Quick tower crane layout method based on Welzl algorithm

Abstract

The invention discloses a Welzl algorithm-based rapid tower crane layout method, which comprises the following steps of: reading a field plan, extracting coordinate data of a building main body outline and a land red line range from the field plan, constructing a building vertex set P which needs to be covered by a tower crane and a position point set A which allows the tower crane to be laid on the basis of the coordinate data, and calculating a minimum surrounding circle Ci through the Welzl algorithm according to the point set P, whether the radius of the minimum surrounding circle Ci is smaller than or equal to the working radius Rt of the tower crane to be arranged or not is judged, if Ci is smaller than or equal to Rt, all points in the point set P are removed, the position of the tower crane is recorded and output, if Ci is larger than Rt, circulation is conducted till all building vertexes in the point set P are covered by the working radius of the tower crane, circulation can be completed, and the arrangement position of the tower crane is output. According to the method, the optimal arrangement position of the tower crane is determined by automatically calculating the minimum surrounding circle of the building, so that all building areas needing to be constructed are quickly and accurately covered, the construction efficiency is improved, and the method has important practical application value.

Description

Technical Field

[0001] The invention relates to the field of building construction, and in particular to a tower crane rapid deployment method based on a Welzl algorithm. Background Art

[0002] The layout of tower cranes in the early stage of a project is particularly important. Reasonable tower crane layout can effectively improve construction efficiency and safety. Existing tower crane layout methods mostly rely on manual experience and simple geometric calculations. It is difficult to quickly and accurately determine the position of tower cranes in complex building layouts, thus affecting construction efficiency. Especially when the building shape is irregular and the tower crane coverage is limited, how to quickly and accurately layout tower cranes to cover all building areas that need construction has become an urgent problem to be solved. Summary of the invention

[0003] The object of the present invention is to provide a tower crane rapid deployment method based on the Welzl algorithm, comprising the following steps:

[0004] S1. Read the site plan in dxf format and extract the coordinate data of the main building outline and the land red line range from it;

[0005] S2. Based on the coordinate data of the main building outline and the red line range of the land, a set of building vertices P that the tower crane needs to cover and a set of location points A where the tower crane is allowed to be deployed are constructed;

[0006] S3. Calculate the minimum enclosing circle C based on the point set P using the Welzl algorithm i , determine the minimum enclosing circle C i Is the radius of the tower crane less than or equal to the working radius R of the tower crane to be deployed? t ;The initial value of i is 1;

[0007] If C i ≤R t , then remove all points in the point set P, record the crane position, and jump to step S8;

[0008] If C i >R t , then proceed to step S4;

[0009] S4, determine the minimum enclosing circle C i The two building vertices on the i1 and Z i2 ; Connect building vertices Z i1 , Z i2 , recorded as auxiliary line L i12 ;

[0010] Z i1 , Z i2 is the center of the circle, R tDraw a helper circle with radius N i1 、N i2 , determine the auxiliary circle N i1 、N i2 With auxiliary line L i12 The intersection points are denoted as J i1 , J i2 ;

[0011] Determine auxiliary circle N i1 Whether it overlaps with the working range of the deployed tower crane, if so, proceed to step S6, if not, proceed to step S5;

[0012] S5. Determine the location of N i1 Inside and at a distance of J i1 The nearest permitted crane deployment point, denoted as T i1 , and located at N i2 Inside and at a distance of J i2 The nearest permitted crane deployment point, denoted as T i2 ;

[0013] T i1 , T i2 is the center of the circle, R t Arrange tower cranes for the radius;

[0014] S6. Determine the location of N i1 Inside, the distance from the deployed crane is greater than k and the distance J i1 The nearest permitted crane deployment point, denoted as T i1 , and located at N i2 J inside, whose distance from the deployed crane is greater than k and closest to J2 i2 The nearest permitted crane deployment point, denoted as T i2 ;

[0015] T i1 , T i2 is the center of the circle, R t Arrange tower cranes for the radius;

[0016] S7, remove the building vertices covered by the working radius of the deployed tower crane in the point set P, obtain a new point set P, set i=i+1, and repeat steps S3 to S7 until all the building vertices in the point set P are covered by the working radius of the deployed tower crane;

[0017] S8. Output tower crane layout location.

[0018] Furthermore, in step S1, the plan is read through the dxfgrabber library, and the coordinate data of the building outline and the land red line are respectively obtained through dxf.entities.

[0019] Further, in step S2, the steps of constructing a set of building vertices P that the tower crane needs to cover and a set of location points A where the tower crane is allowed to be deployed include:

[0020] 1) The coordinate data of the main building outline and the land red line range are processed into origins, and then all coordinate points within the land red line range are processed into grids to obtain multiple data points;

[0021] 2) Keep the area outside the main building outline and d away from the main building 1 -d 2 m, and the data points are located within the land red line;

[0022] 3) Delete the data points whose distance to the building's yin-yang corner is less than or equal to hm, and construct the point set A that allows the deployment of tower crane points with the retained data points;

[0023] 4) Extract the vertex coordinates of the building and obtain the point set P of the vertex coordinates of the building that needs to be covered.

[0024] Further, 1 d 2 The values ​​of and h are determined by the actual needs of the construction site.

[0025] Further, 1 =3,d 2 =5,h=8.

[0026] Further, in step S3, the minimum enclosing circle C i Refers to the circle with the smallest radius that covers all building vertices.

[0027] Further, in step S4, when the minimum enclosing circle C i When the number of building vertices on the Z axis is greater than 2, the two building vertices with the farthest distance are selected as Z. i1 and Z i2 .

[0028] Furthermore, in step S6, when the number of cycles is greater than 1, in order to prevent the tower crane from colliding in actual operation, T i1 , T i2 The location is an area not covered by the established tower crane working radius.

[0029] Furthermore, the k value in step S6 is the anti-collision distance, k=2m.

[0030] Furthermore, in step S8, after the tower crane layout position is output, the tower crane layout position is visualized.

[0031] The technical effect of the present invention is unquestionable, and the beneficial effects of the present invention are as follows:

[0032] The present invention proposes a tower crane rapid layout method based on the Welzl algorithm, which automatically calculates the minimum enclosing circle of a building and determines the optimal layout position of the tower crane, thereby quickly and accurately covering all building areas that need construction, thereby improving construction efficiency and having important practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a flow chart of Example 11;

[0034] Figure 2 This is a schematic diagram of the data set A of tower crane locations that can be deployed after data processing;

[0035] Figure 3 This is a schematic diagram of the first cycle of tower crane deployment;

[0036] Figure 4 This is the schematic diagram of the second cycle of tower crane layout, which is also the final layout diagram. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with the embodiments, but it should not be understood that the above subject matter of the present invention is limited to the following embodiments. Without departing from the above technical ideas of the present invention, various substitutions and changes are made according to the common technical knowledge and customary means in the art, which should all be included in the protection scope of the present invention.

[0038] Embodiment 1:

[0039] A tower crane rapid deployment method based on Welzl algorithm comprises the following steps:

[0040] S1. Read the site plan in dxf format and extract the coordinate data of the main building outline and the land red line range from it;

[0041] S2. Based on the coordinate data of the main building outline and the red line range of the land, a set of building vertices P that the tower crane needs to cover and a set of location points A where the tower crane is allowed to be deployed are constructed;

[0042] S3. Calculate the minimum enclosing circle C based on the point set P using the Welzl algorithm i , determine the minimum enclosing circle C i Is the radius of the tower crane less than or equal to the working radius R of the tower crane to be deployed? t ;The initial value of i is 1;

[0043] If C i ≤R t , then remove all points in the point set P, record the crane position, and jump to step S8;

[0044] If C i >R t , then proceed to step S4;

[0045] S4, determine the minimum enclosing circle C i The two building vertices on the i1 and Z i2 ; Connect building vertices Z i1 , Z i2 , recorded as auxiliary line L i12 ;

[0046] Z i1 , Z i2 is the center of the circle, R t Draw a helper circle with radius N i1 、N i2 , determine the auxiliary circle N i1 、N i2 With auxiliary line L i12 The intersection points are denoted as J i1 , J i2 ;

[0047] Determine auxiliary circle N i1 Whether it overlaps with the working range of the deployed tower crane, if so, proceed to step S6, if not, proceed to step S5;

[0048] S5. Determine the location of N i1 Inside and at a distance of J i1 The nearest permitted crane deployment point, denoted as T i1 , and located at N i2 Inside and at a distance of J i2 The nearest permitted crane deployment point, denoted as T i2 ;

[0049] T i1 , T i2 is the center of the circle, R t Arrange tower cranes for the radius;

[0050] S6. Determine the location of N i1 Internal, and deployed tower cranes (working scope and N i1 Overlapping deployed cranes) with a distance greater than k and a distance J i1 The nearest permitted crane deployment point, denoted as T i1 , and located at N i2 Internal, and deployed tower cranes (working scope and N i2 The J that is closest to J2 and has a distance greater than k. i2 The nearest permitted crane deployment point, denoted as t i2 ;

[0051] T i1 , T i2 is the center of the circle, R tArrange tower cranes for the radius;

[0052] S7, remove the building vertices covered by the working radius of the deployed tower crane in the point set P, obtain a new point set P, set i=i+1, and repeat steps S3 to S7 until all the building vertices in the point set P are covered by the working radius of the deployed tower crane;

[0053] S8. Output tower crane layout location.

[0054] Embodiment 2:

[0055] The main structure of this embodiment is the same as that of Embodiment 1. Furthermore, in step S1, the plan view is read through the dxfgrabber library, and the coordinate data of the building main body outline and the land red line are respectively obtained through dxf.entities.

[0056] Embodiment 3:

[0057] The main structure of this embodiment is the same as any one of Embodiments 1 to 2. Further, in step S2, the step of constructing a vertex set P of buildings that the tower crane needs to cover and a location point set A where the tower crane is allowed to be deployed includes:

[0058] 1) The coordinate data of the main building outline and the land red line range are processed into origins (i.e., the minimum X, Y coordinate value of all coordinate data is determined and used as the origin (0, 0), and the remaining coordinate points are moved accordingly in XY), and then all coordinate points within the land red line range are rasterized to obtain multiple data points;

[0059] 2) Keep the area outside the main building outline and d away from the main building 1 -d 2 m, and the data points are located within the land red line;

[0060] 3) Delete the data points whose distance to the building's yin-yang corner is less than or equal to hm, and construct the point set A that allows the deployment of tower crane points with the retained data points;

[0061] 4) Extract the vertex coordinates of the building and obtain the point set P of the vertex coordinates of the building that needs to be covered.

[0062] Embodiment 4:

[0063] The main structure of this embodiment is the same as that of embodiment 3. Furthermore, d 1 d 2 The values ​​of and h are determined by the actual needs of the construction site.

[0064] Embodiment 5:

[0065] The main structure of this embodiment is the same as any one of Embodiments 3 to 4. Further, d 1 =3,d2 =5,h=8.

[0066] Embodiment 6:

[0067] The main structure of this embodiment is the same as any one of Embodiments 1 to 5. Further, in step S3, the minimum enclosing circle C i Refers to the circle with the smallest radius that covers all building vertices.

[0068] Embodiment 7:

[0069] The main structure of this embodiment is the same as any one of Embodiments 1 to 6. Further, in step S4, when the minimum enclosing circle C i When the number of building vertices on the Z axis is greater than 2, the two building vertices with the farthest distance are selected as Z. i1 and Z i2 .

[0070] Embodiment 8:

[0071] The main structure of this embodiment is the same as any one of Embodiments 1 to 7. Further, in step S6, when the number of cycles is greater than 1, in order to prevent the tower crane from colliding in actual operation, T i1 , T i2 The location is an area not covered by the established tower crane working radius.

[0072] Embodiment 9:

[0073] The main structure of this embodiment is the same as any one of Embodiments 1 to 8. Furthermore, the k value in step S6 is the anti-collision distance, k=2m.

[0074] Embodiment 10:

[0075] The main structure of this embodiment is the same as any one of Embodiments 1 to 9. Furthermore, in step S8, after the tower crane layout position is output, the tower crane layout position is visualized.

[0076] Embodiment 11:

[0077] The main structure of this embodiment is the same as any one of Embodiments 1 to 10. Furthermore, the present invention provides a tower crane rapid deployment method based on an improved Welzl algorithm, comprising the following steps:

[0078] S1. Drawing reading

[0079] SS1. Read the site dxf format plan;

[0080] SS2. Extract the x and y data of the main building outline and land red line range on site, and convert all data into origin;

[0081] S2. Data processing

[0082] SS1. Rasterize the coordinate points within the red line of the land use area, and set the accuracy to 1m;

[0083] SS2. After rasterization, pre-process the data points to ensure that they meet the following requirements: 1. They are located within the land red line; 2. They are located outside the main building outline;

[0084] SS3. Under normal circumstances, in order to ensure that the tower crane is normally attached to the main structure, it is necessary to retain data points within 3-5m from the main building.

[0085] SS4. In order to ensure the requirements for tower crane disassembly, rotation and standardized attachment, delete the data points within 8m of the building's corners to obtain the points where tower cranes are allowed to be deployed.

[0086] SS5. Extract the vertex coordinates of the building;

[0087] SS6. Get the data, the building vertex set P that needs to be covered and the point set A where tower cranes are allowed to be deployed.

[0088] S3. Procedure for arranging tower crane:

[0089] SS1. Apply Welzl algorithm to tower crane layout:

[0090] SS2. Based on the point set P, the minimum enclosing circle Ci (i = 1, 2, ...) is quickly calculated using the Welzl algorithm.

[0091] SS3. Determine whether the radius of Ci is ≤ the radius Rt of the tower crane to be deployed:

[0092] SS4. If yes, directly cover all points in P and remove them, and record the position of the crane.

[0093] SS5. If not, find points Z1 and Z2 on the minimum enclosing circle Ci, and draw auxiliary lines Z1Z2 and the minimum enclosing circle Ci.

[0094] SS6. Draw auxiliary circles N1 and N2 with Z1 and Z2 as the center and Rt as the radius.

[0095] SS7. Find the intersection points J1 and J2 of N1, N2 and Z1Z2, and determine whether J1 and J2 are inside the minimum enclosing circle Ci:

[0096] SS8. If yes, find the point T1 inside N1 and closest to J1, and the point T2 inside N2 and closest to J2, and arrange the tower crane with T1 and T2 as the center and Rt as the radius;

[0097] SS9. Remove the points in P that are covered by the existing cranes to obtain a new point set P;

[0098] SS10. Repeat the above steps until there are no more points left in P;

[0099] SS11. In the subsequent cycles, it should be noted that in order to prevent the possibility of collision of tower cranes in actual operation, step SS8 is updated to find point T1 which is inside N1, outside the deployed tower crane (the anti-collision distance can be increased according to actual use) and closest to J1, and point T2 which is inside N2, outside the deployed tower crane and closest to J2, and deploy the tower crane with T1 and T2 as the center and Rt as the radius.

[0100] S4. Output and visualize the tower crane layout location.

[0101] Furthermore, the steps are all implemented by Python language;

[0102] Furthermore, the site plan is saved in .dxf format, the name of the building main body outline layer in the plan is set as required, and the building main body outline should be an outline including all building components;

[0103] Further, the plan is read through the dxfgrabber library, and the coordinate points of the building main body outline and the land red line are respectively obtained through dxf.entities;

[0104] Furthermore, to ensure the normal attachment of the tower crane, the distance between the data point and the main building can be modified according to the actual situation;

[0105] Furthermore, to ensure the tower crane disassembly, rotation and standardized attachment requirements, the tower crane is not allowed to be arranged at the corners of the building, and the distance can be modified according to the actual situation;

[0106] Furthermore, the radius Rt of the tower crane to be deployed can be modified according to actual conditions;

[0107] Furthermore, the correctness of the Welzl algorithm is based on a theorem: for any n points on a plane, take the n+1th point outside its minimum covering circle. Then the n+1th point must be on the minimum covering circle of these n+1 points. The Welzl algorithm has a significant advantage in calculating the minimum enclosing circle;

[0108] Furthermore, the above steps are only analyzed by taking the case where there are 2 P midpoint sets on the enclosing circle obtained by the Welzl algorithm as an example. If there are 3 points on the minimum enclosing circle obtained by the Welzl algorithm, the 2 points with the farthest distance can be selected by calculation to carry out the above tower crane layout process.

Claims

1. A tower crane rapid deployment method based on Welzl algorithm, characterized in that: The following steps are involved: S1. Read the site plan in dxf format and extract the coordinate data of the main building outline and the land red line range from it; S2. Based on the coordinate data of the main building outline and the red line range of the land, a set of building vertices P that the tower crane needs to cover and a set of location points A where the tower crane is allowed to be deployed are constructed; S3. Calculate the minimum enclosing circle C based on the point set P using the Welzl algorithm i , determine the minimum enclosing circle C i Is the radius of the tower crane less than or equal to the working radius R of the tower crane to be deployed? t ;The initial value of i is 1; If C i ≤R t , then remove all points in the point set P, record the crane position, and jump to step S8; If C i >R t , then proceed to step S4; S4, determine the minimum enclosing circle C i The two building vertices on the i1 and Z i2 ; Connect building vertices Z i1 , Z i2 , recorded as auxiliary line L i12 ; Z i1 , Z i2 is the center of the circle, R t Draw a helper circle with radius N i1 、N i2 , determine the auxiliary circle N i1 、N i2 With auxiliary line L i12 The intersection points are denoted as J i1 , J i2 ; Determine auxiliary circle N i1 Whether it overlaps with the working range of the deployed tower crane, if so, proceed to step S6, if not, proceed to step S5; S5. Determine the location of N i1 Inside and at a distance of J i1 The nearest permitted crane deployment point, denoted as T i1 , and located at N i2 Inside and at a distance of J i2 The nearest permitted crane deployment point, denoted as T i2 ; T i1 、T i1 is the center of the circle, R i Arrange tower cranes for the radius; S6. Determine the location of N i1 Inside, the distance from the deployed crane is greater than k and the distance J i1 The nearest permitted crane deployment point, denoted as T i1 , and located at N i2 J inside, whose distance from the deployed crane is greater than k and closest to J2 i2 The nearest permitted crane deployment point, denoted as T i2 ; T i1 , T i2 is the center of the circle, R t Arrange tower cranes for the radius; S7. Remove the building vertices covered by the working radius of the deployed tower crane in the point set P to obtain a new point set P. Let i=i+1, and repeat steps S3 to S7 until all the building vertices in the point set P are covered by the working radius of the deployed tower crane. S8. Output tower crane layout location.

2. A tower crane rapid deployment method based on Welzl algorithm according to claim 1, characterized in that: In step S1, the plan is read through the dxfgrabber library, and the coordinate data of the building outline and the land red line are respectively obtained through dxf.entities.

3. The tower crane rapid deployment method based on the Welzl algorithm according to claim 1 is characterized in that: In step S2, the steps of constructing a set of building vertices P that the tower crane needs to cover and a set of location points A where the tower crane is allowed to be deployed include: 1) The coordinate data of the main building outline and the land red line range are processed into origins, and then all coordinate points within the land red line range are processed into grids to obtain multiple data points; 2) Keep the data points that are outside the main building outline, d1-d2m away from the main building, and within the land red line; 3) Delete the data points whose distance to the building's yin-yang corner is less than or equal to hm, and construct the point set A where the tower crane points are allowed to be arranged with the retained data points; 4) Extract the vertex coordinates of the building and obtain the point set P of the vertex coordinates of the building that needs to be covered.

4. A tower crane rapid deployment method based on Welzl algorithm according to claim 3, characterized in that: The values ​​of d1, d2 and h are determined by the actual needs of the construction site.

5. The tower crane rapid deployment method based on Welzl algorithm according to claim 3 is characterized in that: d1=3, d2=5, h=8.

6. The tower crane rapid deployment method based on Welzl algorithm according to claim 1, characterized in that: In step S3, the minimum enclosing circle C i Refers to the circle with the smallest radius that covers all building vertices.

7. The tower crane rapid deployment method based on Welzl algorithm according to claim 1 is characterized in that: In step S4, when the minimum enclosing circle C i When the number of building vertices on the Z axis is greater than 2, the two farthest building vertices are selected as Z i1 and Z i2 .

8. The tower crane rapid deployment method based on Welzl algorithm according to claim 1 is characterized in that: In step S6, when the number of cycles is greater than 1, to prevent the tower crane from colliding during actual operation, t i1 , T i2 The location is an area not covered by the established tower crane working radius.

9. The tower crane rapid deployment method based on Welzl algorithm according to claim 1, characterized in that: The k value in step S6 is the anti-collision distance, k=2m.

10. The tower crane rapid deployment method based on Welzl algorithm according to claim 1, characterized in that: In step S8, after the tower crane layout position is output, the tower crane layout position is visualized.

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