The detection method of the node coordinates where two cylindrical rods intersect
A detection method and a technology of cylindrical rods, which are applied to measuring devices, instruments, etc., can solve the problems of low measurement efficiency and low efficiency of axis center calculation of steel structures, etc.
Active Publication Date: 2016-01-13
CHINA NAT OFFSHORE OIL CORP +1
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[0003] At present, for the calculation of the coordinates of the nodes where two cylindrical rods intersect, the axis of the cylinder is calculated after measuring thousands of point clouds on the surface of the cylinder; due to this method, it is necessary to use a total station to measure too many points , not only the measurement efficiency is very low, but also the calculation efficiency of the axis center of the steel structure is very low
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[0084] Such as Figure 1-Figure 5 Shown, the present invention adopts following specific steps:
[0085] Step 1: Measure and collect the three-dimensional coordinates of several points on the surface of two cylindrical rods;
[0086] The second step: using a mathematical method to form a unit vector set with a uniform density and a different hemisphere shape at the coordinate origin (0, 0, 0,).
[0087] Step 3: Project the collected measurement points onto the plane with each unit vector as the normal vector, and use the least squares method to judge the degree of the point set after projection is close to the circle; and find the group with the best corresponding roundness The unit vector is used as the initial vector of the fitting cylinder, and at the same time, the coordinates of the center of the projected circle are used as the initial value of the passing point of the axis line.
[0088] Step 4: On the basis of the calculated initial value, use the indirect adjustment...
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The invention provides a method for detecting coordinates of a cross node of two cylindrical rod members. The method includes steps of measuring and collecting three-dimensional coordinates of a plurality of points on the surfaces of the two cylindrical rod members; forming a unit vector set on the origin of coordinates; projecting collected measuring points to planes taking different unit vectors as origin of coordinates respectively, judging the circle approximating degree of point sets through a least square method, and taking a set of the unit vectors with the highest roundness as initial vectors for cylinder fitting and taking circle center coordinates of the projection circle as initial values of a point on an axial line; fitting axial lines of the two cylinders through an indirect adjustment method with constraint conditions; and calculating a common perpendicular segment of the two optimum axial lines and taking the middle point of the common perpendicular segment as the cross node of the two cylinders. According to the invention, the two optimum axial lines can be fitted accurately only through stochastic collection of a plurality of points on the surfaces of the cylinders, and the three-dimensional coordinates of the cross node of the two cylinders can be calculated accurately. Besides, manufacturing errors of a steel structure can be obtained through analysis.
Description
technical field [0001] The invention relates to a method for detecting node coordinates of marine steel structures, in particular to a method for detecting node coordinates where two cylindrical rods of marine steel structures intersect. It belongs to the field of marine engineering construction. Background technique [0002] The node coordinates of the marine steel structure are very important for the size of the structure, force analysis, etc. How to accurately calculate the coordinates of the node where two cylindrical members intersect is very necessary. [0003] At present, for the calculation of the coordinates of the nodes where two cylindrical rods intersect, the axis of the cylinder is calculated after measuring thousands of point clouds on the surface of the cylinder; due to this method, it is necessary to use a total station to measure too many points , not only the measurement efficiency is very low, but also the calculation efficiency of the axis center of the...
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IPC IPC(8): G01B21/00
Inventor 张士舰刘春杰肖立权李海峰李金富陈冰华孙云虎孟令河
Owner CHINA NAT OFFSHORE OIL CORP