CN114595499A - An accurate registration method of BIM and GIS applied to long-distance water diversion projects - Google Patents

Abstract

The invention discloses a BIM + GIS precise registration method for long-distance diversion and water transfer engineering. The method comprises the steps of model segmentation design, segmentation base point setting, BIM coordinate system setting, segmentation model assembling, segmentation model derivation, GIS coordinate system resetting, GIS coordinate system conversion, GIS registration and the like. The invention innovatively provides a technical framework and a method for registration of the BIM + GIS of the long-distance water diversion project, breaks through the technical bottleneck of the application of the BIM + GIS of the long-distance project, and has great application value.

Description

An accurate registration method of BIM and GIS applied to long-distance water diversion projects

technical field

The invention relates to a BIM and GIS registration technology applied in engineering, in particular to a BIM+GIS accurate registration method for a long-distance water diversion project, which provides key technical support for the BIM+GIS fusion application.

Background technique

BIM takes the model as the carrier and can collect engineering data in the whole life cycle of engineering design, construction and operation. GIS is an information system that stores, manages, describes and analyzes geographic space-related topography, landform, location distribution and other information, and provides storage, operation and processing functions for spatial elements such as geographic location.

In the past, GIS and BIM played their respective roles based on their own fields. With the development of the times and technology, the two gradually moved towards cross-border integration: BIM requires GIS to bring BIM into a larger scene, so as to achieve a comprehensive grasp of the macro situation and unified scheduling. ; GIS needs BIM to make GIS break through the gap between indoor and outdoor, and achieve seamless integration of indoor and outdoor applications.

GIS+BIM has overlapping points in data and applications, such as spatial analysis, data representation, information management, etc., so the integration of the two has produced infinite possibilities. GIS and BIM fusion technology is widely used in transportation, water conservancy, construction, energy and other industries.

The application of BIM+GIS must first solve the registration problem. BIM design software is a plane local coordinate system, GIS is a spherical geographic coordinate system and a projected coordinate system. When the plane BIM model is transferred to the spherical surface, there will inevitably be model offset and warping, so it is necessary to convert the plane coordinate system model into the spherical coordinate system. Through coordinate transformation, BIM, oblique photographic model, terrain and other multi-source GIS data are unified into a coordinate system to achieve the alignment of various information; on this basis, data fusion processing is performed to achieve smooth connection and natural texture stitching.

It is easy to realize BIM+GIS registration for point-shaped water conservancy projects such as pumping stations and power stations. However, due to the long lines of long-distance water diversion projects, the influence of the curvature of the earth when placed on a spherical surface cannot be ignored. It can be understood by analogy that dropping a piece of dust on the globe can be well integrated, but placing a pencil on the globe will cause the two ends to become warped.

GIS has the ability of coordinate conversion, and the coordinate conversion of point, line and surface is very mature, but it is still a big challenge to apply the conversion ability to BIM model data. It is necessary to offset and deform the vertices of the order of millions of the model one by one to adapt the "straight" model to the "curved" spherical surface, which requires complex calculations of computer graphics. Especially for long-distance projects, the cumulative error of the conversion calculation cannot be ignored, and there are obvious offsets in height and plane.

Limited by the underlying capabilities of the current BIM and GIS software, there is a way to solve the BIM+GIS registration problem of long-distance water diversion projects through plane scenes. By placing the BIM model on a flat scene, the offset and warping problems of the spherical surface on the model are avoided. In short, integrate the BIM model into a flat world map instead of a globe, so that the model fits perfectly. However, this method affects the performance of GIS functions based on spherical surface measurement, excavation, and sunshine analysis.

SUMMARY OF THE INVENTION

In order to solve the problems existing in the prior art, the present invention initiates a method of coordinate transformation after segmentation of a plane BIM model to realize the accurate registration of BIM+GIS for long-distance water diversion projects. In short, a long model is divided into several segments, the base point of each segment is agreed, and the coordinate transformation is performed segment by segment to disperse the accumulated error to each segment.

The technical scheme adopted by the present invention to solve its technical problems is:

An accurate registration method of BIM and GIS applied to long-distance water diversion projects, comprising the following steps:

S1. Model segmented design: The segmented design of the BIM model of the long-distance water diversion project can be segmented according to the actual bid or fixed length, and the segment length should be less than the modeling range of the BIM software used.

S2. Segment base point setting: select a base point for each segment. The plane coordinates of the base point must be a clear integer and be close to the model entity to reduce the amount of data for subsequent vertex transformation calculations.

S3, BIM coordinate system setting: There are often multiple buildings in a segment, and each building is created by a different file. Each building model is positioned through the base point of this section. The specific method is as follows: inserting a CAD plan with a coordinate grid in the plan view of each single building. By rotating, moving and other operations, the CAD drawing and the BIM model are made to coincide. On this basis, according to the coordinates set in step S2, first move the project base point of each building model file to coincide with the corresponding coordinate point of the CAD drawing, and then drag the measurement point to coincide with the project base point. After this step, the BIM model obtains the coordinate values consistent with the general floor plan of the project.

The project base point can be understood as the insertion base point of the BIM model. Traction movement means that the model will move with the base point, and the relative position between the model and the base point remains unchanged; non-traction movement means that the model remains stationary when the base point moves, and the relative position between the model and the base point changes.

The measurement point can be understood as the coordinate calculation base point of the BIM model. Traction movement means that the coordinate value of the measurement point remains unchanged at (0,0), and the coordinate value of the project base point changes; non-traction movement means that the coordinate value of the measurement point changes, and the coordinate value of the project base point remains unchanged at (0,0).

S4. Segmented model assembly: Assemble the buildings in the segment into one file by linking. Select "Project base point to project base point" for the positioning method. The effect achieved is that each building in the segment belongs to its own position in the BIM software and is precisely registered.

S5. Segmented model export: Use the export plug-in to export the BIM model of each segmented assembly. Select the plane coordinates when exporting, and input the coordinates of the base point in step S2 for the coordinate values.

S6. GIS coordinate system reset: load the export file in step S5 into the GIS software, and its own coordinate system is a plane unprojected coordinate system at this time. Determine the corresponding projected coordinate system according to the actual position of the project on the earth, reset the coordinate system, and set the BIM model data as the projected coordinate system.

S7. GIS coordinate system conversion: through projection conversion, the projected coordinate system in step S6 is converted into a geographic coordinate system, so that the plane BIM model can fit the spherical surface.

The relationship between the geographic coordinate system and the projected coordinate system is:

Among them, ΔX ₀ , ΔY ₀ , and ΔZ ₀ are translation parameters, ε _x ε _y ε _z are rotation parameters, and m is a scale factor.

The derivation process is as follows,

Taking the total differentiation of equation (2), we get:

Among them, da and df are the differential of the semimajor axis of the ellipsoid and the oblateness of the ellipsoid, and the expressions of J and A are:

Multiply both sides of Equation (3) by J ^-1 to the left at the same time and shift the terms, we get:

According to the Bursa model, we have:

and substituting the increment for the differential, i.e.

Substitute equations (7), (8), (9), (10) and J ^-1 into equation (6), and simplify to obtain equation (1).

S8. GIS registration: On the basis of integrating the BIM model into the spherical surface, further superimpose GIS data such as DEM, DOM, TIF, and oblique photography. For small deviations, use the registration function of the GIS software to adjust.

Through the above methods, the BIM model gets the correct coordinate values, resets it to the projected coordinate system, and then converts it to a geographic coordinate system such as CGC2000 through projection conversion to adapt to the spherical environment, unifies the BIM and GIS coordinate systems, and realizes coordinate registration.

The beneficial effects of the present invention are: achieving a breakthrough in BIM+GIS registration for long-distance water diversion projects, and laying a foundation for the BIM+GIS integrated application of such projects.

The invention has the advantages and characteristics of clear logic, simple operation, good spatial intuition and the like, and has popularization and application value in practice. At present, there is no clear technical method for BIM+GIS registration of long-distance water diversion projects. In practice, different methods are used to avoid the technical difficulties. The invention innovatively proposes a technical framework and method for BIM+GIS registration of long-distance water diversion projects, organically integrates BIM technology and GIS spatial analysis technology into the digital process of long-distance water diversion projects, and provides a reliable solution. .

Description of drawings

Fig. 1 is the flow chart of the method of the present invention;

Figure 2 is the project base point setting diagram;

Figure 3 is a diagram of measuring point settings.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, a BIM and GIS accurate registration method applied to a long-distance water diversion project of the present invention, the specific implementation process includes the following 8 steps:

S1. Model segment design: According to the general plan of the project, the BIM model of the tunnel about 114 kilometers long for the long-distance water diversion project is divided into 16 sections according to the actual bidding section, and the length of each section ranges from 3.2 to 10.9 kilometers. Less than the maximum range of commonly used BIM software. Taking the BIM software Revit as an example, the maximum extent of the model is a modeling work plane with a diameter of 20 miles (about 32 kilometers).

S2. Subsection base point setting: select a base point for each subsection, which needs to be an integer coordinate point in the engineering coordinate system to facilitate accurate positioning. Taking the first subsection as an example, the tunnel in this section is 7.1 kilometers long, and an integer coordinate point (422500, 3270000) is selected near the midpoint as the project base point. The base point is close to the model entity, which reduces the amount of data for subsequent vertex transformation calculations. The other segments operate sequentially in the same way.

S3. BIM coordinate system setting: Complete the BIM coordinate system setting in each segment. The first section contains 3 tunnels and 2 buildings, and a total of 5 BIM models are created. Insert a CAD plan with a coordinate grid in the plan view of each BIM model. Through operations such as rotation, movement, etc., the outline of the building in the CAD drawing coincides with the BIM model. On this basis, move the project base point of the BIM model file to the CAD drawing (422500, 3270000) point without traction, as shown in Figure 2. Then drag and move the measurement point to coincide with the project base point, as shown in Figure 3. After the above settings, the BIM model obtains the coordinate values consistent with the general floor plan of the project, and the insertion point of each model is the (422500, 3270000) point. The other segments operate sequentially in the same way.

S4. Segmented model assembly: Assemble the 5 BIM models in the first segment into one file, select "project base point to project base point" for the positioning method, and the 5 models overlap with the assembly file according to the insertion point for accurate registration. The other segments operate sequentially in the same way.

S5. Segmented model export: Use the export plug-in to export the BIM model of each segmented assembly. Select the plane coordinates when exporting, and input the coordinates of the base point in step S2 for the coordinate values. The first segment assembles the model input (422500, 3270000), and the other segments are the same.

S6. GIS coordinate system reset: The built-in coordinate system of the BIM export file is a plane unprojected coordinate system. According to the target geographic coordinate system and the actual position of the project on the earth, the corresponding projected coordinate system is judged. Since my country has fully activated the 2000 National Geographic Coordinate System, the project is located in the northern hemisphere, with a longitude of about 120°. It is judged that the corresponding projected coordinate system is 3Degree GKzone40N (CGCS 2000), EPSG Code 4549. Load the exported file into GIS software, reset the coordinate system, and select 3Degree GK Zone 40N. 16 segments are operated in the same way.

S7. GIS coordinate system conversion: Through projection conversion, convert the projected coordinate system 3Degree GK Zone 40N in step S6 to the geographic coordinate system CCS_China_2000, so that the plane BIM model can be placed in a spherical scene.

S8. GIS registration: On the basis of integrating the BIM model into the spherical surface, further superimpose GIS data such as DEM, DOM, TIF, and oblique photography. For small deviations, use the GIS registration function for fine-tuning. 16 segments are operated in the same way.

The above embodiments describe the present invention in conjunction with the accompanying drawings, but it should not be construed as a limitation on the scope of the present invention. , the technical solutions obtained by equivalent replacement or equivalent transformation, all belong to the protection scope of the present invention.

Claims (4)

1. a BIM and GIS accurate registration method applied to long-distance water diversion project is characterized in that: it comprises the following steps: S1. Model segmented design: segment the BIM model of the long-distance water diversion project, and segment it according to the actual bidding section or fixed length, and the segment length is smaller than the modeling range of the BIM software used; S2. Segment base point setting: select a base point for each segment. The plane coordinates of the base point must be a clear integer and be close to the model entity to reduce the amount of data for subsequent vertex transformation calculations; S3. BIM coordinate system setting: there are often multiple buildings in a segment, and each building is created by a different file; each building model is positioned through the base point of this segment, the specific method is: in the plan view of each single building Insert a CAD plan with a coordinate grid; make the CAD drawing and BIM model coincide by rotating and moving operations; on this basis, according to the coordinates set in step S2, first pull the project base point of each building model file without pulling Move to coincide with the corresponding coordinate point of the CAD drawing, and then drag the measurement point to move to coincide with the base point of the project, so that the BIM model can obtain the coordinate value consistent with the general layout drawing of the project; S4. Segmented model assembly: Assemble the buildings in the segment into one file by linking; select "project base point to project base point" for the positioning method; the effect achieved is that each building in the segment belongs to its own in the BIM software bit, precise registration; S5, segmented model export: use the export plug-in to export the assembled BIM model of each segment; select plane coordinates when exporting, and input the coordinate value of the base point coordinates of step S2; S6. GIS coordinate system reset: load the export file of step S5 into the GIS software, and its own coordinate system is a plane unprojected coordinate system, and the corresponding projected coordinate system is judged according to the actual position of the project on the earth, and the Set the coordinate system and set the BIM model data as the projected coordinate system; S7, GIS coordinate system conversion: through projection conversion, the projected coordinate system in step S6 is converted into a geographic coordinate system, so that the plane BIM model can fit the spherical surface; S8. GIS registration: On the basis of integrating the BIM model into the spherical surface, further superimpose GIS data such as DEM, DOM, TIF, and oblique photography; for minor deviations, use the registration function of the GIS software to adjust. 2. The method for accurate registration of BIM and GIS applied to long-distance water diversion projects according to claim 1, characterized in that: in step S3, the project base point is the insertion base point of the BIM model, and the project base point Movement without traction means that the model remains stationary when the base point moves, and the relative position of the model and the base point changes. 3. The method for accurate registration of BIM and GIS applied to long-distance water diversion projects according to claim 1, characterized in that: in step S3, the measurement point is the coordinate calculation base point of the BIM model; the measurement Point traction movement means that the coordinate value of the measurement point remains unchanged at (0,0), and the coordinate value of the project base point changes. 4. The BIM and GIS accurate registration method applied to long-distance water diversion project according to claim 1 is characterized in that: in step S7, the relationship between the geographic coordinate system and the projected coordinate system is:

where ΔX ₀ , ΔY ₀ , ΔZ ₀ are translation parameters, ε _x ε _y ε _z are rotation parameters, and m is scale factor; the derivation process is as follows:

Taking the total differentiation of equation (2), we get:

Among them, da and df are the differential of the semimajor axis of the ellipsoid and the oblateness of the ellipsoid, and the expressions of J and A are:

Multiply both sides of Equation (3) by J ^-1 to the left at the same time and shift the terms, we get:

According to the Bursa model, we have:

and substituting the increment for the differential, i.e.

Substitute equations (7), (8), (9), (10) and J ^-1 into equation (6), and simplify to obtain equation (1).

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