coordinate area; according to the computer image processing algorithm, the color image acquired by the image acquisition device is converted into a grayscale image, and each divided small image area is divided into several small color blocks of appropriate size; the average pixel value of each small color block, that is, the brightness value, is calculated; the average value of the brightness value of each small color block that divides the small image area is taken as the brightness average value of the small image area; the brightness value of each small color block is compared with the brightness average value of the small image area; if the brightness values ​​of M consecutive small color blocks are all less than the brightness average value, the center point of the central color block among the M color blocks is taken as the reference (for example, if the brightness values ​​of 5 consecutive small color blocks are all less than the brightness average value, the center point of the third color block among the 5 color blocks is taken as the reference); according to the relationship between the image coordinates and the actual coordinates of the inner wall of the box girder, the rotation angle of the fill light is calculated, and the angle of the fill light is adjusted by the control system to perform fill light processing on the small image area.

[0039] The advantages of the present invention are:

[0040] The present invention provides an annular light frame around the periphery of the image acquisition device, on which multiple fill lights are arranged. The annular multi-fill light fill light structure provided around the image acquisition device can provide sufficient illumination for the inspection robot in low-light or no-light environments, ensuring that the image acquisition device and other sensors carried by the robot can capture clear, high-quality images and data.

[0041] The annular light stand of the present invention is installed on the inspection robot body with a quick-disassembly structure, which facilitates the disassembly of the annular light stand and the inspection robot body, so that both can conveniently enter the box beam through the manhole at the bottom of the box beam;

[0042] The brightness and illumination angle of each fill light of the present invention can be automatically adjusted based on the light intensity and position of the imaging area, thereby ensuring the uniformity of light for image capture and further improving the imaging effect of the image acquisition device.

[0043] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A fill light adjustment system for a box girder inspection robot, comprising: The inspection robot body is provided with an image acquisition device for inspecting and photographing the box girder, characterized in that an annular light stand is provided on the periphery of the image acquisition device, the annular light stand is connected to the inspection robot body, and a plurality of independent fill lights and light sensors are evenly distributed on the annular light stand, the fill lights can be independently adjusted in brightness and angle, and all the fill lights and light sensors are connected to a control system; The number of the light sensors is the same as the number of the fill lights, and the illumination area formed by the N fill lights is divided into N small areas, and the N light sensors detect the light intensity of the corresponding small areas; The control system adjusts the brightness and illumination angle of the corresponding fill light based on the light intensity detected by each light sensor; specifically includes: Calculate the light intensity difference between the light intensity detected by each light sensor and its reference light intensity value, and compare the light intensity difference with the light intensity threshold. If the light intensity difference is greater than the light intensity threshold, calculate the driving current value corresponding to the fill light that needs to be adjusted, and issue a dimming instruction to the control system, which controls the corresponding fill light to adjust the brightness. The reference light intensity value is: the average light intensity value of the area corresponding to the clearest image captured by the image acquisition device under laboratory environment testing; The image acquisition device acquires an image of the inner wall of the box girder, calibrates the relationship between the image coordinates and the actual coordinates of the inner wall of the box girder, and draws a corresponding fill light area in the image coordinate area; according to a computer image processing algorithm, the color image acquired by the image acquisition device is converted into a grayscale image, and each divided small image area is divided into a plurality of small color blocks; the average pixel value of each small color block, that is, the brightness value, is calculated; the average value of the brightness value of each small color block that divides the small image area is taken as the brightness average value of the small image area; the brightness value of each small color block is compared with the brightness average value of the small image area; if the brightness values ​​of M consecutive small color blocks are all less than the brightness average value, the center point of the central color block among the M color blocks is taken as a reference, and according to the relationship between the image coordinates and the actual coordinates of the inner wall of the box girder, the rotation angle of the fill light is calculated, and the angle of the fill light is adjusted by a control system to perform fill light processing on the small image area.

2. The fill light adjustment system for the box girder inspection robot according to claim 1, characterized in that: The light sensor is installed at the front end of the corresponding fill light.

3. The fill light adjustment system for the box girder inspection robot according to any one of claims 1 to 2, characterized in that: The image acquisition device is a camera, and the fill light is an LED light, a xenon lamp or a laser light.

4. The fill light adjustment system for a box girder inspection robot according to any one of claims 1 to 2, characterized in that: The annular light stand is a U-shaped bracket with its opening facing downward and its two ends are detachably connected to the inspection robot body through quick-release structures. A reinforcement bracket is installed in the middle of the annular light stand. The top of the reinforcement bracket is screwed to the cross bar of the annular light stand, and the bottom end is detachably connected to the inspection robot body through a quick-release structure. The quick-release structure includes one of a snap-on structure and a plug and slot matching structure.

5. The fill light adjustment system for the box girder inspection robot according to any one of claims 1 to 2, characterized in that: The control system of the inspection robot body is connected to the controller of each fill light to achieve brightness adjustment of each fill light.

6. The fill light adjustment system for a box girder inspection robot according to any one of claims 1 to 2, characterized in that: The fill light is mounted on an electric pan-tilt platform, which is mounted on the annular light stand. The control system of the inspection robot body is connected to the controller of each electric pan-tilt platform to achieve angle adjustment of each fill light.

Images