A high-precision flexible detection platform at the end of a long-arm bridge inspection robot

Abstract

This invention relates to the field of flexible imaging inspection gimbal technology, and particularly to a high-precision flexible inspection gimbal at the end of a bridge inspection long-arm robot. It includes a flexible support hinge, a gimbal docking auxiliary structure, and an image acquisition system. The rear end of the flexible support hinge is connected to the end of the long arm of the bridge inspection long-arm robot. The gimbal docking auxiliary structure and the image acquisition system are located at the front end of the flexible support hinge. The gimbal docking auxiliary structure is used for flexible contact with the wall of the bridge main beam, and the image acquisition system is used to acquire images of the bridge main beam wall. This invention enables the inspection gimbal to safely and stably dock against the bottom wall of the bridge main beam even when the bridge structure is not visible, achieving close-range, high-precision imaging inspection of small cracks in the main beam, ensuring the operational safety of the bridge inspection long-arm robot's ultra-long connecting rod.

Description

Technical Field

[0001] This invention relates to the field of flexible photographic inspection gimbal technology, and in particular to a high-precision flexible inspection gimbal at the end of a bridge inspection long-arm robot. Background Technology

[0002] Currently, the detection of cracks on the bottom surface of the main girder of large bridges with high piers and thick sections mainly relies on manual labor. This process requires deploying heavy-duty truss or boom-type bridge inspection vehicles on the bridge deck. Inspectors are transported to the bottom wall of the main girder via truss passageways or suspended baskets and use handheld inspection tools to check for cracks. This traditional inspection method requires inspectors to climb and work at heights, resulting in high labor intensity, high risk, and low inspection efficiency. Bridge inspection vehicles also occupy a large area, and the equipment deployment speed is slow, seriously affecting traffic.

[0003] Using a lightweight bridge inspection long-arm robot equipped with an inspection gimbal to achieve high-precision inspection of the bottom surface of the main beam of large bridges will effectively improve inspection efficiency, reduce operational difficulty, and minimize the impact on traffic. However, due to the long arm and lightweight structure of the bridge inspection long-arm robot, the platform experiences significant disturbance during the end-effector inspection gimbal's transport process and when taking pictures, resulting in unclear images. Summary of the Invention

[0004] To achieve accurate photographic detection of minor cracks in the main beam using a bridge inspection long-arm robot inspection gimbal, this invention provides a high-precision flexible inspection gimbal at the end of a bridge inspection long-arm robot. This solves the problem of large platform disturbances and unclear images during transmission and photography caused by the long arm length and lightweight structure of existing end-effector inspection gimbals.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a high-precision flexible inspection gimbal for the end effector of a bridge inspection long-arm robot, comprising a flexible support hinge, an inspection gimbal docking auxiliary structure, and an image acquisition system. The rear end of the flexible support hinge is connected to the end effector of the long arm of the bridge inspection long-arm robot, while the inspection gimbal docking auxiliary structure and the image acquisition system are located at the front end of the flexible support hinge. The inspection gimbal docking auxiliary structure is used for flexible contact with the wall of the bridge main beam, and the image acquisition system is used for acquiring images of the bridge main beam wall.

[0007] The flexible support hinge includes a long-arm end-stage support rod, a gimbal base, a support hinge, and an elastic connection mechanism. The long-arm end-stage support rod is connected to the gimbal base through the support hinge and the elastic connection mechanism, and the support hinge is located below the elastic connection mechanism. The rear end of the long-arm end-stage support rod is connected to the end of the long arm of the bridge inspection long-arm robot. The detection gimbal docking auxiliary structure and the image acquisition system are both set on the gimbal base.

[0008] The detection gimbal docking auxiliary structure includes an arc-shaped fixed-distance stop bar. The lower end of the fixed-distance stop bar is fixedly connected to the front end of the gimbal base, and the upper end of the fixed-distance stop bar extends towards the end support rod of the long arm.

[0009] The fixed-distance stop bar includes two parallel arc-shaped bars, the upper ends of which are connected by a connecting rod, and multiple auxiliary bearings are spaced apart along the length of the two arc-shaped bars.

[0010] The image acquisition system includes a pose adjustment mechanism, a camera base, a camera, and a laser rangefinder. The pose adjustment mechanism is mounted on the gimbal base, the camera base is mounted on the pose adjustment mechanism, and both the camera and the laser rangefinder are mounted on the camera base. The camera is used to take pictures, and the laser rangefinder is used to measure the distance to take the picture.

[0011] The pose adjustment mechanism includes a gimbal pitch axis support, a pitch joint, a lateral movement support, and a lateral movement joint. The gimbal pitch axis support is mounted on the gimbal base. The lateral movement support is connected to the gimbal pitch axis support via the pitch joint. The lateral movement joint is mounted on the lateral movement support and connected to the camera base.

[0012] The elastic connection mechanism includes an adjusting nut, a spring connecting column, and a constraint spring. The two ends of the constraint spring are respectively connected to two spring connecting columns. The two spring connecting columns are slidably connected to the end support rod of the long arm and the gimbal base, respectively. Each spring connecting column is axially limited by the adjusting nut.

[0013] The long arm end support rod is equipped with a sensor bracket, and the sensor bracket is equipped with a sensor; the rear end of the gimbal base is equipped with a trigger swing rod;

[0014] When the gimbal base rotates to a set angle relative to the long arm's final support rod, the swing arm trigger sensor is activated.

[0015] The advantages and beneficial effects of this invention are as follows: The high-precision flexible imaging detection gimbal proposed in this invention for the end of a bridge inspection long-arm robot can safely and stably stop against the bottom wall of the main beam of the bridge when the structure under the bridge is not visible, and achieve close-range high-precision imaging detection of small cracks in the main beam.

[0016] This invention enables flexible contact between the final support rod of the bridge inspection long-arm robot and the main beam wall, allowing for stable docking and ensuring the operational safety of the ultra-long connecting rod of the bridge inspection long-arm robot.

[0017] This invention enables the smooth docking of a long-arm robot in both active and passive modes, reducing the vibration control requirements of the bridge inspection long-arm robot and providing a new approach for the accurate photographic detection of small cracks in the main beam. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a high-precision flexible detection gimbal at the end of a bridge inspection long-arm robot according to the present invention;

[0019] Figure 2 This is a schematic diagram of the working state of the high-precision flexible detection gimbal at the end of a bridge inspection long-arm robot according to the present invention.

[0020] In the diagram: 1 is the final support rod of the long arm, 2 is the gimbal base, 3 is the support hinge, 4 is the trigger swing arm, 5 is the sensor bracket, 6 is the sensor, 7 is the adjusting nut, 8 is the spring connecting column, 9 is the constraint spring, 10 is the gimbal pitch axis support, 11 is the pitch joint, 12 is the lateral movement support, 13 is the lateral movement joint, 14 is the camera base, 15 is the camera, 16 is the laser rangefinder, 17 is the distance stop bar, 18 is the auxiliary bearing, 19 is the bridge inspection long arm robot, and 20 is the bridge. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1 As shown, the present invention provides a high-precision flexible inspection gimbal for the end effector of a bridge inspection long-arm robot, comprising a flexible support hinge, an inspection gimbal docking auxiliary structure, and an image acquisition system. The rear end of the flexible support hinge is connected to the end effector of the long arm of the bridge inspection long-arm robot, and the inspection gimbal docking auxiliary structure and the image acquisition system are disposed at the front end of the flexible support hinge. The inspection gimbal docking auxiliary structure is used for flexible contact with the wall of the bridge main beam, and the image acquisition system is used for acquiring images of the wall of the bridge main beam.

[0023] In embodiments of the present invention, the flexible support hinge includes a long-arm end-stage support rod 1, a gimbal base 2, a support hinge 3, and an elastic connection mechanism. The long-arm end-stage support rod 1 is connected to the gimbal base 2 through the support hinge 3 and the elastic connection mechanism, and the support hinge 3 is located below the elastic connection mechanism. The rear end of the long-arm end-stage support rod 1 is connected to the end of the long arm of the bridge inspection long-arm robot. The detection gimbal docking auxiliary structure and the image acquisition system are both set on the gimbal base 2.

[0024] In an embodiment of the present invention, the detection gimbal docking auxiliary structure includes an arc-shaped fixed-distance stop bar 17. The lower end of the fixed-distance stop bar 17 is fixedly connected to the front end of the gimbal base 2, and the upper end of the fixed-distance stop bar 17 extends toward the end support bar 1 of the long arm.

[0025] Specifically, the fixed-distance stop bar 17 includes two parallel arc-shaped bars, the upper ends of which are connected by a connecting rod, and multiple auxiliary bearings 18 are spaced apart along the length direction on the two arc-shaped bars.

[0026] In an embodiment of the present invention, the image acquisition system includes a pose adjustment mechanism, a camera base 14, a camera 15, and a laser rangefinder 16. The pose adjustment mechanism is mounted on a gimbal base 2, the camera base 14 is mounted on the pose adjustment mechanism, and both the camera 15 and the laser rangefinder 16 are mounted on the camera base 14. The camera 15 is used to take pictures, and the laser rangefinder 16 is used to measure the distance to take pictures.

[0027] In an embodiment of the present invention, the pose adjustment mechanism includes a gimbal pitch axis support 10, a pitch joint 11, a lateral movement support 12, and a lateral movement joint 13. The gimbal pitch axis support 10 is mounted on the gimbal base 2. The lateral movement support 12 is connected to the gimbal pitch axis support 10 via the pitch joint 11. The lateral movement joint 13 is mounted on the lateral movement support 12 and connected to the camera base 14. The pitch joint 11 and the lateral movement joint 13 are adjustment mechanisms for detecting the gimbal's observation angle and range; both the pitch joint 11 and the lateral movement joint 13 are existing technologies.

[0028] In an embodiment of the present invention, the elastic connection mechanism includes an adjusting nut 7, a spring connecting column 8, and a constraint spring 9. The two ends of the constraint spring 9 are respectively connected to two spring connecting columns 8. The two spring connecting columns 8 are respectively slidably connected to the long arm end support rod 1 and the gimbal base 2, and each spring connecting column 8 is axially limited by the adjusting nut 7.

[0029] Specifically, one adjusting nut 7 is connected to a spring connecting post 8 via a thread and presses against the baffle of the gimbal base 2; one end of the spring connecting post 8 is connected to the adjusting nut 7, and the other end is hooked to the constraint spring 9. The support hinge 3 is a free-rotating hinge, and its rotation angle is limited by the constraint spring 9, with both ends of the constraint spring 9 hooked to the spring connecting post 8.

[0030] Furthermore, a sensor bracket 5 is provided on the long arm end support rod 1, and a sensor 6 is provided on the sensor bracket 5; a trigger swing rod 4 is provided at the rear end of the gimbal base 2; when the gimbal base 2 is rotated relative to the long arm end support rod 1 to a set angle, the trigger swing rod 4 triggers the sensor 6.

[0031] The present invention provides a high-precision flexible inspection gimbal at the end of a bridge inspection long-arm robot, the working principle of which is as follows:

[0032] like Figure 2As shown, the present invention provides a high-precision flexible detection gimbal at the end of a bridge inspection long-arm robot 19, which is mounted on the top of a bridge 20. The long arm of the bridge inspection long-arm robot 19 extends, and as the end-stage support rod 1 rotates to the bottom wall of the main beam of the bridge 20, the distance stop 17 first contacts the bottom wall of the main beam. The end-stage support rod 1 continues to rise, and the support hinge 3 passively unfolds. Under the constraint of the bottom wall of the main beam, the distance stop 17 slides forward along the wall. After the support hinge 3 unfolds to a certain angle, the swing arm 4 is triggered to press the sensor 6, and the end-stage support rod 1 stops moving. The detection gimbal then smoothly rests on the wall of the main beam. At this time, the pitch joint 11 and the lateral joint 13 are adjusted so that the camera 15 is aimed at the surface defect location of the main beam wall for high-precision imaging. During imaging, the laser rangefinder 16 measures the accurate distance of the camera 15, providing accurate distance parameters for subsequent defect identification.

[0033] In this embodiment of the invention, the fixed-distance stop bar 17 and the flexible support hinge work together to ensure the smooth and safe stopping of the detection gimbal against the bottom wall of the main beam. The fixed-distance stop bar 17 facilitates contact between the end-of-arm detection gimbal and the main beam wall, while the flexible support hinge ensures safety during the contact process. Because the length of the end-of-arm support rod 1 is approximately 4 meters, its acceleration is very small to achieve stability control of the bridge inspection robot. Therefore, the end-of-arm support rod 1 cannot stop immediately after the fixed-distance stop bar 17 contacts the main beam. Here, the support hinge 3 provides a smooth, accommodating rotation to stop the end-of-arm support rod 1, preventing excessive rotation and damage. The constraint spring 9 provides the preload for the support hinge 3 to close, and also provides smooth, accommodating rotation for the end-of-arm support rod 1 relative to the gimbal base 2. To ensure immediate cessation of the rotation of the end-of-arm support rod 1, a sensor 6 and a trigger lever 4 are installed at the support hinge 3. When the gimbal base 2 rotates at a specific angle relative to the long arm end support rod 1, the swing arm 4 triggers the sensor 6, and the drive unit of the long arm end support rod 1 immediately stops rotating accordingly.

[0034] Specifically, the flexibility of the supporting hinge 3 is achieved by the constraint spring 9 and the adjusting nut 7. The tension constraint of the constraint spring 9 is crucial for the safe operation of the inspection gimbal of the bridge inspection long-arm robot. If the stiffness and preload of the constraint spring 9 are too small, the hinge angle between the long-arm final stage support rod 1 and the gimbal base 2 cannot be stable. If the stiffness is too large or the preload is too large, the supporting hinge 3 will not provide safety protection. Therefore, to adjust the preload, two adjusting nuts 7 need to be set at both ends of the connection to quickly and accurately adjust the preload.

[0035] In this embodiment, the auxiliary bearing 18 is rotatably connected to the fixed-distance stop 17. The auxiliary bearing 18 is provided to ensure that after the fixed-distance stop 17 contacts the wall of the main beam and before the last stage support rod 1 of the long arm stops moving, as the last stage support rod 1 of the long arm continues to rotate, the support hinge 3 smoothly unfolds, and the fixed-distance stop 17 slides forward along the wall. The auxiliary bearings 18 are evenly distributed on the fixed-distance stop 17 to reduce the sliding friction or jamming of the fixed-distance stop 17. The camera 15 and the laser rangefinder 16 are jointly mounted on the camera base 14. The relative positions of the camera 15 and the laser rangefinder 16 remain unchanged. After the attitude is adjusted by the pitch joint 11 and the lateral joint 13, the laser rangefinder 16 always accurately measures the imaging distance of the camera 15, providing a guarantee for crack identification.

[0036] This invention provides a high-precision flexible inspection gimbal at the end of a bridge inspection long-arm robot. Mounted on the final support rod of the long-arm robot, it is transported to the observation position. Utilizing its flexible joints, the inspection gimbal can be stably stopped and pressed against the bottom wall of the bridge main beam. After adjusting the camera's shooting angle or range through the pitch or lateral joints, the imaging distance is measured using a laser rangefinder, and the camera takes pictures simultaneously. This enables the bridge inspection long-arm robot inspection gimbal to accurately photograph and detect small cracks in the main beam.

[0037] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, extensions, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A high-precision flexible inspection gimbal at the end of a bridge inspection long-arm robot, characterized in that, It includes a flexible support hinge, a detection gimbal docking auxiliary structure, and an image acquisition system. The rear end of the flexible support hinge is connected to the end of the long arm of the bridge inspection long-arm robot. The detection gimbal docking auxiliary structure and the image acquisition system are set at the front end of the flexible support hinge. The detection gimbal docking auxiliary structure is used to flexibly contact the wall of the bridge main beam, and the image acquisition system is used to acquire images of the wall of the bridge main beam. The flexible support hinge includes a long-arm end-stage support rod (1), a gimbal base (2), a support hinge (3), and an elastic connection mechanism. The long-arm end-stage support rod (1) is connected to the gimbal base (2) through the support hinge (3) and the elastic connection mechanism, and the support hinge (3) is located below the elastic connection mechanism. The rear end of the long-arm end-stage support rod (1) is connected to the end of the long arm of the bridge inspection long-arm robot. The detection gimbal docking auxiliary structure and the image acquisition system are both set on the gimbal base (2). The detection gimbal docking auxiliary structure includes a fixed-distance stop bar (17) with an arc-shaped structure. The lower end of the fixed-distance stop bar (17) is fixedly connected to the front end of the gimbal base (2), and the upper end of the fixed-distance stop bar (17) extends toward the end support bar (1) of the long arm. The fixed-distance stop bar (17) includes two parallel arc-shaped bars, the upper ends of which are connected by a connecting rod, and multiple auxiliary bearings (18) are spaced apart along the length direction on the two arc-shaped bars.

2. The high-precision flexible inspection gimbal at the end of the bridge inspection long-arm robot according to claim 1, characterized in that, The image acquisition system includes a pose adjustment mechanism, a camera base (14), a camera (15), and a laser rangefinder (16). The pose adjustment mechanism is mounted on the gimbal base (2), the camera base (14) is mounted on the pose adjustment mechanism, and both the camera (15) and the laser rangefinder (16) are mounted on the camera base (14). The camera (15) is used to take pictures, and the laser rangefinder (16) is used to measure the distance to take pictures.

3. The high-precision flexible inspection gimbal at the end of the bridge inspection long-arm robot according to claim 2, characterized in that, The posture adjustment mechanism includes a gimbal pitch axis support (10), a pitch joint (11), a lateral movement support (12), and a lateral movement joint (13). The gimbal pitch axis support (10) is mounted on the gimbal base (2). The lateral movement support (12) is connected to the gimbal pitch axis support (10) via the pitch joint (11). The lateral movement joint (13) is mounted on the lateral movement support (12) and is connected to the camera base (14).

4. The high-precision flexible inspection gimbal at the end of the bridge inspection long-arm robot according to claim 1, characterized in that, The elastic connection mechanism includes an adjusting nut (7), a spring connecting column (8), and a constraint spring (9). The two ends of the constraint spring (9) are connected to the two spring connecting columns (8) respectively. The two spring connecting columns (8) are slidably connected to the long arm end support rod (1) and the gimbal base (2) respectively. Each spring connecting column (8) is axially limited by the adjusting nut (7).

5. The high-precision flexible inspection gimbal at the end of the bridge inspection long-arm robot according to claim 1, characterized in that, The long arm end support rod (1) is provided with a sensor bracket (5), and the sensor bracket (5) is provided with a sensor (6); the rear end of the gimbal base (2) is provided with a trigger swing rod (4). When the gimbal base (2) is rotated to a set angle relative to the long arm end support rod (1), the swing arm (4) triggers the sensor (6).

Images