A tower bolt loosening laser automatic detection device and detection method

Abstract

This invention discloses an automatic laser detection device and method for loose tower bolts, comprising a laser vibration measurement unit, a rotating and tilting platform, and a mobile robot. The laser vibration measurement unit is connected to the mobile robot via the rotating and tilting platform and is used to collect vibration data. The laser vibration measurement unit is wirelessly connected to a vibration analysis host, which is used to diagnose the connection status of the tower. It also includes an excitation unit installed at the bottom of the tower for exciting the entire tower. This invention automatically calculates the optimal measurement point based on the location of the measured point, achieving automated detection of loose tower bolts while solving the problem of laser vibration measurement accuracy being affected by the measurement angle. Furthermore, the detection method is simple, requiring minimal human intervention, and improves the efficiency and accuracy of tower bolt connection status detection, providing reliable data for bolt connection status inspection.

Description

Technical Field

[0001] This invention belongs to the field of tower bolt loosening detection technology, and relates to a laser automatic detection device for tower bolt loosening. Background Technology

[0002] Power transmission towers are crucial load-bearing structures for high-voltage transmission lines, and their structural reliability directly impacts the safety and stability of the lines. Bolts are key components connecting the various structural parts of the tower; loose bolts can cause tower deformation and other problems. Therefore, power companies need to regularly inspect the condition of tower bolts. Traditional methods rely on manual tapping and listening to the sounds to judge bolt looseness, lacking intelligent technology. Currently, commonly used technologies include vibration detection, ultrasonic testing, sound recognition detection, and image recognition detection. Ultrasonic testing is suitable for detecting the looseness of individual bolts but not for inspecting a large number of bolts on a tower. Sound recognition detection is a non-contact measurement method that can identify whether bolts are loose, but in outdoor environments, the sound signal from tapping is easily interfered with by noise, affecting the identification results. Image recognition detection requires image capture, which is easily missed or obstructed by the viewing angle, affecting the identification results. Furthermore, with numerous tower bolts, capturing images is time-consuming and labor-intensive, making it unsuitable for rapid on-site inspection. Vibration detection has two methods: one involves installing vibration sensors, but this method requires climbing the tower to install multiple sensors beforehand, which is cumbersome. Another method involves measuring vibration using a laser vibrometer. This non-contact, long-distance method is well-suited for on-site inspection of transmission tower bolts. However, because it requires measuring vibration signals at multiple points on the tower, technicians must manually adjust the laser measuring device to measure each point individually, thus automation is not yet possible. In actual testing, the angle between the laser beam and the surface of the object being measured affects the accuracy of the measurement. This invention aims to integrate the laser vibrometer with a power robot and, through program calculation, determine the optimal position of the measuring device at different measurement angles. This will lead to the design of an automated detection program to achieve accurate and automated vibration data measurement.

[0003] In summary, existing laser vibration measuring devices have low automation in detecting loose bolts on towers. The measurement accuracy is affected by the angle between the laser beam and the surface of the object being measured. The position and angle of the laser vibration measuring device need to be manually adjusted, which is cumbersome, labor-intensive, and the accuracy deviation of manual operation is difficult to control. Therefore, they cannot meet the accurate measurement requirements of on-site testing. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an automatic laser detection device and method for loose tower bolts, so as to solve the technical problems existing in the prior art.

[0005] The technical solution adopted in this invention is as follows: A laser automatic detection device for loose tower bolts, comprising a laser vibration measurement unit, a rotating and tilting platform, and a mobile robot. The laser vibration measurement unit is connected to the mobile robot through the rotating and tilting platform. The laser vibration measurement unit is used to collect vibration data. The laser vibration measurement unit is wirelessly connected to a vibration analysis host. The vibration analysis host is used to diagnose the connection status of the tower. The device also includes an excitation unit, which is installed at the bottom of the tower and is used to excite the entire tower.

[0006] The aforementioned mobile robot is equipped with a main control circuit for controlling its flight and the pitch and rotation of its rotation and pitch platform, a power supply connected to the main control circuit, and a housing. The main control circuit and the power supply are mounted on the housing, and the main control circuit is also connected to the rotation and pitch platform.

[0007] A detection method for a laser-automatic detection device for loose tower bolts is disclosed. The method comprises the following steps: First, a mobile robot integrating a laser vibration measurement unit is placed at one support column of a transmission tower (close to the bottom of the support column). The vibration unit is activated to vibrate the tower. Then, the power supply of the laser vibration measurement unit is turned on, and the standard tower type is set (for known standard towers, a tower library can be set to standardize the coordinates of the measurement points for convenient on-site data collection), or the coordinate data of n measurement points for a special tower are set (for special towers, the coordinate information of the measurement points can be pre-calculated and imported into the detection software). After setting, the laser vibration measurement unit automatically calculates the movement azimuth and pitch angle based on the coordinate information of the measurement points. Second, the mobile robot is controlled to walk and the rotation and pitch platform is controlled to rotate and pitch, so that the laser of the laser vibration measurement unit is aligned with the detection area near the bolt, and vibration data is collected. The data collection time for each data collection is 30 seconds. The collected data is transmitted to the vibration analysis host for processing, diagnosis, and output of the detection results. The next detection is repeated according to the set parameters until the number of detections matches the set number of measurement points, at which point the detection stops.

[0008] The above calculation method for the moving orientation and pitch angle is as follows: Assume that the angle between the four pillars of the iron tower and the ground is 'a'. The effect is best when the angle between the laser beam and the surface of the measured point of the iron tower is 'b'. The horizontal angle of the moving robot is 'c', where 'c' is negative when tilting downwards and positive when tilting upwards. Then the pitch angle is 'abc'. Given that the length of the support angle steel between the measured point x and the ground is L2, and the height of the laser lens from the ground is h, we can calculate L3 = h / sin a and L4 = h / tan a using trigonometric functions. Then, using the triangle sine theorem, we know that (L1 + L4) / sinb = (L2 - L3) / sin(ab), and thus we can obtain L1 = -L4 + (L2 - L3)sinb / sin(ab).

[0009] The range of values ​​for a and b is: 80° < a < 90°, 0° < b < 90°.

[0010] The beneficial effects of this invention are as follows: Compared with the prior art, this invention utilizes the advantages of mobile robots and laser vibration measuring devices for detecting loose tower bolts. It automatically calculates the optimal measurement point based on the location of the measured point, thereby achieving automated detection of loose tower bolts and solving the problem that the accuracy of laser vibration measurement is affected by the measurement angle. Moreover, the detection method is simple, requires little human intervention, and has a high degree of automation, improving the detection efficiency and accuracy of tower bolt connection status and providing reliable data for bolt connection status detection. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the device structure;

[0012] Figure 2 This is a schematic diagram of the structure of the present invention installed at the tower;

[0013] Figure 3 This is a schematic diagram of the trigonometric function calculation model;

[0014] Figure 4 This is a flowchart of the testing process. Detailed Implementation

[0015] The present invention will be further described below with reference to specific embodiments.

[0016] Example 1: As Figure 1-4 As shown, an automatic laser detection device for loose tower bolts includes a laser vibration measurement unit 1, a rotating and tilting platform 2, and a mobile robot 3. The laser vibration measurement unit 1 is connected to the mobile robot 3 via the rotating and tilting platform 2. The laser vibration measurement unit 1 is used to collect vibration data. The laser vibration measurement unit is wirelessly connected to a vibration analysis host, which is used to analyze and diagnose the connection status of the tower. The device also includes an excitation unit, which is installed at the bottom of the tower and is used to excite the entire tower.

[0017] The aforementioned mobile robot 3 is equipped with a main control circuit 4 that controls its flight and the pitch and rotation of the rotation and tilt platform 2, a power supply 5 connected to the main control circuit 4, and a housing. The main control circuit 4 and the power supply 5 are mounted on the housing. The main control circuit is also connected to the rotation and tilt platform. The power supply provides power to the mobile robot, the rotation and tilt platform, and the laser vibration measurement unit. The main control circuit 4 controls the rotation and tilt platform to adjust its angle and controls the laser vibration measurement unit to collect vibration data. The vibration data collected by the laser vibration measurement unit can be transmitted to the vibration analysis host for processing and analysis through wireless communication or network cable, etc., and combined with the algorithm to realize the diagnosis of the tower connection status.

[0018] The mobile robot 3 is equipped with a tilt sensor, which is used to measure the levelness of the mobile robot 3. The tilt sensor realizes the error compensation of the pitch angle, which facilitates more precise pitch control.

[0019] Example 2: Figure 2-4 As shown, a detection method for a laser-based automatic detection device for loose tower bolts is described. The method involves: first, placing a mobile robot integrating a laser vibration measurement unit at one support column of a transmission tower (close to the bottom of the support column); starting the vibration unit to vibrate the tower; then, starting the power supply of the laser vibration measurement unit; setting the standard tower type (for known standard towers, a tower library can be set up to standardize the coordinates of the measurement points for convenient on-site data collection); or setting the coordinate data of n measurement points for a special tower (for special towers, the coordinate information of the measurement points can be pre-calculated and imported into the detection software); and then, after setting, the laser vibration measurement unit... The optical vibration measurement unit automatically calculates the azimuth and pitch angle based on the coordinates of the measured point. Then, it controls the movement of the mobile robot and the rotation and pitch of the rotating platform, aligning the laser of the laser vibration measurement unit with the detection area near the bolt and collecting vibration data. Each data acquisition session lasts 30 seconds. The collected data is transmitted to the vibration analysis host for processing and diagnostic output (compared to vibration data during installation; if the result exceeds the set value, looseness is determined). The system repeats the detection process according to the set parameters until the number of detections matches the set number of measurement points, at which point the detection stops.

[0020] The above method for calculating the movement orientation and pitch angle (i.e., the method for calculating the angle between the beam and the surface of the object being measured) is as follows: Assume that the angle between the four pillars of the tower and the ground is 'a'. The effect is best when the angle between the laser beam and the surface of the tower being measured is 'b'. The horizontal angle of the moving robot is 'c', where 'c' is negative when tilting downwards and positive when tilting upwards. Then the pitch angle is 'abc'. Given that the length of the support angle steel between the measuring point x and the ground is L2, and the height of the laser lens from the ground is h, we can calculate L3 = h / sin a and L4 = h / tan a using trigonometric functions. Then, using the sine theorem of triangles, we know that (L1 + L4) / sinb = (L2 - L3) / sin(ab), and thus we can obtain L1 = -L4 + (L2 - L3)sinb / sin(ab).

[0021] The range of values ​​for a and b is: 80° < a < 90°, 0° < b < 90°.

[0022] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of protection of the claims.

Claims

1. A detection method for a laser-based automatic detection device for loose tower bolts, characterized in that: The automatic laser detection device for loose tower bolts includes a laser vibration measurement unit (1), a rotating and tilting platform (2), and a mobile robot (3). The laser vibration measurement unit (1) is connected to the mobile robot (3) through the rotating and tilting platform (2). The laser vibration measurement unit (1) is used to collect vibration data. The laser vibration measurement unit is connected to the vibration analysis host wirelessly. The vibration analysis host is used to analyze the diagnosis of the tower connection status. It also includes an excitation unit, which is installed at the bottom of the tower and is used to excite the entire tower. The mobile robot (3) is equipped with an inclination sensor, which is used to measure the levelness of the mobile robot (3). The detection method is as follows: First, a mobile robot integrating a laser vibration measurement unit is placed at one support of a power transmission tower. The excitation unit is activated to vibrate the tower. Then, the power supply of the laser vibration measurement unit is turned on, and the standard tower type or the coordinate data of n measured points of a special tower is set. After the settings are completed, the laser vibration measurement unit automatically calculates the movement azimuth and pitch angle based on the coordinate information of the measured points. Second, the mobile robot is controlled to walk and the rotation and pitch platform is rotated and pitched so that the laser of the laser vibration measurement unit is aligned with the detection area near the bolt, and vibration data is collected. The data collection time for each data collection is 30 seconds. The collected data is transmitted to the vibration analysis host for processing, diagnosis, and output of the detection results. The next detection is repeated according to the set parameters until the number of detections matches the set number of measurement points, at which point the detection stops. The calculation method for the movement orientation and pitch angle is as follows: Assume that the angle between the four pillars of the iron tower and the ground is 'a'. The effect is best when the angle between the laser beam and the surface of the measured point on the iron tower is 'b'. The horizontal angle of the moving robot is 'c', where 'c' is negative when tilting downwards and positive when tilting upwards. Then the pitch angle is 'abc'. Given that the length of the support angle steel between the measured point x and the ground is L2, and the height of the laser lens from the ground is h, we can calculate L3 = h / sin a and L4 = h / tan a using trigonometric functions. Then, using the triangle sine theorem, we know that (L1 + L4) / sinb = (L2 - L3) / sin(ab), and thus we can obtain L1 = -L4 + (L2 - L3)sinb / sin(ab).

2. The detection method of the automatic laser detection device for loose tower bolts according to claim 1, characterized in that: The mobile robot (3) is equipped with a main control circuit for controlling its flight and controlling the pitch and rotation of the rotating platform (2), a power supply connected to the main control circuit, and a housing. The main control circuit and the power supply are mounted on the housing, and the main control circuit is also connected to the rotating platform (2).

3. The detection method of the automatic laser detection device for loose tower bolts according to claim 1, characterized in that: The range of values ​​for a and b is: 80° < a < 90°, 0° < b < 90°.

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