Study and application of non-contact coordinate measuring system

Abstract

As to the inspection of small and medium workpieces with complex surfaces such as blades, a non-contact optical measuring system is built up in the paper. With the system, the measurement task of such parts can be accomplished in a rapid, precise and efficient manner. Based on the laser displacement sensor, probe head and the mechanical framework of CMM etc, the system combines the advantages of optical sensor and CMM together to cope with the measurement of sculptured surfaces. In the system, the unit direction vector of measuring beam can be obtained through calibration method, which is based on solving of a series of overdetermined nonlinear equations. After that, the one-dimensional length of the laser beam can be transformed to the three-dimensional coordinates of the points on the surface. At the same time, the coordinates of measuring points can be converted to the same world coordinate system to complete the construction of point clouds through coordinate system transformation. Finally, a standard gauging block is measured by the system at 10 different orientations. Compared with the real value, the errors of the 10 measuring results are all smaller than 0.05mm, which manifests the practicability and validity of the system.