A coordinate transformation method for building facade measurement

Abstract

The present invention discloses a method for measuring coordinate conversion of building facades, comprising the following steps: 1. collecting the three-dimensional coordinates of each element feature point on the building facade in a free coordinate system by a non-reflective prism total station; 2. selecting two feature points on the lower left and lower right of the main line of the house on the building facade to establish a plumb plane; 3. calculating the coordinates of the projection points of each element feature point on the plumb plane; 4. calculating the angle between the plumb plane and the YOH plane of the free coordinate system; 5. converting the projection points of each element feature point on the plumb plane to the YOH plane by Rodriguez rotation; 6. respectively taking the Y coordinate and H coordinate of each element feature point on the YOH plane as the horizontal coordinate and vertical coordinate in the facade coordinate system, importing the points into the drawing software, and editing them into a drawing. The method directly converts each element feature point on the building facade to the front facade through spatial projection and spatial rotation, avoids the frequent use of coordinate inverse calculation and coordinate forward calculation, and simplifies the calculation process.

Description

Technical Field

[0001] The invention relates to a coordinate conversion method for measuring a building facade. Background Art

[0002] Building elevation drawings are an important basis for the design and construction of building exterior decoration and building reconstruction (expansion). The projection surface of the building elevation drawing is a plumb plane parallel to the building facade. In order to conform to the habit of common drawing software to draw in the horizontal plane, coordinate conversion must be performed first in the internal work process. The traditional coordinate conversion method for measuring building facades requires frequent use of coordinate inverse calculation and coordinate forward calculation, involving multiple coordinate azimuth calculations, and the internal work calculations are relatively complicated. Therefore, it is necessary to invent a coordinate conversion method for measuring building facades that can achieve the goal of simplifying internal work calculations. Summary of the Invention

[0003] In order to solve the problems existing in the prior art, the present invention provides a building facade measurement coordinate conversion method to solve the above technical problems, which is specifically implemented by the following technical solutions:

[0004] A method for measuring coordinates of a building facade comprises the following steps:

[0005] S1: Set up a non-reflective prism total station in front of the building facade to be measured, ensuring that the total station's observation field can completely cover the building facade to be measured, and use the total station to observe the feature points of the main lines, doors, windows, columns, steps and other elements on the building facade, and obtain the three-dimensional coordinates P of each feature point in the free coordinate system. i =(X i , Y i , H i ) T (i=1, 2, ..., n); where X and Y are the plane coordinates of the observation point, H is the elevation of the observation point, and n is the number of observation points;

[0006] S2: Select the lower left feature point A and the lower right feature point B of the main line of the building facade as the facade reference points, and use the computer to calculate the reference points according to the formula Obtain the coefficients of the plane equation aX+bY+d=0 of the plumb line ∏ where points A and B are located; A , Y A ) is the plane coordinate of point A, (X B , Y B ) is the plane coordinate of point B;

[0007] S3: Using a computer according to the formula Get the projection point P of each feature point on the plumb line ∏ i ′=(X′ i , Y i ′,H′i ) T ;in,

[0008] S4: Using a computer according to the formula The included angle θ between the plumb line ∏ and the plane of the free coordinate system YOH is obtained; where, is the normal vector of the plumb bob surface ∏, is the unit normal vector (1, 0, 0) of the YOH plane, and <> represents the dot product of the vectors;

[0009] S5: Use computer to calculate the formula P i ″=P i ′cos(θ)+(k×P i ′)sin(θ)+k<k,P i ′>(1-cos(θ)), and the three-dimensional coordinates P of each feature point after spatial rotation are obtained i ″=(X″ i , Y i ″,H″ i ) T ;in, × represents the cross product of vectors;

[0010] S6: Take Y respectively i ″ and H″ i Import the horizontal and vertical coordinates of each feature point in the elevation coordinate system into the drawing software to display the points and edit them to form an elevation drawing.

[0011] In general, compared with the prior art, the above technical solution conceived by the present invention directly converts the characteristic points of each element on the building facade to the front facade through spatial projection and spatial rotation, avoiding the frequent use of coordinate inverse calculation and coordinate forward calculation, simplifying the calculation process, and improving calculation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein:

[0013] Figure 1 It is a measurement schematic diagram of the present invention;

[0014] In the picture: 1- total station, 2- building facade. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present invention are described clearly and completely below with reference to the accompanying drawings.

[0016] The building facade measurement coordinate conversion method of this embodiment includes the following steps:

[0017] Step 1: Set up a non-reflective prism total station in front of the building facade to be measured, ensuring that the total station's observation field can completely cover the building facade to be measured. Use the total station to observe the feature points of the main lines, doors, windows, columns, steps and other elements on the building facade, and obtain the three-dimensional coordinates P of each feature point in the free coordinate system. i =(X i , Y i , H i ) T (i=1, 2, ..., n); where X and Y are the plane coordinates of the observation point, H is the elevation of the observation point, and n is the number of observation points;

[0018] Step 2: Select the lower left feature point A and the lower right feature point B of the main line of the building facade as the facade reference points, and use the computer to calculate the reference points according to the formula Obtain the coefficients of the plane equation aX+bY+d=0 of the plumb line ∏ where points A and B are located; A , Y A ) is the plane coordinate of point A, (X B , Y B ) is the plane coordinate of point B;

[0019] Step 3: Use a computer to calculate the Get the projection point P of each feature point on the plumb line ∏ i ′=(X′ i , Y i ′, H′ i ) T ;in,

[0020] Step 4: Use a computer to calculate the The included angle θ between the plumb line ∏ and the plane of the free coordinate system YOH is obtained; where, is the normal vector of the plumb bob surface ∏, is the unit normal vector (1, 0, 0) of the YOH plane, and <> represents the dot product of the vectors;

[0021] Step 5: Use a computer to calculate the value of the formula P i ″=P i ′cos(θ)+(k×P i ′)sin(θ)+k<k,P i ′>(1-cos(θ)), and the three-dimensional coordinates P of each feature point after spatial rotation are obtained i ″=(X″ i , Y i ″,H″ i ) T ;in, × represents the cross product of vectors;

[0022] Step 6: Take Y respectively i ″ and H″ i Import the horizontal and vertical coordinates of each feature point in the elevation coordinate system into the drawing software to display the points and edit them to form an elevation drawing.

[0023] The content of the present invention is not limited to the embodiments listed. Any equivalent transformation of the technical solution of the present invention made by ordinary technicians in this field after reading the description of the present invention is covered by the claims of the present invention.

Claims

1. A method for measuring coordinates of a building facade, characterized in that: The method comprises the following steps: S1: Set up a non-reflective prism total station in front of the building facade to be measured, ensuring that the total station's observation field can completely cover the building facade to be measured, and use the total station to observe the feature points of the main lines, doors, windows, columns, steps and other elements on the building facade, and obtain the three-dimensional coordinates P of each feature point in the free coordinate system. i =(X i , Y i , H i ) T (i=1, 2, ..., n); where X and Y are the plane coordinates of the observation point, H is the elevation of the observation point, and n is the number of observation points; S2: Select the lower left feature point A and the lower right feature point B of the main line of the building facade as the facade reference points, and use the computer to calculate the reference points according to the formula Obtain the coefficients of the plane equation aX+bY+d=0 of the plumb line ∏ where points A and B are located; A , Y A ) is the plane coordinate of point A, (X B , Y B ) is the plane coordinate of point B; S3: Using a computer according to the formula Get the projection point P of each feature point on the plumb line ∏ i ′=(X′ i , Y i ′,H′ i ) T ;in, S4: Using a computer according to the formula The included angle θ between the plumb line ∏ and the plane of the free coordinate system YOH is obtained; where, is the normal vector of the plumb bob surface ∏, is the unit normal vector (1, 0, 0) of the YOH plane, and <> represents the dot product of the vectors; S5: Use computer to calculate the formula P i ″=P i ′cos(θ)+(k×P i ′)sin(θ)+k<k,P i ′>(1-cos(θ)), and the three-dimensional coordinates P of each feature point after spatial rotation are obtained i ″=(X″ i , Y i ″,H″ i ) T ;in, × represents the cross product of vectors; S6: Take Y respectively i ″ and H″ i Import the horizontal and vertical coordinates of each feature point in the elevation coordinate system into the drawing software to display the points and edit them to form an elevation drawing.

2. A building facade measurement coordinate conversion method according to claim 1, characterized in that: In step S2, two characteristic points, the lower left and the lower right of the main line of the building on the facade of the building, are used to establish a plumb plane.

3. A building facade measurement coordinate conversion method according to claim 1, characterized in that: In step S3, it is ensured that each feature point is strictly located on the same plumb plane after projection transformation.

4. A building facade measurement coordinate conversion method according to claim 1, characterized in that: In step S5, spatial rotation is used to transform the feature points of each element after the projection transformation to the front elevation.

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