Steel member cylinder fitting algorithm

Abstract

The invention discloses a steel member cylinder fitting algorithm which comprises the following steps: setting a plurality of measuring points on a to-be-measured section circle, arranging a high-precision laser instrument to acquire three-dimensional coordinates of the measuring points, and converting the three-dimensional coordinates measured at different measuring positions into a common coordinate system by adopting a transfer algorithm; calculating a fitting plane equation by utilizing the coordinate points after station transfer to obtain plane equation parameters, and taking the plane as an evaluation plane for the roundness of the section; projecting the coordinates of the measurement points to the evaluation plane, and calculating the projection coordinate of each point and the distance from each point to the evaluation plane; carrying out plane circle fitting on the coordinate points projected to the same plane by utilizing a linear least square method to obtain a fitting radius and a circle center of a circle; on the basis of plane circle fitting, calculating the cylinder roundness of a plurality of profile circles by adopting a least square method, namely carrying out cylinder fitting. A plurality of algorithms are integrated, so that the method has very strong pertinence on the dimension measurement of the large-scale cylindrical steel member.

Description

technical field [0001] The invention relates to the fields of industrial measurement and steel structure detection, in particular to a cylinder fitting algorithm for steel components. Background technique [0002] In the modern construction industry, people have higher and higher requirements for the machining accuracy of large steel structures (with a size ranging from ten meters to tens of meters). With urgent needs. [0003] Large cylindrical steel members are widely used in large bridges, culverts, tunnels, ships, aerospace, aviation and other fields. The main indicators of cylindrical steel members mainly include the flatness of the end face, the roundness, deflection, and diameter of the cylinder. Compared with small components that can be directly measured by measuring instruments, large cylindrical steel components are usually fixed and immovable objects, their diameters are often very large, and their structures are complex. There are many obstacles around them, an...

AI Technical Summary

Problems solved by technology

Compared with small components that can be directly measured by measuring instruments, large cylindrical steel components are usually fixed and immovable objects, their diameters are often very large, and their structures are complex. There are many obstacles around them, and the measurement space may also be relatively limited. It is often difficult to complete the measurement at one location, and how to convert the data measured at multiple locations into the same coordinate system is a big problem

[0004] At present, the measurement of large cylindrical rigid components generally adopts geometric measurement methods such as the strut method. In addition to requiring a lot of manpower, this method is slow in detection, low in efficiency, cumbersome in operation, high in subjectivity, low in measurement accuracy, and low in automation. , in addition, this method requires the entire component to be in an open field, and it must be ensured that it can be measured as a whole at a certain position, which greatly limits the measurement conditions

At the same time, there are many uncertain factors in this method, which affects the construction efficiency and cannot make an accurate evaluation of the construction quality.

[0005] For large cylindrical rigid members, the traditional method can only measure the shape of the cylindrical end face, and cannot measure the flatness of the end face and the roundness and deflection of the entire cylinder.

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