Precise butt-joint positioning method based on large-span two-way fish-bellied steel truss installation

Abstract

The invention relates to the technical field of steel structure installation, in particular to an accurate butt joint positioning method based on large-span bidirectional fish-bellied steel truss installation, which comprises the following steps: acquiring a plurality of measuring points on each truss, and obtaining structural form data of each measuring point according to the elevation and plane position of each measuring point; in any installation execution step, constructing an overall displacement vector of the truss structure according to the truss structure corresponding to each measuring point, and extracting relative displacement corresponding to each measuring point based on the variation trend of the overall displacement vector; according to the attitude of the truss structure where the measuring points are located, the distance change rate of the adjacent measuring points is calculated according to the relative displacement, and the deformation type corresponding to each measuring point is defined; combining the overall displacement and the relative displacement under different deformation types into displacement, circularly judging the displacement under each installation step, and determining a key node corresponding to each installation step; and feeding back the mounting precision of each measuring point according to the maximum displacement of the key node. And the positioning precision and efficiency during installation of the truss are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel structure installation, in particular to a precise butt joint positioning method based on large-span bidirectional fish belly type steel truss installation. BACKGROUND

[0002] With the development of building function diversification, the demand for large-span space structures (such as stadiums, airport terminals, exhibition centers, etc.) is increasing. Such structures usually adopt a bidirectional fish belly type steel truss system, which consists of top chord bars, web bars and folded line bottom chord bars to form a fish belly type space truss. The truss has many connecting nodes and complex stress paths. It has the problems of large span and heavy self-weight, and needs to solve the problems of high-altitude installation, deformation control and precise butt joint.

[0003] For example, Chinese Patent Publication No. CN118495355A discloses a hoisting positioning method based on BIM modular prefabrication. Based on the IFC standard of BIM modular prefabrication, a prefabricated module space for providing a prefabricated module storage space is established. Based on the prefabricated module geometric information stored in the entity unit space, the independent boundary coordinate information of the prefabricated module based on the independent coordinate system of the prefabricated module is obtained, and hoisting is carried out. During hoisting, the prefabricated modules after each hoisting are subjected to conflict detection, and finally the final construction sequence node information is determined to complete the automatic splicing of the prefabricated modules.

[0004] For example, Chinese Patent Publication No. CN119143017A discloses a positioning method and system for unmanned tower crane. Based on the position system of the unmanned tower crane and the position of the tower crane part of the unmanned tower crane, the first spatial coordinates of the tower crane part are defined. According to the position of the tower crane part of the unmanned tower crane and the position marked by the satellite system, the second spatial coordinates are defined. According to the second spatial coordinates and the first spatial coordinates, the actual position information of the tower crane part is defined. Based on the actual position information of the tower crane part and the actual position information of the unmanned tower crane, the GNSS coordinates of the tower crane part are defined. According to the GNSS coordinates of the tower crane part and the GNSS coordinates of the working position, the position deviation of the tower crane part relative to the working position is defined. According to the position deviation, the environmental characteristics and the position accuracy level of the working position, the position control accuracy of the tower crane part in the working process is defined.

[0005] In the prior art, the module boundary is hoisted and installed according to the construction node sequence, and the position matching during hoisting is used to complete the position control accuracy of the tower crane part. However, the existing technology tends to align large structures, which causes problems such as mixed overall deformation and local deformation, rough precision control and difficult problem positioning in truss structure installation. The specific displacement of the truss installation cannot be determined, resulting in reduced installation precision. SUMMARY

[0006] In order to solve the above technical problems, the technical scheme adopted by the present application is: based on the installation precision butt joint positioning method of large-span two-way fish belly type steel truss, comprising: S1, obtaining a plurality of measuring points on each truss, obtaining the structure form data of each measuring point according to the elevation and plane position of each measuring point.

[0007] S2, during the execution of any installation step, the overall trend analysis of the truss structure corresponding to each measuring point is carried out, the overall displacement vector of the truss structure is constructed, and the relative displacement corresponding to each measuring point is extracted based on the change trend of the overall displacement vector.

[0008] S3, the relative displacement is calculated according to the attitude of the truss structure where the measuring point is located, the spacing change rate of adjacent measuring points is calculated, and the deformation type corresponding to each measuring point is defined.

[0009] S4, the overall displacement and the relative displacement under different deformation types are combined into displacement, the displacement under each installation step is judged in a loop, and the key node corresponding to each installation step is determined.

[0010] S5, based on the key node corresponding to each installation step, the displacement of each key node is converted into a change curve, and the installation precision of each measuring point is fed back according to the maximum displacement of the key node.

[0011] The beneficial effects of the present application are: first, the present application sets measuring points at key positions such as edges, junctions and centers, respectively establishes boundary reference set, main truss reference set and subsystem reference set, and then extracts overall displacement vector and relative displacement through singular value decomposition; the overall rigid body motion and local elastic deformation existing during the current truss installation are distinguished according to the structural relationship of the measuring points in the position, so as to judge the displacement value measured by each measuring point, prevent the transmission and accumulation of local error, and magnify and transmit the value of a measuring point in the subsequent installation step, and provide clear input parameters for precise control.

[0012] Second, the present application identifies the peak time point as a characteristic index through spacing change rate time sequence analysis, further establishes axial component analysis of relative displacement between different trusses, identifies the dominant deformation type through the number of peak time overlaps, emphasizes problem identification for change rate peak value, and is inclined to early warning mode to monitor the current butt joint positioning.

[0013] Thirdly, the application carries out multiple classification processing on the correlation coefficient of displacement components and overall displacement vector, and the displacement mean and displacement standard deviation of each displacement component, strengthens the appearance scene of the overall displacement vector, and then uses the division processing of the overlapping area to process the conflict part between the overall displacement vectors, prevents the conflict problem of the displacement calculation result of the measuring point caused by single dimension analysis processing, focuses the final analysis on part of the measuring points, and completes the identification of the connecting and installing precision. BRIEF DESCRIPTION OF DRAWINGS

[0014] The application will be further described below in combination with the drawings and embodiments.

[0015] Figure 1 is a process schematic diagram of the installation precision butt joint positioning method based on large-span bidirectional fish belly type steel truss.

[0016] Figure 2 is a structure schematic diagram of the truss installation structure of the installation precision butt joint positioning method based on large-span bidirectional fish belly type steel truss.

[0017] Figure 3 is a structure schematic diagram of step 1 of the truss installation of the installation precision butt joint positioning method based on large-span bidirectional fish belly type steel truss.

[0018] Figure 4 is a structure schematic diagram of step 2 of the truss installation of the installation precision butt joint positioning method based on large-span bidirectional fish belly type steel truss.

[0019] Figure 5 is a structure schematic diagram of step 3 of the truss installation of the installation precision butt joint positioning method based on large-span bidirectional fish belly type steel truss.

[0020] Figure 6 is a structure schematic diagram of step 4 of the truss installation of the installation precision butt joint positioning method based on large-span bidirectional fish belly type steel truss.

[0021] Figure 7 is a structure schematic diagram of step 5 of the truss installation of the installation precision butt joint positioning method based on large-span bidirectional fish belly type steel truss.

[0022] Figure 8 is a structure schematic diagram of step 6 of the truss installation of the installation precision butt joint positioning method based on large-span bidirectional fish belly type steel truss.

[0023] Figure 9 is a process schematic diagram of step S1 of the installation precision butt joint positioning method based on large-span bidirectional fish belly type steel truss.

[0024] Figure 10is a flowchart of step S2 of the installation precision butt joint positioning method based on the large-span bidirectional fish belly type steel truss.

[0025] Figure 11 is a flowchart of step S3 of the installation precision butt joint positioning method based on the large-span bidirectional fish belly type steel truss.

[0026] Figure 12 is a flowchart of step S4 of the installation precision butt joint positioning method based on the large-span bidirectional fish belly type steel truss.

[0027] Figure 13 is a flowchart of step S5 of the installation precision butt joint positioning method based on the large-span bidirectional fish belly type steel truss. DETAILED DESCRIPTION

[0028] Embodiments of the present application are described in detail below. The embodiments described below are exemplary only, and are not to be understood as limiting the present application. If a specific technique or condition is not mentioned in the embodiments, the technique or condition described in the literature in the art or according to the product manual is used.

[0029] Reference Figure 1 , the installation precision butt joint positioning method based on the large-span bidirectional fish belly type steel truss, comprising: S1, obtaining a plurality of measuring points on each truss, and obtaining the structural configuration data of each measuring point according to the elevation and plan position of each measuring point. Elevation: mainly Z coordinate (elevation) data, used to calculate whether each position under the truss reaches the design height. Plan position: X, Y coordinates, used to control the horizontal position and span of the truss.

[0030] S2, in any installation step, the overall trend of the truss structure corresponding to each measuring point is analyzed, the overall displacement vector of the truss structure is constructed, and the relative displacement corresponding to each measuring point is extracted based on the change trend of the overall displacement vector.

[0031] S3, the relative displacement is calculated according to the attitude of the truss structure where the measuring point is located, the spacing change rate of adjacent measuring points is calculated, and the deformation type corresponding to each measuring point is defined.

[0032] S4, the overall displacement and the relative displacement under different deformation types are combined into displacement, the displacement under each installation step is cyclically judged, and the key node corresponding to each installation step is determined.

[0033] S5, based on the key node corresponding to each installation step, the displacement of each key node is converted into a change curve, and the installation precision of each measuring point is fed back according to the maximum displacement of the key node.

[0034] As Figures 2-8As shown, the positioning points include the edge truss / oblique edge truss / main truss upper chord node and lower chord node, horizontal support node and main truss upper chord mid-span points, generally, the steps of installing the large-span two-way fish-belly steel truss are as follows: Step 1, install the two-end truss columns, and stabilize by cable wind ropes.

[0035] Step 2, install the two-end truss lower chord bars, and adjust the pre-camber by the support jig frame.

[0036] Step 3, install the two-end truss vertical web bars and upper chord bars.

[0037] Step 4, install the truss oblique web bars.

[0038] Step 5, continue to install the truss lower chord bars, wherein the lower chord bars on one side are temporarily stabilized by the temporary support plate due to the conflict with the lower stand and the jig frame position.

[0039] Step 6, sequentially install the remaining vertical web bars, upper chord bars and oblique web bars, and unload at an appropriate time after the welding is completed.

[0040] The six steps represent the processing steps of the pre-hoisting area, in which the measuring points at multiple positions are set, and the displacement analysis of the truss is realized by centralized monitoring of the measuring points in the pre-hoisting preparation installation step and the actual hoisting condition.

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

[0042] Step 3 measures measuring point 3 and measuring point 7, and simultaneously measures measuring point 1 and measuring point 9; in step 4, the positions of measuring point 1, measuring point 2, measuring point 4, measuring point 8, measuring point 9 and measuring point 10 arranged at the corresponding positions after the oblique edge truss is added are re-measured; step 5 records the positions of measuring point 6, measuring point 3, measuring point 4, measuring point 7 and measuring point 8 after the truss lower chord bars are added, and finally records measuring point 5 and the relative positions of other measuring points after installation.

[0043] After the positions of these points are measured, the vertical height difference of the current measuring points is calculated according to the center points of the upper chord nodes and the lower chord nodes after installation, that is, the positions of measuring point 5 and measuring point 6 before and after installation are measured, to determine whether a stable frame is formed after installation and the relative positions of the points.

[0044] At this time, steps 1-6 represent the process during installation, and the actual calibration installation is inclined to be combined and installed in a relatively complete structure, such as installing three spliced steel structures in the figure or installing two spliced structures.

[0045] The data statistics of the measuring points are obtained once before loading the structure, once during loading, twice within 24 hours after loading, once a week after loading, and once before unloading; and the data of the truss corresponding to the measuring points are also summarized once a day to record the installation data.

[0046] In step S1, multiple measuring points are set at the edge of the truss, the intersection of the inclined truss, and the center of the truss, and the positioning accuracy of the current truss after installation is determined by the average coordinate values obtained from these measuring points.

[0047] As shown in Figure 9 The implementation of step S1 includes: S11, selecting the edge of the truss, the intersection of the inclined truss, and the center of the truss to set multiple measuring points and obtain the coordinate values of each measuring point on the same truss; the current structure data represents the three-dimensional coordinates of each measuring point and the types corresponding to each measuring point, such as top chord measuring point and bottom chord measuring point.

[0048] S12, continuously positioning the coordinates of each measuring point, calculating the average value of the continuously measured coordinates, and if there is a deviation in the continuous measurement of the measuring point, recording the correction amount of the corresponding measuring point, and synchronizing the coordinate value of the corresponding measuring point to the structure data with the correction amount.

[0049] The deviation is determined by the difference between the average coordinate value and the standard coordinate value, and the value is biased towards the point of the truss in the Z-axis. At this time, the space of the truss is marked in the form of three-dimensional coordinates, and whether the size of the Z-axis measurement has an error is checked. If there is an error, the corresponding correction amount is recorded to facilitate subsequent analysis of the change trend; the correction amount is equal to the theoretical reference value minus the measurement average value.

[0050] The deviation in the X-axis and Y-axis is identified by the subsequent relative displacement and overall displacement to determine whether the displacement of the arranged measuring point is too large.

[0051] In an embodiment of the present application, the overall displacement is determined by calculating the change of the coordinate average value of the measuring point and whether the current measuring point has a vector sum of overall forward / backward displacement and settlement / lifting to determine the displacement trend of the overall displacement; after obtaining the trend of the overall displacement, the relative displacement of each measuring point is further analyzed to determine whether there is an overall displacement and local deformation during the current deformation or calibration, so as to complete the positioning of multiple measuring points.

[0052] In the formation of the overall displacement vector, rigid body transformation based on SVD (singular value decomposition) will be used to solve, respectively, the reference coordinates and the geometric centroid of the current measuring point, the geometric centroid is the average of its coordinate values, and then subtract the geometric centroid from each measuring point to obtain the decentralized coordinates.

[0053] Then calculate the outer product and accumulate for all measuring points, that is, multiply and sum the decentralized reference coordinates and current measuring point coordinates to obtain a covariance matrix; singular value decomposition is performed on the covariance matrix, singular value decomposition is performed by ; wherein, is the covariance matrix, is a 3x3 orthogonal matrix, which describes the main change direction corresponding to the reference coordinates; is a 3x3 diagonal matrix, the diagonal elements are singular values; is the transpose of the 3x3 orthogonal matrix; then the optimal rotation matrix satisfies ; wherein, is the transpose of the matrix , and is the orthogonal matrix corresponding to the matrix , which describes the main change direction of the current measuring point coordinates.

[0054] After the optimal rotation matrix is calculated, the optimal translation vector can be directly obtained, and the optimal translation vector is obtained by using the current measuring point coordinates - (R*reference coordinates). This vector will represent the overall change of the overall displacement trend, and this vector is considered as the overall displacement vector currently calculated.

[0055] As for the subsequent change trend of the overall displacement vector, the state of the current overall displacement before and after each installation step is analyzed, and whether there is a large change in the overall displacement vector of each measuring point combination at a certain time after hoisting is analyzed, and the relative displacement of adjacent measuring points at the time of change is extracted. It should be noted that all the coordinate values used are processed data.

[0056] As for the relative displacement, the current measuring point coordinates after decentralization = R*decentralized reference coordinates + translation vector, the corresponding translation vector is calculated, and the least squares method is used to find the optimal translation vector; then the relative displacement = current measuring point coordinates - (R*reference coordinates + translation vector) is obtained. The displacement of each measuring point relative to the structure.

[0057] As Figure 10As shown, the implementation of step S2 includes: S21, based on the structural position of each measuring point, extracting the multi-level dependency relationship of each measuring point, and setting the label information corresponding to each measuring point; the current dependency relationship comprehensively describes the measuring points at different positions, and describes the continuity of each measuring point on the truss structure, such as the current two measuring points both representing edge positions, which need to be mainly constructed with absolute plane position (X, Y) and auxiliary elevation Z to form the overall displacement vector; at this time, the measuring points on the edge position will be used as the main data for judging the current covariance matrix, and the overall displacement vectors of measuring points with different dependency relationships will be calculated respectively to prevent the error of part of the measuring points from being absorbed by the whole during the processing of multiple steps, resulting in the problem of error insensitivity in the calculation of 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, i.e. first-level dependency (position correlation between boundary nodes), second-level dependency (correlation between main truss nodes and boundary nodes), and third-level dependency (correlation between subsystem nodes and main truss nodes); the extraction method is to derive the node connection matrix based on the BIM model, and identify the dependency relationship through the adjacency table algorithm.

[0059] The label information is to configure labels for the relevant measuring points when the covariance matrix is formed after the decentralization processing, and to explain, for example, the measuring points at the edge truss / chordal edge truss / main truss top chord node and bottom chord node, horizontal support node, and main truss top chord mid-span position.

[0060] S22, based on the label information and dependency relationship of each measuring point, the measuring points are divided into multiple reference point sets; the reference point set includes but is not limited to boundary reference set, main truss reference set, and subsystem reference set; the boundary reference set includes the nodes of the edge truss and the chordal edge truss, representing the boundary constraint of the structure. The main truss reference set is divided according to the truss unit, and includes the nodes on the same main truss. The subsystem reference set, such as the horizontal support node, is separately set.

[0061] S23, extract the reference coordinates and current three-dimensional coordinates corresponding to each reference point set, 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 reference point set in the form of the optimal rotation matrix.

[0062] S24, for the change trend of the overall displacement vector at multiple time points, compare the overall displacement vectors of different reference point sets, eliminate 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.

[0063] Because the positions of the measuring points are different, the dimensions monitored by each measuring point will change, such as the edge truss / inclined edge truss node, which will mainly be the absolute plane position (X, Y) and the elevation Z as a supplement, and belongs to the reference for calculating the overall displacement. These points are the first to be installed and relatively stable, and are the preferred reference point set for calculating the overall displacement vector. Abnormal displacement of these points may mean the accumulation of support settlement, slip or installation deviation.

[0064] For the upper chord node of the main truss, the elevation Z is mainly used, and the plane position (X, Y) is used as a supplement. The measured elevation needs to be strictly compared with the designed elevation, and the lateral displacement needs to be simultaneously observed to prevent instability at the corresponding position.

[0065] For the lower chord node of the main truss, the elevation Z is mainly used, and the plane position (X, Y) is equally important. It needs to be analyzed in coordination with the upper chord node to calculate the vertical height difference change rate of the same panel. The upper and lower chord nodes highlight the vertical change under the overall displacement analysis.

[0066] For the horizontal strut node, the relative displacement (ΔX, ΔY) in the plane is mainly used to identify the relative displacement of the horizontal strut node relative to the main truss node, preventing the horizontal strut from failing to effectively constrain the main truss. The point set corresponding to this point will indicate whether the structure has undergone overall torsion.

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

[0068] The edge truss / inclined edge truss node will serve 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 serve as the main truss reference set. The horizontal strut node will serve as multiple independent subsystem reference sets.

[0069] Therefore, when the overall displacement vector is set in step S23, the implementation further includes: based on the label information corresponding to the current reference point set, sequentially processing the boundary reference set, the main truss reference set, and the subsystem reference set to obtain displacement components of each reference point set. The displacement component represents a component extracted from the overall displacement vector. Multiple displacement components will be set in the form of plane position (X, Y), relative displacement (ΔX, ΔY) in the plane, and elevation Z.

[0070] Based on the value range of each displacement component, the correlation coefficient of the displacement component and the overall displacement vector is used to preliminarily classify each displacement component, which is taken as a first classification result of the preliminary classification.

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

[0072] In the above correlation coefficient calculation, the displacement component and the overall displacement vector can be calculated using cosine similarity, and the displacement component can be classified into multiple categories according to the value of the cosine similarity, and the relationship between the local displacement and the overall displacement is labeled; for example, the truss displacement is highly correlated with the overall displacement, and the overall deformation trend of the structure is obvious; the boundary displacement has a high correlation with the overall displacement, and the external environment has a significant impact; and the displacement of each reference point set has a low correlation with the overall displacement, and the local deformation is obvious. These classifications will represent the specific deformation trend of the overall displacement vector; at this time, the cosine similarity threshold will be set for different reference point sets, and classification will be performed according to the threshold to explain the displacement at different positions; for example, in the order of the boundary reference set, the main truss reference set and the subsystem reference set, 0.85, 0.75 and 0.4 are set as the cosine similarity threshold, and the displacement component corresponding to the current reference point set is classified to describe the description corresponding to multiple reference point sets.

[0073] As for using the displacement mean and the displacement standard deviation, the dispersion degree of the displacement component will be explained, and the second classification is also to explain whether the displacement component value is dispersed or concentrated, and the information obtained from these classifications is synchronized to the overall displacement vector corresponding to the displacement component to explain the specific situation corresponding to each overall displacement component; at this time, the confidence interval method can be used to explain the second classification of the displacement component corresponding value relative to the upper and lower limit values of the confidence interval, for example, according to the confidence interval of the displacement component mean ± three times the standard deviation in the historical data, the confidence interval is set for the current displacement mean and displacement standard deviation, and the second classification is performed to explain the current displacement change when the current value is within the confidence interval and exceeds the upper limit value of the confidence interval; for example, when it exceeds the upper limit value of the confidence interval, the current truss will have significant positive direction deformation, which may be affected by external load; if it is within the confidence interval, it means that the displacement is within the normal range, and if it is less than the lower limit value of the confidence interval, there will be significant negative direction deformation, which needs to be checked urgently; since the displacement component at this time is mainly based on the form of subtracting the reference coordinate from the decentralized current measurement point coordinate, the displacement component extracted at this time will have positive and negative signs to represent the displacement change relative to the reference coordinate, and the upper and lower limit values of the confidence interval at this time will represent the value range of the positive and negative signs.

[0074] Preferably, the above combination of 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, and the second classification result is combined in the same way, that is, the relationship between the local displacement component and the overall displacement + the dispersion degree of the displacement component are comprehensively explained as the processing process of the current step S23, and these data are synchronized to the database corresponding to the overall displacement, which is convenient for further viewing of related data in the future.

[0075] The implementation of comparing the overall displacement vectors of different reference point sets in step S24 includes: judging whether there is an overlapping area in the current reference point set, if there is an overlapping area, for the measuring points in the overlapping area, the overall displacement vectors of different reference point sets are fused by using a weighted average method.

[0076] If there is no overlapping area, the slope residual value of each overall displacement vector is recorded based on the change trend of each overall displacement vector, and the priority of each overall displacement vector is set based on the value of the slope residual value, and each overall displacement vector is sorted in descending order of priority.

[0077] At this time, based on the change of the overall displacement in multiple time periods, the slope residual value of the change is calculated to explain the change of the current value relative to the reference coordinate, and the greater the slope residual value, the greater the overall displacement vector setting, that is, by normalizing all calculated slope residual values based on the value of the slope residual value, the weight size of each overall displacement vector setting is explained, so that the overall displacement vector is output based on the 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 the above-mentioned weighted fusion is performed on the overlapping area, the weight is set based on the type corresponding to the reference point set, and the boundary reference set, the main truss reference set and the subsystem reference set are set in the form of 0.32, 0.6 and 0.08 in turn. At this time, the coordinates of the measuring points on the main truss reference set are emphasized, and the weight of 0.60 ensures the dominant role of the main truss displacement in the comprehensive evaluation; the measuring points of the boundary are easily affected by the external environment such as wind and temperature, and are secondary important points of the main truss, and the weight of 0.32 reflects the importance of the boundary node, and part of the weight ratio is reserved to the horizontal support node in the subsystem reference set, to prevent the subsystem from being completely ignored, resulting in unknown overall displacement.

[0080] In an embodiment of the present application, step S3 is biased to judge whether there is an angle change between the installed steel truss and multiple measuring points, and whether there is a situation such as bending deformation, shear deformation and torsional deformation at the corresponding position, if there is no deformation, the deformation type is taken as 0 to indicate that the current structure is relatively stable.

[0081] It should be noted that the relative displacement is the displacement vector of the measuring point relative to the truss structure where it is located, and the interval change rate further identifies the change of the distance between adjacent measuring points, and the interval 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 in continuous combination.

[0082] For example, Figure 11As shown, the implementation of step S3 includes: S31, determining the time point corresponding to the current interval change rate, when the adjacent measuring points belong to the same truss structure, taking the time point at which the current interval change rate reaches the maximum value as the output data; At this time, the truss structure is illustrated at the edge truss / inclined edge truss / main truss top chord node and bottom chord node, horizontal support node and main truss top chord midspan of multiple different nodes. The adjacent measuring points belong to the same truss structure, which means that the current analyzed measuring points are any two points in the edge truss / inclined edge truss / main truss, which represent the interval change identification in the dimension corresponding to the same reference point set, to identify whether there is further change.

[0083] S32, when the adjacent measuring points do not belong to the same truss structure, mapping the relative displacement of the adjacent measuring points to the axial direction to form the axial component corresponding to the relative displacement; taking the time point at which the axial component calculates the maximum value of the interval change rate as the output data. When the adjacent measuring points do not belong to the same truss structure, it means that one of the analyzed measuring points is an edge truss and the other is a point on the main truss, and the reference point sets of the two points are different. At this time, the interval change rate analyzed and processed should be supplementary data. The rod connecting the two truss structures is used as the basis for judgment at this time, and the relative displacement is mapped to the direction of the corresponding rod to obtain the axial component of the relative axial direction. At this time, the axial component represents the interval value calculated in the axial direction of the relative displacement vector of the two measuring points. At this time, the maximum change rate value of the axial component is directly considered to judge whether the deformation of the current truss structure exists. If the two measuring points do not belong to the same truss structure and are connected by multiple rods, and the angle after the rod connection is not a single angle, the direction after the connection of the two measuring points is regarded as the axial direction for processing, 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, the interval change rate value at each position is used to retrieve the deformation type corresponding to each measuring point.

[0085] At this time, the deformation type includes but is not limited to tensile, compressive, bending deformation, shear deformation and no obvious deformation.

[0086] Tensile represents that the interval change rate of the same truss measuring point > 0.01 or the interval change rate in the axial direction of different truss measuring points > 0.01, which means that there is an axial tensile problem in the current measuring point; Compressive represents that the interval change rate of the same truss measuring point < 0.01 or the interval change rate in the axial direction of different truss measuring points < 0.01, which means that the adjacent measuring points are in the form of aggregation of multiple different truss structures, and emphasize that there is a problem of obvious tensile and compression in a certain direction.

[0087] As for bending deformation and shear deformation, the interval change rate is in the range of 0.001-0.01, which represents that the deformation is relatively small compared to the tensile and compressive deformation, but there is still relative deformation.

[0088] When the interval change rate is <0.001, it represents that there is no deformation at the corresponding position, at this time, the interval change rate of 0.01 represents that it has obviously entered the plastic deformation stage in the industrial scene, even if the positioning calibration of the current measurement points is based on the installation process, at this time, the value can still be selected for judgment; as for 0.001, it represents the controllable accuracy in the normal measurement scene, and greater than this value indicates that there is a certain uncontrollable strain or deformation.

[0089] In defining the deformation type, in addition to the interval change rate of the adjacent measurement points, the time interval of the adjacent measurement points also needs to be further verified, so the implementation mode of step S33 further includes: comparing the multiple groups of adjacent measurement points, taking the time point corresponding to the maximum interval change rate as the peak time point, and counting the number of peak time points at the same time point.

[0090] According to the number of coincident peak time points and the deformation type, the dominant deformation type of the current measurement point is determined.

[0091] At this time, the specific situation of each deformation feature will be further described in the form of supplementary description, and the output deformation type will be specifically as follows: at t=10s, the AB, BC and CD groups of adjacent measurement points simultaneously reach tensile deformation (interval change rate >0.01), indicating that the truss structure in this region significantly tensile at t=10s, and the deformation range covers the AB, BC and CD three sections of the rod. The more specific deformation type is described by concentrating the multiple groups of adjacent measurement points currently defined as tensile through the coincident peak time points.

[0092] Preferably, when determining the dominant deformation type of the current measurement point, the number of coincident peak points and the deformation type at this time are taken as input data to the database, a time window (such as a time length of five minutes) is set for the interval change rate of each group of adjacent measurement points to form a time sequence, then the peak points close in time are aggregated into a peak time cluster, the coincidence index of each cluster is calculated, the coincidence index is, for example, cluster coincidence degree=number of peak values in the cluster / total number of measurement point pairs, then a coincidence range is set, such as high coincidence (>70%), medium coincidence (30%-70%) and low coincidence (<30%), high coincidence represents that most measurement point pairs are synchronized and the overall deformation is coordinated; medium coincidence represents that part of the measurement point pairs are synchronized and the deformation is coordinated in the partition; low coincidence represents that few measurement point pairs are synchronized and the deformation is independent in the local; at this time, the current dominant deformation type is explained in the form of deformation description represented by the coincidence degree + deformation deduced from the relative type.

[0093] For example, when the coincidence degree is greater than 70% and the spatial distribution is uniform, the dominant deformation type is the overall temperature deformation, and a description rule is formed by the current coincidence peak time point number and the specific description of the deformation type, and the current main deformation type is extracted through the regular expression recorded in the database.

[0094] In an embodiment of the present application, in step S4, the overall displacement and the relative displacement are combined into a displacement amount, and the displacement amount of each measuring point of the truss structure before and after each installation step is checked, and the displacement amounts are counted to determine the installation step that affects the accuracy at the current time, so as to identify the time period when the installation accuracy problem occurs and the corresponding groups of truss structures.

[0095] The deformation type output by step S3 is further focused on the judgment of the combined overall displacement and relative displacement in step S4, the severity and influence range of the deformation are determined through displacement amount analysis, and the key installation step is found, and the measuring points corresponding to the key installation step are taken as the output data.

[0096] When integrating the overall displacement and the relative displacement, the weights of 0.6 and 0.4 are adopted, the corresponding displacement values are integrated, the displacement amount is calculated, and the displacement amount represents the comprehensive displacement value of the overall displacement and the relative displacement to determine the degree of proximity to the corresponding deformation type.

[0097] The selected key node needs to at least meet the conditions that the displacement amount exceeds the threshold value, the form of the displacement amount is consistent with the deformation type derived in step S3, and the displacement amount has a mutation; when the three conditions are met, the corresponding measuring point is taken as the selected key node, and the change curve and the maximum displacement amount fed back by the key node are used to further illustrate the accuracy of the current installation.

[0098] As shown in Figure 12 The implementation mode of step S4 includes: S41, the overall displacement and the relative displacement are weighted and summed to obtain the displacement amount of each measuring point under all installation steps, and the displacement amount of each measuring point is matched with the deformation type.

[0099] S42, if the matching is consistent, the value of the displacement amount of the current measuring point is used to extract the corresponding displacement threshold value and the mutation point, and when the displacement amount of the current measuring point is greater than the displacement threshold value and belongs to the mutation point, the current measuring point is taken as the key node output. In the consistent case, the data with large displacement amount and belonging to the mutation point are found to determine the point that mainly affects the installation of the truss.

[0100] S43, if inconsistent, the corresponding measuring point is output as a key node, and the inconsistent situation represents that the data obtained by the measuring point has accuracy problems or the structural stability of the current installation step has problems, which represent that the current input data has serious problems, at this time, the corresponding measuring point can be output to determine the problem of the current installation accuracy, and the subsequent workers can be assisted to perform maintenance work according to the output measuring point.

[0101] Preferably, when the displacement amount mutation point is extracted, by checking a plurality of displacement amount values under a plurality of installation steps, checking the change rate of the displacement amount value at consecutive time points, and selecting the point with a change rate greater than 50% as the mutation point identified at this time; or the value of the displacement amount change rate can be derived according to time, and the measuring point greater than 0.5% per installation step is also regarded as the current mutation point; or the displacement amount change rate is accumulated, and the measuring point greater than 100% after accumulation is regarded as the current mutation point, so as to select the key node for subsequent output.

[0102] As for the displacement amount threshold, 0.5mm can be selected, which is a common threshold for accuracy control and can be directly used to judge whether the displacement amount at the corresponding position is too large.

[0103] Preferably, the implementation manner of step S41 further includes: S411, statistics of relative displacement and overall displacement of each measuring point under the corresponding installation step are obtained, and a logical relationship between the relative displacement and the overall displacement is established.

[0104] S412, based on the logical relationship between the overall displacement and the relative displacement, when the overall displacement is significantly greater than the relative displacement, the overall motion is mainly analyzed; when the relative displacement is significantly greater than the overall displacement, the local deformation is mainly analyzed; if the two are of the same order of magnitude, composite deformation analysis is performed, and the deformation types corresponding to the overall displacement and the relative displacement are derived.

[0105] S413, when the deformation types derived from the overall displacement and the relative displacement are in a containing relationship with the deformation types input by each measuring point, it is considered that the deformation types are matched and consistent.

[0106] These logical relationships represent the physical logic of the truss when the relative coordinate changes, that is, the relative displacement and the overall displacement under different deformation types are further described to illustrate the specific characteristics of the corresponding deformation type.

[0107] The logical relationship can be represented as follows: the overall performance is translation, and the relative displacement of each part is uniform, which will be close to the case of rigid body translation + uniform strain, and will be specifically corresponding to thermal expansion / contraction deformation caused by temperature effect or uniform load. The logical relationship here represents the close case to illustrate the physical logical relationship between the relative displacement and the overall displacement under the deformation type.

[0108] Overall rotation with regular bending, close to rigid body rotation + gradient bending deformation, deviating to bending-torsion combination caused by eccentric load.

[0109] Overall almost no movement, but local deformation is significant, close to the minimum overall displacement + local high strain scenario at this time, indicating local damage or stress concentration, emphasizing local damage deformation.

[0110] Each part of the deformation is consistent with the overall movement, close to the complex overall movement + coordinated local deformation at this time, indicating that there is a problem with the foundation deformation or support system, representing the foundation settlement or support system deformation, the corresponding point needs to be tracked and processed in time.

[0111] After completing the logical relationship analysis of 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 overall movement type or local deformation type is dominant at present, if the two are comparable, enter the composite deformation analysis.

[0112] The criterion for significant difference here is to obtain a proportion threshold, such as when the overall displacement level is > 5 times the relative displacement level, it can be considered that the overall displacement is significantly greater than the relative displacement; the same is true for the relative displacement, when between this proportion threshold, it means that the level is comparable, and composite deformation analysis is needed.

[0113] Preferably, the proportion threshold is based on the average value of the ratio of the overall displacement significantly greater than the relative displacement in the historical data, and the average value of the ratio of the relative displacement significantly greater than the overall displacement, to determine the part that is significantly exceeded, and perform the subsequent analysis process.

[0114] At the same time, it is also necessary to determine whether the overall displacement and the relative displacement determined at present conform to mechanics, and whether their distribution positions are reasonable, the test principle is: when a pure rigid body translation, the internal structure should not produce strain, all relative displacement should be zero.

[0115] The specific test method is as follows: strain uniformity test: check whether the strain value of each part is close to zero and uniformly distributed; strain-position correlation analysis: strain should not change regularly with position; abnormal strain point identification: mark the area where the strain is significantly non-zero. The judgment of unreasonable condition is: if systematic strain gradient is detected → there may be unrecognized rotation or bending; if local high strain area appears → there may be local constraint or damage, at this time, it is necessary to further check the specific values of the overall displacement and the relative displacement, whether they conform to the set logical relationship, and determine whether these deformation types are further described, indicating whether the current deformation type belongs to the simple deformation type or the conforming deformation type.

[0116] The simple deformation types include pure rigid body motion type and pure local deformation type, and the complex deformation types are coordinated complex type and non-coordinated complex type; in the judgment process of step S3, the local deformation type is identified through the relative displacement, and in step S4, the global displacement is introduced, and the global displacement is taken as the basis for further classification and identification of the deformation type, and a more detailed deformation type is reacquired, if the more detailed deformation type acquired is consistent with the content described in the local deformation of the deformation type derived in step S3, that is, the deformation type derived by the logical relationship of the current global displacement and the relative displacement and the deformation type directly derived by the relative displacement exist the containing relationship, then it is considered that the matching is consistent.

[0117] Preferably, the current containing relationship further includes that if the complex deformation type (such as global translation + stretching) derived by the global displacement and the relative displacement contains a single deformation type (such as stretching deformation), that is, the label composed of the current complex deformation type contains the label of the deformation type derived by the relative displacement, it is considered as the containing relationship.

[0118] The pure rigid body motion type is the result of relative global motion analysis, the relative displacement thereof is close to zero, and the global displacement is significant, and the subclasses thereof include translation type, rotation type, scaling type and the like; the pure local deformation type is that the global displacement is close to zero, and the relative displacement is significant, and the subclasses thereof include axial stretching and contraction deformation, bending deformation, shear deformation, torsion deformation and the like.

[0119] The coordinated complex type is that the global displacement and the relative displacement are consistent in physical meaning, and the subclasses thereof can include translation + uniform stretching corresponding to thermal expansion and the like; the non-coordinated complex type is that the global displacement and the relative displacement are contradictory, which indicates that the local damage is accompanied by the global constraint, and implies that the structure exists abnormal local deformation such as stretching and contraction.

[0120] Preferably, in the analysis of the simple deformation type mainly using the global motion type or the local deformation type, and in the complex deformation analysis, the weight value of the current displacement amount in the weighted summation will be further adjusted, such as when the global motion is mainly in the current scene, the weight of the global displacement is 0.8, and the weight of the relative displacement is 0.2, when the relative displacement is mainly in the current scene, the weight of the global displacement is 0.2, and the weight of the relative displacement is 0.8, and when the displacement is consistent in the current scene, the weight of the global displacement is 0.5, and the weight of the relative displacement is 0.5, so as to adjust the value of the current displacement amount, and complete the processing of the deformation type.

[0121] In an embodiment of the present application, after determining the measuring points susceptible to installation and the relative flow prone to displacement fluctuation, the displacement is converted into a curve in time sequence, and the data of each test is used as the basis for current judgment, such as selecting the time period corresponding to the maximum displacement, to determine whether the current truss installation is within the preset accuracy, and the whole installation process is fed back according to the data to improve the accuracy of truss installation and positioning.

[0122] As shown in Figure 13 The implementation of step S5 includes: S51, periodically obtaining the maximum displacement of each key node, and determining the displacement overrun degree according to the maximum displacement of each key node, displacement overrun degree=(measured maximum displacement-allowed displacement) / allowed displacement, which is an index of absolute accuracy, indicating the ratio of maximum displacement to design allowed deviation.

[0123] S52, map the displacement overrun degree to the accuracy level matrix, and sort the key nodes according to the accuracy level fed back by the current displacement overrun degree, and output the sorted key nodes according to their associated installation steps.

[0124] When feeding back, the accuracy level matrix: set multiple intervals according to the maximum displacement, set each interval based on the maximum allowed displacement of the corresponding measuring point, and record the relative accuracy level; then output the current data in the form of a relative report to complete the identification and processing of positioning.

[0125] As the maximum displacement interval is divided into [0, allowed value x 0.5], (allowed value x 0.5, allowed value], (allowed value, ∞) respectively, and its accuracy level is defined respectively, such as excellent accuracy, good accuracy and unqualified accuracy, these data will show the association between the installation step where the maximum displacement occurs and the specific construction operation, and further feedback the displacement value of each measuring point at the time point corresponding to the accuracy level, which shows the part with the worst accuracy in the key node at each installation step, to locate the weak part in the current truss installation process. Form a processing process like installation step execution→node displacement monitoring→accuracy evaluation→overrun warning→process adjustment. As for the setting of the overrun warning, it will be recorded as yellow warning, orange warning and red warning when the displacement reaches 80% of the allowed value, 90% of the allowed value and exceeds the allowed value respectively. By feeding back the total displacement data measured at this time to the external terminal, workers can adjust the current truss installation according to the corresponding data to improve the accuracy of the truss installation.

[0126] Although the embodiments of the present application have been shown and described above, it is to be understood that the above-described embodiments are merely exemplary, and are not to be construed as limiting the present application, and that changes, modifications, substitutions and variations can be made thereto without departing from the scope of the present application.

Claims

1. A method for precise butt joint positioning based on large-span two-way fish-belly steel truss installation, 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.

2. The method 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 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.

3. The method of claim 1, wherein the method is characterized by, 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 method 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 method of claim 3, wherein the method further comprises: 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 method of claim 1, wherein the method is characterized by, 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 method according to claim 6, wherein, 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 method of claim 1, wherein the method is characterized by, Step S4 can be implemented in the following ways: S41, the overall displacement and relative displacement are weighted and summed to obtain the displacement of each measuring point under all installation steps, and the displacement of each measuring point is matched with the deformation type; S42, if the match is consistent, extract the corresponding displacement threshold and mutation point based on the displacement value of the current measuring point. When the displacement of the current measuring point is greater than the displacement threshold and belongs to the mutation point, output the current measuring point as the key node. S43, if inconsistent, the corresponding measurement point will be output as the critical node.

9. The method of claim 8, wherein the method further comprises: The implementation of step S41 also includes: S411, Statistically analyze the relative and overall displacements of each measuring point under the corresponding installation steps, and establish the logical relationship between the relative and overall displacements; 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. 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.

10. The method of claim 1, wherein the method is used for precise positioning of large-span bidirectional fish-belly steel truss installation. 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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