Weld inspection method and wall-climbing robot

Abstract

The present application provides a weld inspection method and a wall-climbing robot, which relate to the technical field of weld inspection. The method uses a laser sensor carried by the wall-climbing robot to detect the weld width, the position offset of the weld relative to the center line of the wall-climbing robot, and the distance from the boundaries on both sides of the weld to the center line in real time, and adjusts the movement direction of the robot based on the position offset to achieve alignment with the weld. By analyzing the change in weld width and the symmetry of the distance from the boundaries on both sides of the weld to the center line, T-shaped welds and inspection modes are identified, and the wall-climbing robot is automatically controlled to turn according to the inspection mode for subsequent inspections, thereby achieving accurate identification of T-shaped welds and improving the accuracy of weld tracking and weld inspection efficiency.

Description

Technical Field

[0001] The present application relates to the technical field of weld inspection, and in particular to a weld inspection method and a wall-climbing robot. Background Art

[0002] Wind turbine tower weld inspection is a critical step in ensuring the safe operation of wind turbines. Traditionally, weld inspections require workers to climb the tower and use weld inspection equipment. However, this approach is inefficient, costly, and dangerous. While some research has explored replacing manual inspections with wall-climbing robots, these approaches often face technical bottlenecks, such as insufficient weld tracking accuracy and a lack of T-weld recognition capabilities. This makes inspection results inadequate. Summary of the Invention

[0003] The present application provides a weld inspection method and a wall-climbing robot to at least solve the above technical problems existing in the prior art.

[0004] According to a first aspect of the present application, a weld inspection method is provided, which is applied to a wall-climbing robot, wherein the wall-climbing robot includes a laser sensor. The method includes:

[0005] The laser sensor is used to detect in real time the width of the weld, the position offset of the weld relative to the center line of the wall-climbing robot, the first distance from the first boundary of the weld to the center line of the wall-climbing robot, and the second distance from the second boundary of the weld to the center line of the wall-climbing robot;

[0006] Adjusting the movement direction of the wall-climbing robot based on the position offset so that the center line of the wall-climbing robot remains aligned with the weld;

[0007] Determine the current weld type and the current inspection mode according to the weld width, a first distance from a first boundary of the weld to the center line of the wall-climbing robot, and a second distance from a second boundary of the weld to the center line of the wall-climbing robot;

[0008] If it is determined that the current weld type is a T-type weld and the inspection mode is a longitudinal weld mode, the wall-climbing robot is controlled to complete the straight motion and then turn to perform a transverse weld inspection;

[0009] If it is determined that the current weld type is a T-type weld and the inspection mode is a transverse weld mode, the wall-climbing robot is controlled to complete the circumferential covering action and then turn to perform longitudinal weld inspection.

[0010] In one embodiment, the wall-climbing robot further includes a magnetic leakage device, and the method further includes:

[0011] During the inspection process, weld defects are detected based on magnetic flux leakage equipment.

[0012] In one embodiment, the real-time detection of the weld width, the position offset of the weld relative to the center line of the wall-climbing robot, the first distance from the first boundary of the weld to the center line of the wall-climbing robot, and the second distance from the second boundary of the weld to the center line of the wall-climbing robot by the laser sensor includes:

[0013] Based on the principle of optical triangulation, a laser sensor is used to project a laser line onto the weld and obtain the coordinates of each point on the laser line. The projection range of the laser line is determined according to the preset weld width.

[0014] According to the coordinates of each point on the laser line, the weld width, the position offset of the weld relative to the center line of the wall-climbing robot, the first distance from the first boundary of the weld to the center line of the wall-climbing robot, and the second distance from the second boundary of the weld to the center line of the wall-climbing robot are calculated.

[0015] In one embodiment, adjusting the movement direction of the wall-climbing robot based on the position offset includes:

[0016] Calculating motion parameters of the wall-climbing robot according to the position offset and the PID control algorithm, wherein the motion parameters include left wheel speed and right wheel speed;

[0017] The movement direction of the wall-climbing robot is adjusted according to the movement parameters.

[0018] In one embodiment, the determining of the current weld type and the current inspection mode based on the weld width, the first distance from the first boundary of the weld to the center line of the wall-climbing robot, and the second distance from the second boundary of the weld to the center line of the wall-climbing robot includes:

[0019] When the weld width exceeds a set threshold, determining that the current weld type is a T-type weld;

[0020] When the weld width exceeds a set threshold and the difference between the first distance and the second distance does not exceed a first set difference threshold, determining that the current inspection mode is a longitudinal seam mode;

[0021] When the weld width exceeds a set threshold and the difference between the first distance and the second distance exceeds a second set difference threshold, it is determined that the current inspection mode is a transverse seam mode.

[0022] In one embodiment, the wall-climbing robot further includes an IMU sensor, and controlling the wall-climbing robot to turn and perform transverse seam inspection after completing the straight-line motion includes:

[0023] Controlling the wall-climbing robot to continue moving in the current direction for a set distance and then stop, wherein the set distance is determined according to the length of the wall-climbing robot;

[0024] Based on the IMU sensor, the wall-climbing robot is controlled to perform a 90-degree rotation according to the preset direction by keeping one wheel stationary and the other wheel rotating in the opposite direction, and then begins to inspect the transverse seams.

[0025] In one embodiment, controlling the wall-climbing robot to turn and perform longitudinal seam inspection after completing the circumferential covering action includes:

[0026] Control the wall-climbing robot to continue moving along the circumference of the tower until the T-shaped weld is detected for the third time;

[0027] After the T-shaped weld is detected for the third time, the wall-climbing robot is controlled to continue moving in the current direction for a set distance and then stop, wherein the set distance is determined according to the length of the wall-climbing robot;

[0028] Based on the IMU sensor, the wall-climbing robot is controlled to perform a 90-degree rotation according to the preset direction by keeping one wheel stationary and the other wheel rotating in the opposite direction, and begins to perform longitudinal seam inspection.

[0029] According to a second aspect of the present application, a wall-climbing robot is provided, wherein the wall-climbing robot is used to perform the above-mentioned weld inspection method, and the wall-climbing robot comprises:

[0030] A magnetic adsorption chassis, comprising a vehicle body, a front wheel structure, and a rear wheel structure. The front wheel structure comprises two front wheels, and the rear wheel structure comprises two rear wheels. The two front wheels and the two rear wheels are connected to the vehicle body via hinges. The front wheels are omnidirectional wheels comprising a non-contact magnetic array, and the rear wheels are magnetic wheels.

[0031] The detection system includes a laser sensor, an IMU sensor and an odometer, and the laser sensor, IMU sensor and odometer are all installed on the center line of the vehicle body on the side close to the tower to be inspected.

[0032] In one embodiment, the distance from the center line of the wall-climbing robot to the hinge is equal to the distance from the hinge to the wheel.

[0033] In one possible implementation manner, the wall-climbing robot further includes a magnetic leakage device, which adopts an integrated sensor structure and includes a yoke, a magnet, a magnetic bridge, and a magnetic sensitive detection element.

[0034] The weld inspection method and wall-climbing robot of the present application use a laser sensor carried by the wall-climbing robot to detect the weld width, the position offset of the weld relative to the center line of the wall-climbing robot, and the distance from the boundaries on both sides of the weld to the center line in real time, adjust the robot's movement direction based on the position offset to achieve alignment with the weld, identify T-shaped welds and inspection modes by analyzing the change in weld width and the symmetry of the distance from the boundaries on both sides of the weld to the center line, and automatically control the steering of the wall-climbing robot according to the inspection mode for subsequent inspections, thereby achieving accurate identification of T-shaped welds and improving the accuracy of weld tracking and weld inspection efficiency.

[0035] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present application, nor is it intended to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and other objects, features and advantages of the exemplary embodiments of the present application will become readily understood by reading the detailed description below with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present application are shown in an illustrative and non-limiting manner, in which:

[0037] In the drawings, the same or corresponding reference numerals denote the same or corresponding parts.

[0038] Figure 1 A schematic diagram of the implementation process of the weld inspection method provided in an embodiment of the present application is shown;

[0039] Figure 2 A schematic diagram showing a working scenario of a wall-climbing robot in a weld inspection method according to an embodiment of the present application is shown;

[0040] Figure 3 A schematic diagram illustrating the implementation flow of the laser sensor detection operation of the weld inspection method provided in an embodiment of the present application is shown;

[0041] Figure 4 A schematic diagram showing the working principle of the laser sensor of the weld inspection method provided in an embodiment of the present application is shown;

[0042] Figure 5 A schematic diagram illustrating the implementation flow of the robot control operation of the weld inspection method provided in an embodiment of the present application is shown;

[0043] Figure 6 A schematic diagram illustrating the implementation flow of the weld type and inspection mode determination operation of the weld inspection method provided in an embodiment of the present application is shown;

[0044] Figure 7 An example diagram of a T-shaped weld of the weld inspection method provided in an embodiment of the present application is shown;

[0045] Figure 8 A schematic diagram showing the steering of a wall-climbing robot in a weld inspection method according to an embodiment of the present application is shown;

[0046] Figure 9 A schematic diagram showing a method for connecting the wheels and the body of a wall-climbing robot provided in an embodiment of the present application is shown;

[0047] Figure 10 A diagram showing the working principle of the magnetic flux leakage device of the wall-climbing robot provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0048] In order to make the purpose, features, and advantages of this application more obvious and easy to understand, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of this application.

[0049] Figure 1 A schematic diagram of the implementation process of the weld inspection method provided in an embodiment of the present application is shown.

[0050] refer to Figure 1 The present invention provides a weld inspection method for a wall-climbing robot equipped with a laser sensor. The method includes:

[0051] Operation 101 is to detect in real time by a laser sensor the weld width, the position offset of the weld relative to the center line of the wall-climbing robot, the first distance from the first boundary of the weld to the center line of the wall-climbing robot, and the second distance from the second boundary of the weld to the center line of the wall-climbing robot.

[0052] The weld inspection method of this application is primarily used for weld inspection of wind turbine towers. Due to the curved surface characteristics of wind turbine towers, the wall-climbing robot in this embodiment is preferably a rear-wheel-driven magnetic wall-climbing robot. Typically, a wall-climbing robot is equipped with a laser sensor. To enable the laser sensor to detect welds on the surface of the wind turbine tower, the laser sensor is positioned on the side of the wall-climbing robot closest to the wind turbine tower and located at the centerline of the wall-climbing robot.

[0053] Before inspecting the wind turbine tower, the staff will place the wall-climbing robot on the weld on the surface of the wind turbine tower and try to align the center line of the wall-climbing robot with the weld. Then the wall-climbing robot will start inspecting the weld.

[0054] During the weld inspection process, in order to ensure the weld tracking accuracy, that is, the alignment accuracy of the wall-climbing robot's center line with the weld during the inspection process, it is necessary to continuously use laser sensors to detect the position offset of the weld relative to the center line of the wall-climbing robot.

[0055] And reference Figure 2 , Figure 2 A schematic diagram of a wall-climbing robot working scenario of a weld inspection method provided in an embodiment of the present application is shown. Figure 2 The wall-climbing robot 1 is inspecting the longitudinal seams of the wind turbine tower. Figure 2 It can be seen that the welds of wind turbine towers are usually formed by alternating transverse seams and longitudinal seams. When inspecting the welds of wind turbine towers, it is necessary to perform conversion control between transverse seams and longitudinal seams. Usually, the intersection of transverse seams and longitudinal seams can be understood as a T-shaped weld. The biggest difference between T-shaped welds and transverse and longitudinal seams is the weld width. Since the T-shaped weld identified under the transverse seam inspection is completely deviated to one side, whether the distance from the weld boundary to the weld is symmetrical can be regarded as a judgment condition for determining the current inspection mode, that is, whether the inspection is a transverse seam inspection or a longitudinal seam inspection. Among them, since the center line of the climbing robot is aligned with the weld during the inspection process, the distance from the weld boundary to the weld can be regarded as the distance from the weld boundary to the center line of the wall-climbing robot.

[0056] Therefore, in addition to obtaining the position offset, the laser sensor is also required to detect the weld width, the first distance from the weld's first boundary to the centerline of the wall-climbing robot, and the second distance from the weld's second boundary to the centerline of the wall-climbing robot. The weld boundary refers to the widthwise boundary (edge) of the weld that can be detected by the laser sensor.

[0057] In operation 102 , a movement direction of the wall-climbing robot is adjusted based on the position offset so that a center line of the wall-climbing robot is aligned with the weld.

[0058] During the inspection of welds, the wall-climbing robot may deviate. Therefore, it is necessary to continuously correct the movement direction of the wall-climbing robot by obtaining the position offset so that the center line of the wall-climbing robot remains aligned with the weld.

[0059] Operation 103 , determining the current weld type and the current inspection mode based on the weld width, the first distance from the first boundary of the weld to the center line of the wall-climbing robot, and the second distance from the second boundary of the weld to the center line of the wall-climbing robot.

[0060] During the inspection process, in order to ensure timely identification of T-type welds, the current weld type is continuously judged based on the weld width.

[0061] Due to the characteristics of wind turbine tower welds, which include both transverse and longitudinal welds, inspection modes are divided into longitudinal and transverse weld modes. The longitudinal weld mode refers to inspecting longitudinal welds, while the transverse weld mode refers to inspecting transverse welds. Because wall-climbing robots switch from transverse to longitudinal welds and from longitudinal to transverse welds differently, in addition to determining the weld type, the current inspection mode must also be determined. This allows the robot to determine whether to switch from transverse to longitudinal welds or vice versa when a T-shaped weld is detected.

[0062] In one embodiment of the present application, whether a T-shaped weld is detected is determined by analyzing the change in weld width during the inspection process, and the inspection mode is determined by determining the symmetry of the first distance and the second distance.

[0063] Operation 104 : If it is determined that the current weld type is a T-type weld and the inspection mode is a longitudinal weld mode, the wall-climbing robot is controlled to complete the straight motion and then turn to perform transverse weld inspection.

[0064] When a T-shaped weld is detected, if the current mode is longitudinal seam mode, that is, the longitudinal seam is inspected, the wall-climbing robot is controlled to continue to complete the straight movement in the current direction, then turn, and start transverse seam inspection after turning.

[0065] Operation 105 : If it is determined that the current weld type is a T-type weld and the inspection mode is a transverse weld mode, the wall-climbing robot is controlled to complete the circumferential covering action and then turn to perform longitudinal weld inspection.

[0066] When a T-shaped weld is detected, if the current mode is transverse seam mode, that is, inspection is carried out on the transverse seam. Since the transverse seams are usually distributed around the wind turbine tower, it is necessary to first control the wall-climbing robot to complete the circumferential coverage action, that is, to complete the inspection of the transverse seams in a circle, and then control the wall-climbing robot to continue to complete the straight action in the current direction and turn, and start the longitudinal seam inspection after turning.

[0067] In one embodiment of the present application, reference Figure 2 The inspection process can be to first inspect the longitudinal seam, then turn to start the transverse seam inspection when a T-shaped weld is detected, walk around for about 1.5 circles and then turn to start the longitudinal seam inspection, and then repeat the cycle until all the welds of the wind turbine tower are inspected.

[0068] Therefore, the embodiment of the present application uses the laser sensor carried by the wall-climbing robot to detect the weld width, the position offset of the weld relative to the robot center line, and the distance from the boundaries on both sides of the weld to the center line in real time, and adjusts the robot's movement direction based on the offset to achieve alignment with the weld. By analyzing the change in weld width and the symmetry of the distance from the boundaries on both sides of the weld to the center line, the T-shaped weld and inspection mode are identified, and the longitudinal or transverse seam inspection mode is automatically switched according to the inspection mode for subsequent inspections, thereby achieving accurate identification of T-shaped welds and improving the accuracy of weld tracking and weld inspection efficiency.

[0069] In one embodiment of the present application, the wall-climbing robot is equipped with a magnetic flux leakage device. During the inspection process, the wall-climbing robot continuously performs defect detection on the weld based on the magnetic flux leakage device.

[0070] The core purpose of weld inspection is to detect defects such as cracks, holes, corrosion, and surface unevenness. Magnetic flux leakage detection technology has significant advantages in identifying material defects. Therefore, this embodiment of the application also incorporates magnetic flux leakage equipment on the wall-climbing robot to detect weld defects in real time during the inspection process.

[0071] Figure 3 A schematic diagram of the implementation flow of the laser sensor detection operation of the weld inspection method provided in an embodiment of the present application is shown.

[0072] refer to Figure 3 In one embodiment of the present application, the operation 101 of detecting, in real time using a laser sensor, the weld width, the position offset of the weld relative to the center line of the wall-climbing robot, the first distance from the first boundary of the weld to the center line of the wall-climbing robot, and the second distance from the second boundary of the weld to the center line of the wall-climbing robot, includes:

[0073] Operation 201 : Based on the principle of optical triangulation, a laser sensor is used to project a laser line onto the weld, and the coordinates of each point on the laser line are obtained. The projection range of the laser line is determined according to a preset weld width.

[0074] refer to Figure 4 , Figure 4 A schematic diagram illustrating the operating principle of a laser sensor in the weld inspection method provided by an embodiment of the present application shows that, based on the principle of optical triangulation, a laser sensor is used to project a laser line onto the weld and obtain the coordinates of each point on the laser line. This can include: laser sensor 2, based on the principle of optical triangulation, emits a laser line, which is projected onto the surface of the wind turbine tower through a linear optical system. After the laser line is diffusely reflected on the surface of the wind turbine tower, the reflected light is received by the sensor array with high quality. After being assigned by the optical system, a two-dimensional evaluation is performed to obtain distance information in the Z-axis direction and the precise position of each point on the output laser line on the X-axis. The position of the laser line on the X-axis is the coordinate of each point on the laser line.

[0075] To ensure the laser sensor can detect weld-related data smoothly, the laser line projection range is configured based on the wind turbine tower's preset weld width. The projection range can be understood as the laser sensor's maximum recognition range, and the preset weld width can be understood as the average weld width of the wind turbine tower's transverse and longitudinal welds actually collected.

[0076] Operation 202 calculates the weld width, the position offset of the weld relative to the center line of the wall-climbing robot, the first distance from the first boundary of the weld to the center line of the wall-climbing robot, and the second distance from the second boundary of the weld to the center line of the wall-climbing robot based on the coordinates of each point on the laser line.

[0077] The coordinates of each point on the laser line are traversed, and the coordinates of the two boundary points of the weld are taken. The distance calculation formula between the two points is used to calculate the weld width based on the coordinates of the two boundary points. The position offset of the weld to the center line of the wall-climbing robot is then calculated using the directed distance calculation formula between a point and a line. The first distance from the boundary point corresponding to the first boundary to the center line of the wall-climbing robot is calculated using the distance calculation formula between a point and a line. The second distance from the boundary point corresponding to the second boundary to the center line of the wall-climbing robot is calculated using the distance calculation formula between a point and a line.

[0078] Figure 5 A schematic diagram of the implementation flow of the robot control operation of the weld inspection method provided in an embodiment of the present application is shown.

[0079] refer to Figure 5 The above operation 102, adjusting the movement direction of the wall-climbing robot based on the position offset, includes:

[0080] In operation 301 , motion parameters of the wall-climbing robot are calculated according to the position offset and the PID control algorithm. The motion parameters include the left wheel speed and the right wheel speed.

[0081] In one embodiment of the present application, a PID (Proportional-Integral-Derivative Controller) control algorithm includes:

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088] in, 、 、 is the PID coefficient, which can be adjusted according to actual conditions. 、 、 To calculate the median value, Indicates the position offset to be used next time. Indicates the current position offset, Indicates the left wheel speed, Indicates the right wheel speed, Indicates the current speed of the wall-climbing robot. The left and right wheels are the driving wheels. For example, if the wall-climbing robot is rear-wheel driven, the left and right wheels are the left and right wheels of the rear wheels. If the wall-climbing robot is front-wheel driven, the left and right wheels are the left and right wheels of the front wheels.

[0089] After obtaining the position offset, the PID control algorithm is used to calculate the left and right wheel speeds.

[0090] In operation 302 , a movement direction of the wall-climbing robot is adjusted according to movement parameters.

[0091] The robot is controlled to move toward the weld according to the left and right wheel speeds.

[0092] Figure 6 A schematic diagram of the implementation flow of the weld type and inspection mode judgment operation of the weld inspection method provided in an embodiment of the present application is shown.

[0093] refer to Figure 6 In one embodiment of the present application, the above operation 103, based on the weld width, the first distance from the first boundary of the weld to the center line of the wall-climbing robot, and the second distance from the second boundary of the weld to the center line of the wall-climbing robot, determines the current weld type and the current inspection mode, including:

[0094] Operation 401 : When the weld width exceeds a set threshold, it is determined that the current weld type is a T-type weld.

[0095] refer to Figure 7 , Figure 7 An example diagram of a T-shaped weld of the weld inspection method provided in an embodiment of the present application is shown. Figure 7 (a) shows the T-type weld detected in the longitudinal seam mode. Figure 7 (b) shows the T-type weld detected in transverse seam mode. Figure 7 As can be seen, in both longitudinal and transverse seam modes, the weld width x that the laser sensor initially identifies is a small, stable value. When a T-shaped weld is detected, the weld width x increases. Therefore, a threshold for the weld width can be configured. When the threshold is exceeded, a T-shaped weld is identified. The threshold can be configured based on actual conditions.

[0096] Operation 402 : When the weld width exceeds a set threshold and the difference between the first distance and the second distance does not exceed a first set difference threshold, determining that the current inspection mode is a longitudinal seam mode.

[0097] refer to Figure 7As can be seen from (a), the first and second distances of a T-shaped weld detected in longitudinal seam mode are approximately equal. Therefore, when the weld width exceeds the set threshold and the difference between the first and second distances does not exceed the first set difference threshold, the current inspection mode is determined to be longitudinal seam mode. The first set difference range can be understood as a symmetrical acceptable error range and can be configured based on actual conditions.

[0098] Operation 403 : When the weld width exceeds a set threshold and the difference between the first distance and the second distance exceeds a second set difference threshold, it is determined that the current inspection mode is a transverse seam mode.

[0099] refer to Figure 7 (b) As can be seen, the first and second distances of the T-shaped weld detected in the transverse weld mode are not equal and differ significantly. Therefore, when the weld width exceeds the set threshold and the difference between the first and second distances exceeds the second set difference threshold, the current inspection mode is determined to be the transverse weld mode. The second set difference threshold is used to distinguish from errors and is configured to be greater than the average weld width of the transverse or longitudinal weld. The specific value can be configured according to actual conditions and is not specifically limited in this application.

[0100] Figure 8 A schematic diagram of the steering of a wall-climbing robot in the weld inspection method provided in an embodiment of the present application is shown.

[0101] In one embodiment of the present application, the wall-climbing robot also includes an IMU (Inertial Measurement Unit) sensor, which controls the wall-climbing robot to turn and perform transverse seam inspection after completing the straight-line action, including: controlling the wall-climbing robot to continue moving in the current direction for a set distance and then stop, and the set distance is determined according to the length of the wall-climbing robot; based on the IMU sensor, the wall-climbing robot is controlled to perform a 90-degree rotation according to the preset direction by keeping one wheel stationary and the other wheel rotating in the opposite direction, and then the transverse seam inspection is started.

[0102] refer to Figure 8 (a), Figure 8 (a) shows a schematic diagram of a wall-climbing robot moving from a longitudinal weld to a transverse weld. During longitudinal weld inspection, the robot 1 detects a T-shaped weld and then continues forward a set distance L before stopping. One wheel of the robot remains stationary while the other wheel moves in the opposite direction, rotating the robot 90 degrees according to the preset direction and calibrating it using the IMU. The preset direction can be configured as counterclockwise or clockwise, depending on the actual situation. For example, if clockwise rotation allows the robot to reach a weld in the opposite direction, the preset direction is configured as clockwise.

[0103] In one embodiment of the present application, the wall-climbing robot is controlled to complete the circumferential covering action and then turn to perform longitudinal seam inspection, including: controlling the wall-climbing robot to continue moving along the circumference of the tower until a T-shaped weld is detected for the third time; after the T-shaped weld is detected for the third time, controlling the wall-climbing robot to continue moving in the current direction for a set distance and then stop, where the set distance is determined according to the length of the wall-climbing robot; based on the IMU sensor, the wall-climbing robot is controlled to perform a 90-degree turn according to the preset turn by having one wheel stationary and the other wheel rotating in the opposite direction, and the longitudinal seam inspection is started.

[0104] In actual engineering, based on stress distribution considerations, longitudinal seams are alternately distributed on the front and back sides relative to transverse seams, that is, one longitudinal seam is in the 0-degree direction, the second longitudinal seam is in the 180-degree direction, and the third longitudinal seam is in the 0-degree direction. Therefore, in order to achieve full inspection of the welds of the wind turbine tower, when the T-type weld is detected for the first time, half of the transverse seam is detected, and when the T-type weld is detected for the second time, the transverse seam is fully detected. However, due to the alternating distribution of longitudinal seams, it is impossible to switch to the longitudinal seams of the next cycle. Therefore, when the transverse seam switches to the longitudinal seam, after the T-type weld is detected for the first time, the wall-climbing robot is controlled again to continue moving along the circumference of the tower until the T-type weld is detected for the third time. Among them, controlling the wall-climbing robot to continue moving along the circumference of the tower can be regarded as calibrating the mileage of the wall-climbing robot by the odometer so that its walking distance is about 1.5 laps.

[0105] Further, after the T-weld is detected for the third time, refer to Figure 8 (b), Figure 8 (b) shows a schematic diagram of a wall-climbing robot transitioning from a horizontal seam to a vertical seam. The robot 1 is controlled to advance a set distance L and then stop. One wheel of the robot is then held stationary while the other wheel moves in the opposite direction, rotating the robot 90 degrees. This is then calibrated using the IMU. The set distance is approximately the length of the wall-climbing robot and can be adjusted based on actual conditions.

[0106] Based on the above-mentioned weld inspection method, an embodiment of the present application also provides a wall-climbing robot for performing the above-mentioned weld inspection method. The wall-climbing robot includes a magnetic adsorption chassis and a detection system.

[0107] The magnetic adsorption chassis includes a vehicle body, a front wheel structure, and a rear wheel structure. The front wheel structure includes two front wheels, and the rear wheel structure includes two rear wheels. The two front wheels and the two rear wheels are connected to the vehicle body through hinges. The front wheels are omnidirectional wheels including non-contact magnetic arrays, and the rear wheels are magnetic wheels. The wall-climbing robot is driven by the rear wheels. Specifically, the way the front wheels or rear wheels are connected to the vehicle body through hinges can be referred to. Figure 9 , Figure 9A schematic diagram of the connection method between the wheel body and the body of the wall-climbing robot provided in an embodiment of the present application is shown. In the figure, m is the distance from the center line of the wall-climbing robot to the hinge, n is the distance from the hinge to the wheel 3, h1 is the vertical distance from the center of the wall-climbing robot body 4 to the wind turbine tower, h2 is the vertical distance from the rotation center of the wheel 5 to the wind turbine tower, and α is the hinge activity angle.

[0108] The detection system includes a laser sensor, an IMU sensor and an odometer. The laser sensor, IMU sensor and odometer are all installed on the center line of the vehicle body on the side close to the tower to be inspected. The center line of the vehicle body is the center line of the direction of the two front wheels or the two rear wheels.

[0109] It should be noted that the overall structure of the wall-climbing robot of the present application can be understood based on the existing wall-climbing robots. The present application only limits the front wheels of the existing wall-climbing robots to omnidirectional wheels including non-contact magnetic arrays, and limits the rear wheels to magnetic wheels, and improves the connection method between the wheels and the body. Other structures can be understood with reference to the existing wall-climbing robots and will not be repeated here.

[0110] In one embodiment of the present application, the distance from the center line of the wall-climbing robot to the hinge is equal to the distance from the hinge to the wheel.

[0111] refer to Figure 9 , the geometric relationship between the wind turbine tower and the wall-climbing robot can be expressed as:

[0112]

[0113]

[0114] Wherein, R is the radius of the wind turbine tower, m is the distance from the center line of the wall-climbing robot to the hinge, n is the distance from the hinge to the wheel 3, h1 is the vertical distance from the center of the wall-climbing robot body 4 to the wind turbine tower, h2 is the vertical distance from the rotation center of the wheel 5 to the wind turbine tower, and α is the hinge movable angle.

[0115] According to the geometric relationship between the wind turbine tower and the wall-climbing robot, it can be inferred that the optimal way is that the vertical distance h2 from the rotation center of wheel 5 to the wind turbine tower is equal to the vertical distance h1 from the center of the vehicle body to the wind turbine tower, that is, the distance m from the center line of the wall-climbing robot to the hinge is equal to the distance n from the hinge to the wheel 3.

[0116] Figure 10 A diagram showing the working principle of the magnetic flux leakage device of the wall-climbing robot provided in an embodiment of the present application is shown.

[0117] refer to Figure 10In one embodiment of the present application, the wall-climbing robot further includes a magnetic flux leakage device 6 , which utilizes an integrated sensor structure and includes a yoke 61 , a magnet 62 , a magnetic bridge 63 , and a magnetically sensitive detection element 64 . The magnetic flux leakage device of the present application supports dual functions of magnetic field leakage detection and magnetic disturbance detection, complementing each other for cross-verification and ensuring that no welds are missed. Specifically, the waveform protrusion within the elliptical circle in the figure indicates a detected weld defect.

[0118] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this disclosure can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in this application can be achieved. This is not a limitation herein.

[0119] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0120] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A weld inspection method, characterized in that: Applied to a wall-climbing robot, the wall-climbing robot includes a laser sensor, and the method includes: The laser sensor is used to detect in real time the width of the weld, the position offset of the weld relative to the center line of the wall-climbing robot, the first distance from the first boundary of the weld to the center line of the wall-climbing robot, and the second distance from the second boundary of the weld to the center line of the wall-climbing robot; Adjusting the movement direction of the wall-climbing robot based on the position offset so that the center line of the wall-climbing robot remains aligned with the weld; Determine the current weld type and the current inspection mode according to the weld width, a first distance from a first boundary of the weld to the center line of the wall-climbing robot, and a second distance from a second boundary of the weld to the center line of the wall-climbing robot; If it is determined that the current weld type is a T-type weld and the inspection mode is a longitudinal weld mode, the wall-climbing robot is controlled to complete the straight motion and then turn to perform a transverse weld inspection; If it is determined that the current weld type is a T-type weld and the inspection mode is a transverse weld mode, the wall-climbing robot is controlled to complete the circumferential covering action and then turn to perform longitudinal weld inspection; The determining of the current weld type and the current inspection mode according to the weld width, the first distance from the first boundary of the weld to the center line of the wall-climbing robot, and the second distance from the second boundary of the weld to the center line of the wall-climbing robot includes: When the weld width exceeds a set threshold, determining that the current weld type is a T-type weld; When the weld width exceeds a set threshold and the difference between the first distance and the second distance does not exceed a first set difference threshold, determining that the current inspection mode is a longitudinal seam mode; When the weld width exceeds a set threshold and the difference between the first distance and the second distance exceeds a second set difference threshold, determining that the current inspection mode is a transverse seam mode; The wall-climbing robot further includes an IMU sensor, and controlling the wall-climbing robot to turn and perform transverse seam inspection after completing a straight-line motion includes: Controlling the wall-climbing robot to continue moving in the current direction for a set distance and then stop, wherein the set distance is determined according to the length of the wall-climbing robot; Based on the IMU sensor, the wall-climbing robot is controlled to rotate 90 degrees according to the preset direction by keeping one wheel stationary while the other wheel rotates in the opposite direction, and then begins to inspect the transverse seams. Controlling the wall-climbing robot to turn and perform longitudinal seam inspection after completing the circumferential covering action includes: Control the wall-climbing robot to continue moving along the circumference of the tower until the T-shaped weld is detected for the third time; After the T-shaped weld is detected for the third time, the wall-climbing robot is controlled to continue moving in the current direction for a set distance and then stop, wherein the set distance is determined according to the length of the wall-climbing robot; Based on the IMU sensor, the wall-climbing robot is controlled to perform a 90-degree rotation according to the preset direction by keeping one wheel stationary and the other wheel rotating in the opposite direction, and begins to perform longitudinal seam inspection.

2. The method according to claim 1, characterized in that The wall-climbing robot further includes a magnetic leakage device, and the method further includes: During the inspection process, weld defects are detected based on magnetic flux leakage equipment.

3. The method according to claim 1, characterized in that The real-time detection of the weld width, the position offset of the weld relative to the center line of the wall-climbing robot, the first distance from the first boundary of the weld to the center line of the wall-climbing robot, and the second distance from the second boundary of the weld to the center line of the wall-climbing robot by the laser sensor includes: Based on the principle of optical triangulation, a laser sensor is used to project a laser line onto the weld and obtain the coordinates of each point on the laser line. The projection range of the laser line is determined according to the preset weld width. According to the coordinates of each point on the laser line, the weld width, the position offset of the weld relative to the center line of the wall-climbing robot, the first distance from the first boundary of the weld to the center line of the wall-climbing robot, and the second distance from the second boundary of the weld to the center line of the wall-climbing robot are calculated.

4. The method according to claim 1, wherein Adjusting the movement direction of the wall-climbing robot based on the position offset includes: Calculating motion parameters of the wall-climbing robot according to the position offset and the PID control algorithm, wherein the motion parameters include left wheel speed and right wheel speed; The movement direction of the wall-climbing robot is adjusted according to the movement parameters.

5. A wall-climbing robot, characterized in that: The wall-climbing robot is used to perform the method according to any one of claims 1 to 4, and the wall-climbing robot comprises: A magnetic adsorption chassis, comprising a vehicle body, a front wheel structure, and a rear wheel structure. The front wheel structure comprises two front wheels, and the rear wheel structure comprises two rear wheels. The two front wheels and the two rear wheels are connected to the vehicle body via hinges. The front wheels are omnidirectional wheels comprising a non-contact magnetic array, and the rear wheels are magnetic wheels. The detection system includes a laser sensor, an IMU sensor and an odometer, and the laser sensor, IMU sensor and odometer are all installed on the center line of the vehicle body on the side close to the tower to be inspected.

6. The wall-climbing robot according to claim 5, characterized in that: The distance from the center line of the wall-climbing robot to the hinge is equal to the distance from the hinge to the wheel.

7. The wall-climbing robot according to claim 5, characterized in that: The wall-climbing robot also includes a magnetic leakage device, which adopts an integrated sensor structure and includes a yoke, a magnet, a magnetic bridge and a magnetic sensitive detection element.

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