Mass center measuring method and system for hoisting height measurement of large structure

Abstract

The invention provides a mass center measuring method for hoisting height measurement of a large structure. The mass center measuring method comprises the following steps: selecting a hoisting point Q and a hoisting point Q'on a to-be-measured structure; selecting n height measurement points P1-Pn which are not completely coplanar, installing a distance measurement sensor on each height measurement point, and measuring the coordinates of the hoisting point Q, the hoisting point Q'and the height measurement points P1-Pn in the coordinate system of the structure body to be measured; hoisting the to-be-measured structure to a free state by using the hoisting point Q, and collecting a group of height measurement data measured by the distance measurement sensor; hoisting the to-be-measured structure to a free state by using the hoisting point Q and the hoisting point Q ', and collecting another group of height measurement data measured by the distance measurement sensor; using a least square method to solve a linear equation set composed of each height measurement point coordinate and height measurement data; the equation of the plumb line passing through the hoisting point Q in the body coordinate system of the to-be-measured structure and the equation of the plumb line passing through the hoisting point Q'in the body coordinate system of the to-be-measured structure are obtained through calculation, and the mass center of the to-be-measured structure is obtained through solving with the least square method.

Description

Technical Field

[0001] This invention relates to a method and system for measuring the center of mass during the hoisting and height measurement of large structures, belonging to the field of testing and measurement technology. Background Technology

[0002] During the installation and testing of large structures (with a diameter of 3m or more), it is necessary to measure their center of gravity and make adjustments based on the measurement results to ensure that the actual center of gravity of the large structure is consistent with the design center of gravity, thereby meeting the relevant requirements for installation and testing.

[0003] Currently, traditional methods for measuring the center of mass typically use the three-point force measurement method or the hanging plotting method. When using the three-point force measurement method, for large structures, the force measuring platform needs to have a large size and high load-bearing capacity. At the same time, special tooling needs to be designed to fix large structures, and relatively complex hoisting operations are required when adjusting the installation posture of the structure, which makes it difficult to meet the needs of rapid measurement and adjustment. When using the hanging plotting method, since the plotting can only be done in a two-dimensional plane, it is impossible to accurately measure the three-dimensional position of the center of mass of large structures whose center of mass is significantly deviated from the axis of symmetry or the plane of symmetry. Summary of the Invention

[0004] The technical problem to be solved by this invention is that existing centroid measurement methods for large structures are difficult to implement, complex to operate, and have low efficiency and accuracy. This invention proposes a method and system for measuring the centroid of large structures, which is simple and fast, has high calculation accuracy, and can calculate the three-dimensional position of the centroid of large structures, thus effectively improving the operational efficiency of centroid measurement and adjustment of large structures.

[0005] The technical solution adopted in this invention is: a method for measuring the centroid of a large structure during hoisting, comprising:

[0006] Select lifting points Q and Q' on the structure to be tested;

[0007] Choose n elevation measurement points P1, P2, ..., Pn, which are not all coplanar. n Distance sensors are installed at each elevation measurement point to measure the elevation of hoisting points Q, Q', and elevation points P1, P2, ..., P'. n The coordinates (x) of the structure under test in the body coordinate system O0e1e2e3 q ,y q ,z q ), (x q ',y q ',z q '), (x1,y1,z1), (x2,y2,z2),..., (x n ,y n,z n ); where n≥4, and n is a positive integer;

[0008] The structure under test is hoisted to a free state using hoisting point Q, and a set of height measurement data Z1, Z2, ..., Zn is collected from the distance measurement sensor. n Using lifting points Q and Q', the structure to be measured is hoisted to a free state, and another set of height measurement data Z1', Z2', ..., Z' is collected from the distance measuring sensor. n ';

[0009] The least squares method is used to solve the system of linear equations composed of the coordinates of each altimeter and the altimeter data.

[0010] The equations of the vertical line passing through the lifting point Q and the vertical line passing through the lifting point Q' in the coordinate system of the structure under test are calculated.

[0011] Solving the system of equations using the least squares method The centroid (x) of the structure under test is obtained by solving the problem. c ,y c ,z c ).

[0012] Furthermore, the distance measuring sensor is used to measure the altitude at each measuring point P1, P2, ..., P n The height above the ground when it is in the hoisting state.

[0013] Furthermore, the system of linear equations composed of the coordinates of each altimeter and the altimeter data is as follows:

[0014]

[0015] Among them, a 31 ,a 32 ,a 33 This refers to the projection of the coordinate base along the vertical direction into the coordinate system of the structure under test while using lifting point Q during the lifting process; a' 31 ,a' 32 ,a' 33 Z0 is the projection of the coordinate base in the vertical direction of the structure under test into the coordinate system of the structure under test when using the lifting point Q'; Z0 is the height of the origin of the coordinate system of the structure under test when using the lifting point Q; Z'0 is the height of the origin of the coordinate system of the structure under test when using the lifting point Q'.

[0016] Furthermore, the equation of the vertical line passing through the hoisting point Q in the coordinate system of the structure under test is:

[0017]

[0018] Where (x,y,z) are the coordinates of a point on the vertical line passing through the lifting point Q in the coordinate system of the large structure body when it is being lifted using the lifting point Q; the distance between point (x,y,z) and the lifting point Q is t.

[0019] Furthermore, the equation of the vertical line passing through the hoisting point Q' in the coordinate system of the structure under test is as follows:

[0020]

[0021] Where (x′,y′,z′) are the coordinates of a point on the vertical line passing through the lifting point Q' in the large structure body coordinate system when it is being lifted using the lifting point Q'; the distance between point (x′,y′,z′) and the lifting point Q' is t'.

[0022] Furthermore, the centroid (x) of the structure under test c ,y c ,z c )middle:

[0023]

[0024] A centroid measurement system for measuring the height of large structures during hoisting includes:

[0025] Several distance measuring sensors are respectively installed on n non-coplanar height measuring points P1, P2, ..., P on any selected structure to be measured. n Above; where n≥4, and n is a positive integer;

[0026] The data acquisition module is used to collect height data Z1, Z2, ..., Z from several distance measuring sensors. n and Z1', Z2', ..., Z n '; Among them, the height measurement data Z1, Z2, ..., Z n This refers to the data measured by several distance measuring sensors when the structure under test is hoisted to a free state using hoisting point Q; height measurement data Z1', Z2', ..., Z n 'Refers to the data measured by several distance measuring sensors when the structure under test is hoisted to a free state using hoisting point Q';

[0027] The data processing module uses the least squares method to solve a system of linear equations composed of the coordinates of each elevation point and the elevation data; it calculates the equations of the plumb line passing through the hoisting point Q and the plumb line passing through the hoisting point Q' in the coordinate system of the structure under test; and then uses the least squares method to solve the system of equations. The centroid (x) of the structure under test is obtained by solving the problem. c ,y c ,z c ).

[0028] The advantages of this invention compared to the prior art are:

[0029] The method of the present invention only requires hoisting the large structure to be measured at two different locations during the centroid measurement process, without the need for external large equipment and tooling, which can significantly reduce the cost of centroid measurement.

[0030] All measurement data are linear dimensions, which can be achieved using simple measuring equipment such as tape measures and laser rangefinders. The position coordinates of the hoisting points and height measurement points can also be measured through the digital model of the large structure. The measurement process is simple and easy to perform.

[0031] After the coordinates of the hoisting point and the height measurement point are measured, they can be reused when measuring the center of gravity again, making it suitable for application scenarios where the center of gravity needs to be adjusted and measured multiple times.

[0032] The centroid calculation process is fully streamlined, and the matrix operations involved are easy to implement. The solution process can be completed by a computer program, allowing the centroid calculation result to be obtained directly after the measurement is completed. The centroid calculation algorithm can be inherited into relevant computer software for the implementation of the measurement platform. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the measurement method of the present invention. Detailed Implementation

[0034] The present invention will be described in conjunction with the accompanying drawings.

[0035] A method for measuring the centroid of large structures, which consists of three parts: selection of hoisting points and measuring point locations, hoisting height measurement, and centroid calculation.

[0036] The main features of this calculation method are: first, select two hoisting points and no less than four non-coplanar height measurement points for the large structure, and then measure the coordinates of the hoisting points and height measurement points relative to the coordinate system of the large structure body;

[0037] Then, by sequentially hoisting the large structure to two hoisting points, the large structure is hoisted to a stable free state, and the height of each measuring point to the horizontal plane is measured to obtain two sets of height measurement data.

[0038] Using two sets of height measurement data and the position coordinates of the hoisting point and the height measurement point, through spatial coordinate transformation from the ground coordinate system to the large structure body coordinate system, the equations of the plumb lines passing through the two hoisting points in the large structure body coordinate system can be obtained respectively. The intersection of the two plumb lines is the coordinate of the centroid in the body coordinate system.

[0039] like Figure 1 As shown, the present invention provides a method for measuring the centroid of a large structure, comprising the following steps:

[0040] 1. Select two lifting points Q and Q' on the large structure to be measured. The two lifting points should be as far apart as possible to improve measurement accuracy.

[0041] 2. Select n (n≥4) elevation points P1, P2…P… n Laser rangefinder sensors are installed at each elevation measurement point to measure the height of each point from the ground during hoisting. Simultaneously, the height of hoisting points Q, Q' and elevation measurement points P1, P2…P' are also measured. n The coordinates in the large structure's body coordinate system O0e1e2e3 (this coordinate system can be arbitrarily selected according to needs and measurement convenience) are respectively (x q ,y q ,z q ), (x q ',y q ',z q '), (x1,y1,z1), (x2,y2,z2)…(x n ,y n ,z n );

[0042] 3. Using lifting point Q, hoist the structure to be measured to a stable free state, and collect a set of height measurement data Z1, Z2, ..., Z6 from the distance measuring sensor. n Using lifting points Q and Q', the structure to be measured is hoisted to a stable free state, and another set of height measurement data Z1', Z2', ..., Z' is collected from the distance measuring sensor. n ';

[0043] 4. Solve the following two sets of linear equations consisting of the coordinates of the altimeter and the measured altitude using the least squares method.

[0044]

[0045] and

[0046]

[0047] Among them, a 31 ,a 32 ,a 33 To project the coordinate base along the vertical direction into the coordinate system of the structure under test while using lifting point Q during the lifting process, a' 31 ,a' 32 ,a' 33Z0 is the projection of the coordinate base in the vertical direction of the structure under test into the coordinate system of the structure under test when using the lifting point Q'; Z0 is the height of the origin of the coordinate system of the structure under test when using the lifting point Q; Z'0 is the height of the origin of the coordinate system of the structure under test when using the lifting point Q'.

[0048] 5. Calculate the equation of the vertical line passing through the lifting point Q in the coordinate system of the structure under test: Where (x,y,z) are the coordinates of a point on the vertical line passing through the lifting point Q in the coordinate system of the large structure body when it is being lifted using the lifting point Q; the distance between the point (x,y,z) and the lifting point Q is t;

[0049] The equation of the plumb line passing through the lifting point Q' in the coordinate system of the structure under test is calculated as follows: Where (x′,y′,z′) are the coordinates of a point on the vertical line passing through the lifting point Q' in the large structure body coordinate system when it is being lifted using the lifting point Q'; the distance between point (x′,y′,z′) and the lifting point Q' is t';

[0050] 6. Solve the following system of equations using the least squares method to find the intersection of the two vertical lines.

[0051]

[0052] Two sets of intersection points can be obtained. The midpoint of these two sets of intersection points (take the average value) is used as the calculated value of the centroid.

[0053]

[0054] A centroid measurement system for measuring the height of large structures during hoisting includes:

[0055] Several distance measuring sensors are respectively installed on n non-coplanar height measuring points P1, P2, ..., P on any selected structure to be measured. n Above; where n≥4, and n is a positive integer;

[0056] The data acquisition module is used to collect height data Z1, Z2, ..., Z from several distance measuring sensors. n and Z1', Z2', ..., Z n '; Among them, the height measurement data Z1, Z2, ..., Z n This refers to the data measured by several distance measuring sensors when the structure under test is hoisted to a free state using hoisting point Q; height measurement data Z1', Z2', ..., Z n 'Refers to the data measured by several distance measuring sensors when the structure under test is hoisted to a free state using hoisting point Q';

[0057] The data processing module uses the least squares method to solve a system of linear equations composed of the coordinates of each elevation point and the elevation data; it calculates the equations of the plumb line passing through the hoisting point Q and the plumb line passing through the hoisting point Q' in the coordinate system of the structure under test; and then uses the least squares method to solve the system of equations. The centroid (x) of the structure under test is obtained by solving the problem. c ,y c ,z c ).

[0058] The parts of this invention not described in detail are well-known to those skilled in the art.

Claims

1. A method of measuring the center of mass of a large structure hoisted by a crane, the method comprising: Comprise: Select hoisting point Q and hoisting point Q' on the structure to be measured; Select n height measuring points P1, P2, …, P n , which are not all coplanar Install a distance measuring sensor at each height measuring point to measure the hoisting points Q, Q' and the height measuring points P1, P2, …, P n In the coordinate system O0e1e2e3 of the structure body to be measured, the coordinates (x q ,y q ,z q ), (x q ’,y q ’,z q ), (x1, y1, z1), (x2, y2, z2), …, (x n ,y n ,z n ) of the hoisting points Q, Q' and the height measuring points P1, P2, …, P are measured; wherein n ≥ 4, n is a positive integer The measured structure is hoisted to a free state using hoisting point Q, and a set of measured height data Z1, Z2,..., Z n The measured structure is hoisted to a free state using hoisting point Q, hoisting point Q', and another set of measured height data Z1', Z2',..., Z n ' measured by the distance measuring sensor is collected. Solve the linear equation group composed of each measuring point coordinate and height data by using the least square method; Calculate the equation of the plumb line passing through hoisting point Q in the coordinate system of the structure to be measured and the equation of the plumb line passing through hoisting point Q' in the coordinate system of the structure to be measured; Solving equation sets using least squares Solving for the centroid (x c ,y c ,z c ) of the structure under test.

2. The method of claim 1, wherein, The distance measuring sensor is used to measure the height of each surveying point P1, P2, …, Pn n Height from the ground in the hoisting state.

3. The method of claim 2, wherein, The linear equation group composed of each measuring point coordinate and height data is as follows: wherein a 31 a 32 a 33 is the projection of the coordinate base in the direction of the plumb line in the coordinate system of the structure to be measured, in the state of hoisting using hoisting point Q; a’ 31 a’ 32 a’ 33 is the projection of the coordinate base in the direction of the plumb line in the coordinate system of the structure to be measured, in the state of hoisting using hoisting point Q'; Z0 is the height of the origin of the coordinate system of the structure to be measured, in the state of hoisting using hoisting point Q; Z'0 is the height of the origin of the coordinate system of the structure to be measured, in the state of hoisting using hoisting point Q'.

4. The method of claim 3, wherein, The equation of the plumb line passing through hoisting point Q in the coordinate system of the structure to be measured is: Where (x, y, z) is the point coordinate on the plumb line passing through hoisting point Q in the coordinate system of the large structure in the state of hoisting using hoisting point Q; the distance between point (x, y, z) and hoisting point Q is t.

5. The method of claim 4, wherein the method is used for measuring the center of mass of a large structure hoisted by a crane. The equation of the plumb line passing through hoisting point Q' in the coordinate system of the structure to be measured is: Where (x', y', z') is the point coordinate on the plumb line passing through hoisting point Q' in the coordinate system of the large structure in the state of hoisting using hoisting point Q'; the distance between point (x', y', z') and hoisting point Q' is t'.

6. The method of claim 5, wherein, the centroid (x c ,y c ,z c ) of the structure under test:

7. A mass center measurement system for hoisting a large structure, characterized by, Comprise: A plurality of distance measurement sensors are respectively installed on n non-entirely coplanar measuring points P1, P2, …, Pn selected from the structure to be measured n above; wherein n≥4, n is a positive integer; a data acquisition module for acquiring the height measurement data Z1, Z2,..., Z n and Z1', Z2',..., Z n '; wherein the height measurement data Z1, Z2,..., Z n denote the data measured by the distance measurement sensors when the structure to be measured is hoisted into the free state using the hoisting point Q; the height measurement data Z1', Z2',..., Z n ' denote the data measured by the distance measurement sensors when the structure to be measured is hoisted into the free state using the hoisting point Q' The data processing module solves a linear equation set composed of the coordinates of each surveying point and surveying data by using a least square method; calculates an equation of a plumb line passing through the hoisting point Q in the coordinate system of the structure body to be measured and an equation of a plumb line passing through the hoisting point Q' in the coordinate system of the structure body to be measured; and solves the equation set by using a least square method to obtain the mass center (x c ,y c ,z c ) of the structure to be measured.

8. The mass center measurement system for hoisting height of a large structure according to claim 7, characterized in that, The linear equation group composed of each measuring point coordinate and height data is as follows: Wherein, the height measuring points P1, P2, …, P n In the coordinate system O0e1e2e3 of the structure body to be measured, the coordinates are (x q ,y q ,z q ), (x q ’,y q ’,z q ), (x1, y1, z1), (x2, y2, z2), …, (x n ,y n ,z n ). a 31 ,a 32 ,a 33 is the projection of the coordinate base in the direction of the plumb line in the coordinate system of the structure to be measured, in the state of hoisting using hoisting point Q';a’ 31 ,a’ 32 ,a’ 33 is the projection of the coordinate base in the direction of the plumb line in the coordinate system of the structure to be measured, in the state of hoisting using hoisting point Q'; Z0 is the height of the origin of the coordinate system of the structure to be measured, in the state of hoisting using hoisting point Q; Z'0 is the height of the origin of the coordinate system of the structure to be measured, in the state of hoisting using hoisting point Q'.

9. The mass center measurement system for hoisting height of a large structure according to claim 8, characterized in that, The equation of the plumb line passing through hoisting point Q in the coordinate system of the structure to be measured is: Where (x, y, z) is the point coordinate on the plumb line passing through hoisting point Q in the coordinate system of the large structure in the state of hoisting using hoisting point Q; the distance between point (x, y, z) and hoisting point Q is t. The equation of the plumb line passing through hoisting point Q' in the coordinate system of the structure to be measured is: Among them, the coordinates of hoisting point Q and hoisting point Q' in the coordinate system O0e1e2e3 of the structure under test are (x q ,y q ,z q ), (x q ',y q ',z q '); (x', y', z') is the point coordinate on the plumb line passing through hoisting point Q' in the coordinate system of the large structure in the state of hoisting using hoisting point Q'; the distance between point (x', y', z') and hoisting point Q' is t'.

10. The mass center measurement system for hoisting height of a large structure according to claim 9, wherein, the centroid (x c ,y c ,z c ) of the structure under test:

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