Bridge box girder inspection robot and automatic inspection method

Abstract

The utility model relates to a bridge box girder inspection robot relates to track traffic bridge operation and maintenance detection technical field provides a compact structure, stable operation, detects no dead angle and can adapt to single track type inspection robot and inspection method of box girder inside bad environment, including track unit and walking unit, track unit includes the track that the section is T shape and is laid in cavity, and the track includes a plurality of turning sections, and the radius of turning section is not less than 500mm, walking unit includes the car body, and the bottom of car body is provided with walking wheel and is provided with auxiliary wheel on both sides of walking wheel, the auxiliary wheel and walking wheel embrace in the track, the top of car body is provided with detection unit, and detection unit includes six axis mechanical arm, and the end of six axis mechanical arm is provided with self light filling camera, and the inside of car body is still provided with intelligent control unit and power supply unit, and intelligent control unit is electrically connected with walking unit and six axis mechanical arm, is used for controlling car body moves along the track, controls mechanical arm posture and receives and handles the image that self light filling camera gathers.

Description

Technical Field

[0001] This invention relates to the field of rail transit bridge operation and maintenance inspection technology, specifically to a bridge box girder inspection robot and an automatic inspection method. Background Technology

[0002] Box girders are a type of beam used in bridge engineering. They are hollow inside with flanges on both sides of the upper part, resembling a box, hence the name. Based on the number of cavities inside their cross-section, they are divided into single-box and multi-box types. The cavities inside the cross-section are closed and narrow spaces, and the side walls and the areas connected by bolts at the back are high-risk areas for apparent damage. In order to prevent the apparent damage from spreading and affecting the strength of the bridge, it is necessary to inspect the corresponding areas to facilitate timely prevention and control.

[0003] During actual inspections, the internal passages of the box girder are narrow, making it difficult for inspectors to reach them and creating blind spots. At the same time, inspectors rely on visual judgment, resulting in low accuracy in identifying defects such as fractures and loosening. Furthermore, when dealing with multiple box girders, different cavities in the same section need to be inspected, which is time-consuming and inefficient.

[0004] The invention application with application number CN202010410472.X discloses a wheel structure rail vehicle bottom inspection device. This wheel-rail dual-purpose vehicle can travel on both the ground and the rail, effectively solving the problem that existing rail vehicle bottom inspection devices must rely on the inspection rail when scanning and taking pictures, and the inspection rail is inconvenient to install and has a high installation cost.

[0005] However, in actual use, this mechanism is only suitable for single-chamber box girders. When faced with multi-chamber boxes, and given that the internal chambers are relatively small, the double-track installation is quite difficult. Furthermore, the lower part requires a color strip for position identification, which is clearly not suitable for the space where box girders are extremely prone to dust accumulation. In addition, the coverage area is not wide enough to meet the usage conditions of multi-box girders. Summary of the Invention

[0006] I. Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a single-track inspection robot and an automated inspection method that is compact in structure, stable in operation, capable of detecting without blind spots, and adaptable to the harsh environment inside box girders.

[0007] II. Specific Technical Solutions A bridge box girder inspection robot is installed inside the cavity of the box girder. It includes a track unit and a walking unit. The track unit comprises an I-shaped or T-shaped track laid within the cavity, with several turning sections having a radius of not less than 500mm. The walking unit includes a vehicle body with walking wheels and auxiliary wheels on either side of the walking wheels at its bottom. The auxiliary wheels and walking wheels encircle the track. A detection unit is located on the top of the vehicle body. The detection unit includes a six-axis robotic arm with a self-illuminating camera at its end. An intelligent control unit and a power supply unit are also located within the vehicle body. The intelligent control unit is electrically connected to the walking unit and the six-axis robotic arm, and is used to control the movement of the vehicle body along the track, control the posture of the robotic arm, and receive and process images captured by the self-illuminating camera.

[0008] Implementation principle and working principle: Compared with existing inspection equipment, this solution integrates a single-track support, a wraparound walking mechanism, a multi-degree-of-freedom robotic arm for detection, and intelligent control. The track unit provides basic guidance and support, and its turning radius (≥500mm) ensures smooth passage through curves inside the box girder. The walking unit, with its wraparound structure formed by the walking wheels and auxiliary wheels, closely conforms to the T-shaped or I-shaped track, ensuring stability and anti-derailment capability when climbing slopes and driving on curves. The detection unit uses a large-reach, high-precision six-axis robotic arm with a wide-temperature-range, self-illuminating high-definition camera at its end, allowing it to flexibly reach into concealed areas such as the inside of U-ribs to collect clear images. The intelligent control unit coordinates the walking, detection, and power supply, achieving full-process automation. The combination of single-track and wraparound walking significantly reduces the installation space requirements and improves maneuverability in narrow, curved areas. The multi-axis robotic arm overcomes the limitations of fixed cameras' field of view, providing the hardware foundation for blind-spot-free detection.

[0009] Preferably, a charging box is provided at one end of the track; when the intelligent control unit detects that the power supply unit's power is lower than a set value, it issues a control command to control the vehicle to automatically return to the charging box along the track for charging; the beneficial effect of this preferred option is that the intelligent control unit monitors the power supply unit's power in real time, and triggers a preset return program when it is lower than the threshold, realizing the machine's autonomous operation and maintenance, significantly reducing manual intervention, and improving continuous operation capability.

[0010] Preferably, the traveling wheels include two front traveling wheels and two rear traveling wheels, with a mounting shaft between each pair of corresponding front and rear traveling wheels. A drive motor that drives the mounting shaft is installed inside the vehicle body, and a transmission chain connects the two mounting shafts. A guide protrusion is provided on the upper surface of the track near the charging box. When the vehicle is charging, the two ends of the guide protrusion are respectively positioned between the two front traveling wheels and the two rear traveling wheels to achieve precise positioning. The beneficial effect of this preferred embodiment is that the transmission system composed of the drive motor, mounting shaft, and chain provides power. During charging, the guide protrusion on the track is embedded in the gap between the front and rear traveling wheels, achieving precise mechanical positioning of the vehicle body, ensuring the reliability of power transmission, and ensuring the accuracy and success rate of charging docking.

[0011] Preferably, the power supply unit includes two independently configured batteries, and a charging post corresponding to each battery is provided on each of the rear sides of the vehicle body; the charging box is provided with a charging slot that cooperates with the charging post; under the control of the intelligent control unit, the two batteries can supply power to the detection unit or the walking unit individually, or cooperate to supply power to the walking unit. The advantages of this preferred embodiment are that the two batteries can be flexibly configured by the intelligent control unit to supply power to the high-power walking unit and the precision detection unit respectively, or to cooperate to output power when needed, thereby improving the safety redundancy of the power supply system, avoiding the paralysis of the entire system due to a single power supply failure, and also facilitating power management and extending the life of key components; at the same time, the cooperation of the two charging posts and the charging slots can ensure the charging of the two batteries on the one hand, and maintain the balance and stability of the equipment when charging or resting through the cooperation of the posts and slots on the other hand.

[0012] Preferably, the track (101) is welded from solid steel plates, with a welding height of not less than 8mm at the joints, and the track surface is treated with galvanizing and anti-rust paint; the section of the track (101) at the manhole of the box girder has a passage width of not less than 800mm; the beneficial effect of this preferred option is that solid steel plates are welded and double-layered with galvanizing and anti-rust paint to resist moisture corrosion inside the box girder; the reserved passage width of the manhole takes into account the needs of human-machine collaborative operation; it ensures the structural strength and long-term corrosion resistance of the track body, and does not affect the normal passage of maintenance personnel, reflecting humanized design.

[0013] Preferably, the six-axis robotic arm has a reach of not less than 1800mm, a repeatability of ±0.5mm, and can achieve ±180° horizontal rotation and pitch adjustment from -45° to 90°. The advantage of this preferred option is that the 1800mm reach combined with the ±180° horizontal rotation and large-angle pitch adjustment capability creates an approximately spherical accessible workspace, ensuring that the robotic arm can effectively cover most of the surfaces to be inspected inside the box girder, especially hard-to-reach corners, which is the core of achieving "no blind spots".

[0014] Preferably, the self-illuminating camera has a resolution of no less than 12 million pixels, supports autofocus from 500mm to 2000mm, and operates within a temperature range of -40℃ to 85℃. The advantages of this preferred configuration are that the high pixel count and autofocus ensure image detail; the wide operating temperature range (-40℃ to 85℃) allows it to withstand extreme temperature differences inside the box girder; the self-illuminating function overcomes the dim lighting conditions inside; and it directly ensures the clarity and stability of the acquired images of defects, providing a high-quality input source for subsequent automatic recognition algorithms.

[0015] Preferably, the intelligent control unit has a trajectory teaching subunit with a teaching trajectory deviation of no more than 5mm, and a built-in algorithm subunit for real-time analysis of acquired images to automatically identify cracks or loosening defects. The advantages of this preferred embodiment are that the trajectory teaching function allows operators to conveniently plan the optimal inspection path; the built-in image recognition algorithm is based on a deep learning model and can perform real-time analysis and annotation of typical defects such as cracks and loosening; it transforms manual experience into a repeatable automated program and achieves an intelligent leap from "image acquisition" to "preliminary defect judgment", greatly improving inspection efficiency and objectivity.

[0016] This solution also provides an automated inspection method for a bridge box girder inspection robot, including the following steps: S1: Laying the track unit along the inspection path in the internal cavity of the box girder; S2: Planning the inspection path through the intelligent control unit and setting the shooting posture of the six-axis robotic arm at key detection points; S3: Controlling the walking unit to automatically cruise along the track and simultaneously controlling the six-axis robotic arm (301) to adjust according to the preset posture, while simultaneously activating the self-illuminating camera to collect images; S4: Analyzing the collected images in real time through the intelligent control unit and automatically marking the type and location of defects; S5: Controlling the robot to automatically return to the charging box for charging when the inspection task is completed or when the battery level is detected to be lower than the set value.

[0017] The beneficial effects of this invention are as follows: 1. The single-track and compact encircling design greatly reduces the space occupied by the box girder, provides good curve passability, and has significantly lower installation and maintenance costs than the traditional double-track solution. In addition, the track design takes into account the needs of manual inspection channels, making it highly adaptable to space and easy to deploy and maintain.

[0018] 2. By working in collaboration with a long-reach, high-degree-of-freedom robotic arm and a high-performance environmentally adaptive camera, it can flexibly and stably acquire high-definition images of all key parts inside the box girder (including the inside of the U-rib and the back of the bolts), completely eliminating blind spots in manual inspection, demonstrating excellent inspection capabilities and achieving comprehensive coverage without dead angles.

[0019] 3. It integrates intelligent control, automatic fault identification, power management and automatic charging return functions, realizing full-process automation from path planning, data collection, analysis and diagnosis to autonomous operation and maintenance, which greatly improves inspection efficiency, accuracy and reliability and reduces safety risks. Attached Figure Description

[0020] Figure 1 This is a top view schematic diagram of the bridge box girder inspection robot in this embodiment.

[0021] Figure 2 This is a schematic diagram of the walking unit of the bridge box girder inspection robot in this embodiment.

[0022] Figure 3 This is a schematic diagram of the transmission of the walking unit of the bridge box girder inspection robot in this embodiment.

[0023] Figure 4 This is a schematic diagram of the guide protrusion of the bridge box girder inspection robot in this embodiment.

[0024] Explanation of reference numerals in the attached figures: Track unit 1, track 101, turning section 102, charging box 103, walking unit 2, vehicle body 201, walking wheel 202, front walking wheel 2021, rear walking wheel 2022, auxiliary wheel 203, mounting shaft 205, drive motor 206, transmission chain 207, charging column 208, storage battery 209, detection unit 3, six-axis robotic arm 301, self-illuminating camera 302. Detailed Implementation

[0025] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0026] like Figure 1-4 As shown: This embodiment uses the internal inspection of a steel box girder of a rail transit bridge as a scenario. The box girder has a closed cavity inside, with an ambient temperature ranging from -5℃ to 60℃ and a humid environment.

[0027] First, the track unit 1 is installed; based on the internal structural survey results of the box girder, the inspection route is designed; solid steel plates with T or I-shaped cross sections are selected as the material for track 101; the track is prefabricated in sections at the factory, and the connection is made using a full welding process with a welding height of 10mm. After welding, the entire track is hot-dip galvanized and coated with epoxy anti-rust paint; on site, track 101 is fixed to the pre-set brackets on the inner wall of the box girder using drilled bolts. During installation, a laser level is used for calibration to ensure that the levelness error of the track installation is less than 2mm / 10m; the radius of all turning sections 102 is designed to be greater than 500mm, specifically 600mm in this embodiment; at the manhole at the top of the box girder, the track is laid in an elevated manner to ensure that the bottom of the track is at least 850mm above the box plate, forming a smooth passage for maintenance personnel.

[0028] The robot body mainly includes a walking unit 2, a detection unit 3, an intelligent control unit, and a power supply unit. The chassis of the vehicle body 201 has dimensions of 210mm (length) × 210mm (width) × 110mm (height) and is made of aluminum alloy to reduce weight. Two pairs of walking wheels 202 are installed at its bottom, namely front walking wheels 2021 and rear walking wheels 2022. Each pair of walking wheels is connected by a mounting shaft 205, one of which is driven by a servo drive motor 206 with a rated power of 750W. The two mounting shafts are synchronized by a transmission chain 207. On both sides of each pair of walking wheels, there is a nylon auxiliary wheel 203. All the walking wheels 202 and the auxiliary wheels 203 together form a ring structure, which is tightly locked onto the T-shaped flange of the track 101 with a fit of more than 95%. This design enables the robot to stably climb a 35° slope and smoothly pass through curves at a speed of 0.15m / s.

[0029] The detection unit 3 is fixed to the top of the vehicle body 201 via a flange; its core is a six-axis collaborative robotic arm 301, weighing 6kg, with a payload of 3kg, a maximum reach of 1850mm, and a repeatability of ±0.5mm; a self-illuminating high-definition camera 302 is installed at the end of the robotic arm via a quick-change interface; the camera uses an all-aluminum alloy shell, has 12 megapixels, supports electric focusing from 550mm to 2000mm, has a built-in LED fill light, and its core photosensitive element can work stably in environments from -40℃ to 85℃, and the video encoding supports H.265.

[0030] The power supply unit includes two independent 48V / 45Ah lithium-ion batteries 209, arranged side-by-side inside the vehicle body 201. The intelligent control unit 4 uses an embedded industrial computer based on the ARM architecture. It dynamically manages the output of the two batteries according to the system load: normally, one battery powers the drive motor 206 and the control system, while the other powers the robotic arm 301 and the camera 302. When greater driving force is required, such as when an increase in slope is detected or the battery power supply for the walking unit is below 20%, the two batteries can be connected in parallel to power the walking unit. Two copper alloy charging posts 208 are exposed at the rear of the vehicle body 201, connected to the two batteries respectively.

[0031] At the starting end of track 101, a charging box 103 is installed. Inside the charging box is a charging module connected to the mains power. Its panel has two charging slots 104 corresponding to the positions of the charging posts 208. When the walking unit returns to the starting position, the charging posts 208 are inserted into the charging slots 104 for charging. After charging is completed, the intelligent control unit cuts off the power supply to complete the charging. At this time, the charging posts 208 are still inserted into the charging slots 104, which can play a good dustproof role. The charging posts 208 and the charging slots 104 can also be magnetically connected to prevent the vehicle body from falling off from the initial position. On the upper surface of the section of track 101 about 1 meter away from the charging box, a guide protrusion 105 with a trapezoidal cross section is welded. The front end of the guide protrusion 105 gradually narrows towards the front, so that the gap between the two rear walking wheels 2022 can cooperate with the guide protrusion 105. Limiting baffles 1051 are set on both sides of the rear end of the guide protrusion 105. The setting of the limiting baffles 1051 can prevent excessive collision between the vehicle body 1 and the charging box.

[0032] The robot's workflow is as follows: System deployment and teaching are specifically steps S1 and S2: After the track is installed, the operator manually remotely controls the robot to run at low speed along the entire track once through a tablet computer connected to the robot's Wi-Fi; during the operation, the operator clicks on the software interface in sequence to record the position coordinates of each key inspection point such as U-rib joint, bolt group, and weld, and sets the preset shooting angle and focal length of the robotic arm for each point; this teaching trajectory is saved.

[0033] Automatic inspection and identification are specifically performed in steps S3 and S4: The automatic inspection task is initiated; the intelligent control unit controls the vehicle body 201 to move according to the taught trajectory; after reaching each preset point, the robotic arm 301 is controlled to move to the preset posture, and the camera 302 automatically focuses and turns on the supplementary light to take pictures; the high-definition images collected are transmitted in real time to the edge computing server deployed at the bridgehead via 5G CPE or wireless local area network; the server's built-in disease identification algorithm based on deep convolutional neural network analyzes the images in real time, automatically selects the identified cracks, rust or loose bolt areas, and generates a preliminary inspection report containing the location and images.

[0034] Autonomous return to charging, specifically step S5: After the inspection task is completed, or when the intelligent control unit detects that the charge of any battery 209 is below 25%, the robot is controlled to return along the track; when approaching the charging box 103, the robot decelerates, and the guide protrusions 105 on the track gradually embed into the gap between the front and rear wheels, guiding the vehicle body 201 to fine-tune its position until the two charging posts 208 are accurately inserted into the charging slots 104 of the charging box 103, and automatic contact charging begins. During charging, the BMS battery management system monitors the battery temperature and voltage to ensure charging safety.

[0035] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims.

Claims

1. A bridge box girder inspection robot, installed inside the cavity of the box girder, characterized in that: The system includes a track unit (1) and a traveling unit (2). The track unit (1) includes a track (101) with an I-shaped or T-shaped cross-section, laid in a cavity. The track (101) includes several turning sections (102), and the radius of each turning section (102) is not less than 500 mm. The traveling unit (2) includes a vehicle body (201). The bottom of the vehicle body (201) is provided with traveling wheels (202) and auxiliary wheels (203) on both sides of the traveling wheels (202). The auxiliary wheels (203) and the traveling wheels (202) surround the track. The vehicle body (201) is equipped with a detection unit (3) on its top. The detection unit (3) includes a six-axis robotic arm (301), and a self-illuminating camera (302) is installed at the end of the six-axis robotic arm (301). The vehicle body (201) is also equipped with an intelligent control unit and a power supply unit. The intelligent control unit is electrically connected to the walking unit (2) and the six-axis robotic arm (301) and is used to control the movement of the vehicle body (201) along the track, control the posture of the robotic arm, and receive and process the images collected by the self-illuminating camera (302).

2. The bridge box girder inspection robot according to claim 1, characterized in that: A charging box (103) is provided at one end of the track (101); when the intelligent control unit identifies that the power supply unit's power is lower than the set value, it issues a control command to control the vehicle body (201) to automatically return to the charging box (103) along the track (101) for charging.

3. The bridge box girder inspection robot according to claim 2, characterized in that: The walking wheels (202) include front walking wheels (2021) and rear walking wheels (2022). There are two front walking wheels (2021) and two rear walking wheels (2022). An installation shaft (205) is provided between the two corresponding front walking wheels (2021) and rear walking wheels (2022). A drive motor (206) for driving the installation shaft (205) to rotate is provided in the vehicle body (201). A transmission chain (207) is connected between the two installation shafts (205). A guide protrusion (105) is provided on the upper surface of the track (101) near the charging box (103). When the vehicle body (201) is charging, the two ends of the guide protrusion (105) are respectively located between the two front walking wheels (2021) and the two rear walking wheels (2022) to achieve precise positioning.

4. The bridge box girder inspection robot according to claim 3, characterized in that: The power supply unit includes two independently installed batteries (209), and a charging post (208) corresponding to the battery (209) is provided on each side of the rear end of the vehicle body (201); the charging box (103) is provided with a charging slot (104) that cooperates with the charging post (208); under the control of the intelligent control unit, the two batteries (209) supply power to the detection unit (3) or the walking unit (2) individually, or cooperate to supply power to the walking unit (2).

5. The bridge box girder inspection robot according to claim 1, characterized in that: The track (101) is formed by welding solid steel plates, and the welding height at the connection is not less than 8mm. The track surface is treated with galvanizing and anti-rust paint. The section of the track (101) at the manhole of the box girder has a passage width of not less than 800mm.

6. The bridge box girder inspection robot according to claim 1, characterized in that: The six-axis robotic arm (301) has an arm span of not less than 1800mm, a repeatability of ±0.5mm, and can achieve ±180° horizontal rotation and -45° to 90° pitch adjustment.

7. The bridge box girder inspection robot according to claim 1, characterized in that: The self-illuminating camera (302) has a pixel count of no less than 12 million, supports autofocus from 500mm to 2000mm, and has an operating temperature range of -40℃ to 85℃.

8. The bridge box girder inspection robot according to claim 1, characterized in that: The intelligent control unit includes a trajectory teaching subunit, with a teaching trajectory deviation of no more than 5mm, and a built-in algorithm subunit for real-time analysis of acquired images to automatically identify cracks or loosening defects.

9. An automated inspection method using a bridge box girder inspection robot as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1: Lay the track unit (1) along the inspection path in the internal cavity of the box girder; S2: The inspection path is planned through the intelligent control unit, and the shooting posture of the six-axis robotic arm (301) at the key detection points is set; S3: Control the walking unit (2) to automatically cruise along the track, and simultaneously control the six-axis robotic arm (301) to adjust according to the preset posture, while activating the self-illuminating camera (302) to collect images; S4: The intelligent control unit performs real-time analysis on the acquired images and automatically labels the disease type and location; S5: After the inspection task is completed or the battery level is detected to be lower than the set value, control the robot to automatically return to the charging box (103) for charging.

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