Weld joint inspection method and wall-climbing robot

Abstract

The invention provides a welding seam inspection method and a wall-climbing robot, and relates to the technical field of welding seam inspection, and the method comprises the steps: detecting the width of a welding seam, the position offset of the welding seam relative to the center line of the wall-climbing robot and the distance from the boundary of the two sides of the welding seam to the center line in real time through a laser sensor carried by the wall-climbing robot; the movement direction of the robot is adjusted based on the position offset, alignment with the welding seam is achieved, the T-shaped welding seam and the inspection mode are recognized by analyzing the width change of the welding seam and the symmetry of the distances from the boundaries on the two sides of the welding seam to the center line, the wall-climbing robot is automatically controlled to steer according to the inspection mode so as to conduct follow-up inspection, and accurate recognition of the T-shaped welding seam is achieved. And the welding seam tracking precision and the welding seam inspection efficiency are improved.

Description

Technical Field

[0001] This application relates to the technical field of weld inspection, and particularly to a weld inspection method and a wall - climbing robot. Background Art

[0002] The weld inspection of wind turbine towers is a key link to ensure the safe operation of wind power generation equipment. In the prior art, the traditional weld inspection method is that workers climb onto the wind turbine tower and use weld inspection equipment for inspection, but there are problems such as low efficiency, high cost, and high danger. Although some studies have tried to use wall - climbing robots to replace manual inspection, there are generally technical bottlenecks such as insufficient weld tracking accuracy and lack of T - type weld recognition ability, resulting in the detection effect being difficult to meet the actual requirements. Summary of the Invention

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

[0004] According to the first aspect of this application, a weld inspection method is provided, which is applied to a wall - climbing robot. The wall - climbing robot includes a laser sensor, and the method includes: Real - time detecting, by the 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; Adjusting the movement direction of the wall - climbing robot based on the position offset so that the center line of the wall - climbing robot is aligned with the weld; Judging 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; If it is determined that the current weld type is a T - type weld and the inspection mode is a longitudinal weld mode, controlling the wall - climbing robot to complete a straight - line action and then turn to perform 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, controlling the wall - climbing robot to complete a circumferential coverage action and then turn to perform longitudinal weld inspection.

[0005] In an implementable embodiment, the wall - climbing robot further includes a magnetic flux leakage device, and the method further includes: During the inspection process, detecting weld defects based on the magnetic flux leakage device.

[0006] In one implementable embodiment, the real-time detection of the weld width, the position offset of the weld with respect 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, the laser sensor projects 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 the preset weld width; According to the coordinates of each point on the laser line, calculate the weld width, the position offset of the weld with respect 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.

[0007] In one implementable embodiment, adjusting the movement direction of the wall-climbing robot based on the position offset includes: According to the position offset and the PID control algorithm, calculate the movement parameters of the wall-climbing robot. The movement parameters include the left wheel speed and the right wheel speed; Adjust the movement direction of the wall-climbing robot according to the movement parameters.

[0008] In one implementable embodiment, judging 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 the set threshold, determine that the current weld type is a T-shaped weld; When the weld width exceeds the set threshold and the difference between the first distance and the second distance does not exceed the first set difference threshold, determine that the current inspection mode is the longitudinal weld mode; When the weld width exceeds the set threshold and the difference between the first distance and the second distance exceeds the second set difference threshold, determine that the current inspection mode is the transverse weld mode.

[0009] In one implementable embodiment, the wall-climbing robot further includes an IMU sensor. Controlling the wall-climbing robot to turn for transverse weld inspection after completing a straight movement includes: Control the wall-climbing robot to continue moving forward a set distance along the current direction and then stop. The set distance is determined according to the length of the wall-climbing robot; Based on the IMU sensor, control the wall-climbing robot to perform a 90-degree rotation according to the preset steering direction by the method of keeping one wheel stationary and rotating the other wheel in the reverse direction, and start transverse weld inspection.

[0010] In one implementable embodiment, controlling the wall-climbing robot to turn for longitudinal weld inspection after completing a circumferential coverage action includes: Control the wall-climbing robot to continue moving circumferentially along the tower barrel until the T-shaped weld is detected for the third time; After the T-shaped weld is detected for the third time, control the wall-climbing robot to continue moving forward a set distance in the current direction and then stop, where the set distance is determined according to the length of the wall-climbing robot; Based on the IMU sensor, control the wall-climbing robot to perform a 90-degree rotation according to a preset steering direction by the method of one wheel staying stationary and the other wheel rotating in the reverse direction, and start the longitudinal weld inspection.

[0011] According to a second aspect of the present application, there is provided a wall-climbing robot for performing the above-mentioned weld inspection method, and the wall-climbing robot includes: A magnetic adsorption chassis, 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, 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; A detection system, the detection system includes a laser sensor, an IMU sensor and an odometer, and the laser sensor, the IMU sensor and the odometer are all installed on the center line of the side of the vehicle body close to the tower barrel to be inspected.

[0012] In an implementable manner, 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.

[0013] In an implementable manner, the wall-climbing robot further includes a magnetic flux leakage device, the magnetic flux leakage device adopts an integrated sensor structure, and the magnetic flux leakage device includes a yoke, a magnet, a magnetic bridge and a magnetic sensitive detection element.

[0014] The weld inspection method and the wall-climbing robot of the present application, through the laser sensor carried by the wall-climbing robot, can detect the weld width, the position offset of the weld relative to the center line of the wall-climbing robot, and the distances from the two sides of the weld to the center line in real time. Based on the position offset, the movement direction of the robot is adjusted to align with the weld. By analyzing the change in the weld width and the symmetry of the distances from the two sides of the weld to the center line, the T-shaped weld and the inspection mode are identified, and the wall-climbing robot is automatically controlled to turn for subsequent inspection according to the inspection mode, realizing the accurate identification of the T-shaped weld, improving the accuracy of weld tracking and the efficiency of weld inspection.

[0015] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it used 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

[0016] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features, and advantages of the exemplary embodiments of the present application will become readily understood. In the drawings, several embodiments of the present application are shown in an exemplary rather than restrictive manner, wherein: In the drawings, the same or corresponding reference numerals denote the same or corresponding parts.

[0017] Figure 1 The schematic diagram of the implementation process of the weld inspection method provided by the embodiment of the present application is shown; Figure 2 The schematic diagram of the working scenario of the wall-climbing robot for the weld inspection method provided by the embodiment of the present application is shown; Figure 3 The schematic diagram of the implementation process of the laser sensor detection operation for the weld inspection method provided by the embodiment of the present application is shown; Figure 4 The schematic diagram of the working principle of the laser sensor for the weld inspection method provided by the embodiment of the present application is shown; Figure 5 The schematic diagram of the implementation process of the robot control operation for the weld inspection method provided by the embodiment of the present application is shown; Figure 6 The schematic diagram of the implementation process of the weld type and inspection mode judgment operation for the weld inspection method provided by the embodiment of the present application is shown; Figure 7 The example diagram of the T-shaped weld for the weld inspection method provided by the embodiment of the present application is shown; Figure 8 The schematic diagram of the turning of the wall-climbing robot for the weld inspection method provided by the embodiment of the present application is shown; Figure 9 The schematic diagram of the connection mode between the wheel body and the vehicle body of the wall-climbing robot provided by the embodiment of the present application is shown; Figure 10 The working principle diagram of the magnetic flux leakage device of the wall-climbing robot provided by the embodiment of the present application is shown. Detailed implementation manners

[0018] To make the objects, features, and advantages of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0019] Figure 1 The schematic diagram of the implementation process of the weld inspection method provided by the embodiment of the present application is shown.

[0020] Reference Figure 1 , an embodiment of the present application provides a weld inspection method, which is applied to a wall-climbing robot equipped with a laser sensor. The method includes: Operation 101, detecting 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 in real time through the laser sensor.

[0021] The weld inspection method of the present application is mainly used for inspecting the welds of wind power tower barrels. Due to the curved surface characteristics of wind power tower barrels, the wall-climbing robot in the embodiment of the present application is preferably a magnetically adsorbed wall-climbing robot driven by the rear wheels. Usually, a laser sensor is mounted on the wall-climbing robot. In order to enable the laser sensor to obtain the welds on the surface of the wind power tower barrel, the laser sensor is arranged on one side of the wall-climbing robot close to the wind power tower barrel and on the center line of the wall-climbing robot.

[0022] Before the wind power tower barrel needs to be inspected, the staff places the wall-climbing robot at the weld on the surface of the wind power tower barrel and tries to align the center line of the wall-climbing robot with the weld. Then the wall-climbing robot starts to perform weld inspection.

[0023] During the weld inspection process, in order to ensure the weld tracking accuracy, that is, the alignment accuracy between the center line of the wall-climbing robot and the weld during the inspection process, it is necessary to continuously use the laser sensor to detect the position offset of the weld relative to the center line of the wall-climbing robot.

[0024] And reference Figure 2 , Figure 2 shows a schematic diagram of the working scenario of the wall-climbing robot for the weld inspection method provided by the embodiment of the present application. Figure 2 The wall-climbing robot 1 in is inspecting the longitudinal weld of the wind power tower barrel. Reference Figure 2 It can be seen that the welds of the wind power tower barrel are usually formed by alternately distributed transverse welds and longitudinal welds. When inspecting the welds of the wind power tower barrel, it is necessary to perform the conversion control between the transverse welds and the longitudinal welds. Usually, the intersection of the transverse weld and the longitudinal weld can be understood as a T-shaped weld. The biggest difference between the T-shaped weld and the transverse and longitudinal welds is the weld width. And since the T-shaped weld identified during the transverse weld inspection is entirely deviated to one side, whether the distances from the boundaries of the weld to the weld are symmetric can be regarded as the judgment condition for determining the current inspection mode, that is, whether the inspection is a transverse weld inspection or a longitudinal weld inspection. Among them, during the inspection process, since the center line of the wall-climbing robot is aligned with the weld, the distances from the boundaries of the weld to the weld can be regarded as the distances from the boundaries of the weld to the center line of the wall-climbing robot.

[0025] Therefore, in addition to obtaining the position offset, it is also necessary to detect 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 based on the laser sensor. Herein, the boundary of the weld refers to the boundary (edge) of the weld in the width direction that the laser sensor can detect.

[0026] Operation 102: Adjust the movement direction of the wall-climbing robot based on the position offset so that the center line of the wall-climbing robot is aligned with the weld.

[0027] During the inspection of the weld by the wall-climbing robot, the situation of deviation may occur. Therefore, it is necessary to continuously correct the movement direction of the wall-climbing robot through the obtained position offset so that the center line of the wall-climbing robot is aligned with the weld.

[0028] Operation 103: Judge 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.

[0029] During the inspection process, in order to ensure the timely identification of T-shaped welds, the current weld type is continuously judged based on the weld width.

[0030] Based on the characteristics of the welds on the wind power tower barrel, which include transverse welds and longitudinal welds, the inspection mode is divided into the longitudinal weld mode and the transverse weld mode. The longitudinal weld mode refers to the inspection of longitudinal welds, and the transverse weld mode refers to the inspection of transverse welds. Since the switching methods of the wall-climbing robot from transverse welds to longitudinal welds and from longitudinal welds to transverse welds are different, therefore, in addition to judging the weld type, it is also necessary to judge the current inspection mode so that when a T-shaped weld is detected, it can be determined whether it is a transverse-to-longitudinal weld transition or a longitudinal-to-transverse weld transition according to the current inspection mode.

[0031] In an embodiment of the present application, it is judged whether a T-shaped weld is detected by analyzing the change of the weld width during the inspection process, and the inspection mode is judged by judging the symmetry of the first distance and the second distance.

[0032] Operation 104: If it is determined that the current weld type is a T-shaped weld and the inspection mode is the longitudinal weld mode, control the wall-climbing robot to complete the straight movement and then turn to perform the transverse weld inspection.

[0033] When a T-shaped weld is detected, if the current is the longitudinal weld mode, that is, the inspection of longitudinal welds, then control the wall-climbing robot to continue to complete the straight movement along the current direction, then turn, and start the transverse weld inspection after turning.

[0034] Operation 105: If it is determined that the current weld type is a T-shaped weld and the inspection mode is the transverse weld mode, control the wall-climbing robot to complete the circumferential coverage action and then turn to perform the longitudinal weld inspection.

[0035] When a T-shaped weld is detected, if the current is the horizontal weld mode, that is, the inspection is carried out for the horizontal weld. Since the horizontal weld usually distributes around the wind power tower barrel for one week, it is necessary to first control the wall-climbing robot to complete the circumferential coverage action, that is, to complete the detection of the horizontal welds in one week. Then, control the wall-climbing robot to continue to complete the straight-line action along the current direction and turn. After turning, start the vertical weld inspection.

[0036] In an embodiment of the present application, referring to Figure 2 , the inspection process can be to first perform the vertical weld inspection. Then, when a T-shaped weld is detected, turn to start the horizontal weld inspection. After walking around for about 1.5 circles, turn to start the vertical weld inspection, and then repeat until all the welds of the wind power tower barrel are inspected.

[0037] Therefore, in the embodiment of the present application, through the laser sensor carried by the wall-climbing robot, the weld width, the position offset of the weld relative to the center line of the robot, and the distances from the two boundaries of the weld to the center line are detected in real time. Based on the offset, the movement direction of the robot is adjusted to align with the weld. By analyzing the change in the weld width and the symmetry of the distances from the two boundaries of the weld to the center line, the T-shaped weld and the inspection mode are identified, and the vertical or horizontal weld inspection mode is automatically switched according to the inspection mode for subsequent inspection, realizing the accurate identification of the T-shaped weld and improving the accuracy of weld tracking and the efficiency of weld inspection.

[0038] In an 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.

[0039] The core purpose of weld inspection is to detect whether there are defects such as cracks, holes, corrosion, and surface unevenness in the weld. The magnetic flux leakage detection technology has significant advantages in the field of material defect identification. Therefore, the embodiment of the present application also equips the wall-climbing robot with a magnetic flux leakage device to detect weld defects in real time during the inspection process.

[0040] Figure 3 Fig. shows the implementation flow diagram of the laser sensor detection operation of the weld inspection method provided by the embodiment of the present application.

[0041] Referring to Figure 3 , in an embodiment of the present application, for the above operation 101, 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 detected in real time by the laser sensor, including: Operation 201, based on the principle of optical triangulation, uses the laser sensor to project a laser line onto the weld and obtains the coordinates of each point on the laser line. The projection range of the laser line is determined according to the preset weld width.

[0042] Reference Figure 4 , Figure 4 shows a schematic diagram of the working principle of the laser sensor of the weld inspection method provided by the embodiment of the present application. Based on the principle of optical triangulation, using the laser sensor to project a laser line onto the weld, and obtaining the coordinates of each point on the laser line may include: The laser sensor 2 emits a laser line based on the principle of optical triangulation. The laser line is projected onto the surface of the wind power tower through a linear optical system. After the laser line undergoes diffuse reflection on the surface of the wind power tower, the reflected light is received by the sensor array with high quality. After being assigned values by the optical system, two-dimensional evaluation is performed to obtain the distance information in the Z-axis direction and output the exact position of each point on the laser line on the X-axis. Among them, the position of the laser line on the X-axis is the coordinates of each point on the laser line.

[0043] In order to enable the laser sensor to smoothly detect the weld-related data, the projection range of the laser line is also configured based on the preset weld width of the wind power tower. The projection range can be understood as the maximum recognition interval of the laser sensor, and the preset weld width can be understood as the average weld width of the transverse and longitudinal welds of the actually collected wind power tower.

[0044] Operation 202, calculate 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 according to the coordinates of each point on the laser line.

[0045] Traverse the coordinates of each point on the laser line, propose to take the coordinates of the two boundary points of the weld, and use the distance calculation formula between two points to calculate the weld width based on the coordinates of the two boundary points. Then, calculate the position offset of the weld to the center line of the wall-climbing robot through the directed distance calculation formula between a point and a straight line, and calculate the first distance from the boundary point corresponding to the first boundary to the center line of the wall-climbing robot and the second distance from the boundary point corresponding to the second boundary to the center line of the wall-climbing robot based on the distance calculation formula between a point and a straight line.

[0046] Figure 5 shows a schematic diagram of the implementation process of the robot control operation of the weld inspection method provided by the embodiment of the present application.

[0047] Reference Figure 5 , the above operation 102, adjusting the movement direction of the wall-climbing robot based on the position offset, includes: Operation 301, calculate the motion parameters of the wall-climbing robot according to the position offset and the PID control algorithm, and the motion parameters include the left wheel speed and the right wheel speed.

[0048] In an embodiment of the present application, the PID (Proportional-Integral-Derivative Controller) control algorithm includes:

[0049]

[0050]

[0051]

[0052]

[0053]

[0054] Among them, 、 、 are PID coefficients, which can be adjusted according to the actual situation. 、 、 are intermediate calculation values. represents the position offset for the next use. represents the current position offset. represents the left wheel speed, represents the right wheel speed. represents the speed of the current wall-climbing robot. The left and right wheels are driving wheels. For example, if the wall-climbing robot is rear-wheel drive, the left and right wheels are the left and right wheels of the rear wheels; if the wall-climbing robot is front-wheel drive, the left and right wheels are the left and right wheels of the front wheels.

[0055] After obtaining the position offset, the PID control algorithm is used to calculate the left wheel speed and the right wheel speed.

[0056] Operation 302: Adjust the movement direction of the wall-climbing robot according to the motion parameters.

[0057] Control the robot to move in the direction of the weld according to the left wheel speed and the right wheel speed.

[0058] Figure 6 shows the implementation flow diagram of the weld type and inspection mode judgment operation of the weld inspection method provided by the embodiment of the present application.

[0059] Refer to Figure 6 , in an implementation manner of the present application, for the above operation 103, judging 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: Operation 401: When the weld width exceeds the set threshold, determine that the current weld type is a T-shaped weld.

[0060] Refer to Figure 7 ,Figure 7 The figure shows an example diagram of a T-shaped weld seam for the weld seam inspection method provided by an embodiment of the present application. Figure 7 (a) shows the T-shaped weld seam detected in the longitudinal seam mode. Figure 7 (b) shows the T-shaped weld seam detected in the transverse seam mode. As can be seen from Figure 7 it, whether in the longitudinal and transverse mode or the transverse seam mode, the weld seam width x at which the laser sensor starts to recognize is a relatively small and stable value. When a T-shaped weld seam is detected, the weld seam width x will increase. Therefore, a set threshold for the weld seam width can be configured. When it exceeds the set threshold, it is determined that a T-shaped weld seam is recognized. Among them, the set threshold can be configured according to the actual situation.

[0061] Operation 402: When the weld seam width exceeds the set threshold and the difference between the first distance and the second distance does not exceed the first set difference threshold, it is determined that the current inspection mode is the longitudinal seam mode.

[0062] Referring to Figure 7 (a), it can be seen that the first distance and the second distance of the T-shaped weld seam detected in the longitudinal seam mode are approximately equal. Therefore, when the weld seam width exceeds the set threshold and the difference between the first distance and the second distance does not exceed the first set difference threshold, it is determined that the current inspection mode is the longitudinal seam mode. Among them, the first set difference range can be understood as a symmetric acceptable error range and can be configured according to the actual situation.

[0063] Operation 403: When the weld seam width exceeds the set threshold and the difference between the first distance and the second distance exceeds the second set difference threshold, it is determined that the current inspection mode is the transverse seam mode.

[0064] Referring to Figure 7 (b), it can be seen that the first distance and the second distance of the T-shaped weld seam detected in the transverse seam mode are not equal and the difference is large. Therefore, when the weld seam width exceeds the set threshold and the difference between the first distance and the second distance exceeds the second set difference threshold, it is determined that the current inspection mode is the transverse seam mode. Among them, the second set difference threshold is used to distinguish from the error and is configured to be greater than the average weld seam width of the transverse seam or the longitudinal seam. The specific value can be configured according to the actual situation and is not specifically limited in this application.

[0065] Figure 8 The figure shows a schematic diagram of the turning of a wall-climbing robot for the weld seam inspection method provided by an embodiment of the present application.

[0066] In an embodiment of the present application, the wall - climbing robot further includes an IMU (Inertial Measurement Unit) sensor. Controlling the wall - climbing robot to turn for transverse seam inspection after completing a straight - line movement includes: controlling the wall - climbing robot to continue moving forward 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, controlling the wall - climbing robot to perform a 90 - degree rotation according to a preset turning direction by keeping one wheel stationary and rotating the other wheel in the reverse direction, and then starting the transverse seam inspection.

[0067] Reference Figure 8 (a), Figure 8 Figure (a) shows a schematic diagram of the wall - climbing robot turning from a longitudinal seam to a transverse seam. When the wall - climbing robot 1 is performing longitudinal seam inspection, after the laser sensor detects a T - shaped weld seam, it continues to move forward for a set distance L and then stops. Then, keep one wheel of the robot stationary and move the other wheel in the reverse direction, so that the robot rotates 90 degrees according to the preset turning direction and is calibrated by the IMU. Among them, the preset turning direction can be configured to rotate counterclockwise or clockwise according to the actual situation. For example, if rotating clockwise can make the wall - climbing robot turn to the weld seam in another direction, then configure the preset turning direction to rotate clockwise.

[0068] In an embodiment of the present application, controlling the wall - climbing robot to turn for longitudinal seam inspection after completing a circumferential coverage movement includes: controlling the wall - climbing robot to continue moving along the circumferential direction of the tower barrel until the T - shaped weld seam is detected for the third time; after the T - shaped weld seam is detected for the third time, controlling the wall - climbing robot to continue moving forward 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, controlling the wall - climbing robot to perform a 90 - degree turn according to a preset turning direction by keeping one wheel stationary and rotating the other wheel in the reverse direction, and then starting the longitudinal seam inspection.

[0069] In actual engineering, considering the stress distribution, the longitudinal seams are distributed alternately on the front and back sides relative to the transverse seams, that is, one section of the longitudinal seam is in the 0 - degree direction, the second section of the longitudinal seam is in the 180 - degree direction, and the third section of the longitudinal seam is in the 0 - degree direction. Therefore, in order to achieve a full inspection of the wind turbine tower barrel weld seams, when the T - shaped weld seam is detected for the first time, half of the transverse seams are inspected, and when the T - shaped weld seam is detected for the second time, the transverse seams are completely inspected. Since the longitudinal seams are alternately distributed and it is impossible to turn to the longitudinal seams in the next cycle, when turning from the transverse seam to the longitudinal seam, after the T - shaped weld seam is initially detected, the wall - climbing robot is further controlled to continue moving along the circumferential direction of the tower barrel until the T - shaped weld seam is detected for the third time. Among them, controlling the wall - climbing robot to continue moving along the circumferential direction of the tower barrel can be regarded as calibrating the mileage of the wall - climbing robot through the odometer so that its walking distance is about 1.5 laps.

[0070] Further, after the T - shaped weld seam is detected for the third time, reference Figure 8 (b), Figure 8(b) shows a schematic diagram of the wall-climbing robot turning from a horizontal seam to a vertical seam. Control the wall-climbing robot 1 to continue moving forward a set distance L and then stop. After that, keep one wheel of the robot stationary and the other wheel move in the reverse direction to rotate the robot by 90 degrees, and calibrate it through the IMU. Among them, the set distance is about the length of the wall-climbing robot and can be adjusted according to the actual situation.

[0071] Based on the above weld inspection method, an embodiment of the present application further provides a wall-climbing robot for performing the above weld inspection method. The wall-climbing robot includes a magnetic adsorption chassis and a detection system.

[0072] Among them, 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 rear-wheel driven. Specifically, the way of connecting the front wheels or the rear wheels to the vehicle body through hinges can refer to Figure 9 , Figure 9 shows a schematic diagram of the connection method between the wheel body and the vehicle body of the wall-climbing robot provided by the embodiment of the present application. 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 wheel 3, h1 is the vertical distance from the center of the wall-climbing robot vehicle body 4 to the wind power tower barrel, h2 is the vertical distance from the rotation center of wheel 5 to the wind power tower barrel, and α is the hinge movement angle.

[0073] The detection system includes a laser sensor, an IMU sensor and an odometer. The laser sensor, the IMU sensor and the odometer are all installed on the center line of the vehicle body on the side of the vehicle body close to the tower barrel to be inspected. The vehicle body center line is the center line in the direction of the two front wheels or the two rear wheels.

[0074] 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 robot. The present application only limits the front wheels of the existing wall-climbing robot to omnidirectional wheels including non-contact magnetic arrays, limits the rear wheels to magnetic wheels, and improves the connection method between the wheels and the vehicle body. Other structures can be understood by referring to the existing wall-climbing robot and will not be elaborated here.

[0075] In an 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.

[0076] Reference Figure 9 , the geometric relationship between the wind power tower barrel and the wall-climbing robot can be expressed as:

[0077]

[0078] Among them, R is the radius of the wind power tower barrel, m is the distance from the center line of the wall-climbing robot to the hinge, n is the distance from the hinge to wheel 3, h1 is the vertical distance from the center of the body 4 of the wall-climbing robot to the wind power tower barrel, h2 is the vertical distance from the rotation center of wheel 5 to the wind power tower barrel, and α is the movable angle of the hinge.

[0079] According to the geometric relationship between the wind power tower barrel 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 power tower barrel is equal to the vertical distance h1 from the center of the body to the wind power tower barrel, 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 wheel 3.

[0080] Figure 10 The working principle diagram of the magnetic flux leakage device of the wall-climbing robot provided by the embodiment of the present application is shown.

[0081] Reference Figure 10 Referring to, in an embodiment of the present application, the wall-climbing robot further includes a magnetic flux leakage device 6. The magnetic flux leakage device adopts an integrated sensor structure. The magnetic flux leakage device includes a yoke 61, a magnet 62, a magnetic bridge 63, and a magnetic sensitive detection element 64. Among them, the magnetic flux leakage device of the present application supports dual functions of magnetic flux leakage field detection and magnetic disturbance detection, so as to perform cross-verification through their complementarity to ensure that the detection of welds is not missed. Specifically, the waveform protrusion within the ellipse in the figure indicates that there are defects in the detected weld.

[0082] It should be understood that various forms of the processes shown above can be used, steps can be reordered, added, or deleted. For example, the steps recorded in the present disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired results of the technical solutions disclosed in the present application can be achieved. This is not limited herein.

[0083] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0084] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope 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: Real - time detecting, by the 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; Adjusting the moving direction of the wall - climbing robot based on the position offset so that the center line of the wall - climbing robot is aligned with the weld; Judging 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; If it is determined that the current weld type is a T - shaped weld and the inspection mode is the longitudinal - weld mode, controlling the wall - climbing robot to complete a straight - moving action and then turn to perform a transverse - weld inspection; If it is determined that the current weld type is a T - shaped weld and the inspection mode is the transverse - weld mode, controlling the wall - climbing robot to complete a circumferential - covering action and then turn to perform a longitudinal - weld inspection.

2. The method according to claim 1, wherein The wall - climbing robot further includes a magnetic flux leakage device, and the method further includes: During the inspection process, detecting weld defects based on the magnetic flux leakage device.

3. The method according to claim 1, characterized in that The real - time detecting, by the 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: Based on the principle of optical triangulation, using the laser sensor to project a laser line onto the weld and obtaining the coordinates of each point on the laser line, and the projection range of the laser line is determined according to a preset weld width; Calculating 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 according to the coordinates of each point on the laser line.

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

5. The method according to claim 1, characterized in that, The judging 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 - shaped weld; When the weld width exceeds the set threshold and the difference between the first distance and the second distance does not exceed the first set difference threshold, determining that the current inspection mode is the longitudinal - weld mode; When the weld width exceeds the set threshold and the difference between the first distance and the second distance exceeds the second set difference threshold, determining that the current inspection mode is the transverse - weld mode.

6. The method according to claim 1, wherein The wall - climbing robot further includes an IMU sensor, and the controlling the wall - climbing robot to complete a straight - moving action and then turn to perform a transverse - weld inspection includes: Control the wall-climbing robot to stop after moving forward a set distance along the current direction, where the set distance is determined according to the length of the wall-climbing robot; Based on the IMU sensor, control the wall-climbing robot to perform a 90-degree rotation according to a preset steering direction by keeping one wheel stationary and rotating the other wheel in the reverse direction, and start the transverse seam inspection.

7. The method according to claim 6, wherein Control the wall-climbing robot to turn and perform longitudinal seam inspection after completing the circumferential coverage action, including: Control the wall-climbing robot to continue moving along the circumferential direction of the tower barrel until the T-shaped weld is detected for the third time; After the T-shaped weld is detected for the third time, control the wall-climbing robot to stop after moving forward a set distance along the current direction, where the set distance is determined according to the length of the wall-climbing robot; Based on the IMU sensor, control the wall-climbing robot to perform a 90-degree rotation according to a preset steering direction by keeping one wheel stationary and rotating the other wheel in the reverse direction, and start the longitudinal seam inspection.

8. A wall-climbing robot, characterized in that, The wall-climbing robot is used to execute the method according to any one of claims 1-7, and the wall-climbing robot includes: A magnetic adsorption chassis, 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, the rear wheel structure includes two rear wheels, the two front wheels and the two rear wheels are connected to the vehicle body by hinges, the front wheels are omnidirectional wheels including non-contact magnetic arrays, and the rear wheels are magnetic wheels; A detection system, the detection system includes a laser sensor, an IMU sensor and an odometer, and the laser sensor, the IMU sensor and the odometer are all installed on the center line of the vehicle body on the side of the vehicle body close to the tower barrel to be inspected.

9. The wall-climbing robot according to claim 8, wherein, 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.

10. The wall-climbing robot according to claim 8, characterized in that, The wall-climbing robot further includes a magnetic flux leakage device, the magnetic flux leakage device adopts an integrated sensor structure, and the magnetic flux leakage device includes a yoke, a magnet, a magnetic bridge and a magnetosensitive detection element.

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