CN115046488B - A method for measuring the spacing between nodes of a grid building - Google Patents

Abstract

The invention discloses a method for measuring the spacing of grid building nodes, comprising: step 1): resetting the equipment; step 2): collecting the image of the grid building and detecting the adjacent bolt balls in the image; step 3): adjusting the posture of the laser rangefinder so that the laser spot of the laser rangefinder coincides with the center of the circle where the bolt balls are located; step 4): obtaining the distance from the laser rangefinder to the bolt balls, the horizontal angle and the vertical angle of the posture sensor, and calculating a vector; step 5): adjusting the posture of the laser rangefinder so that the laser spot of the laser rangefinder coincides with the center of the circle where the bolt balls are located closest to the lower left of the bolt balls; step 6): obtaining the distance from the laser rangefinder to the bolt balls, the horizontal angle and the vertical angle of the posture sensor, and calculating a vector; step 7): obtaining the distance between the two bolt balls through the distance and the vector in the above step 4 and the distance and the vector in the above step 6. The invention ensures the real-time performance and accuracy of the safety monitoring of large grid buildings.

Description

A method for measuring the spacing between nodes of a grid building

Technical Field

The invention relates to the technical field of computer vision, and in particular to a method for measuring the spacing between nodes of a grid building.

Background technique

As the scale and number of grid buildings are getting larger and larger, accidents frequently occur due to the lack of necessary safety monitoring and early warning measures, causing great losses to the lives, property and economic property of the people and the country. Therefore, it is of great social and economic significance to study a method for measuring the spacing of grid building nodes, measure and evaluate the safety status of grid buildings, discover safety hazards in time, and ensure the safe operation of large grid buildings. At present, it is difficult to conduct engineering quality acceptance after the completion of grid buildings. After a certain number of years of use, it is impossible to evaluate the quality of grid buildings. The main reasons are: the manual detection method not only requires a lot of manpower and material resources, but also can only do random inspections, which makes it impossible to guarantee the overall quality of grid buildings. However, once there are problems with three nodes in the grid building, the entire building will collapse; non-destructive ultrasonic crack detection, although with high accuracy, is subject to the complex structure of grid buildings, so it is not suitable for all grid building detection; foreign grid detection equipment is expensive and not suitable for all enterprises.

Summary of the invention

In order to overcome the above technical problems, the purpose of the present invention is to provide a spacing measurement method for grid building nodes, which can collect steel structure images through a variable-focus high-definition camera, and then use target detection algorithms, laser rangefinders, and attitude sensors to achieve high-precision spacing measurement of grid building nodes, and then judge whether the grid building structure is abnormal based on the spacing data, thereby ensuring the real-time and accuracy of large-scale grid building safety monitoring. In addition, edge computing is used to analyze the spacing data of grid building nodes in multiple dimensions, deeply mine valuable information, and eliminate the unsafe factors of grid buildings to a great extent.

In order to achieve the above object, the technical solution adopted by the present invention is:

A method for measuring the spacing of grid building nodes comprises the following steps:

Step 1): Reset the zoomable high-definition camera, laser rangefinder and attitude sensor equipment;

Step 2): Load the target detection model, use a zoomable high-definition camera to capture an image of the grid building, and use the loaded target detection model to detect adjacent bolt balls Q ₁ and Q ₂ in the image;

Step 3): by adjusting the relative positions of the bolt ball and the laser spot of the laser rangefinder in the image of the grid building, the posture of the laser rangefinder is adjusted, and finally the laser spot of the laser rangefinder coincides with the center of the circle where the bolt ball _Q1 is located;

Step 4): Get the distance L ₁ from the laser rangefinder to the bolt ball Q ₁ , the horizontal angle θ ₁ and the vertical angle θ ₂ of the attitude sensor, and calculate the vector

Step 5): by adjusting the relative positions of the bolt ball in the image of the grid building and the laser spot of the laser rangefinder in the image, the attitude of the laser rangefinder is adjusted, and finally the laser spot of the laser rangefinder coincides with the center of the circle of the bolt ball Q ₂ closest to the lower left of the bolt ball Q ₁ ;

Step 6): Get the distance L ₂ from the laser rangefinder to the bolt ball Q ₂ , the horizontal angle θ ₃ and the vertical angle θ ₄ of the attitude sensor, and calculate the vector

Step 7): Use the distance _L1 and vector in step 4 above The distance _L2 and vector in step 6 above/> The distance L of the steel beam between the two bolt balls is calculated to determine whether the steel beam is deformed.

The step 1 uses a variable-focus high-definition camera to collect images of the grid building, specifically:

Step 1.1: Reset the focus of the variable-focus high-definition camera and reset the motor _M1 of the hollow rotating platform where the variable-focus high-definition camera is located;

Step 1.2: Reset the laser focal length of the laser rangefinder, and reset the motors M ₂ and M ₃ of the hollow rotating platform where the laser sensor is located;

Step 1.3: Reset the entire hollow rotating platform motor _M4 where the zoom HD camera and laser rangefinder are located;

Step 1.4: The zoomable HD camera starts to adjust the focus and capture images.

The step 2 uses the loaded target detection model to detect adjacent bolt balls _Q1 and _Q2 in the image as follows:

Step 2.1: Use the embedded AI core board to load the target detection model weights;

Step 2.2: Adjust the focal length of the variable-focus high-definition camera, and collect images of the grid building at the same time, and input the collected images into the target detection network for target detection until 5-8 target bolt balls are detected;

Step 2.3: Determine the bolt balls Q ₁ and Q ₂ that need to be inspected, and fine-tune the focus of the zoom HD camera so that the bolt ball Q ₁ can appear clearly in the field of view of the zoom HD camera.

The step 3 makes the laser spot of the laser rangefinder coincide with the center of the circle where the bolt ball _Q1 is located as follows:

Step 3.1: Adjust motor M ₂ and motor M ₃ until the laser beam of the laser ranging can be mapped to the bolt ball;

Step 3.2: Adjust the focal length of the laser beam of the laser rangefinder to reduce the spot of the laser beam;

Step 3.3: Adjust motor M ₂ and motor M ₃ until the laser beam of the laser rangefinder can be mapped to the center of the bolt ball.

The vector calculated in step 4 is Specifically:

x ₁ =L ₁ *cos θ ₁ cos θ ₂

y ₁ =L ₁ *sinθ ₁ cosθ ₂

z ₁ =L ₁ *sinθ ₂

x ₁ : vector The x-axis coordinate

y ₁ : vector The y-axis coordinate

z ₁ : vector The z-axis coordinate

The specific steps of step 5 to make the laser spot of the laser rangefinder coincide with the center of the circle of the bolt ball _Q2 closest to the bolt ball _Q1 are:

Step 5.1: Determine the relative position of the bolt ball _Q2 and the laser spot through the image;

Step 5.2: Adjust motor M ₂ and motor M ₃ until the laser beam of the laser ranging can be mapped to the center direction of the bolt ball Q ₂ ;

Step 5.3: Adjust the focal length of the laser beam to reduce the spot of the laser beam;

Step 5.4: Adjust motor M ₂ and motor M ₃ until the laser beam of the laser ranging can be mapped to the center of the bolt ball Q ₂ .

The vector calculated in step 6 is Specifically:

x ₂ =L ₂ *cosθ ₃ cosθ ₄

y ₂ =L ₂ *sinθ ₃ cosθ ₄

z ₂ =L ₂ *sinθ ₄

x ₂ : vector The x-axis coordinate

y ₂ : vector The y-axis coordinate

z ₂ : vector The z-axis coordinate

The calculation formula of the distance L in step 7 is as follows:

Beneficial effects of the present invention:

The present invention effectively combines a high-precision laser rangefinder, a multi-axis 0.001° attitude sensor, and a deep learning target detection algorithm, so that the measurement method of grid building nodes no longer relies on manual monitoring, improves measurement efficiency and accuracy, and achieves high-precision measurement of grid building node spacing. Based on the spacing data, it is then determined whether the grid building structure is abnormal, ensuring the real-time and accuracy of large-scale grid building safety monitoring. In addition, the measurement method is not limited by application scenarios and can adapt to various complex environments and scenarios that cannot be monitored manually.

The method proposed by the present invention has high measurement accuracy, low time cost and economic cost, and can realize high-precision measurement of the spacing between grid building nodes in a complex environment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart of the method of the present invention.

FIG. 2 is a schematic diagram of calculating the adjustment angle of the laser rangefinder according to the present invention.

FIG. 3 is a schematic diagram of calculating the distance between adjacent bolt balls according to the present invention.

Detailed ways

The present invention is further described in detail below in conjunction with the embodiments.

The specific steps of the present invention are described in detail with reference to FIG1 , FIG2 , and FIG3 , where FIG1 is a flow chart of the method.

Step 1): Reset the camera, laser rangefinder, attitude sensor and other equipment;

Step 1.1: Reset the focus of the camera and reset the motor M1 of the hollow rotating platform where the camera is located, so that the reset photoelectric switch corresponding to the hollow rotating platform is in a closed state;

Step 1.2: Reset the laser focal length of the laser rangefinder to make the laser beam divergent, and reset the motors M ₂ and M ₃ of the hollow rotating platform where the laser sensor is located, so that the hollow rotating platforms of the two devices are in a reset state;

Step 1.3: Reset the entire hollow rotating platform motor _M4 where the camera and laser rangefinder are located;

Step 1.4: The camera begins to intermittently expand its focus and collect images.

Step 2): Load the target detection model, use a variable-focus high-definition camera to capture an image of the grid building, and use the loaded target detection model to detect adjacent bolt balls Q ₁ and Q ₂ in the image;

Step 2.1: Use Huawei HISI3519 embedded AI core board to load the YOLOv3 bolt ball target detection model;

Step 2.2: Adjust the focal length of the variable-focus high-definition camera, collect images of the grid building, and send the collected images to the target detection network for recognition until the number of bolt balls appearing in the image is greater than 5 and less than 8, as shown in the flowchart of Figure 1;

Step 2.3: Determine the bolt balls Q ₁ and Q ₂ that need to be inspected, and fine-tune the focus of the camera so that the bolt ball Q ₁ can appear clearly in the camera's field of view.

Step 3): According to the relative positions of the bolt ball in the steel structure image and the laser spot of the laser rangefinder in the image, the posture of the laser rangefinder is adjusted, and finally the laser spot of the laser rangefinder coincides with the center of the circle where the bolt ball _Q1 is located;

Step 3.1: Adjust motor _M2 and motor _M3 until the laser beam of the laser ranging can be mapped to the bolt ball;

Step 3.2: gradually reduce the focal length of the laser beam and reduce the spot of the laser beam;

Step 3.3: Repeat steps 3.1 and 3.2 until the laser beam of the laser rangefinder can be completely mapped to the center of the bolt ball and the laser beam of the laser rangefinder has been focused to the minimum state;

Step 4): Get the distance L ₁ from the laser rangefinder to the bolt ball Q ₁ , the horizontal angle θ ₁ and the vertical angle θ ₂ of the attitude sensor, and calculate the vector as shown in picture 2;

The coordinates of the vector are calculated using the following formula:

x ₁ =L ₁ *cos θ ₁ cos θ ₂

y ₁ =L ₁ *sinθ ₁ cosθ ₂

z ₁ =L ₁ *sinθ ₂

Step 4.1: Calculate the horizontal mapping of the laser beam and obtain the horizontal distance:

L ₁₁ =L ₁ *cos θ ₂

Get the vertical coordinates:

z ₁ =L ₁ *sinθ ₂

Calculate the x- and y-axis coordinates from the horizontal distance L ₁₁ :

x ₁ =L ₁₁ *cos θ ₁

y ₁ =L ₁₁ *sinθ ₁

Step 5): According to the relative positions of the bolt ball in the steel structure image and the laser spot of the laser rangefinder in the image, the posture of the laser rangefinder is adjusted, and finally the laser spot of the laser rangefinder coincides with the center of the circle of the bolt ball _Q2 closest to the bolt ball _Q1 .

Step 5.1: Determine the relative position of the bolt ball _Q2 and the laser spot through the image, and thus determine the direction in which the laser attitude needs to be adjusted;

Step 5.2: Adjust motor M ₃ and motor M ₄ until the laser beam of the laser ranging can be mapped to the center direction of the bolt ball Q ₂ ;

Step 5.3: Adjust the focal length of the laser beam to reduce the spot of the laser beam;

Step 5.4: Adjust motor M ₃ and motor M ₄ until the laser beam of the laser distance measurement can be mapped to the center of the bolt ball Q ₂ .

Step 6): Get the distance L ₂ from the laser rangefinder to the bolt ball Q ₂ , the horizontal angle θ ₃ and the vertical angle θ ₄ of the attitude sensor, and calculate the vector The calculation method is the same as step 4;

Step 7): Use the distance _L1 and vector in step 4 above The distance _L2 and vector in step 6 above/> The distance L between the two bolt balls is obtained, the schematic diagram is shown in Figure 3, and the calculation formula is as follows:

The vector calculated by steps 4 and 6 Calculate the cosine value cosθ of the vector angle, and then use the cosine theorem to calculate the length of the other side of the plane triangle in space.

Claims (8)

1. The method for measuring the space between the grid construction nodes is characterized by comprising the following steps of;

Step 1): resetting the variable-focus high-definition camera, the laser range finder and the gesture sensor device;

step 2): loading a target detection model, collecting an image of a net rack building by using a variable-focus high-definition camera, and detecting adjacent bolt balls Q ₁ and Q ₂ in the image by using the loaded target detection model;

Step 3): adjusting the posture of the laser range finder by the relative positions of the bolt ball and the laser spot of the laser range finder in the image of the grid frame building, and finally enabling the laser spot of the laser range finder to coincide with the circle center of the bolt ball Q ₁;

Step 4): obtaining the distance L ₁ from the laser range finder to the bolt ball Q ₁, calculating the horizontal angle theta ₁ and the vertical angle theta ₂ of the attitude sensor to obtain a vector

Step 5): adjusting the posture of the laser range finder by the relative positions of the bolt ball and the laser spot of the laser range finder in the image of the grid frame building, and finally enabling the laser spot of the laser range finder to coincide with the center of the nearest bolt ball Q ₂ at the left lower part of the bolt ball Q ₁;

Step 6): obtaining the distance L ₂ from the laser range finder to the bolt ball Q ₂, calculating the horizontal angle theta ₃ and the vertical angle theta ₄ of the attitude sensor to obtain a vector

Step 7): through the distance L ₁ and the vector in the step 4Distance L ₂ and vector/>, above in step 6And calculating the distance L of the steel beam between the two bolt balls, so as to judge whether the steel beam is deformed.

2. The method for measuring the space between nodes of a network frame building according to claim 1, wherein the step 1 of capturing the image of the network frame building by using the variable-focus high-definition camera specifically comprises:

step 1.1: resetting the focal length of the variable-focus high-definition camera, and resetting a motor M ₁ of a hollow rotary platform where the variable-focus high-definition camera is positioned;

step 1.2: resetting the laser focal length of the laser range finder and resetting a motor M ₂、M₃ of a hollow rotating platform where the laser sensor is positioned;

Step 1.3: resetting the whole hollow rotary platform motor M ₄ where the variable-focus high-definition camera and the laser range finder are positioned;

step 1.4: the variable-focus high-definition camera starts to adjust the focal length and collect images.

3. The method for measuring the distance between nodes of a grid structure according to claim 1, wherein the step 2 uses the loaded object detection model to detect the adjacent bolt balls Q ₁ and Q ₂ in the image specifically comprises:

Step 2.1: loading target detection model weights by using an embedded AI core plate;

Step 2.2: the focal length of the variable-focus high-definition camera is adjusted, meanwhile, an image of a net rack building is collected, the collected image is input into a target detection network to carry out target detection until 5-8 target bolt balls are detected;

Step 2.3: and determining bolt balls Q ₁ and Q ₂ to be detected, and fine-adjusting the focal length of the variable-focus high-definition camera to enable the bolt ball Q ₁ to clearly appear in the field of view of the variable-focus high-definition camera.

4. The method for measuring the distance between grid construction nodes according to claim 1, wherein the step 3 is characterized in that the overlapping of the laser spot of the laser range finder and the center of the circle where the bolt ball Q ₁ is located is specifically:

Step 3.1: adjusting the motors M ₂ and M ₃ until the laser beam of the laser ranging can be mapped to the bolt ball;

Step 3.2: adjusting the focal length of the laser beam of the laser range finder to reduce the spots of the laser beam;

step 3.3: the motors M ₂, M ₃ are adjusted until the laser beam of the laser rangefinder can be mapped to the center of the bolt ball.

5. The method for measuring the distance between nodes of a grid structure according to claim 1, wherein the vector is calculated in the step 4The method comprises the following steps:

x₁＝L₁*cosθ₁cosθ₂

y₁＝L₁*sinθ₁cosθ₂

z₁＝L₁*sinθ₂

x ₁: vector quantity X-axis coordinates of (a)

Y ₁: vector quantityY-axis coordinates of (c)

Z ₁: vector quantityIs defined by the z-axis coordinate of (c).

6. The method for measuring the space between grid construction nodes according to claim 1, wherein the specific step of overlapping the laser spot of the laser range finder with the center of the nearest bolt ball Q ₂ of the bolt ball Q ₁ in step 5 is:

step 5.1: judging the relative position of the bolt ball Q ₂ and the laser spot through the image;

step 5.2: adjusting the motors M ₂ and M ₃ until the laser beam of the laser ranging can be mapped to the spherical center direction of the bolt ball Q ₂;

Step 5.3: adjusting the focal length of the laser beam to reduce the spot of the laser beam;

step 5.4: motor M ₂ is adjusted and motor M ₃ is adjusted until the laser beam of the laser range can be mapped to the center of bolt ball Q ₂.

7. The method for measuring the distance between nodes of a grid structure according to claim 1, wherein the vector is calculated in the step 6The method comprises the following steps:

x₂＝L₂*cosθ₃cosθ₄

y₂＝L₂*sinθ₃cosθ₄

z₂＝L₂*sinθ₄

x ₂: vector quantity X-axis coordinates of (a)

Y ₂: vector quantityY-axis coordinates of (c)

Z ₂: vector quantityIs defined by the z-axis coordinate of (c).

8. The method for measuring the distance between nodes of a grid structure according to claim 1, wherein the distance L in the step 7 is calculated as follows: