Levelness difference detection method after steel structure beam installation

Abstract

The invention discloses a levelness difference detection method after installation of a steel structure beam. A laser projection device is movably installed above the steel structure beam which is mainly used for bearing in a construction site; step 2, horizontally projecting a plurality of projection layers on the steel structure beam through the laser projection device; step 3, installing a camera opposite to each projection layer of the steel structure beam detection area, and obtaining grid pattern data of each projection layer through the cameras; 4, importing the grid pattern data into an image processor, extracting grid vertex and edge features through the image processor, calculating the displacement of the grid vertex and the levelness difference # imgabs0 #, analyzing the deformation condition of each projection layer, and obtaining the levelness difference data of a plurality of projection layers; and step 5, analyzing the levelness difference data of the plurality of projection layers, automatically identifying areas exceeding an allowable range, and adjusting the areas exceeding the allowable range. The method is simple, efficient and reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, and particularly relates to a method for detecting the level difference after the installation of a steel structure beam. Background Art

[0002] In the construction of modern factory buildings, as the main load-bearing member, the installation accuracy of the steel structure beam is directly related to the overall structural stability and safety of the factory building. However, in the actual construction process, due to the influence of factors such as stress, welding, and material deformation, the steel structure beam often has a level difference during the installation process, resulting in structural displacement or deformation. If these problems are not discovered and corrected in time, it will cause problems such as structural deformation and stress concentration, seriously affecting the service life and safety of the factory building.

[0003] The traditional method for detecting the level of a steel structure beam mainly relies on manual measurement using a level, wire-pulling method, etc. This method has the disadvantages of complex operation, low efficiency, and is easily affected by human factors, resulting in inaccurate measurement results. Based on this, a method for detecting the level difference after the installation of a steel structure beam in a factory building is required. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for detecting the level difference after the installation of a steel structure beam, which solves the problems of complex operation, low efficiency, and inaccurate measurement of the traditional method for detecting the level difference after the installation of a steel structure beam.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions: A method for detecting the level difference after the installation of a steel structure beam, comprising the following steps: Step 1: Install a laser projection device movably above the main load-bearing steel structure beam at the construction site; Step 2: Horizontally project multiple projection layers on the steel structure beam through the laser projection device; Step 3: Install a camera opposite each projection layer in the detection area of the steel structure beam, and obtain the grid pattern data of each projection layer through the camera; Step 4: Import the grid pattern data into an image processor, extract the grid vertex and edge features through the image processor, calculate the displacement of the grid vertices and the level difference , analyze the deformation of each projection layer, and obtain the level difference data of multiple projection layers; Step 5: Analyze the level difference data of multiple projection layers, automatically identify the areas that exceed the allowable range, and adjust the exceeded areas.

[0006] Preferably, the laser projection device is configured with an intelligent control module and is movably installed on a guide rail arranged along the length direction of the steel structure beam. It includes a laser projector and a stepping motor, and the stepping motor meshes with the guide rail through a gear.

[0007] Preferably, the camera is adjustably installed on the steel structure beam through a three-axis adjustable bracket, and the three-axis adjustable bracket is fixed in the detection area of the steel structure beam by magnetic adsorption; Among them, the three-axis adjustable bracket includes: X-axis adjustment: Translate the camera along the length direction (X-axis) of the steel structure beam; Y-axis adjustment: Move the camera up and down in the vertical direction (Y-axis) through the lifting function of the bracket; Z-axis adjustment: Move the camera in the front-back direction (Z-axis).

[0008] Preferably, the specific content of step three is as follows: A0, Divide a detection segment every 10 meters on the steel structure beam, and a total of 5 detection segments are set; A1, Project a grid pattern layer by layer through the laser projection device in each detection segment; A2, Take pictures of the projected grid pattern through the camera to obtain the grid pattern data of all projected layers; A3, Recheck the length direction of the steel structure beam through a laser rangefinder.

[0009] Preferably, the specific content of A2 is as follows: Fix and install laser receivers at both ends of each detection segment of the steel structure beam, and the laser receivers are arranged at the edge of the grid pattern; After each projection by the laser projector, the laser receivers synchronously receive the projection signal. Whenever the laser projector completes one layer of grid projection, the laser receivers immediately receive and detect the projected grid line signal; The laser receivers capture the position and intensity of the grid lines through the built-in photoelectric sensors and real-time feedback the received signal data to the control system. The control system checks the projection effect of each layer of grid pattern according to the signal data fed back by the laser receivers.

[0010] Preferably, at both ends of each detection segment of the steel structure beam, at least three marking points are respectively set to form a plane. The marking points are fixed on the surface of the steel structure beam by magnetic adsorption, and the coordinate data of the marking points are used to assist image processing correction and calculate the level difference.

[0011] Preferably, the specific content of step four is as follows: S1, The image processor extracts the grid vertex coordinates from the grid pattern data; S2, The graphics processor identifies the grid lines through an edge detection algorithm and further extracts the position coordinates of the grid vertices ( xi , y i ); S3. Convert the position coordinates ( x i , y i ) of the grid vertices into three-dimensional space coordinates ( x i , y i , z i ) through the calibration parameters of the camera and the known projection distance; S4. In the three-dimensional coordinate system, set the designed position coordinates of each grid vertex as ( x i0 , y i0 , z i0 ); S5. Apply the least squares method to fit the vertex coordinates, minimizing the sum of squared deviations between the measured coordinates and the designed position coordinates to obtain the measured coordinates closest to the designed position; , wherein, is the total number of grid vertices; S6. Calculate the displacements , , of each grid vertex, and the levelness difference , and aggregate each parameter to form the levelness difference data; The displacements , and of each layer of grid vertices are , , ; The levelness difference is .

[0012] In the present invention, a laser projection device is used to project a plurality of projection layers, i.e., grid patterns, on the steel structure beam, and the levelness is detected through image analysis technology and hierarchical distribution analysis. Standard grid patterns can be projected at different heights of the steel structure beam, with one layer of grid projected every 1 meter, and a total of 10 layers of grids are projected to ensure the detection of the entire cross-section of the steel structure beam.

[0013] The image processor analyzes the deformation of each projection layer and calculates the displacements and levelness differences of the grid vertices , Aggregate each parameter to form the level difference data. The multi-level and comprehensive detection improves the level accuracy of the steel structure beam.

[0014] The laser projector moves precisely along the length direction of the steel structure beam through a stepper motor, moving 1 meter per step to ensure that a standard grid pattern is projected at each position. The high-resolution camera is installed on a three-axis adjustable bracket to precisely adjust the shooting angle and distance, ensuring that the image is clear and undistorted, enabling this detection to adapt to steel structure beams of different specifications and positions, enhancing the adjustment during the factory building construction process, and improving the installation quality and construction efficiency. Brief Description of the Drawings

[0015] Figure 1 It is a schematic flow chart of the present invention; Figure 2 It is a broken line chart of the level difference of the present invention. In the figure, the horizontal axis is the number of projection layers, and the vertical axis is the level data; Figure 3 It is a bar chart of the level difference of the present invention. In the figure, the horizontal axis is the number of projection layers, and the vertical axis is the level data. Detailed Embodiment

[0016] The following further describes the present invention with reference to the drawings: As Figures 1 to 3 shown, a method for detecting the level difference after the installation of a steel structure beam includes the following steps: Step 1. Install a laser projection device movably above the main load-bearing steel structure beam at the construction site.

[0017] The laser projection device is configured with an intelligent control module to adjust the projection angle and intensity according to the on-site environment, and dynamically adjust the density of the projected grid according to the force condition and installation position. Increase the grid projection density at the main stress section and key installation positions of the steel structure beam. On the contrary, in areas with less force or simple structures, the grid projection density will be appropriately reduced. The laser projection device can be movably installed on a guide rail arranged along the length direction of the steel structure beam, including a laser projector and a stepper motor. The stepper motor is engaged with the guide rail through a gear. By controlling the stepper motor, the laser projection device can be precisely moved, and the moving step length is set to 1 meter. By controlling and debugging the moving speed and step length of the stepper motor, the laser projection device can move uniformly along the X-axis direction, covering the entire detection area of the steel structure beam section by section. When moving to the specified position each time, the laser projection device projects a standard grid pattern, preparing for the detection of the level difference.

[0018] Step 2. Horizontally project multiple projection layers on the steel structure beam through the laser projection device, and the projection layer is a standard grid pattern.

[0019] Perform multi-layer grid projection in the vertical direction of the beam. Starting from the bottom of the steel structure beam, project a layer of grid every 1 meter upwards layer by layer until the top of the steel structure beam. A total of 10 layers of grids are projected to cover the entire cross-section of the steel structure beam, and perform horizontal detection along the length direction of the steel structure beam.

[0020] Step 3: Install cameras on the opposite side of each projection layer in the detection area of the steel structure beam. After each layer of projection is completed, the camera starts to capture the grid pattern of that projection layer and keeps the shooting angle and distance consistent. Obtain the grid pattern data of each projection layer through the camera.

[0021] The resolution of the camera is not less than 40 million pixels. The camera can be adjusted and installed on the steel structure beam through a three-axis adjustable bracket. The three-axis adjustable bracket is fixed in the detection area of the steel structure beam by means of magnetic adsorption.

[0022] The three-axis adjustable bracket precisely adjusts the shooting angle and distance of the camera. The three-axis adjustable bracket enables the camera to be precisely adjusted in three directions, specifically: X-axis (horizontal left and right direction): The camera moves left and right in the X-axis direction to accurately align the camera with the center position of the grid pattern of each layer. Y-axis (vertical up and down direction): The camera moves up and down in the Y-axis direction by lifting on the bracket to adjust the height of the camera so that the height of the grid pattern of each layer is the same. Z-axis (front and back direction): The camera moves back and forth in the Z-axis direction through the bracket to adjust the distance between the camera and the steel structure beam.

[0023] The detailed steps are as follows: A0, Divide a detection segment every 10 meters on the steel structure beam, and a total of 5 detection segments are set. A1, Project the grid pattern layer by layer through the laser projection device within each detection segment. A2, Capture the projected grid pattern through the camera to obtain the grid pattern data of all projection layers. Fix and install laser receivers at both ends of each detection segment of the steel structure beam. The laser receivers are arranged at the edge of the grid pattern; after each projection by the laser projector, the laser receivers synchronously receive the projection signal. Whenever the laser projector completes a layer of grid projection, the laser receivers immediately receive and detect the projected grid line signal; the laser receivers capture the position and intensity of the grid line through the built-in photoelectric sensor and real-time feedback the received signal data to the control system. The control system verifies the projection effect of the grid pattern of each layer according to the signal data fed back by the laser receivers and obtains the grid pattern data of all projection layers. A3, Recheck the length direction of the steel structure beam through a laser rangefinder.

[0024] Step 4: Import the grid pattern data into the image processor. The image processor extracts the grid vertices and edge features, calculates the displacements of the grid vertices and the differences in levels, and analyzes the deformation of each projection layer to obtain the level difference data of multiple projection layers. During each detection process, the level difference data of each layer of the grid is automatically recorded and stored in the central database. At both ends of each detection segment of the steel structure beam, at least three marking points are respectively set to form a plane. The marking points are fixed on the surface of the steel structure beam by magnetic adsorption, and the coordinate data of the marking points are used to assist in image processing correction and calculation of the level difference.

[0025] Specifically:

[0026] Specifically: S1, the image processor extracts the grid vertex coordinates from the grid pattern data; S2, the graphics processor identifies the grid lines through the edge detection algorithm and further extracts the position coordinates of the grid vertices ( x i , y i ); S3, convert the position coordinates of the grid vertices ( x i , y i ) into three-dimensional space coordinates through the calibration parameters of the camera and the known projection distance ( x i , y i , z i ); S4, in the three-dimensional coordinate system, set the designed position coordinates of each grid vertex as ( x i0 , y i0 , z i0 ); S5, apply the least squares method to fit the vertex coordinates, minimize the sum of squared deviations between the measured coordinates and the designed position coordinates, and obtain the measured coordinates closest to the designed position; , wherein, is the total number of grid vertices; The function of this formula is to find the optimal coordinates by adjusting the positions of the grid vertices, minimizing the measurement error, thus ensuring higher precision of the grid during image processing and analysis. Especially in the grid data obtained by laser measurement devices, there are often tiny errors. The least squares method optimizes these coordinates to ensure the accuracy and precision of the system detection results; S6. Calculate the displacements of each grid vertex , , , and the levelness difference , aggregate each parameter to form the levelness difference data; The displacements of each layer of grid vertices , and are , , ; The levelness difference is .

[0027] Step Five. Analyze the levelness difference data of multiple projection layers, automatically identify the areas beyond the allowable range, and adjust the exceeded areas.

[0028] Display the levelness difference data of each layer on the monitoring device in real time, visually present the detection results through charts and images. The monitoring device is equipped with a high-resolution display screen and a data processor, which can receive and process these levelness difference data in real time. The data processor visually presents the levelness difference data of each layer in the form of charts and images, specifically including: Charts: Generate real-time updated line charts and bar charts to show the levelness differences of each layer of grids. The line chart shows the changing trends of the levelness differences of each grid vertex, and the bar chart shows the average levelness differences and standard deviations of each detection segment; Line chart: The horizontal axis represents the positions of the grid vertices, and the vertical axis represents the levelness differences. Through the line chart, the changing situations of the levelness of each grid vertex can be visually seen; Bar chart: Each bar represents the average levelness difference of a detection segment, and the height of the bar represents the magnitude of the levelness difference. The bar chart can help identify the overall installation quality.

[0029] On a projection layer of a steel structure beam, the levelness difference data of 10 grid vertices were collected. The following are the example data of each grid vertex: Based on the above data, a line chart of the levelness difference is generated, as shown in Figure 2The figure shows the horizontal degree differences of each grid vertex, which helps to visually observe the changes of each grid vertex, automatically identify the areas beyond the allowable range, and adjust the exceeded areas.

[0030] As Figure 3 shown in the bar chart: It shows the horizontal degree differences of each grid vertex and marks the average value, which is convenient for overall evaluation of the installation quality.

[0031] The above embodiments are only several descriptions of the concept and implementation of the present invention, and are not intended to limit it. Under the concept of the present invention, the technical solutions without substantial transformation are still within the protection scope.

Claims

1. A method for detecting the levelness difference of a steel structure beam after installation, characterized in that: The following steps are involved: Step 1: A laser projection device can be movably installed above the main load-bearing steel structure beam at the construction site; Step 2: horizontally projecting multiple projection layers onto the steel structure beam by means of the laser projection device; Step 3: Install a camera opposite to each projection layer in the steel structure beam detection area, and obtain the grid pattern data of each projection layer through the camera; Step 4: Import the grid pattern data into the image processor, extract the grid vertex and edge features through the image processor, and calculate the displacement of the grid vertex and the horizontal difference , analyze the deformation of each projection layer and obtain the horizontality difference data of multiple projection layers; Step 5: Analyze the level difference data of multiple projection layers, automatically identify the areas beyond the allowable range, and adjust the exceeded areas.

2. The method for detecting the difference in levelness of a steel structure beam after installation according to claim 1 is characterized in that: The laser projection device is equipped with an intelligent control module, and can be movably mounted on a guide rail arranged along the length direction of the steel structure beam. It includes a laser projector and a stepper motor, and the stepper motor is meshed with the guide rail through a gear.

3. The method for detecting the difference in levelness of a steel structure beam after installation according to claim 1 is characterized in that: The camera is adjustably mounted on the steel structure beam via a three-axis adjustable bracket, and the three-axis adjustable bracket is fixed to the detection area of ​​the steel structure beam by magnetic adsorption; Among them, the three-axis adjustable bracket includes: X-axis adjustment: the camera is moved along the length direction (X-axis) of the steel structure beam; Y-axis adjustment: The camera can be moved up and down in the vertical direction (Y-axis) through the lifting function of the bracket; Z-axis adjustment: Move the camera in the front-to-back direction (Z-axis).

4. The method for detecting the horizontality difference of the steel structure beam after installation according to claim 1 is characterized in that: The step three is specifically as follows: A0: A detection section is divided every 10 meters on the steel structure beam, with a total of 5 detection sections; A1, in each detection segment, a grid pattern is projected layer by layer through a laser projection device; A2, photographing the projected grid pattern through a camera to obtain grid pattern data of all projection layers; A3, use laser rangefinder to check the length direction of steel structure beam.

5. The method for detecting the difference in levelness of a steel structure beam after installation according to claim 4 is characterized in that: Specifically, A2 is as follows: laser receivers are fixedly installed at both ends of each detection segment of the steel structure beam, and the laser receivers are arranged at the edge of the grid pattern; after each projection of the laser projector, the laser receiver synchronously receives the projection signal, and whenever the laser projector completes a layer of grid projection, the laser receiver immediately receives and detects the projected grid line signal; the laser receiver captures the position and intensity of the grid line through a built-in photoelectric sensor, and feeds back the received signal data to the control system in real time, and the control system verifies the projection effect of each layer of the grid pattern based on the signal data fed back by the laser receiver.

6. The method for detecting the difference in levelness of a steel structure beam after installation according to claim 4 or 5, characterized in that: At both ends of each detection segment of the steel structure beam, at least three marking points are set to form a plane. The marking points are fixed on the surface of the steel structure beam by magnetic adsorption, and the coordinate data of the marking points are used to assist image processing correction and calculate the horizontality difference.

7. The method for detecting the difference in levelness of a steel structure beam after installation according to claim 6, characterized in that: The step 4 is specifically as follows: S1, the image processor extracts the grid vertex coordinates from the grid pattern data; S2, the graphics processor identifies the grid lines through the edge detection algorithm and further extracts the position coordinates of the grid vertices ( x i , y i ); S3, the position coordinates of the mesh vertices ( x i , y i ) is converted into three-dimensional space coordinates through the camera calibration parameters and the known projection distance ( x i , y i , z i ); S4, in the three-dimensional coordinate system, let the design position coordinates of each mesh vertex be ( x i0 , y i0 , z i0 ); S5, applying the least square method to fit the vertex coordinates, minimizing the sum of square deviations between the measured coordinates and the designed position coordinates, so as to obtain the measured coordinates closest to the designed position; ， in, is the total number of mesh vertices; S6, calculate the displacement of each mesh vertex , , , and the level difference , aggregate various parameters to form horizontal difference data; Displacement of each layer of mesh vertices , and for ， ， ； The level difference is 。

Images