A precise docking and positioning method for installing large-span, two-way fish-belly steel trusses.

Abstract

This invention relates to the field of steel structure installation technology, specifically a precise docking and positioning method for installing large-span, two-way fish-belly steel trusses. The method includes: acquiring multiple measuring points on each truss; obtaining structural morphology data for each measuring point based on its elevation and planar position; constructing an overall displacement vector for the truss structure corresponding to each measuring point within any installation step; extracting the relative displacement corresponding to each measuring point based on the changing trend of the overall displacement vector; calculating the rate of change of the distance between adjacent measuring points according to the posture of the truss structure where the measuring point is located, and defining the deformation type corresponding to each measuring point; combining the overall displacement and relative displacement under different deformation types into a displacement quantity; iteratively judging the displacement quantity under each installation step to determine the key nodes corresponding to each installation step; and feeding back the installation accuracy of each measuring point according to the maximum displacement of the key nodes. This improves the positioning accuracy and efficiency during truss installation.

Description

Technical Field

[0001] This invention relates to the field of steel structure installation technology, specifically a precise docking and positioning method for installing large-span, two-way fish-belly steel trusses. Background Technology

[0002] With the diversification of building functions, the demand for large-span spatial structures (such as stadiums, airport terminals, and convention centers) is increasing. These structures typically employ a two-way fish-belly steel truss system, consisting of an upper chord, web members, and a polygonal lower chord forming a fish-belly-shaped spatial truss. This results in numerous member connection nodes and complex force paths; the structures also present challenges due to their large span and heavy weight, requiring solutions for high-altitude installation, deformation control, and precise alignment.

[0003] For example, Chinese Patent Publication No. CN118495355A discloses a hoisting and positioning method for BIM modular prefabricated construction. Based on the IFC standard for BIM modular prefabricated construction, a prefabricated module space is established to provide storage space for prefabricated modules. Using this as a foundation, the independent boundary coordinate information of the prefabricated modules is obtained based on the geometric information of the prefabricated modules stored in the physical unit space, and then hoisting is performed. During the hoisting process, conflict detection is performed on the prefabricated modules after each hoisting, and finally, the final construction sequence node information is determined, completing the automatic splicing of the prefabricated modules.

[0004] For example, Chinese Patent Publication No. CN119143017A discloses a positioning method and system for an unmanned tower crane. The method defines the first spatial coordinates of the tower crane portion based on the unmanned tower crane's position system and the location of its crane section. It then defines a second spatial coordinate based on the location of the crane section and the position marked by the satellite system. Finally, it defines the actual position information of the crane section based on the second and first spatial coordinates, and the GNSS coordinates of the crane section based on the actual position information of the crane section and the unmanned tower crane. The method also defines the position deviation of the crane section relative to the working position based on the GNSS coordinates of the crane section and the GNSS coordinates of the working position. Finally, it defines the position control accuracy of the crane section during operation based on the position deviation, multiple environmental features, and the position accuracy level of the working position.

[0005] In existing technologies, prefabricated module boundaries are used to complete hoisting and installation operations according to the construction node sequence, and the position control accuracy of the tower crane is achieved through position matching during tower crane operation. However, existing technologies tend to align large-block structures, which leads to problems such as mixed overall and local deformations, rough precision control, and difficulty in locating problems during truss structure installation. It is impossible to determine the specific displacement of the truss installation, resulting in reduced installation accuracy. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a precise docking and positioning method for the installation of large-span bidirectional fish-belly steel trusses, including: S1, acquiring multiple measuring points on each truss, and obtaining the structural morphology data of each measuring point based on the elevation and planar position of each measuring point.

[0007] S2, during any installation step, perform an overall trend analysis on the truss structure corresponding to each measuring point, construct the overall displacement vector of the truss structure, and extract the relative displacement corresponding to each measuring point based on the changing trend of the overall displacement vector.

[0008] S3 calculates the rate of change of the distance between adjacent measuring points according to the attitude of the truss structure where the measuring point is located, and defines the deformation type corresponding to each measuring point.

[0009] S4 combines the overall displacement and relative displacement under different deformation types into a displacement amount, iteratively judges the displacement amount under each installation step, and determines the key nodes corresponding to each installation step.

[0010] S5, based on the key nodes corresponding to each installation step, converts the displacement of each key node into a change curve, and feeds back the installation accuracy of each measuring point according to the maximum displacement of the key node.

[0011] The beneficial effects of this invention are as follows: First, by setting measuring points at key locations such as edges, junctions, and centers, this invention establishes boundary reference sets, main truss reference sets, and subsystem reference sets respectively. Then, it extracts the overall displacement vector and relative displacement through singular value decomposition. According to the structural relationship of each measuring point, it distinguishes between the overall rigid body motion and local elastic deformation that exist during the current truss installation, and judges the displacement value measured by each measuring point. This prevents the accumulation of local errors from amplifying and transmitting the value of a certain measuring point in subsequent installation steps, and provides clear input parameters for precise control.

[0012] Second, this invention identifies peak time points as characteristic indicators through time-series analysis of spacing change rate, further establishes axial component analysis of relative displacement between different trusses, identifies dominant deformation types by the number of peak time overlaps, emphasizes problem identification based on the peak of the change rate, and leans towards an early warning approach to monitor the current docking positioning.

[0013] Third, this invention employs a dual classification based on correlation coefficients and statistical characteristics. It uses the correlation coefficients between displacement components and the overall displacement vector, as well as the mean and standard deviation of each displacement component, to perform multiple classification processing, emphasizing the scenarios in which the overall displacement vector appears. Subsequently, it utilizes the differentiation processing of overlapping areas to address conflicts between the overall displacement vectors, preventing conflicts in the displacement calculation results of measuring points caused by single-dimensional analysis. The final analysis focuses on certain measuring points to complete the identification of the docking installation accuracy. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Figure 1 This is a flowchart illustrating the precise docking and positioning method for installing large-span, two-way fish-belly steel trusses.

[0016] Figure 2 This is a structural diagram of a truss installation structure based on a precise docking and positioning method for installing large-span, two-way fish-belly steel trusses.

[0017] Figure 3 This is a structural diagram of step 1 of the truss installation process based on the precise docking and positioning method for installing large-span bidirectional fish-belly steel trusses.

[0018] Figure 4 This is a structural diagram of step 2 of the truss installation process, based on the precise docking and positioning method for installing large-span bidirectional fish-belly steel trusses.

[0019] Figure 5 This is a structural diagram of step 3 of the truss installation process, based on the precise docking and positioning method for installing large-span bidirectional fish-belly steel trusses.

[0020] Figure 6 This is a structural diagram of step 4 of the truss installation process, based on the precise docking and positioning method for installing large-span bidirectional fish-belly steel trusses.

[0021] Figure 7 This is a structural diagram of step 5 of the truss installation process, based on the precise docking and positioning method for installing large-span bidirectional fish-belly steel trusses.

[0022] Figure 8 This is a structural diagram of step 6 of the truss installation process, based on the precise docking and positioning method for installing large-span bidirectional fish-belly steel trusses.

[0023] Figure 9 This is a flowchart illustrating step S1 of the precise docking and positioning method for installing large-span bidirectional fish-belly steel trusses.

[0024] Figure 10This is a flowchart illustrating step S2 of the precise docking and positioning method for installing large-span bidirectional fish-belly steel trusses.

[0025] Figure 11 This is a flowchart illustrating step S3 of the precise docking and positioning method for installing large-span bidirectional fish-belly steel trusses.

[0026] Figure 12 This is a flowchart illustrating step S4 of the precise docking and positioning method for installing large-span bidirectional fish-belly steel trusses.

[0027] Figure 13 This is a flowchart illustrating step S5 of the precise docking and positioning method for installing large-span bidirectional fish-belly steel trusses. Detailed Implementation

[0028] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in the art or in accordance with the product manual.

[0029] See Figure 1 A precise docking and positioning method for installing large-span, two-way fish-belly steel trusses is proposed, including: S1, acquiring multiple measuring points on each truss, and obtaining structural morphology data for each measuring point based on its elevation and planar position. Elevation: mainly Z-coordinate (elevation) data, used to calculate whether each position under the truss reaches the design height. Planar position: X and Y coordinates, used to control the horizontal position and span of the truss.

[0030] S2, during any installation step, perform an overall trend analysis on the truss structure corresponding to each measuring point, construct the overall displacement vector of the truss structure, and extract the relative displacement corresponding to each measuring point based on the changing trend of the overall displacement vector.

[0031] S3 calculates the rate of change of the distance between adjacent measuring points according to the attitude of the truss structure where the measuring point is located, and defines the deformation type corresponding to each measuring point.

[0032] S4 combines the overall displacement and relative displacement under different deformation types into a displacement amount, iteratively judges the displacement amount under each installation step, and determines the key nodes corresponding to each installation step.

[0033] S5, based on the key nodes corresponding to each installation step, converts the displacement of each key node into a change curve, and feeds back the installation accuracy of each measuring point according to the maximum displacement of the key node.

[0034] like Figures 2-8As shown, the positioning points include multiple points such as the upper and lower chord nodes of the side truss / slant truss / main truss, horizontal brace nodes, and the upper chord span of the main truss. Generally, the installation steps of a large-span two-way fish-belly steel truss are as follows: Step 1: Install the truss columns at both ends and stabilize them by guy ropes.

[0035] Step 2: Install the lower chords of the trusses at both ends and adjust their pre-camber using the support frame.

[0036] Step 3: Install the vertical web members and top chord members of the trusses at both ends.

[0037] Step 4: Install the diagonal web members of the truss.

[0038] Step 5: Continue installing the lower chord of the truss. One side of the lower chord is temporarily stabilized with a support plate because the position of the grandstand below conflicts with the frame.

[0039] Step 6: Install the remaining vertical web members, top chord members, and diagonal web members in sequence. After welding is completed, unload them at an appropriate time.

[0040] These six steps represent the processing steps for the pre-hoisting area. In this step, multiple measuring points will be set up, and these measuring points will be centrally monitored during the pre-hoisting preparation installation steps and the actual hoisting situation to achieve displacement analysis of the truss.

[0041] When measuring the positioning nodes, step 1 indicates the relative positions of measuring points 1, 2, 9 and 10 in the figure; step 2 measures measuring points 4 and 8, and simultaneously determines the relative positions of measuring points 2 and 10 on the truss.

[0042] Step 3 describes measuring points 3 and 7, as well as measuring points 1 and 9, which are measured simultaneously. Step 4 remeasures the points 1, 2, 4, 8, 9, and 10 after the addition of the inclined truss, placing them at their corresponding positions. Step 5 records measuring point 6, as well as the positions of measuring points 3, 4, 7, and 8 after the addition of the lower chord of the truss. Finally, measuring point 5 is recorded, along with the relative positions of other measuring points after installation.

[0043] After completing the position measurement of these points, it is necessary to calculate the vertical height difference of multiple measuring points based on the center points of the upper and lower chord nodes after installation. That is, measure the positions of measuring points 5 and 6 before and after installation to determine whether each point forms a stable frame after installation, as well as the relative positions of each point.

[0044] Steps 1-6 described here represent the installation process. In actual calibration and installation, the focus is on assembling a relatively complete structure, such as installing the structure shown in the diagram as three assembled steel structures, or as two assembled structures.

[0045] The data statistics for the measuring points will be collected according to the following times: once before loading the structure, once during loading, twice within 24 hours after loading, once a week after loading, and once before unloading. The data for the trusses corresponding to the measuring points will also be collected once a day to record their installation data.

[0046] In step S1, multiple measuring points are set at the edges of the truss, the intersection of the inclined trusses, and the center of the truss. The average coordinate values ​​obtained from these measuring points are used to determine the positioning accuracy of the truss after installation.

[0047] like Figure 9 As shown, the implementation of step S1 includes: S11, selecting multiple measuring points at the edge, the intersection of the inclined truss and the center of the truss, and obtaining the coordinate values ​​of each measuring point on the same truss; the current structural morphology data represents the three-dimensional coordinates of each measuring point, as well as the type of each measuring point, such as upper chord measuring point, lower chord measuring point, etc.

[0048] S12, continuously locate the coordinates of each measuring point, calculate the average coordinate value of the continuous measurements, if there is a deviation in the measuring point under multiple consecutive measurements, record the correction amount of the corresponding measuring point, and synchronize the coordinate value of the corresponding measuring point with the corresponding correction amount to the structural morphology data.

[0049] The deviation here is determined by the difference between its average coordinate and the standard coordinate. The determined value is biased towards the point of the truss on the Z-axis. At this time, the space where the truss is located is marked in the form of three-dimensional coordinates, and the size of its Z-axis measurement is checked for errors. If there are errors, the corresponding correction amount is recorded to facilitate subsequent analysis of the resulting trend. The correction amount is equal to the theoretical reference value minus the measured average value.

[0050] Deviations on the X and Y axes are identified by combining subsequent relative and overall displacements to determine whether the currently arranged measuring points have excessive displacement.

[0051] In one embodiment of the present invention, the overall displacement is determined by calculating the change in the average coordinates of the measuring points and whether there is a vector sum of overall forward / backward movement, settlement / lifting at the current measuring point. After obtaining the overall displacement trend, this step also needs to further analyze the relative displacement of each measuring point to determine whether there is overall displacement and local deformation during the current deformation or calibration, thereby completing the positioning of multiple measuring points.

[0052] When forming the overall displacement vector, a rigid body transformation based on SVD (Singular Value Decomposition) will be used to solve the problem. The reference coordinates and the geometric centroid of the current measuring point will be calculated separately. The geometric centroid is the average value of its coordinates. Then, the geometric centroid will be subtracted from each measuring point to obtain the decentralized coordinates.

[0053] Then, the outer product of all measuring points is calculated and summed, which involves multiplying the decentralized reference coordinates and the current measuring point coordinates and summing the results to obtain a covariance matrix. Singular value decomposition is then performed on the covariance matrix. ;in, It is the covariance matrix. It is a 3×3 orthogonal matrix that describes the main direction of change corresponding to the reference coordinates; It is a 3×3 diagonal matrix with singular values ​​on the diagonal. It is the transpose of a 3×3 orthogonal matrix; then the optimal rotation matrix. satisfy ;in, It is a matrix transpose, It is a matrix The corresponding orthogonal matrix describes the main direction of change of the current measuring point coordinates.

[0054] After calculating the optimal rotation matrix, the optimal translation vector can be obtained directly. The optimal translation vector is obtained by subtracting (R * reference coordinates) from the current measurement point coordinates. This vector represents the overall change in the overall displacement trend, and is considered the currently obtained overall displacement vector.

[0055] As for the subsequent trend of the overall displacement vector, this involves analyzing the state of the overall displacement before and after each installation step, and whether there is a significant change in the overall displacement vector at a certain moment after hoisting through the combination of various measuring points. The relative displacements of adjacent measuring points at moments where changes occur are then extracted. It should be noted that all coordinate values ​​used are data processed through decentralization.

[0056] As for the relative displacement, it needs to be calculated in the form of the current measured point coordinates after decentralization = R × the decentralized reference coordinates + the translation vector. The corresponding translation vector is then obtained, and the optimal translation vector is found using the least squares method. After that, the relative displacement is calculated in the form of the current measured point coordinates - (R * reference coordinates + translation vector) to obtain the displacement of each measured point relative to the structure.

[0057] like Figure 10As shown, the implementation of step S2 includes: S21, based on the structural position of each measuring point, extracting multi-level dependencies for each measuring point and setting the label information corresponding to each measuring point; the dependency relationship described at the present time comprehensively describes the measuring points at different positions, describing the continuity of each measuring point on the truss structure. For example, if both measuring points represent edge positions, the overall displacement vector needs to be constructed with the absolute plane position (X, Y) as the main factor and the elevation Z as the auxiliary factor; at this time, the measuring points at the edge positions will be used as the main data for judging the current covariance matrix, and the overall displacement vector will be calculated separately for the measuring points with different dependencies. This prevents the error of some measuring points from being absorbed by the whole when processing in multiple steps, because each step mainly involves different measuring points, resulting in the problem of insensitivity to error when calculating the overall displacement vector.

[0058] Preferably, the multi-level dependency relationship can be divided into three levels according to the importance of the steel truss structure: first-level dependency (positional association between boundary nodes), second-level dependency (association between main truss nodes and boundary nodes), and third-level dependency (association between subsystem nodes and main truss nodes). The extraction method is based on the node connection matrix exported from the BIM model, and the dependency relationship is identified by the adjacency list algorithm.

[0059] The label information is used to assign labels to the relevant measuring points when the covariance matrix is ​​formed after the corresponding measuring points are decentralized, such as measuring points located at the upper and lower chord nodes of the side truss / slant truss / main truss, horizontal brace nodes, and the middle position of the upper chord span of the main truss.

[0060] S22, based on the label information and dependencies of each measuring point, the measuring points are divided into multiple reference point sets; the reference point sets include, but are not limited to, boundary reference sets, main truss reference sets, and subsystem reference sets; the boundary reference sets contain the nodes of the side trusses and diagonal trusses, representing the boundary constraints of the structure. The main truss reference set is divided according to truss elements and contains nodes on the same main truss. Subsystem reference sets, such as horizontal brace nodes, are set separately.

[0061] S23, extract the reference coordinates and current 3D coordinates corresponding to each set of reference points, construct the covariance matrix in a decentralized form, perform singular value decomposition on the covariance matrix, and set the overall displacement vector corresponding to each set of reference points in the way of the optimal rotation matrix.

[0062] S24: Based on the changing trend of the overall displacement vector at multiple time points, compare the overall displacement vectors of different reference point sets. By removing the overall displacement vector of the reference point set to which each measuring point belongs from the displacement of each measuring point, the relative displacement is obtained, and the relative displacement corresponding to each measuring point after comparison is output.

[0063] Because the location of the measuring points is different, the dimensions monitored by each measuring point will change. For example, for edge truss / sloping edge truss nodes, the absolute plane position (X, Y) will be the main reference and the elevation Z will be the secondary reference. These points belong to the first installed and relatively stable parts, and are the preferred reference point set for calculating the overall displacement vector. Abnormal displacement of these points may mean support settlement, slippage or the accumulation of installation deviation.

[0064] For the upper chord nodes of the main truss, the elevation Z will be the primary factor, and the plane position (X, Y) will be secondary. The measured elevation must be strictly compared with the designed elevation, and lateral displacement must be monitored simultaneously to prevent instability at the corresponding position.

[0065] For the lower chord nodes of the main truss, the elevation Z will be the primary consideration, with equal emphasis on the planar position (X, Y). It is necessary to analyze them in conjunction with the upper chord nodes to calculate the rate of change of vertical height difference between the same section. The vertical changes of the upper and lower chord nodes will be highlighted in the overall displacement analysis.

[0066] For horizontal brace nodes, the relative displacement (ΔX, ΔY) in the plane is the primary factor in identifying the relative displacement of the horizontal brace node relative to the main truss node. This helps prevent situations where the horizontal brace fails to effectively constrain the main truss. The point set corresponding to this point will indicate whether the structure has undergone overall torsion.

[0067] For the mid-span node of the upper chord of the main truss, which represents the point of maximum bending moment and deformation of the structure, its elevation Z is the absolute core and the most critical indicator for measuring the success of the entire installation. It can be divided into a separate set to identify the corresponding data.

[0068] The edge truss / sloping edge truss nodes will be used as the boundary reference set, the upper and lower chord nodes of the main truss and the mid-span node of the upper chord of the main truss will be used as the main truss reference set, and the horizontal brace nodes will be used as multiple independent subsystem reference sets.

[0069] Therefore, when setting the overall displacement vector in step S23, the implementation method also includes: based on the label information corresponding to the current reference point set, processing the boundary reference set, the main truss reference set and the subsystem reference set in sequence to obtain the displacement components of each reference point set. The displacement components represent the components extracted from the overall displacement vector, and multiple displacement components will be set in the form of planar position (X, Y), relative displacement in the plane (ΔX, ΔY) and elevation Z.

[0070] Based on the value range of each displacement component, the displacement components are preliminarily classified by the correlation coefficient between the displacement components and the overall displacement vector, and this classification is taken as the first classification result of the preliminary classification.

[0071] Based on the mean displacement and standard deviation of each displacement component, a second classification result is set for each displacement component; the first and second classification results are combined, and the overall displacement vector corresponding to the combination is output.

[0072] When calculating the correlation coefficients mentioned above, the displacement components and the overall displacement vector can be calculated using cosine similarity. The displacement components are then categorized according to the cosine similarity values, indicating the relationship between local and overall displacements. For example, truss displacements are highly correlated with overall displacements, showing a clear trend of overall structural deformation; boundary displacements are highly correlated with overall displacements, indicating significant external environmental influences; and the displacements of each reference point set are less correlated with overall displacements, indicating significant local deformation. These categories represent the specific deformation trends of the overall displacement vector. At this point, cosine similarity thresholds are set for different reference point sets, and classification is performed based on these thresholds to describe the displacement at different locations. For instance, the cosine similarity thresholds are set to 0.85, 0.75, and 0.4 respectively, according to the order of boundary reference set, main truss reference set, and subsystem reference set, to classify the displacement components corresponding to the current reference point set, thus illustrating the descriptions corresponding to multiple reference point sets.

[0073] Using the displacement mean and standard deviation will illustrate the dispersion of the displacement components. The second classification then indicates whether the displacement component values ​​are dispersed or concentrated. This classification information is then synchronized to the overall displacement vector corresponding to each displacement component to explain the specific situation of each overall displacement component. Confidence intervals can be used here, with the position of the displacement component value relative to the upper and lower limits of the confidence interval indicating its second classification. For example, a confidence interval of ±3 times the standard deviation of the displacement component's historical data can be used to set confidence intervals for the currently calculated displacement mean and standard deviation. The current value being within or exceeding the confidence interval is considered a separate category. The upper limit of the confidence interval is used for a second classification to explain the current displacement change. For example, if the displacement exceeds the upper limit of the confidence interval, the truss will have significant positive deformation, possibly due to external loads. If the displacement is within the confidence interval, it means the displacement is within the normal range. If the displacement is less than the lower limit of the confidence interval, there will be significant negative deformation, requiring urgent inspection. Since the displacement components are mostly based on the current measuring point coordinates minus the reference coordinates after decentering, the extracted displacement components will have both positive and negative signs to indicate the displacement change relative to the reference coordinates. The upper and lower limits of the confidence interval will represent the range of positive and negative signs.

[0074] Preferably, the method of combining the first classification result and the second classification result is to fill the classification obtained from the first classification result into the data corresponding to the overall displacement vector. The same applies to the combination of the second classification result, which is to comprehensively explain the relationship between the local displacement component and the overall displacement plus the degree of dispersion of the displacement component. As the processing procedure of the current step S23, these data are synchronized to the database corresponding to the overall displacement for further viewing of relevant data.

[0075] The method for comparing the overall displacement vectors of different reference point sets in step S24 includes: determining whether there is an overlapping region in the current reference point set; if there is an overlapping region, using a weighted average method to fuse the overall displacement vectors of different reference point sets for the measurement points in the overlapping region.

[0076] If there is no overlapping area, the slope residual value of each overall displacement vector is recorded based on the changing trend of each overall displacement vector; based on the value of the slope residual value, priority is set for each overall displacement vector, and the overall displacement vectors are sorted from largest to smallest according to priority.

[0077] At this point, based on the changes in the overall displacement over multiple time periods, the slope values ​​of these changes are used to calculate the residuals, which illustrate the changes in the current value relative to the reference coordinates. The larger the slope residual value, the larger the overall displacement vector is set. In other words, by taking the slope residual values, all the calculated slope residual values ​​are normalized to illustrate the weight set for each overall displacement vector, so that the overall displacement vector is output based on this priority weight.

[0078] Finally, the overall displacement vector of the reference point set to which each measuring point belongs is removed from the displacement of each measuring point to obtain the relative displacement.

[0079] When performing weighted fusion on overlapping areas, weights are set based on the corresponding types of the reference point sets. The weights for the boundary reference set, main truss reference set, and subsystem reference set are set to 0.32, 0.6, and 0.08 respectively. At this point, the coordinates of the measurement points on the main truss reference set are emphasized; a weight of 0.60 ensures the dominant role of the main truss displacement in the comprehensive evaluation. The boundary measurement points are easily affected by external environmental factors such as wind and temperature, and are considered secondary important points of the main truss. A weight of 0.32 reflects the importance of the boundary nodes, and some weight is reserved for the horizontal support nodes in the subsystem reference set to prevent the subsystem influence from being completely ignored, which would lead to an unknown overall displacement.

[0080] In one embodiment of the present invention, step S3 is biased towards determining whether there is an angular change between multiple measuring points in the installed steel truss, and whether there are conditions such as bending deformation, shear deformation and torsional deformation at the corresponding positions. If there is no deformation, the deformation type is set to 0 to indicate that the current structure is relatively stable.

[0081] It should be noted that relative displacement is the displacement vector of the measuring point relative to the truss structure, while the spacing change rate further identifies the change in distance between adjacent measuring points. The spacing change rate is calculated based on the relative displacement of adjacent measuring points to explain in detail what deformation type each measuring point belongs to under continuous combination.

[0082] like Figure 11As shown, step S3 is implemented as follows: S31, determining the time point corresponding to the current spacing change rate. When adjacent measuring points belong to the same truss structure, the time point when the current spacing change rate reaches its maximum value is used as the output data. The truss structure at this point indicates that it is located at multiple different nodes, such as the upper and lower chord nodes of the side truss / diagonal truss / main truss, the horizontal brace node, and the upper chord span of the main truss. Adjacent measuring points belonging to the same truss structure means that the currently analyzed measuring points are any two points within the side truss / diagonal truss / main truss. These points represent spacing change identification within the same reference point set in the corresponding dimension, to identify whether there are further changes.

[0083] S32, when adjacent measuring points do not belong to the same truss structure, the relative displacement of the adjacent measuring points is mapped to the axial direction to form the axial component corresponding to the relative displacement; the time point when the spacing change rate of the axial component reaches its maximum value is used as the output data. If they do not belong to the same truss structure, it means that one of the measuring points being analyzed may be on a side truss and the other on a main truss, and these two points belong to different reference point sets. In this case, the spacing change rate should be supplementary data; the connecting members of these two truss structures are used as the basis for judgment, and the relative displacement is mapped to the direction of the corresponding member to obtain the axial component of the relative axial direction. Here, the axial component represents the spacing value calculated along the axial direction of the relative displacement vector of the two measuring points. The case where the axial component reaches its maximum change rate is directly considered to determine the deformation of the current truss structure. If two measuring points that do not belong to the same truss structure are connected by multiple members, and the angle after the members are connected is not a single angle, then the direction after the two measuring points are connected is considered as the current processing axial direction, and the corresponding displacement value is mapped to this direction to obtain the corresponding output data.

[0084] S33, according to the position of the adjacent measuring points in the truss structure, and the value of the spacing change rate at each position, retrieves the deformation type corresponding to each measuring point.

[0085] At this time, the deformation types include, but are not limited to, tension, compression, bending deformation, shear deformation, and no obvious deformation.

[0086] Tension indicates that the rate of change of spacing at the same truss measuring point is >0.01 or the rate of change of axial spacing at different truss measuring points is >0.01, indicating that there is an axial tension problem at the current measuring point; Compression indicates that the rate of change of spacing at the same truss measuring point is <0.01 or the rate of change of axial spacing at different truss measuring points is <0.01. Both of these cases represent the combined form of adjacent measuring points with multiple different truss structures, emphasizing that there is a clear tension and compression problem in a certain direction.

[0087] As for bending deformation and shear deformation, their spacing change rates are both within the range of 0.001-0.01, indicating that the deformation is relatively small compared to the deformation of tension and compression, but there is still a relative deformation situation.

[0088] If the spacing change rate is less than 0.001, it means that there is no deformation at the corresponding position. In this case, a spacing change rate of 0.01 in an industrial scenario indicates that the plastic deformation stage has been entered. Even if the positioning calibration of each measuring point is based on the installation process, this value can still be used for judgment. As for 0.001, it represents the controllable accuracy under normal measurement scenarios. If it is greater than this value, it means that there is a certain amount of uncontrollable strain or deformation.

[0089] When defining the deformation type, in addition to the change rate of the distance between adjacent measuring points, it is also necessary to further verify the time interval of adjacent measuring points. Therefore, the implementation of step S33 also includes: comparing multiple sets of adjacent measuring points, taking the time point corresponding to the maximum value of the distance change rate as the peak time point, and counting the number of peak time points at the same time point.

[0090] Based on the number of overlapping peak time points and deformation type, determine the dominant deformation type of the current measuring point.

[0091] At this point, a supplementary description will be provided to further describe the specific details of each deformation characteristic. The output deformation type will be specific, such as at t=10s, the three adjacent measuring points AB, BC, and CD simultaneously reach tensile deformation (spacing change rate > 0.01), indicating that the truss structure in this area undergoes significant tension at t=10s, and the deformation range covers the three members AB, BC, and CD. By focusing on the overlapping peak time points, multiple adjacent measuring points currently defined as tensile are described in a concentrated manner to illustrate a more specific deformation type.

[0092] Preferably, when determining the dominant deformation type of the current measuring point, the number of overlapping peak points and the deformation type are used as input data into the database. A time series is formed for the rate of change of the distance between each group of adjacent measuring points. A time window (e.g., a five-minute time length) is set, and then peak points with similar times are aggregated into peak time clusters. The overlap index of each cluster is calculated, such as cluster overlap = number of peaks within the cluster / total number of measuring point pairs. Then, an overlap range is set, such as high overlap (>70%), medium overlap (30%-70%), and low overlap (<30%). High overlap represents that most measuring point pairs are synchronized, resulting in overall coordinated deformation; medium overlap represents that some measuring point pairs are synchronized, resulting in zoned coordinated deformation; low overlap represents that a few measuring point pairs are synchronized, resulting in localized independent deformation. At this point, the dominant deformation type is described according to the deformation description represented by the overlap degree plus the deformation derived from the relative type.

[0093] For example, if the overlap is greater than 70% and the spatial distribution is uniform, the dominant deformation type will be overall temperature deformation. In this case, a description rule is formed by the number of peak time points of the current overlap and the specific description of the deformation type. The main deformation type is then extracted by using regular expressions recorded in the database.

[0094] In one embodiment of the present invention, in step S4, the overall displacement and relative displacement are combined into a displacement amount, and the displacement amount of the truss structure where each measuring point is located is checked before and after each installation step. These displacement amounts are statistically analyzed to determine the steps that affect the accuracy during the current installation, so as to identify the time period in which the installation accuracy problem occurs and the corresponding multiple sets of truss structures.

[0095] Compared to the deformation type output in step S3, step S4 will further focus on the judgment of the combination of overall displacement and relative displacement. By analyzing the displacement, the severity and scope of the deformation will be determined, and the key installation steps will be identified. The measurement points corresponding to the key installation steps will be used as the output data.

[0096] When integrating the overall displacement and relative displacement, weights of 0.6 and 0.4 will be used to integrate the corresponding displacement values ​​and calculate the displacement amount. The displacement amount represents the comprehensive displacement value of the overall displacement and relative displacement to determine the degree of proximity to the corresponding deformation type.

[0097] The selected key nodes need to meet at least the following conditions: the displacement exceeds the threshold, the form of the displacement is consistent with the deformation type derived in step S3, and there is a sudden change in the displacement. When these three conditions are met, the corresponding measuring point is taken as the currently selected key node, and the change curve and maximum displacement fed back by the key node are used to further illustrate the accuracy of the current installation.

[0098] like Figure 12 As shown, the implementation of step S4 includes: S41, weighted summation of the overall displacement and relative displacement to obtain the displacement of each measuring point under all installation steps, and matching the displacement of each measuring point with the deformation type.

[0099] S42, if a match is found, extract the corresponding displacement threshold and abrupt change point based on the displacement value of the current measuring point. If the displacement of the current measuring point is greater than the displacement threshold and is an abrupt change point, output the current measuring point as a key node. In the case of a match, it is necessary to find the data with large displacement and abrupt change to determine the points that mainly affect the truss installation.

[0100] S43. If there is a discrepancy, the corresponding measurement point will be output as a key node. The discrepancy indicates that there is an accuracy problem with the data obtained from the measurement point, or that there is a problem with the structural stability of the current installation step. These situations all indicate that there is a serious problem with the current input data. At this time, the corresponding measurement point can be output to determine the problem with the current installation accuracy, and the output measurement point can be used to assist the subsequent staff in maintenance and other work.

[0101] Preferably, when extracting displacement abrupt change points, multiple displacement values ​​under multiple installation steps are examined to observe the rate of change of the displacement values ​​at consecutive time points, and points with a rate of change greater than 50% are selected as the abrupt change points at that time. Alternatively, the value of the displacement change rate differentiated over time can be selected, and for each installation step, measurement points with a rate of change greater than 0.5% in each step are also considered as the current abrupt change points. Or, the displacement change rate can be accumulated, and measurement points with an accumulated rate of change greater than 100% are considered as the current abrupt change points, thereby selecting the key nodes for subsequent output.

[0102] As for the displacement threshold, 0.5mm can be selected. This value is a common threshold for precision control and can be directly used to determine whether the displacement at the corresponding position is too large.

[0103] Preferably, the implementation of step S41 further includes: S411, calculating the relative displacement and overall displacement of each measuring point under the corresponding installation step, and establishing the logical relationship between the relative displacement and the overall displacement.

[0104] S412, based on the logical relationship between overall displacement and relative displacement, performs deformation analysis with overall motion as the main component when the overall displacement is significantly greater than the relative displacement; performs deformation analysis with local deformation as the main component when the relative displacement is significantly greater than the overall displacement; if the two are of similar magnitude, enters composite deformation analysis to derive the deformation types corresponding to the overall displacement and relative displacement.

[0105] S413, when the deformation type derived from the overall displacement and relative displacement is inclusive of the deformation type input at each measuring point, it is considered to be consistent with the deformation type.

[0106] These logical relationships represent the physical logic of the truss when relative coordinates change, that is, to further describe the relative displacement and overall displacement under different deformation types, and to explain the specific characteristics of the corresponding deformation types.

[0107] The logical relationship can be represented as follows: the overall behavior is translation, with uniform relative displacement of each part, which closely resembles the case of rigid body translation + uniform strain. It leans towards displacement caused by temperature effects or uniform loads, specifically corresponding to thermal expansion / contraction deformation. This logical relationship represents the approximation to illustrate the physical logical relationship between relative displacement and overall displacement under its deformation type.

[0108] The overall rotation is accompanied by regular bending, which is close to the situation of rigid body rotation + gradient bending deformation, and tends to be a combination of bending and torsion caused by eccentric load.

[0109] The whole structure remains almost still, but there is significant local deformation. This is close to the scenario of minimum overall displacement plus local high strain, which indicates local damage or stress concentration, emphasizing local damage and deformation.

[0110] The deformation of each part is consistent with the overall movement. This situation, which is close to the complex overall movement and coordinated local deformation, indicates that there is a problem with the foundation deformation or support system. It means that the foundation has settled or the support system has deformed. The corresponding points need to be tracked and dealt with in a timely manner.

[0111] After completing the logical relationship analysis in this part, check whether the overall displacement is significantly greater than the relative displacement or the relative displacement is significantly greater than the overall displacement to determine whether the current type is mainly overall motion or local deformation. If the two are of similar magnitude, proceed to the composite deformation analysis.

[0112] The criterion for determining "significantly greater" here is to obtain a proportional threshold. For example, only when the overall displacement magnitude is greater than 5 times the relative displacement magnitude can it be considered that the overall displacement is significantly greater than the relative displacement. The same applies to "significantly greater than" relative displacement. When it is within this proportional threshold, it means that the magnitudes are comparable, and composite deformation analysis is required.

[0113] Preferably, the set ratio threshold is based on the average ratio of the overall displacement being significantly greater than the relative displacement in historical data, and the average ratio of the relative displacement being significantly greater than the overall displacement is obtained to determine the significantly excessive portion and perform subsequent analysis.

[0114] At the same time, it is also necessary to determine whether the current overall displacement and relative displacement conform to mechanics and whether their distribution is reasonable. The verification principle is: when a pure rigid body is translated, no strain should be generated inside the structure, and all relative displacements should be zero.

[0115] The specific inspection methods are as follows: Strain uniformity inspection: Check whether the strain values ​​at each location are close to zero and uniformly distributed; Strain-location correlation analysis: Strain should not show a regular change with location; Abnormal strain point identification: Mark areas with significantly non-zero strain. The judgment of unreasonable situations is as follows: If a systematic strain gradient is detected → there may be unidentified rotation or bending; If a local high-strain area appears → there may be local constraint or damage. In this case, further verification of the specific values ​​of the overall displacement and relative displacement is needed to determine whether they conform to the set logical relationship. These deformation types will then be further described to indicate whether the current deformation type is a simple deformation type or conforms to a specific deformation type.

[0116] Simple deformation types include pure rigid body motion and pure local types, while complex deformation types are coordinated composite and non-coordinated composite types. In the judgment process of step S3, the local deformation type is identified by relative displacement. In step S4, the overall displacement is introduced and used as the basis for further classification and identification of deformation types. A more detailed deformation type is obtained. If the more detailed deformation type obtained is consistent with the deformation type derived in step S3 in terms of local deformation, that is, the deformation type derived from the logical relationship between the current overall displacement and relative displacement has an inclusion relationship with the deformation type directly derived from the relative displacement, then it is considered to be a match.

[0117] Preferably, the current inclusion relationship also includes the following: if the composite deformation type derived from the overall displacement and relative displacement (such as overall translation + stretching) includes a single deformation type (such as stretching deformation), that is, when the label composed of the current composite deformation type includes the label of the deformation type derived from the relative displacement, it is considered an inclusion relationship.

[0118] Pure rigid body motion is the result of relative overall motion analysis, with relative displacement close to zero and overall displacement significant. Its subclasses include translation, rotation, scaling, etc. Pure local deformation is when overall displacement is close to zero and relative displacement is significant. Its subclasses include axial tensile and contraction deformation, bending deformation, shear deformation, torsional deformation, etc.

[0119] The coordinated composite type is where the overall displacement and relative displacement have the same physical meaning. Its subclasses can include types such as translation corresponding to thermal expansion + uniform tension. The incompatible composite type is where the overall displacement and relative displacement are contradictory, indicating that local damage is accompanied by overall constraint, suggesting that the structure has abnormal local deformations such as tension and contraction.

[0120] Preferably, when using simple deformation type analysis with overall motion type or local deformation type as the main type, and when performing composite deformation analysis, the weight value of the current displacement amount for weighted summation will be further adjusted. For example, when the current scenario is dominated by overall motion, the weight of overall displacement is 0.8 and the weight of relative displacement is 0.2; when the scenario is dominated by relative displacement, the weight of overall displacement is 0.2 and the weight of relative displacement is 0.8; and when the scenario is dominated by displacement, the weight of overall displacement is 0.5 and the weight of relative displacement is 0.5. The value of the current displacement amount is adjusted in this way to complete the processing of deformation type.

[0121] In one embodiment of the present invention, after determining the measuring points that are easily affected during installation and the relative process that is prone to displacement fluctuations, these displacements are converted into curves again in the form of a time series. The data fed back from each test is used as the basis for the current judgment. For example, the time period corresponding to the maximum displacement is selected to determine whether the truss is within the preset accuracy when it is completed. The entire installation process is fed back based on these data to improve the accuracy of truss installation and positioning.

[0122] like Figure 13 As shown, the implementation of step S5 includes: S51, periodically obtaining the maximum displacement of each key node, and determining the degree of displacement exceeding the limit based on the maximum displacement obtained for each key node. The degree of displacement exceeding the limit = (measured maximum displacement - allowable displacement) / allowable displacement, which represents the index of absolute accuracy and describes the ratio of the maximum displacement to the design allowable deviation.

[0123] S52 maps the degree of displacement exceeding the limit to the accuracy level matrix. Based on the accuracy level fed back by the current degree of displacement exceeding the limit, multiple key nodes are sorted, and the sorted key nodes are output according to their associated installation steps.

[0124] When providing feedback, the accuracy level matrix will set multiple intervals according to the maximum displacement. Each interval will be set based on the maximum allowable displacement value of the corresponding measuring point and the relative accuracy level will be recorded. Then, the data involved will be output in the form of a relative report to complete the identification and processing of the positioning.

[0125] The maximum displacement range is divided into several intervals: [0, allowable value × 0.5], (allowable value × 0.5, allowable value) and (allowable value, ∞). Each interval is further defined with an accuracy level, such as excellent accuracy, good accuracy, and unacceptable accuracy. This data will illustrate the correlation between the installation steps where the maximum displacement occurs and the specific construction operations. It will also provide feedback on the displacement values ​​of each measuring point at the corresponding accuracy level, indicating the worst-performing part of the key nodes in each installation step, thus identifying the weakest points in the current truss installation process. This forms a process of installation step execution → node displacement monitoring → accuracy assessment → exceeding the limit warning → process adjustment. The exceeding the limit warning will be set in the form of yellow warning, orange warning, and red warning when the displacement reaches 80% of the allowable value, 90% of the allowable value, and exceeds the allowable value, respectively. By feeding back the total displacement data measured at this time to the external intermediate level, staff can adjust the current truss installation based on the corresponding data to improve the accuracy of the truss connection during installation.

[0126] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention, which are still covered within the protection scope of the present invention.

Claims

1. A precise docking and positioning method for installing large-span, two-way fish-belly steel trusses, characterized in that... include: S1, acquire multiple measuring points on each truss, and obtain the structural morphology data of each measuring point based on its elevation and planar position; S2, During any installation step, perform an overall trend analysis on the truss structure corresponding to each measuring point, construct the overall displacement vector of the truss structure, and extract the relative displacement corresponding to each measuring point based on the changing trend of the overall displacement vector. S3, calculate the rate of change of the distance between adjacent measuring points according to the attitude of the truss structure where the measuring point is located, and define the deformation type corresponding to each measuring point; S4. Combine the overall displacement and relative displacement under different deformation types into a displacement amount, and iteratively judge the displacement amount under each installation step to determine the key nodes corresponding to each installation step. S5, based on the key nodes corresponding to each installation step, converts the displacement of each key node into a change curve, and feeds back the installation accuracy of each measuring point according to the maximum displacement of the key node. The implementation of step S4 includes: S41, weighted summation of the overall displacement and relative displacement to obtain the displacement of each measuring point under all installation steps, and matching the displacement of each measuring point with the deformation type; S42, if the match is consistent, extract the corresponding displacement threshold and abrupt change point based on the displacement value of the current measuring point, and output the current measuring point as a key node when the displacement of the current measuring point is greater than the displacement threshold and belongs to the abrupt change point; S43, if the match is inconsistent, output the corresponding measuring point as a key node. The implementation of step S41 also includes: S411, statistically analyzing the relative and overall displacements of each measuring point under the corresponding installation steps, and establishing the logical relationship between the relative and overall displacements; S412, based on the logical relationship between the overall and relative displacements, performing deformation analysis with overall motion as the main component when the overall displacement is significantly greater than the relative displacement; performing deformation analysis with local deformation as the main component when the relative displacement is significantly greater than the overall displacement; if the two are of similar magnitude, entering composite deformation analysis, and deriving the deformation types corresponding to the overall and relative displacements; S413, when the deformation types derived from the overall and relative displacements have an inclusion relationship with the deformation types input by each measuring point, they are considered to be consistent with the deformation types.

2. The precise docking and positioning method for installing large-span bidirectional fish-belly steel trusses according to claim 1, characterized in that, The implementation methods for step S1 include: S11, Select multiple measuring points at the edge of the truss, the junction of the inclined truss and the center of the truss, and obtain the coordinate values ​​of each measuring point on the same truss; S12, continuously locate the coordinates of each measuring point, calculate the average coordinate value of the continuous measurements, if there is a deviation in the measuring point under multiple continuous measurements, record the correction amount of the corresponding measuring point, and synchronize the coordinate value of the corresponding measuring point and the corresponding coordinate value of the correction amount to the structural morphology data.

3. The precise docking and positioning method for installing large-span bidirectional fish-belly steel trusses according to claim 1, characterized in that, Step S2 can be implemented in the following ways: S21. Based on the structural location of each measuring point, multi-level dependency relationships are extracted for each measuring point, and label information corresponding to each measuring point is set. S22, based on the label information and dependencies of each measuring point, the measuring points are divided into multiple reference point sets; the reference point sets include, but are not limited to, the boundary reference set, the main truss reference set, and the subsystem reference set; S23, extract the reference coordinates and current 3D coordinates corresponding to each set of reference points, construct the covariance matrix in a decentralized form, perform singular value decomposition on the covariance matrix, and set the overall displacement vector corresponding to each set of reference points in the way of the optimal rotation matrix. S24: Based on the changing trend of the overall displacement vector at multiple time points, compare the overall displacement vectors of different reference point sets; by removing the overall displacement vector of the reference point set to which each measuring point belongs from the displacement of each measuring point, obtain the relative displacement, and output the relative displacement corresponding to each measuring point after comparison.

4. The precise docking and positioning method for installing a large-span bidirectional fish-belly steel truss according to claim 3, characterized in that, When setting the global displacement vector in step S23, the implementation method also includes: Based on the label information corresponding to the current reference point set, the boundary reference set, the main truss reference set, and the subsystem reference set are processed in sequence to obtain the displacement components of each reference point set. Based on the value range of each displacement component, the displacement components are preliminarily classified by the correlation coefficient between the displacement components and the overall displacement vector, and this classification is taken as the first classification result of the preliminary classification. Based on the mean displacement and standard deviation of each displacement component, a second classification result is set for each displacement component; the first and second classification results are combined, and the overall displacement vector corresponding to the combination is output.

5. The precise docking and positioning method for installing a large-span bidirectional fish-belly steel truss according to claim 3, characterized in that, The implementation methods for comparing the overall displacement vectors of different reference point sets in step S24 include: Determine whether there is an overlapping region in the current set of reference points. If there is an overlapping region, use a weighted average method to fuse the overall displacement vectors of different sets of reference points for the measurement points in the overlapping region. If there is no overlapping area, the slope residual value of each overall displacement vector is recorded based on the changing trend of each overall displacement vector; based on the value of the slope residual value, priority is set for each overall displacement vector, and the overall displacement vectors are sorted from largest to smallest according to priority.

6. The precise docking and positioning method for installing a large-span bidirectional fish-belly steel truss according to claim 1, characterized in that, Step S3 can be implemented in the following ways: S31, determine the time point corresponding to the current spacing change rate. When adjacent measuring points belong to the same truss structure, the time point when the current spacing change rate reaches its maximum value is used as the output data. S32, when adjacent measuring points do not belong to the same truss structure, the relative displacement of adjacent measuring points is mapped to the axial direction to form the axial component corresponding to the relative displacement; the time point when the spacing change rate of the axial component reaches its maximum value is used as the output data. S33, according to the position of the adjacent measuring points in the truss structure, and the value of the spacing change rate at each position, retrieves the deformation type corresponding to each measuring point.

7. The precise docking and positioning method for installing large-span bidirectional fish-belly steel trusses according to claim 6, characterized in that, The implementation of step S33 also includes: Compare multiple groups of adjacent measuring points, take the time point corresponding to the maximum rate of change of the distance as the peak time point, and count the number of peak time points that are at the same time point; Based on the number of overlapping peak time points and deformation type, determine the dominant deformation type of the current measuring point.

8. The precise docking and positioning method for installing large-span bidirectional fish-belly steel trusses according to claim 1, characterized in that, The implementation of step S5 includes: S51, periodically obtaining the maximum displacement of each key node, and determining the degree of displacement exceeding the limit based on the maximum displacement obtained for each key node; S52 maps the degree of displacement exceeding the limit to the accuracy level matrix. Based on the accuracy level fed back by the current degree of displacement exceeding the limit, multiple key nodes are sorted, and the sorted key nodes are output according to their associated installation steps.

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