Complicated Component Detection Based On Three-dimensional Laser Scanning Technology

In the general production process of the iron tower, it must be assembled before leaving the factory in order to ensure erect the tower successfully at the scene. In addition to test elements is correct or not, the more important thing is to examine whether there will be phenomenon such as interference among elements and holes location error (in this case, the tower cannot be assembled properly). Traditional vertical assembly and horizontal assembly have their own limitations, high cost and long cycle can’t adapt to large-scale detection tasks. This paper describes a method to detect elements of iron tower by combining the industrial measurement theory and three-dimensional laser scanning technology to replace the "test assembling" Following works has been done in the paper:1. Establish3-D digital model as the benchmark from manufacturer’s design file by the Pro/E software.2. studying Obtain method of3-D data, according to the subject and considering the performance of the instrument parameters and data quality, I select a handheld3D laser scanning instrument based on laser triangulation. And illustrates the feasibility of the data used for modeling and detection by analyzing the accuracy of collected data.3.This paper put forward a space position detection method for industrial bolt hole The key steps include extract point cloud of bolt hole, deal with the point cloud data, use non-linear least squares to fit related bolt hole center, and last is to convert the measured coordinates system to the model coordinate system by the conversion matrix to calculate error of the corresponding position of the bolt hold center. I study conversion method in detail, first rough alignment and then precise alignment, In order to reduce the error of the coordinate conversion and to improve detection accuracy. Through experiment we know that the space position error of16bolt holes under detected is within2mm and with little fluctuation. The method achieves high detection accuracy.4. Using Geomagic Qualify3D detection methods detecting the contour errors of elements, And give a test report, Those diagrams and tables can intuitively show error situations of elements contour. However, the margin of error is big when using such method; the detection doesn’t have satisfying result when detecting holes on the surface of objects. Detection of3D data around the holes has so large error changes that it cannot reflect the position error of the hole. Therefore, further application of detection method of space position of the bolt holes raised in this text can detect space position error.